[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

This series is to support loading a 32-bit OS, the execution state will change from AArch64 to AArch32 when jumping to kernel. The architecture information will be got through checking FIT image, then U-Boot will load 32-bit OS or 64-bit OS automatically.

Spin-table method is used for secondary cores to load 32-bit OS.
The architecture information will be got through checking FIT image and saved in the os_arch element of spin-table, then the secondary cores will check os_arch and jump to 32-bit OS or 64-bit OS automatically.

PSCI method can also be used for secondary cores to load 32-bit OS.
As PSCI and secure monitor firmware framework are enabled, loading 32-bit OS is supported in such case. The default target exception level returned to U-Boot is EL2, so the corresponding work to switch to AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware together.

---------------------------------------
Changes in v8:
- Fix the issue when U-Boot is running in EL2 or EL1.
- Support loading 32-bit OS with PSCI enabled.

Changes in v7:
- Move the call for armv8_switch_to_el2_m into the first patch.

Changes in v6:
- Modified armv8_switch_to_el1(). It will always jump to ep when switching to AArch64 or AArch32 modes.
- Make other platforms compatible with the new armv8_switch_to_el2() and armv8_switch_to_el1().
- Make secondary_switch_to_el1() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v5:
- Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.
- Make secondary_switch_to_el2() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v4:
- Correct config ARM64_SUPPORT_AARCH32.
- Omit arch and ftaddr arguments.
- Rename "xreg5" to "tmp".
- Use xxx_RES1 to combine all RES1 fields in xxx register.
- Use an immediate cmp directly.
- Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.

Changes in v3:
- Comments the functions and the arguments.
- Rename the real parameters.
- Use the macros instead of the magic values.
- Remove the redundant codes.
- Clean up all of the mess in boot_jump_linux().
- Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't support AArch32 state.
- Adjust the arguments for armv8_switch_to_el2_m and armv8_switch_to_el1_m.

Changes in v2:
- armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
  to switch to AArch64 EL2 or AArch32 Hyp.
- armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
  to switch to AArch64 EL1 or AArch32 SVC.
- Support to call armv8_switch_to_el2_m and armv8_switch_to_el1_m.

----------------------------------------------------------------
Alison Wang (3):
      armv8: Support loading 32-bit OS in AArch32 execution state
      armv8: fsl-layerscape: SMP support for loading 32-bit OS
      armv8: fsl-layerscape: Support loading 32-bit OS with PSCI enabled

 arch/arm/Kconfig                              |   6 ++++
 arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S  |  61 +++++++++++++++++++++++++------
 arch/arm/cpu/armv8/fsl-layerscape/mp.c        |  10 ++++++
 arch/arm/cpu/armv8/sec_firmware_asm.S         |  23 ++++++++++++
 arch/arm/cpu/armv8/start.S                    |   8 +++++
 arch/arm/cpu/armv8/transition.S               |  35 ++++++++++++++----
 arch/arm/include/asm/arch-fsl-layerscape/mp.h |   6 ++++
 arch/arm/include/asm/macro.h                  | 176 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------
 arch/arm/include/asm/system.h                 | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 arch/arm/lib/bootm.c                          |  45 ++++++++++++++++++++---
 arch/arm/mach-rmobile/lowlevel_init_gen3.S    |   9 ++++-
 common/image-fit.c                            |  19 +++++++++-
 12 files changed, 451 insertions(+), 68 deletions(-)

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

To support loading a 32-bit OS, the execution state will change from
AArch64 to AArch32 when jumping to kernel.

The architecture information will be got through checking FIT image,
then U-Boot will load 32-bit OS or 64-bit OS automatically.

Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
Signed-off-by: Alison Wang <alison.wang@nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
---
Changes in v8:
- Fix the issue when U-Boot is running in EL2 or EL1.

Changes in v7:
- Move the call for armv8_switch_to_el2_m into this patch. 

Changes in v6:
- Modified armv8_switch_to_el1(). It will always jump to ep when switching to AArch64 or AArch32 modes.
- Make other platforms compatible with the new armv8_switch_to_el2() and armv8_switch_to_el1().

Changes in v5:
- Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v4:
- Correct config ARM64_SUPPORT_AARCH32.
- Omit arch and ftaddr arguments.
- Rename "xreg5" to "tmp".
- Use xxx_RES1 to combine all RES1 fields in xxx register.
- Use an immediate cmp directly.
- Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.

Changes in v3:
- Comments the functions and the arguments.
- Rename the real parameters.
- Use the macros instead of the magic values.
- Remove the redundant codes.
- Clean up all of the mess in boot_jump_linux().
- Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't support AArch32 state.

Changes in v2:
- armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
  to switch to AArch64 EL2 or AArch32 Hyp.
- armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
  to switch to AArch64 EL1 or AArch32 SVC.

 arch/arm/Kconfig                              |   6 +
 arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S  |  61 +++++++--
 arch/arm/cpu/armv8/start.S                    |   8 ++
 arch/arm/cpu/armv8/transition.S               |  23 +++-
 arch/arm/include/asm/arch-fsl-layerscape/mp.h |   4 +
 arch/arm/include/asm/macro.h                  | 176 +++++++++++++++++++-------
 arch/arm/include/asm/system.h                 | 119 ++++++++++++++++-
 arch/arm/lib/bootm.c                          |  39 +++++-
 arch/arm/mach-rmobile/lowlevel_init_gen3.S    |   9 +-
 common/image-fit.c                            |  19 ++-
 10 files changed, 396 insertions(+), 68 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d7a9b11..18c23c0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -126,6 +126,12 @@ config ENABLE_ARM_SOC_BOOT0_HOOK
 	  ARM_SOC_BOOT0_HOOK which contains the required assembler
 	  preprocessor code.
 
+config ARM64_SUPPORT_AARCH32
+	bool "ARM64 system support AArch32 execution state"
+	default y if ARM64 && !TARGET_THUNDERX_88XX
+	help
+	  This ARM64 system supports AArch32 execution state.
+
 choice
 	prompt "Target select"
 	default TARGET_HIKEY
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
index 5700b1f..8e6ad4b 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
+++ b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
@@ -13,6 +13,7 @@
 #ifdef CONFIG_MP
 #include <asm/arch/mp.h>
 #endif
+#include <asm/u-boot.h>
 
 ENTRY(lowlevel_init)
 	mov	x29, lr			/* Save LR */
@@ -339,11 +340,6 @@ ENTRY(secondary_boot_func)
         gic_wait_for_interrupt_m x0, w1
 #endif
 
-	bl secondary_switch_to_el2
-#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
-	bl secondary_switch_to_el1
-#endif
-
 slave_cpu:
 	wfe
 	ldr	x0, [x11]
@@ -356,19 +352,64 @@ slave_cpu:
 	tbz     x1, #25, cpu_is_le
 	rev     x0, x0                  /* BE to LE conversion */
 cpu_is_le:
-	br	x0			/* branch to the given address */
+	ldr	x5, [x11, #24]
+	ldr	x6, =IH_ARCH_DEFAULT
+	cmp	x6, x5
+	b.eq	1f
+
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+	adr	x3, secondary_switch_to_el1
+	ldr	x4, =ES_TO_AARCH64
+#else
+	ldr	x3, [x11]
+	ldr	x4, =ES_TO_AARCH32
+#endif
+	bl	secondary_switch_to_el2
+
+1:
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+	adr	x3, secondary_switch_to_el1
+#else
+	ldr	x3, [x11]
+#endif
+	ldr	x4, =ES_TO_AARCH64
+	bl	secondary_switch_to_el2
+
 ENDPROC(secondary_boot_func)
 
 ENTRY(secondary_switch_to_el2)
-	switch_el x0, 1f, 0f, 0f
+	switch_el x5, 1f, 0f, 0f
 0:	ret
-1:	armv8_switch_to_el2_m x0
+1:	armv8_switch_to_el2_m x3, x4, x5
 ENDPROC(secondary_switch_to_el2)
 
 ENTRY(secondary_switch_to_el1)
-	switch_el x0, 0f, 1f, 0f
+	mrs	x0, mpidr_el1
+	ubfm	x1, x0, #8, #15
+	ubfm	x2, x0, #0, #1
+	orr	x10, x2, x1, lsl #2	/* x10 has LPID */
+
+	lsl	x1, x10, #6
+	ldr	x0, =__spin_table
+	/* physical address of this cpus spin table element */
+	add	x11, x1, x0
+
+	ldr	x3, [x11]
+
+	ldr	x5, [x11, #24]
+	ldr	x6, =IH_ARCH_DEFAULT
+	cmp	x6, x5
+	b.eq	2f
+
+	ldr	x4, =ES_TO_AARCH32
+	bl	switch_to_el1
+
+2:	ldr	x4, =ES_TO_AARCH64
+
+switch_to_el1:
+	switch_el x5, 0f, 1f, 0f
 0:	ret
-1:	armv8_switch_to_el1_m x0, x1
+1:	armv8_switch_to_el1_m x3, x4, x5
 ENDPROC(secondary_switch_to_el1)
 
 	/* Ensure that the literals used by the secondary boot code are
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index 19c771d..4f5f6d8 100644
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -251,9 +251,17 @@ WEAK(lowlevel_init)
 	/*
 	 * All slaves will enter EL2 and optionally EL1.
 	 */
+	adr	x3, lowlevel_in_el2
+	ldr	x4, =ES_TO_AARCH64
 	bl	armv8_switch_to_el2
+
+lowlevel_in_el2:
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+	adr	x3, lowlevel_in_el1
+	ldr	x4, =ES_TO_AARCH64
 	bl	armv8_switch_to_el1
+
+lowlevel_in_el1:
 #endif
 
 #endif /* CONFIG_ARMV8_MULTIENTRY */
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index 253a39b..bbccf2b 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -11,13 +11,24 @@
 #include <asm/macro.h>
 
 ENTRY(armv8_switch_to_el2)
-	switch_el x0, 1f, 0f, 0f
-0:	ret
-1:	armv8_switch_to_el2_m x0
+	switch_el x5, 1f, 0f, 0f
+0:
+	/*
+	 * x3 is kernel entry point or switch_to_el1
+	 * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
+         * When running in EL2 now, jump to the
+	 * address saved in x3.
+	 */
+	br x3
+1:	armv8_switch_to_el2_m x3, x4, x5
 ENDPROC(armv8_switch_to_el2)
 
 ENTRY(armv8_switch_to_el1)
-	switch_el x0, 0f, 1f, 0f
-0:	ret
-1:	armv8_switch_to_el1_m x0, x1
+	switch_el x5, 0f, 1f, 0f
+0:
+	/* x3 is kernel entry point. When running in EL1
+	 * now, jump to the address saved in x3.
+	 */
+	br x3
+1:	armv8_switch_to_el1_m x3, x4, x5
 ENDPROC(armv8_switch_to_el1)
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/mp.h b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
index f7306ff..ebf84b6 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
@@ -36,4 +36,8 @@ void secondary_boot_func(void);
 int is_core_online(u64 cpu_id);
 u32 cpu_pos_mask(void);
 #endif
+
+#define IH_ARCH_ARM		2	/* ARM */
+#define IH_ARCH_ARM64		22	/* ARM64 */
+
 #endif /* _FSL_LAYERSCAPE_MP_H */
diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h
index 9bb0efa..2553e3e 100644
--- a/arch/arm/include/asm/macro.h
+++ b/arch/arm/include/asm/macro.h
@@ -8,6 +8,11 @@
 
 #ifndef __ASM_ARM_MACRO_H__
 #define __ASM_ARM_MACRO_H__
+
+#ifdef CONFIG_ARM64
+#include <asm/system.h>
+#endif
+
 #ifdef __ASSEMBLY__
 
 /*
@@ -135,13 +140,21 @@ lr	.req	x30
 #endif
 .endm
 
-.macro armv8_switch_to_el2_m, xreg1
-	/* 64bit EL2 | HCE | SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1 */
-	mov	\xreg1, #0x5b1
-	msr	scr_el3, \xreg1
+/*
+ * Switch from EL3 to EL2 for ARMv8
+ * @ep:     kernel entry point
+ * @flag:   The execution state flag for lower exception
+ *          level, ES_TO_AARCH64 or ES_TO_AARCH32
+ * @tmp:    temporary register
+ *
+ * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
+ * For loading 64-bit OS, x0 is physical address to the FDT blob.
+ * They will be passed to the guest.
+ */
+.macro armv8_switch_to_el2_m, ep, flag, tmp
 	msr	cptr_el3, xzr		/* Disable coprocessor traps to EL3 */
-	mov	\xreg1, #0x33ff
-	msr	cptr_el2, \xreg1	/* Disable coprocessor traps to EL2 */
+	mov	\tmp, #CPTR_EL2_RES1
+	msr	cptr_el2, \tmp		/* Disable coprocessor traps to EL2 */
 
 	/* Initialize Generic Timers */
 	msr	cntvoff_el2, xzr
@@ -152,45 +165,90 @@ lr	.req	x30
 	 * and RES0 bits (31,30,27,26,24,21,20,17,15-13,10-6) +
 	 * EE,WXN,I,SA,C,A,M to 0
 	 */
-	mov	\xreg1, #0x0830
-	movk	\xreg1, #0x30C5, lsl #16
-	msr	sctlr_el2, \xreg1
+	ldr	\tmp, =(SCTLR_EL2_RES1 | SCTLR_EL2_EE_LE |\
+			SCTLR_EL2_WXN_DIS | SCTLR_EL2_ICACHE_DIS |\
+			SCTLR_EL2_SA_DIS | SCTLR_EL2_DCACHE_DIS |\
+			SCTLR_EL2_ALIGN_DIS | SCTLR_EL2_MMU_DIS)
+	msr	sctlr_el2, \tmp
+
+	mov	\tmp, sp
+	msr	sp_el2, \tmp		/* Migrate SP */
+	mrs	\tmp, vbar_el3
+	msr	vbar_el2, \tmp		/* Migrate VBAR */
+
+	/* Check switch to AArch64 EL2 or AArch32 Hypervisor mode */
+	cmp	\flag, #ES_TO_AARCH32
+	b.eq	1f
+
+	/*
+	 * The next lower exception level is AArch64, 64bit EL2 | HCE |
+	 * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
+	 */
+	ldr	\tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
+			SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
+			SCR_EL3_NS_EN)
+	msr	scr_el3, \tmp
 
 	/* Return to the EL2_SP2 mode from EL3 */
-	mov	\xreg1, sp
-	msr	sp_el2, \xreg1		/* Migrate SP */
-	mrs	\xreg1, vbar_el3
-	msr	vbar_el2, \xreg1	/* Migrate VBAR */
-	mov	\xreg1, #0x3c9
-	msr	spsr_el3, \xreg1	/* EL2_SP2 | D | A | I | F */
-	msr	elr_el3, lr
+	ldr	\tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
+			SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+			SPSR_EL_M_AARCH64 | SPSR_EL_M_EL2H)
+	msr	spsr_el3, \tmp
+	msr	elr_el3, \ep
+	eret
+
+1:
+	/*
+	 * The next lower exception level is AArch32, 32bit EL2 | HCE |
+	 * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
+	 */
+	ldr	\tmp, =(SCR_EL3_RW_AARCH32 | SCR_EL3_HCE_EN |\
+			SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
+			SCR_EL3_NS_EN)
+	msr	scr_el3, \tmp
+
+	/* Return to AArch32 Hypervisor mode */
+	ldr     \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
+			SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+			SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
+			SPSR_EL_M_HYP)
+	msr	spsr_el3, \tmp
+	msr     elr_el3, \ep
 	eret
 .endm
 
-.macro armv8_switch_to_el1_m, xreg1, xreg2
+/*
+ * Switch from EL2 to EL1 for ARMv8
+ * @ep:     kernel entry point
+ * @flag:   The execution state flag for lower exception
+ *          level, ES_TO_AARCH64 or ES_TO_AARCH32
+ * @tmp:    temporary register
+ *
+ * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
+ * For loading 64-bit OS, x0 is physical address to the FDT blob.
+ * They will be passed to the guest.
+ */
+.macro armv8_switch_to_el1_m, ep, flag, tmp
 	/* Initialize Generic Timers */
-	mrs	\xreg1, cnthctl_el2
-	orr	\xreg1, \xreg1, #0x3	/* Enable EL1 access to timers */
-	msr	cnthctl_el2, \xreg1
+	mrs	\tmp, cnthctl_el2
+	/* Enable EL1 access to timers */
+	orr	\tmp, \tmp, #(CNTHCTL_EL2_EL1PCEN_EN |\
+		CNTHCTL_EL2_EL1PCTEN_EN)
+	msr	cnthctl_el2, \tmp
 	msr	cntvoff_el2, xzr
 
 	/* Initilize MPID/MPIDR registers */
-	mrs	\xreg1, midr_el1
-	mrs	\xreg2, mpidr_el1
-	msr	vpidr_el2, \xreg1
-	msr	vmpidr_el2, \xreg2
+	mrs	\tmp, midr_el1
+	msr	vpidr_el2, \tmp
+	mrs	\tmp, mpidr_el1
+	msr	vmpidr_el2, \tmp
 
 	/* Disable coprocessor traps */
-	mov	\xreg1, #0x33ff
-	msr	cptr_el2, \xreg1	/* Disable coprocessor traps to EL2 */
+	mov	\tmp, #CPTR_EL2_RES1
+	msr	cptr_el2, \tmp		/* Disable coprocessor traps to EL2 */
 	msr	hstr_el2, xzr		/* Disable coprocessor traps to EL2 */
-	mov	\xreg1, #3 << 20
-	msr	cpacr_el1, \xreg1	/* Enable FP/SIMD at EL1 */
-
-	/* Initialize HCR_EL2 */
-	mov	\xreg1, #(1 << 31)		/* 64bit EL1 */
-	orr	\xreg1, \xreg1, #(1 << 29)	/* Disable HVC */
-	msr	hcr_el2, \xreg1
+	mov	\tmp, #CPACR_EL1_FPEN_EN
+	msr	cpacr_el1, \tmp		/* Enable FP/SIMD@EL1 */
 
 	/* SCTLR_EL1 initialization
 	 *
@@ -199,18 +257,50 @@ lr	.req	x30
 	 * UCI,EE,EOE,WXN,nTWE,nTWI,UCT,DZE,I,UMA,SED,ITD,
 	 * CP15BEN,SA0,SA,C,A,M to 0
 	 */
-	mov	\xreg1, #0x0800
-	movk	\xreg1, #0x30d0, lsl #16
-	msr	sctlr_el1, \xreg1
+	ldr	\tmp, =(SCTLR_EL1_RES1 | SCTLR_EL1_UCI_DIS |\
+			SCTLR_EL1_EE_LE | SCTLR_EL1_WXN_DIS |\
+			SCTLR_EL1_NTWE_DIS | SCTLR_EL1_NTWI_DIS |\
+			SCTLR_EL1_UCT_DIS | SCTLR_EL1_DZE_DIS |\
+			SCTLR_EL1_ICACHE_DIS | SCTLR_EL1_UMA_DIS |\
+			SCTLR_EL1_SED_EN | SCTLR_EL1_ITD_EN |\
+			SCTLR_EL1_CP15BEN_DIS | SCTLR_EL1_SA0_DIS |\
+			SCTLR_EL1_SA_DIS | SCTLR_EL1_DCACHE_DIS |\
+			SCTLR_EL1_ALIGN_DIS | SCTLR_EL1_MMU_DIS)
+	msr	sctlr_el1, \tmp
+
+	mov	\tmp, sp
+	msr	sp_el1, \tmp		/* Migrate SP */
+	mrs	\tmp, vbar_el2
+	msr	vbar_el1, \tmp		/* Migrate VBAR */
+
+	/* Check switch to AArch64 EL1 or AArch32 Supervisor mode */
+	cmp	\flag, #ES_TO_AARCH32
+	b.eq	1f
+
+	/* Initialize HCR_EL2 */
+	ldr	\tmp, =(HCR_EL2_RW_AARCH64 | HCR_EL2_HCD_DIS)
+	msr	hcr_el2, \tmp
 
 	/* Return to the EL1_SP1 mode from EL2 */
-	mov	\xreg1, sp
-	msr	sp_el1, \xreg1		/* Migrate SP */
-	mrs	\xreg1, vbar_el2
-	msr	vbar_el1, \xreg1	/* Migrate VBAR */
-	mov	\xreg1, #0x3c5
-	msr	spsr_el2, \xreg1	/* EL1_SP1 | D | A | I | F */
-	msr	elr_el2, lr
+	ldr	\tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
+			SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+			SPSR_EL_M_AARCH64 | SPSR_EL_M_EL1H)
+	msr	spsr_el2, \tmp
+	msr     elr_el2, \ep
+	eret
+
+1:
+	/* Initialize HCR_EL2 */
+	ldr	\tmp, =(HCR_EL2_RW_AARCH32 | HCR_EL2_HCD_DIS)
+	msr	hcr_el2, \tmp
+
+	/* Return to AArch32 Supervisor mode from EL2 */
+	ldr	\tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
+			SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+			SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
+			SPSR_EL_M_SVC)
+	msr     spsr_el2, \tmp
+	msr     elr_el2, \ep
 	eret
 .endm
 
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index c3c88d2..1c3f74d 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -18,6 +18,95 @@
 #define CR_WXN		(1 << 19)	/* Write Permision Imply XN	*/
 #define CR_EE		(1 << 25)	/* Exception (Big) Endian	*/
 
+#define ES_TO_AARCH64		1
+#define ES_TO_AARCH32		0
+
+/*
+ * SCR_EL3 bits definitions
+ */
+#define SCR_EL3_RW_AARCH64	(1 << 10) /* Next lower level is AArch64     */
+#define SCR_EL3_RW_AARCH32	(0 << 10) /* Lower lowers level are AArch32  */
+#define SCR_EL3_HCE_EN		(1 << 8)  /* Hypervisor Call enable          */
+#define SCR_EL3_SMD_DIS		(1 << 7)  /* Secure Monitor Call disable     */
+#define SCR_EL3_RES1		(3 << 4)  /* Reserved, RES1                  */
+#define SCR_EL3_NS_EN		(1 << 0)  /* EL0 and EL1 in Non-scure state  */
+
+/*
+ * SPSR_EL3/SPSR_EL2 bits definitions
+ */
+#define SPSR_EL_END_LE		(0 << 9)  /* Exception Little-endian          */
+#define SPSR_EL_DEBUG_MASK	(1 << 9)  /* Debug exception masked           */
+#define SPSR_EL_ASYN_MASK	(1 << 8)  /* Asynchronous data abort masked   */
+#define SPSR_EL_SERR_MASK	(1 << 8)  /* System Error exception masked    */
+#define SPSR_EL_IRQ_MASK	(1 << 7)  /* IRQ exception masked             */
+#define SPSR_EL_FIQ_MASK	(1 << 6)  /* FIQ exception masked             */
+#define SPSR_EL_T_A32		(0 << 5)  /* AArch32 instruction set A32      */
+#define SPSR_EL_M_AARCH64	(0 << 4)  /* Exception taken from AArch64     */
+#define SPSR_EL_M_AARCH32	(1 << 4)  /* Exception taken from AArch32     */
+#define SPSR_EL_M_SVC		(0x3)     /* Exception taken from SVC mode    */
+#define SPSR_EL_M_HYP		(0xa)     /* Exception taken from HYP mode    */
+#define SPSR_EL_M_EL1H		(5)       /* Exception taken from EL1h mode   */
+#define SPSR_EL_M_EL2H		(9)       /* Exception taken from EL2h mode   */
+
+/*
+ * CPTR_EL2 bits definitions
+ */
+#define CPTR_EL2_RES1		(3 << 12 | 0x3ff)           /* Reserved, RES1 */
+
+/*
+ * SCTLR_EL2 bits definitions
+ */
+#define SCTLR_EL2_RES1		(3 << 28 | 3 << 22 | 1 << 18 | 1 << 16 |\
+				 1 << 11 | 3 << 4)	    /* Reserved, RES1 */
+#define SCTLR_EL2_EE_LE		(0 << 25) /* Exception Little-endian          */
+#define SCTLR_EL2_WXN_DIS	(0 << 19) /* Write permission is not XN       */
+#define SCTLR_EL2_ICACHE_DIS	(0 << 12) /* Instruction cache disabled       */
+#define SCTLR_EL2_SA_DIS	(0 << 3)  /* Stack Alignment Check disabled   */
+#define SCTLR_EL2_DCACHE_DIS	(0 << 2)  /* Data cache disabled              */
+#define SCTLR_EL2_ALIGN_DIS	(0 << 1)  /* Alignment check disabled         */
+#define SCTLR_EL2_MMU_DIS	(0)       /* MMU disabled                     */
+
+/*
+ * CNTHCTL_EL2 bits definitions
+ */
+#define CNTHCTL_EL2_EL1PCEN_EN	(1 << 1)  /* Physical timer regs accessible   */
+#define CNTHCTL_EL2_EL1PCTEN_EN	(1 << 0)  /* Physical counter accessible      */
+
+/*
+ * HCR_EL2 bits definitions
+ */
+#define HCR_EL2_RW_AARCH64	(1 << 31) /* EL1 is AArch64                   */
+#define HCR_EL2_RW_AARCH32	(0 << 31) /* Lower levels are AArch32         */
+#define HCR_EL2_HCD_DIS		(1 << 29) /* Hypervisor Call disabled         */
+
+/*
+ * CPACR_EL1 bits definitions
+ */
+#define CPACR_EL1_FPEN_EN	(3 << 20) /* SIMD and FP instruction enabled  */
+
+/*
+ * SCTLR_EL1 bits definitions
+ */
+#define SCTLR_EL1_RES1		(3 << 28 | 3 << 22 | 1 << 20 |\
+				 1 << 11) /* Reserved, RES1                   */
+#define SCTLR_EL1_UCI_DIS	(0 << 26) /* Cache instruction disabled       */
+#define SCTLR_EL1_EE_LE		(0 << 25) /* Exception Little-endian          */
+#define SCTLR_EL1_WXN_DIS	(0 << 19) /* Write permission is not XN       */
+#define SCTLR_EL1_NTWE_DIS	(0 << 18) /* WFE instruction disabled         */
+#define SCTLR_EL1_NTWI_DIS	(0 << 16) /* WFI instruction disabled         */
+#define SCTLR_EL1_UCT_DIS	(0 << 15) /* CTR_EL0 access disabled          */
+#define SCTLR_EL1_DZE_DIS	(0 << 14) /* DC ZVA instruction disabled      */
+#define SCTLR_EL1_ICACHE_DIS	(0 << 12) /* Instruction cache disabled       */
+#define SCTLR_EL1_UMA_DIS	(0 << 9)  /* User Mask Access disabled        */
+#define SCTLR_EL1_SED_EN	(0 << 8)  /* SETEND instruction enabled       */
+#define SCTLR_EL1_ITD_EN	(0 << 7)  /* IT instruction enabled           */
+#define SCTLR_EL1_CP15BEN_DIS	(0 << 5)  /* CP15 barrier operation disabled  */
+#define SCTLR_EL1_SA0_DIS	(0 << 4)  /* Stack Alignment EL0 disabled     */
+#define SCTLR_EL1_SA_DIS	(0 << 3)  /* Stack Alignment EL1 disabled     */
+#define SCTLR_EL1_DCACHE_DIS	(0 << 2)  /* Data cache disabled              */
+#define SCTLR_EL1_ALIGN_DIS	(0 << 1)  /* Alignment check disabled         */
+#define SCTLR_EL1_MMU_DIS	(0)       /* MMU disabled                     */
+
 #ifndef __ASSEMBLY__
 
 u64 get_page_table_size(void);
@@ -98,8 +187,34 @@ int __asm_flush_l3_dcache(void);
 int __asm_invalidate_l3_icache(void);
 void __asm_switch_ttbr(u64 new_ttbr);
 
-void armv8_switch_to_el2(void);
-void armv8_switch_to_el1(void);
+/*
+ * Switch from EL3 to EL2 for ARMv8
+ *
+ * @args:        For loading 64-bit OS, fdt address.
+ *               For loading 32-bit OS, zero.
+ * @mach_nr:     For loading 64-bit OS, zero.
+ *               For loading 32-bit OS, machine nr
+ * @fdt_addr:    For loading 64-bit OS, zero.
+ *               For loading 32-bit OS, fdt address.
+ * @entry_point: kernel entry point
+ * @es_flag:     execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
+ */
+void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
+			 u64 entry_point, u64 es_flag);
+/*
+ * Switch from EL2 to EL1 for ARMv8
+ *
+ * @args:        For loading 64-bit OS, fdt address.
+ *               For loading 32-bit OS, zero.
+ * @mach_nr:     For loading 64-bit OS, zero.
+ *               For loading 32-bit OS, machine nr
+ * @fdt_addr:    For loading 64-bit OS, zero.
+ *               For loading 32-bit OS, fdt address.
+ * @entry_point: kernel entry point
+ * @es_flag:     execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
+ */
+void armv8_switch_to_el1(u64 args, u64 mach_nr, u64 fdt_addr,
+			 u64 entry_point, u64 es_flag);
 void gic_init(void);
 void gic_send_sgi(unsigned long sgino);
 void wait_for_wakeup(void);
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 53c3141..7015573 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -193,10 +193,6 @@ static void do_nonsec_virt_switch(void)
 {
 	smp_kick_all_cpus();
 	dcache_disable();	/* flush cache before swtiching to EL2 */
-	armv8_switch_to_el2();
-#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
-	armv8_switch_to_el1();
-#endif
 }
 #endif
 
@@ -273,6 +269,24 @@ bool armv7_boot_nonsec(void)
 }
 #endif
 
+#ifdef CONFIG_ARM64
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+static void switch_to_el1(void)
+{
+	if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
+	    (images.os.arch == IH_ARCH_ARM))
+		armv8_switch_to_el1(0, (u64)gd->bd->bi_arch_number,
+				    (u64)images.ft_addr,
+				    (u64)images.ep,
+				    ES_TO_AARCH32);
+	else
+		armv8_switch_to_el1((u64)images.ft_addr, 0, 0,
+				    images.ep,
+				    ES_TO_AARCH64);
+}
+#endif
+#endif
+
 /* Subcommand: GO */
 static void boot_jump_linux(bootm_headers_t *images, int flag)
 {
@@ -292,7 +306,22 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
 
 	if (!fake) {
 		do_nonsec_virt_switch();
-		kernel_entry(images->ft_addr, NULL, NULL, NULL);
+
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+		armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
+				    (u64)switch_to_el1, ES_TO_AARCH64);
+#else
+		if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
+		    (images->os.arch == IH_ARCH_ARM))
+			armv8_switch_to_el2(0, (u64)gd->bd->bi_arch_number,
+					    (u64)images->ft_addr,
+					    (u64)images->ep,
+					    ES_TO_AARCH32);
+		else
+			armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
+					    images->ep,
+					    ES_TO_AARCH64);
+#endif
 	}
 #else
 	unsigned long machid = gd->bd->bi_arch_number;
diff --git a/arch/arm/mach-rmobile/lowlevel_init_gen3.S b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
index 88ff56e..11acce0 100644
--- a/arch/arm/mach-rmobile/lowlevel_init_gen3.S
+++ b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
@@ -61,11 +61,18 @@ ENTRY(lowlevel_init)
 	/*
 	 * All slaves will enter EL2 and optionally EL1.
 	 */
+	adr	x3, lowlevel_in_el2
+	ldr	x4, =ES_TO_AARCH64
 	bl	armv8_switch_to_el2
+
+lowlevel_in_el2:
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+	adr	x3, lowlevel_in_el1
+	ldr	x4, =ES_TO_AARCH64
 	bl	armv8_switch_to_el1
-#endif
 
+lowlevel_in_el1:
+#endif
 #endif /* CONFIG_ARMV8_MULTIENTRY */
 
 	bl      s_init
diff --git a/common/image-fit.c b/common/image-fit.c
index 77dc011..ea56d5b 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -27,6 +27,7 @@ DECLARE_GLOBAL_DATA_PTR;
 #include <u-boot/md5.h>
 #include <u-boot/sha1.h>
 #include <u-boot/sha256.h>
+#include <generated/autoconf.h>
 
 /*****************************************************************************/
 /* New uImage format routines */
@@ -1161,11 +1162,18 @@ int fit_image_check_os(const void *fit, int noffset, uint8_t os)
 int fit_image_check_arch(const void *fit, int noffset, uint8_t arch)
 {
 	uint8_t image_arch;
+	int aarch32_support = 0;
+
+#ifdef CONFIG_ARM64_SUPPORT_AARCH32
+	aarch32_support = 1;
+#endif
 
 	if (fit_image_get_arch(fit, noffset, &image_arch))
 		return 0;
 	return (arch == image_arch) ||
-		(arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64);
+		(arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64) ||
+		(arch == IH_ARCH_ARM64 && image_arch == IH_ARCH_ARM &&
+		 aarch32_support);
 }
 
 /**
@@ -1614,6 +1622,9 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	int type_ok, os_ok;
 	ulong load, data, len;
 	uint8_t os;
+#ifndef USE_HOSTCC
+	uint8_t os_arch;
+#endif
 	const char *prop_name;
 	int ret;
 
@@ -1697,6 +1708,12 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 		return -ENOEXEC;
 	}
 #endif
+
+#ifndef USE_HOSTCC
+	fit_image_get_arch(fit, noffset, &os_arch);
+	images->os.arch = os_arch;
+#endif
+
 	if (image_type == IH_TYPE_FLATDT &&
 	    !fit_image_check_comp(fit, noffset, IH_COMP_NONE)) {
 		puts("FDT image is compressed");
-- 
2.1.0.27.g96db324

[U-Boot] [PATCH v8 2/3] armv8: fsl-layerscape: SMP support for loading 32-bit OS

[Alison Wang]

Spin-table method is used for secondary cores to load 32-bit OS. The
architecture information will be got through checking FIT image and
saved in the os_arch element of spin-table, then the secondary cores
will check os_arch and jump to 32-bit OS or 64-bit OS automatically.

Signed-off-by: Alison Wang <alison.wang@nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
---
Changes in v8:
- None.

Changes in v7:
- Move the call for armv8_switch_to_el2_m into the first patch.

Changes in v6:
- Make secondary_switch_to_el1() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v5:
- Make secondary_switch_to_el2() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v4:
- Omit arch and ftaddr arguments.

Changes in v3:
- Adjust the arguments for armv8_switch_to_el2_m and armv8_switch_to_el1_m. 

Changes in v2:
- Support to call armv8_switch_to_el2_m and armv8_switch_to_el1_m.

 arch/arm/cpu/armv8/fsl-layerscape/mp.c        | 10 ++++++++++
 arch/arm/include/asm/arch-fsl-layerscape/mp.h |  2 ++
 arch/arm/lib/bootm.c                          |  6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/mp.c b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
index f607c39..ca30137 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/mp.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
@@ -22,6 +22,16 @@ phys_addr_t determine_mp_bootpg(void)
 	return (phys_addr_t)&secondary_boot_code;
 }
 
+void update_os_arch_secondary_cores(uint8_t os_arch)
+{
+	u64 *table = get_spin_tbl_addr();
+	int i;
+
+	for (i = 1; i < CONFIG_MAX_CPUS; i++)
+		table[i * WORDS_PER_SPIN_TABLE_ENTRY +
+			SPIN_TABLE_ELEM_OS_ARCH_IDX] = os_arch;
+}
+
 int fsl_layerscape_wake_seconday_cores(void)
 {
 	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/mp.h b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
index ebf84b6..d0832b5 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
@@ -13,6 +13,7 @@
 *      uint64_t entry_addr;
 *      uint64_t status;
 *      uint64_t lpid;
+*      uint64_t os_arch;
 * };
 * we pad this struct to 64 bytes so each entry is in its own cacheline
 * the actual spin table is an array of these structures
@@ -20,6 +21,7 @@
 #define SPIN_TABLE_ELEM_ENTRY_ADDR_IDX	0
 #define SPIN_TABLE_ELEM_STATUS_IDX	1
 #define SPIN_TABLE_ELEM_LPID_IDX	2
+#define SPIN_TABLE_ELEM_OS_ARCH_IDX	3
 #define WORDS_PER_SPIN_TABLE_ENTRY	8	/* pad to 64 bytes */
 #define SPIN_TABLE_ELEM_SIZE		64
 
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 7015573..17758d3 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -270,6 +270,10 @@ bool armv7_boot_nonsec(void)
 #endif
 
 #ifdef CONFIG_ARM64
+__weak void update_os_arch_secondary_cores(uint8_t os_arch)
+{
+}
+
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
 static void switch_to_el1(void)
 {
@@ -307,6 +311,8 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
 	if (!fake) {
 		do_nonsec_virt_switch();
 
+		update_os_arch_secondary_cores(images->os.arch);
+
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
 		armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
 				    (u64)switch_to_el1, ES_TO_AARCH64);
-- 
2.1.0.27.g96db324

[U-Boot] [PATCH v8 3/3] armv8: fsl-layerscape: Support loading 32-bit OS with PSCI enabled

[Alison Wang]

As PSCI and secure monitor firmware framework are enabled, this patch is
to support loading 32-bit OS in such case. The default target exception
level returned to U-Boot is EL2, so the corresponding work to switch to
AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware
together.

Signed-off-by: Alison Wang <alison.wang@nxp.com>
---
 arch/arm/cpu/armv8/sec_firmware_asm.S | 23 +++++++++++++++++++++++
 arch/arm/cpu/armv8/transition.S       | 12 ++++++++++++
 arch/arm/include/asm/system.h         |  2 ++
 3 files changed, 37 insertions(+)

diff --git a/arch/arm/cpu/armv8/sec_firmware_asm.S b/arch/arm/cpu/armv8/sec_firmware_asm.S
index 0c6a462..1b39f1d 100644
--- a/arch/arm/cpu/armv8/sec_firmware_asm.S
+++ b/arch/arm/cpu/armv8/sec_firmware_asm.S
@@ -50,4 +50,27 @@ ENTRY(_sec_firmware_support_psci_version)
 	smc	#0
 	ret
 ENDPROC(_sec_firmware_support_psci_version)
+
+/*
+ * Switch from AArch64 EL2 to AArch32 EL2
+ * @param inputs:
+ * x0: argument, zero
+ * x1: machine nr
+ * x2: fdt address
+ * x3: kernel entry point
+ * @param outputs for secure firmware:
+ * x0: function id
+ * x1: kernel entry point
+ * x2: machine nr
+ * x3: fdt address
+*/
+ENTRY(armv8_el2_to_aarch32)
+	mov	x0, x3
+	mov	x3, x2
+	mov	x2, x1
+	mov	x1, x0
+	ldr	x0, =0xc000ff04
+	smc	#0
+	ret
+ENDPROC(armv8_el2_to_aarch32)
 #endif
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index bbccf2b..adb9f35 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -13,6 +13,14 @@
 ENTRY(armv8_switch_to_el2)
 	switch_el x5, 1f, 0f, 0f
 0:
+	cmp x4, #ES_TO_AARCH64
+	b.eq 2f
+	/*
+	 * When loading 32-bit kernel, it will jump
+	 * to secure firmware again, and never return.
+	 */
+	bl armv8_el2_to_aarch32
+2:
 	/*
 	 * x3 is kernel entry point or switch_to_el1
 	 * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
@@ -32,3 +40,7 @@ ENTRY(armv8_switch_to_el1)
 	br x3
 1:	armv8_switch_to_el1_m x3, x4, x5
 ENDPROC(armv8_switch_to_el1)
+
+WEAK(armv8_el2_to_aarch32)
+	ret
+ENDPROC(armv8_el2_to_aarch32)
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 1c3f74d..5bd5a2f 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -215,6 +215,8 @@ void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
  */
 void armv8_switch_to_el1(u64 args, u64 mach_nr, u64 fdt_addr,
 			 u64 entry_point, u64 es_flag);
+void armv8_el2_to_aarch32(u64 args, u64 mach_nr, u64 fdt_addr,
+			  u64 entry_point);
 void gic_init(void);
 void gic_send_sgi(unsigned long sgino);
 void wait_for_wakeup(void);
-- 
2.1.0.27.g96db324

[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Ryan Harkin]

Hi Alison,

On 10 November 2016 at 02:49, Alison Wang <b18965@freescale.com> wrote:
> This series is to support loading a 32-bit OS, the execution state will change from AArch64 to AArch32 when jumping to kernel. The architecture information will be got through checking FIT image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
>
> Spin-table method is used for secondary cores to load 32-bit OS.
> The architecture information will be got through checking FIT image and saved in the os_arch element of spin-table, then the secondary cores will check os_arch and jump to 32-bit OS or 64-bit OS automatically.
>
> PSCI method can also be used for secondary cores to load 32-bit OS.
> As PSCI and secure monitor firmware framework are enabled, loading 32-bit OS is supported in such case. The default target exception level returned to U-Boot is EL2, so the corresponding work to switch to AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware together.
>
> ---------------------------------------
> Changes in v8:
> - Fix the issue when U-Boot is running in EL2 or EL1.

Thanks for sticking with this.  Great news: it works for my setup.

I tested booting an arm64 kernel on FVP Foundation and AEMv8 modes and
on Juno R0, R1 and R2.  I also tested and Versatile Express TC2 can
still load it's Aarch32 kernel.

I didn't test running an Aarch32 kernel or any of the new
functionality on my ARMv8 platforms.

But I checked and the patches are bisect-able on my ARMv8 platforms.

Tested-by: Ryan Harkin <ryan.harkin@linaro.org>


> - Support loading 32-bit OS with PSCI enabled.
>
> Changes in v7:
> - Move the call for armv8_switch_to_el2_m into the first patch.
>
> Changes in v6:
> - Modified armv8_switch_to_el1(). It will always jump to ep when switching to AArch64 or AArch32 modes.
> - Make other platforms compatible with the new armv8_switch_to_el2() and armv8_switch_to_el1().
> - Make secondary_switch_to_el1() always jump to ep when switching to AArch64 or AArch32 modes.
>
> Changes in v5:
> - Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.
> - Make secondary_switch_to_el2() always jump to ep when switching to AArch64 or AArch32 modes.
>
> Changes in v4:
> - Correct config ARM64_SUPPORT_AARCH32.
> - Omit arch and ftaddr arguments.
> - Rename "xreg5" to "tmp".
> - Use xxx_RES1 to combine all RES1 fields in xxx register.
> - Use an immediate cmp directly.
> - Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.
>
> Changes in v3:
> - Comments the functions and the arguments.
> - Rename the real parameters.
> - Use the macros instead of the magic values.
> - Remove the redundant codes.
> - Clean up all of the mess in boot_jump_linux().
> - Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't support AArch32 state.
> - Adjust the arguments for armv8_switch_to_el2_m and armv8_switch_to_el1_m.
>
> Changes in v2:
> - armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
>   to switch to AArch64 EL2 or AArch32 Hyp.
> - armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
>   to switch to AArch64 EL1 or AArch32 SVC.
> - Support to call armv8_switch_to_el2_m and armv8_switch_to_el1_m.
>
> ----------------------------------------------------------------
> Alison Wang (3):
>       armv8: Support loading 32-bit OS in AArch32 execution state
>       armv8: fsl-layerscape: SMP support for loading 32-bit OS
>       armv8: fsl-layerscape: Support loading 32-bit OS with PSCI enabled
>
>  arch/arm/Kconfig                              |   6 ++++
>  arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S  |  61 +++++++++++++++++++++++++------
>  arch/arm/cpu/armv8/fsl-layerscape/mp.c        |  10 ++++++
>  arch/arm/cpu/armv8/sec_firmware_asm.S         |  23 ++++++++++++
>  arch/arm/cpu/armv8/start.S                    |   8 +++++
>  arch/arm/cpu/armv8/transition.S               |  35 ++++++++++++++----
>  arch/arm/include/asm/arch-fsl-layerscape/mp.h |   6 ++++
>  arch/arm/include/asm/macro.h                  | 176 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------
>  arch/arm/include/asm/system.h                 | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
>  arch/arm/lib/bootm.c                          |  45 ++++++++++++++++++++---
>  arch/arm/mach-rmobile/lowlevel_init_gen3.S    |   9 ++++-
>  common/image-fit.c                            |  19 +++++++++-
>  12 files changed, 451 insertions(+), 68 deletions(-)
>

[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/11/2016 05:58 AM, Ryan Harkin wrote:
> Hi Alison,
>
> On 10 November 2016 at 02:49, Alison Wang <b18965@freescale.com> wrote:
>> This series is to support loading a 32-bit OS, the execution state will change from AArch64 to AArch32 when jumping to kernel. The architecture information will be got through checking FIT image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>
>> Spin-table method is used for secondary cores to load 32-bit OS.
>> The architecture information will be got through checking FIT image and saved in the os_arch element of spin-table, then the secondary cores will check os_arch and jump to 32-bit OS or 64-bit OS automatically.
>>
>> PSCI method can also be used for secondary cores to load 32-bit OS.
>> As PSCI and secure monitor firmware framework are enabled, loading 32-bit OS is supported in such case. The default target exception level returned to U-Boot is EL2, so the corresponding work to switch to AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware together.
>>
>> ---------------------------------------
>> Changes in v8:
>> - Fix the issue when U-Boot is running in EL2 or EL1.
>
> Thanks for sticking with this.  Great news: it works for my setup.
>
> I tested booting an arm64 kernel on FVP Foundation and AEMv8 modes and
> on Juno R0, R1 and R2.  I also tested and Versatile Express TC2 can
> still load it's Aarch32 kernel.
>
> I didn't test running an Aarch32 kernel or any of the new
> functionality on my ARMv8 platforms.
>
> But I checked and the patches are bisect-able on my ARMv8 platforms.
>
> Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
>

Great! Thanks to Ryan and Alison to work this out.

York

[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

> On 10 November 2016 at 02:49, Alison Wang <b18965@freescale.com> wrote:
> > This series is to support loading a 32-bit OS, the execution state
> will change from AArch64 to AArch32 when jumping to kernel. The
> architecture information will be got through checking FIT image, then
> U-Boot will load 32-bit OS or 64-bit OS automatically.
> >
> > Spin-table method is used for secondary cores to load 32-bit OS.
> > The architecture information will be got through checking FIT image
> and saved in the os_arch element of spin-table, then the secondary
> cores will check os_arch and jump to 32-bit OS or 64-bit OS
> automatically.
> >
> > PSCI method can also be used for secondary cores to load 32-bit OS.
> > As PSCI and secure monitor firmware framework are enabled, loading
> 32-bit OS is supported in such case. The default target exception level
> returned to U-Boot is EL2, so the corresponding work to switch to
> AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure
> firmware together.
> >
> > ---------------------------------------
> > Changes in v8:
> > - Fix the issue when U-Boot is running in EL2 or EL1.
> 
> Thanks for sticking with this.  Great news: it works for my setup.
> 
> I tested booting an arm64 kernel on FVP Foundation and AEMv8 modes and
> on Juno R0, R1 and R2.  I also tested and Versatile Express TC2 can
> still load it's Aarch32 kernel.
> 
> I didn't test running an Aarch32 kernel or any of the new functionality
> on my ARMv8 platforms.
> 
> But I checked and the patches are bisect-able on my ARMv8 platforms.
> 
> Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
> 
[Alison Wang] Thanks for your verification.


Best Regards,
Alison Wang

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/09/2016 07:02 PM, Alison Wang wrote:
> To support loading a 32-bit OS, the execution state will change from
> AArch64 to AArch32 when jumping to kernel.
>
> The architecture information will be got through checking FIT image,
> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>
> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
> Signed-off-by: Alison Wang <alison.wang@nxp.com>
> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
> ---
> Changes in v8:
> - Fix the issue when U-Boot is running in EL2 or EL1.
>

Alison,

There is a conflict when merging with upstream code. Alex Graf merged 
his change to support EFI booting. See commit 
69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines


         if (current_el() == 3) {
                 smp_kick_all_cpus();
                 dcache_disable();
                 armv8_switch_to_el2();
                 dcache_enable();
         }

Function armv8_switch_to_el2() didn't take any argument before you 
change. With your proposed change to support 32-bit OS, you added 
arguments to this function, and presume this function always load OS. 
This may be flawed. Would it be possible to keep armv8_switch_to_el2() 
but introduce another function to carry out switching EL while loading OS?

York

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alexander Graf]

On 21/11/2016 21:23, york sun wrote:
> On 11/09/2016 07:02 PM, Alison Wang wrote:
>> To support loading a 32-bit OS, the execution state will change from
>> AArch64 to AArch32 when jumping to kernel.
>>
>> The architecture information will be got through checking FIT image,
>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>
>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>> ---
>> Changes in v8:
>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>
>
> Alison,
>
> There is a conflict when merging with upstream code. Alex Graf merged
> his change to support EFI booting. See commit
> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>
>
>          if (current_el() == 3) {
>                  smp_kick_all_cpus();
>                  dcache_disable();
>                  armv8_switch_to_el2();
>                  dcache_enable();
>          }
>
> Function armv8_switch_to_el2() didn't take any argument before you
> change. With your proposed change to support 32-bit OS, you added
> arguments to this function, and presume this function always load OS.
> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
> but introduce another function to carry out switching EL while loading OS?

Alison introduced it based on my comments - and I'd prefer if we only 
have the function call based version :).

It should be reasonably straight forward to move to it here. Just create 
a new helper stub that enables the dcache and calls entry().


Alex

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/21/2016 12:40 PM, Alexander Graf wrote:
>
>
> On 21/11/2016 21:23, york sun wrote:
>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>> To support loading a 32-bit OS, the execution state will change from
>>> AArch64 to AArch32 when jumping to kernel.
>>>
>>> The architecture information will be got through checking FIT image,
>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>
>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>> ---
>>> Changes in v8:
>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>
>>
>> Alison,
>>
>> There is a conflict when merging with upstream code. Alex Graf merged
>> his change to support EFI booting. See commit
>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>
>>
>>          if (current_el() == 3) {
>>                  smp_kick_all_cpus();
>>                  dcache_disable();
>>                  armv8_switch_to_el2();
>>                  dcache_enable();
>>          }
>>
>> Function armv8_switch_to_el2() didn't take any argument before you
>> change. With your proposed change to support 32-bit OS, you added
>> arguments to this function, and presume this function always load OS.
>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>> but introduce another function to carry out switching EL while loading OS?
>
> Alison introduced it based on my comments - and I'd prefer if we only
> have the function call based version :).
>
> It should be reasonably straight forward to move to it here. Just create
> a new helper stub that enables the dcache and calls entry().
>

Alex,

Do you always load OS when calling armv8_switch_to_el2()? In this case 
of efi booting, kernel entry point needs to be passed to the new 
armv8_switch_to_el2 function. The new armv8_switch_to_el2 function 
doesn't return, so you cannot continue to run the code.

York

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alexander Graf]

On 21/11/2016 21:45, york sun wrote:
> On 11/21/2016 12:40 PM, Alexander Graf wrote:
>>
>>
>> On 21/11/2016 21:23, york sun wrote:
>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>>> To support loading a 32-bit OS, the execution state will change from
>>>> AArch64 to AArch32 when jumping to kernel.
>>>>
>>>> The architecture information will be got through checking FIT image,
>>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>>
>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>>> ---
>>>> Changes in v8:
>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>>
>>>
>>> Alison,
>>>
>>> There is a conflict when merging with upstream code. Alex Graf merged
>>> his change to support EFI booting. See commit
>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>>
>>>
>>>          if (current_el() == 3) {
>>>                  smp_kick_all_cpus();
>>>                  dcache_disable();
>>>                  armv8_switch_to_el2();
>>>                  dcache_enable();
>>>          }
>>>
>>> Function armv8_switch_to_el2() didn't take any argument before you
>>> change. With your proposed change to support 32-bit OS, you added
>>> arguments to this function, and presume this function always load OS.
>>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>>> but introduce another function to carry out switching EL while loading OS?
>>
>> Alison introduced it based on my comments - and I'd prefer if we only
>> have the function call based version :).
>>
>> It should be reasonably straight forward to move to it here. Just create
>> a new helper stub that enables the dcache and calls entry().
>>
>
> Alex,
>
> Do you always load OS when calling armv8_switch_to_el2()? In this case
> of efi booting, kernel entry point needs to be passed to the new
> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
> doesn't return, so you cannot continue to run the code.

We always call some random function pointer in the new flow. That can be 
a kernel entry point, but it can also just be a function pointer. In 
this case, the code would basically look like this:

static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2)
{
     dcache_enable();
     return entry(arg1, arg2);
}

if (current_el() == 3) {
     ...
     return armv8_switch_to_el2(efi_run_in_el2, entry, 
&loaded_image_info, &systab);
}


Alex

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/21/2016 01:07 PM, Alexander Graf wrote:
>
>
> On 21/11/2016 21:45, york sun wrote:
>> On 11/21/2016 12:40 PM, Alexander Graf wrote:
>>>
>>>
>>> On 21/11/2016 21:23, york sun wrote:
>>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>>>> To support loading a 32-bit OS, the execution state will change from
>>>>> AArch64 to AArch32 when jumping to kernel.
>>>>>
>>>>> The architecture information will be got through checking FIT image,
>>>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>>>
>>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>>>> ---
>>>>> Changes in v8:
>>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>>>
>>>>
>>>> Alison,
>>>>
>>>> There is a conflict when merging with upstream code. Alex Graf merged
>>>> his change to support EFI booting. See commit
>>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>>>
>>>>
>>>>          if (current_el() == 3) {
>>>>                  smp_kick_all_cpus();
>>>>                  dcache_disable();
>>>>                  armv8_switch_to_el2();
>>>>                  dcache_enable();
>>>>          }
>>>>
>>>> Function armv8_switch_to_el2() didn't take any argument before you
>>>> change. With your proposed change to support 32-bit OS, you added
>>>> arguments to this function, and presume this function always load OS.
>>>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>>>> but introduce another function to carry out switching EL while loading OS?
>>>
>>> Alison introduced it based on my comments - and I'd prefer if we only
>>> have the function call based version :).
>>>
>>> It should be reasonably straight forward to move to it here. Just create
>>> a new helper stub that enables the dcache and calls entry().
>>>
>>
>> Alex,
>>
>> Do you always load OS when calling armv8_switch_to_el2()? In this case
>> of efi booting, kernel entry point needs to be passed to the new
>> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
>> doesn't return, so you cannot continue to run the code.
>
> We always call some random function pointer in the new flow. That can be
> a kernel entry point, but it can also just be a function pointer. In
> this case, the code would basically look like this:
>
> static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2)
> {
>      dcache_enable();
>      return entry(arg1, arg2);
> }
>
> if (current_el() == 3) {
>      ...
>      return armv8_switch_to_el2(efi_run_in_el2, entry,
> &loaded_image_info, &systab);
> }
>

Alex,

Since you are most familiar with EFI boot code, can you send a patch to 
address this? I can squash it with Alison's patch after testing. My 
current test branch is 
http://git.denx.de/?p=u-boot/u-boot-fsl-qoriq.git;a=shortlog;h=refs/heads/test_qoriq.

Thanks.

York

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

Hi, Alex,

> On 11/21/2016 01:07 PM, Alexander Graf wrote:
> >
> >
> > On 21/11/2016 21:45, york sun wrote:
> >> On 11/21/2016 12:40 PM, Alexander Graf wrote:
> >>>
> >>>
> >>> On 21/11/2016 21:23, york sun wrote:
> >>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
> >>>>> To support loading a 32-bit OS, the execution state will change
> >>>>> from
> >>>>> AArch64 to AArch32 when jumping to kernel.
> >>>>>
> >>>>> The architecture information will be got through checking FIT
> >>>>> image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
> >>>>>
> >>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
> >>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
> >>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
> >>>>> ---
> >>>>> Changes in v8:
> >>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
> >>>>>
> >>>>
> >>>> Alison,
> >>>>
> >>>> There is a conflict when merging with upstream code. Alex Graf
> >>>> merged his change to support EFI booting. See commit
> >>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
> >>>>
> >>>>
> >>>>          if (current_el() == 3) {
> >>>>                  smp_kick_all_cpus();
> >>>>                  dcache_disable();
> >>>>                  armv8_switch_to_el2();
> >>>>                  dcache_enable();
> >>>>          }
> >>>>
> >>>> Function armv8_switch_to_el2() didn't take any argument before you
> >>>> change. With your proposed change to support 32-bit OS, you added
> >>>> arguments to this function, and presume this function always load
> OS.
> >>>> This may be flawed. Would it be possible to keep
> >>>> armv8_switch_to_el2() but introduce another function to carry out
> switching EL while loading OS?
> >>>
> >>> Alison introduced it based on my comments - and I'd prefer if we
> >>> only have the function call based version :).
> >>>
> >>> It should be reasonably straight forward to move to it here. Just
> >>> create a new helper stub that enables the dcache and calls entry().
> >>>
> >>
> >> Alex,
> >>
> >> Do you always load OS when calling armv8_switch_to_el2()? In this
> >> case of efi booting, kernel entry point needs to be passed to the
> new
> >> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
> >> doesn't return, so you cannot continue to run the code.
> >
> > We always call some random function pointer in the new flow. That can
> > be a kernel entry point, but it can also just be a function pointer.
> > In this case, the code would basically look like this:
> >
> > static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2) {
> >      dcache_enable();
> >      return entry(arg1, arg2);
> > }
> >
> > if (current_el() == 3) {
> >      ...
> >      return armv8_switch_to_el2(efi_run_in_el2, entry,
> > &loaded_image_info, &systab); }
> >
> 
> Alex,
> 
> Since you are most familiar with EFI boot code, can you send a patch to
> address this? I can squash it with Alison's patch after testing. My
> current test branch is
> http://git.denx.de/?p=u-boot/u-boot-fsl-
> qoriq.git;a=shortlog;h=refs/heads/test_qoriq.
> 
> 
[Alison Wang] Please send a patch to fix this issue. It blocks our efforts for
the patch set armv8: Support loading 32-bit OS in AArch32 execution state.

Thanks.


Best Regards,
Alison Wang

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alexander Graf]

On 11/21/2016 10:48 PM, york sun wrote:
> On 11/21/2016 01:07 PM, Alexander Graf wrote:
>>
>> On 21/11/2016 21:45, york sun wrote:
>>> On 11/21/2016 12:40 PM, Alexander Graf wrote:
>>>>
>>>> On 21/11/2016 21:23, york sun wrote:
>>>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>>>>> To support loading a 32-bit OS, the execution state will change from
>>>>>> AArch64 to AArch32 when jumping to kernel.
>>>>>>
>>>>>> The architecture information will be got through checking FIT image,
>>>>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>>>>
>>>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>>>>> ---
>>>>>> Changes in v8:
>>>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>>>>
>>>>> Alison,
>>>>>
>>>>> There is a conflict when merging with upstream code. Alex Graf merged
>>>>> his change to support EFI booting. See commit
>>>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>>>>
>>>>>
>>>>>           if (current_el() == 3) {
>>>>>                   smp_kick_all_cpus();
>>>>>                   dcache_disable();
>>>>>                   armv8_switch_to_el2();
>>>>>                   dcache_enable();
>>>>>           }
>>>>>
>>>>> Function armv8_switch_to_el2() didn't take any argument before you
>>>>> change. With your proposed change to support 32-bit OS, you added
>>>>> arguments to this function, and presume this function always load OS.
>>>>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>>>>> but introduce another function to carry out switching EL while loading OS?
>>>> Alison introduced it based on my comments - and I'd prefer if we only
>>>> have the function call based version :).
>>>>
>>>> It should be reasonably straight forward to move to it here. Just create
>>>> a new helper stub that enables the dcache and calls entry().
>>>>
>>> Alex,
>>>
>>> Do you always load OS when calling armv8_switch_to_el2()? In this case
>>> of efi booting, kernel entry point needs to be passed to the new
>>> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
>>> doesn't return, so you cannot continue to run the code.
>> We always call some random function pointer in the new flow. That can be
>> a kernel entry point, but it can also just be a function pointer. In
>> this case, the code would basically look like this:
>>
>> static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2)
>> {
>>       dcache_enable();
>>       return entry(arg1, arg2);
>> }
>>
>> if (current_el() == 3) {
>>       ...
>>       return armv8_switch_to_el2(efi_run_in_el2, entry,
>> &loaded_image_info, &systab);
>> }
>>
> Alex,
>
> Since you are most familiar with EFI boot code, can you send a patch to
> address this? I can squash it with Alison's patch after testing. My
> current test branch is
> http://git.denx.de/?p=u-boot/u-boot-fsl-qoriq.git;a=shortlog;h=refs/heads/test_qoriq.

While trying to fix this up, I ran across another compile breakage:

arch/arm/cpu/armv8/fsl-layerscape/mp.c:114: undefined reference to 
`initiator_type'
arch/arm/cpu/armv8/fsl-layerscape/mp.c:123: undefined reference to 
`initiator_type'


Alex

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/22/2016 09:02 AM, Alexander Graf wrote:
> On 11/21/2016 10:48 PM, york sun wrote:
>> On 11/21/2016 01:07 PM, Alexander Graf wrote:
>>>
>>> On 21/11/2016 21:45, york sun wrote:
>>>> On 11/21/2016 12:40 PM, Alexander Graf wrote:
>>>>>
>>>>> On 21/11/2016 21:23, york sun wrote:
>>>>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>>>>>> To support loading a 32-bit OS, the execution state will change from
>>>>>>> AArch64 to AArch32 when jumping to kernel.
>>>>>>>
>>>>>>> The architecture information will be got through checking FIT image,
>>>>>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>>>>>
>>>>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>>>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>>>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>>>>>> ---
>>>>>>> Changes in v8:
>>>>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>>>>>
>>>>>> Alison,
>>>>>>
>>>>>> There is a conflict when merging with upstream code. Alex Graf merged
>>>>>> his change to support EFI booting. See commit
>>>>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>>>>>
>>>>>>
>>>>>>           if (current_el() == 3) {
>>>>>>                   smp_kick_all_cpus();
>>>>>>                   dcache_disable();
>>>>>>                   armv8_switch_to_el2();
>>>>>>                   dcache_enable();
>>>>>>           }
>>>>>>
>>>>>> Function armv8_switch_to_el2() didn't take any argument before you
>>>>>> change. With your proposed change to support 32-bit OS, you added
>>>>>> arguments to this function, and presume this function always load OS.
>>>>>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>>>>>> but introduce another function to carry out switching EL while loading OS?
>>>>> Alison introduced it based on my comments - and I'd prefer if we only
>>>>> have the function call based version :).
>>>>>
>>>>> It should be reasonably straight forward to move to it here. Just create
>>>>> a new helper stub that enables the dcache and calls entry().
>>>>>
>>>> Alex,
>>>>
>>>> Do you always load OS when calling armv8_switch_to_el2()? In this case
>>>> of efi booting, kernel entry point needs to be passed to the new
>>>> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
>>>> doesn't return, so you cannot continue to run the code.
>>> We always call some random function pointer in the new flow. That can be
>>> a kernel entry point, but it can also just be a function pointer. In
>>> this case, the code would basically look like this:
>>>
>>> static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2)
>>> {
>>>       dcache_enable();
>>>       return entry(arg1, arg2);
>>> }
>>>
>>> if (current_el() == 3) {
>>>       ...
>>>       return armv8_switch_to_el2(efi_run_in_el2, entry,
>>> &loaded_image_info, &systab);
>>> }
>>>
>> Alex,
>>
>> Since you are most familiar with EFI boot code, can you send a patch to
>> address this? I can squash it with Alison's patch after testing. My
>> current test branch is
>> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgit.denx.de%2F%3Fp%3Du-boot%2Fu-boot-fsl-qoriq.git%3Ba%3Dshortlog%3Bh%3Drefs%2Fheads%2Ftest_qoriq&data=01%7C01%7Cyork.sun%40nxp.com%7C0b9b6fdb53c94e1a953d08d412f9502f%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0&sdata=ALW8GdHxkPJghve%2BxbKQ1E9ssjFxSOf35PvVuY34ZiA%3D&reserved=0.
>
> While trying to fix this up, I ran across another compile breakage:
>
> arch/arm/cpu/armv8/fsl-layerscape/mp.c:114: undefined reference to
> `initiator_type'
> arch/arm/cpu/armv8/fsl-layerscape/mp.c:123: undefined reference to
> `initiator_type'
>

Possibly cause by a new set of patches sent by Priyanka for LS2088A. 
Let's use upstream master branch plus Alison's three patches.

York

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alexander Graf]

On 11/22/2016 06:07 PM, york sun wrote:
> On 11/22/2016 09:02 AM, Alexander Graf wrote:
>> On 11/21/2016 10:48 PM, york sun wrote:
>>> On 11/21/2016 01:07 PM, Alexander Graf wrote:
>>>> On 21/11/2016 21:45, york sun wrote:
>>>>> On 11/21/2016 12:40 PM, Alexander Graf wrote:
>>>>>> On 21/11/2016 21:23, york sun wrote:
>>>>>>> On 11/09/2016 07:02 PM, Alison Wang wrote:
>>>>>>>> To support loading a 32-bit OS, the execution state will change from
>>>>>>>> AArch64 to AArch32 when jumping to kernel.
>>>>>>>>
>>>>>>>> The architecture information will be got through checking FIT image,
>>>>>>>> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>>>>>>>>
>>>>>>>> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
>>>>>>>> Signed-off-by: Alison Wang <alison.wang@nxp.com>
>>>>>>>> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
>>>>>>>> ---
>>>>>>>> Changes in v8:
>>>>>>>> - Fix the issue when U-Boot is running in EL2 or EL1.
>>>>>>>>
>>>>>>> Alison,
>>>>>>>
>>>>>>> There is a conflict when merging with upstream code. Alex Graf merged
>>>>>>> his change to support EFI booting. See commit
>>>>>>> 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
>>>>>>>
>>>>>>>
>>>>>>>            if (current_el() == 3) {
>>>>>>>                    smp_kick_all_cpus();
>>>>>>>                    dcache_disable();
>>>>>>>                    armv8_switch_to_el2();
>>>>>>>                    dcache_enable();
>>>>>>>            }
>>>>>>>
>>>>>>> Function armv8_switch_to_el2() didn't take any argument before you
>>>>>>> change. With your proposed change to support 32-bit OS, you added
>>>>>>> arguments to this function, and presume this function always load OS.
>>>>>>> This may be flawed. Would it be possible to keep armv8_switch_to_el2()
>>>>>>> but introduce another function to carry out switching EL while loading OS?
>>>>>> Alison introduced it based on my comments - and I'd prefer if we only
>>>>>> have the function call based version :).
>>>>>>
>>>>>> It should be reasonably straight forward to move to it here. Just create
>>>>>> a new helper stub that enables the dcache and calls entry().
>>>>>>
>>>>> Alex,
>>>>>
>>>>> Do you always load OS when calling armv8_switch_to_el2()? In this case
>>>>> of efi booting, kernel entry point needs to be passed to the new
>>>>> armv8_switch_to_el2 function. The new armv8_switch_to_el2 function
>>>>> doesn't return, so you cannot continue to run the code.
>>>> We always call some random function pointer in the new flow. That can be
>>>> a kernel entry point, but it can also just be a function pointer. In
>>>> this case, the code would basically look like this:
>>>>
>>>> static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2)
>>>> {
>>>>        dcache_enable();
>>>>        return entry(arg1, arg2);
>>>> }
>>>>
>>>> if (current_el() == 3) {
>>>>        ...
>>>>        return armv8_switch_to_el2(efi_run_in_el2, entry,
>>>> &loaded_image_info, &systab);
>>>> }
>>>>
>>> Alex,
>>>
>>> Since you are most familiar with EFI boot code, can you send a patch to
>>> address this? I can squash it with Alison's patch after testing. My
>>> current test branch is
>>> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgit.denx.de%2F%3Fp%3Du-boot%2Fu-boot-fsl-qoriq.git%3Ba%3Dshortlog%3Bh%3Drefs%2Fheads%2Ftest_qoriq&data=01%7C01%7Cyork.sun%40nxp.com%7C0b9b6fdb53c94e1a953d08d412f9502f%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0&sdata=ALW8GdHxkPJghve%2BxbKQ1E9ssjFxSOf35PvVuY34ZiA%3D&reserved=0.
>> While trying to fix this up, I ran across another compile breakage:
>>
>> arch/arm/cpu/armv8/fsl-layerscape/mp.c:114: undefined reference to
>> `initiator_type'
>> arch/arm/cpu/armv8/fsl-layerscape/mp.c:123: undefined reference to
>> `initiator_type'
>>
> Possibly cause by a new set of patches sent by Priyanka for LS2088A.
> Let's use upstream master branch plus Alison's three patches.

No worries, the patch below fixes it. Just wanted to let you know.

Alex


diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c 
b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
index 59b0870..d6ee546 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
@@ -191,7 +191,7 @@ void enable_caches(void)
  }
  #endif

-inline u32 initiator_type(u32 cluster, int init_id)
+u32 initiator_type(u32 cluster, int init_id)
  {
         struct ccsr_gur *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
         u32 idx = (cluster >> (init_id * 8)) & TP_CLUSTER_INIT_MASK;

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alexander Graf]

On 11/21/2016 10:48 PM, york sun wrote:
> Alex,
>
> Since you are most familiar with EFI boot code, can you send a patch to
> address this? I can squash it with Alison's patch after testing. My
> current test branch is
> http://git.denx.de/?p=u-boot/u-boot-fsl-qoriq.git;a=shortlog;h=refs/heads/test_qoriq.

Ok, you should have a patch now :). I was still able to boot SLES with it.


Alex

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/22/2016 09:32 AM, Alexander Graf wrote:
> On 11/21/2016 10:48 PM, york sun wrote:
>> Alex,
>>
>> Since you are most familiar with EFI boot code, can you send a patch to
>> address this? I can squash it with Alison's patch after testing. My
>> current test branch is
>> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgit.denx.de%2F%3Fp%3Du-boot%2Fu-boot-fsl-qoriq.git%3Ba%3Dshortlog%3Bh%3Drefs%2Fheads%2Ftest_qoriq&data=01%7C01%7Cyork.sun%40nxp.com%7C822c0a7505844c4f759408d412fd7f66%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0&sdata=4OCWr5ZP%2B1ufIO%2FgZo69qgfMW%2F3YUb5ibJvOhhOOlEI%3D&reserved=0.
>
> Ok, you should have a patch now :). I was still able to boot SLES with it.
>

Great! Thanks.

York

[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/09/2016 07:02 PM, Alison Wang wrote:
> This series is to support loading a 32-bit OS, the execution state will change from AArch64 to AArch32 when jumping to kernel. The architecture information will be got through checking FIT image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
>
> Spin-table method is used for secondary cores to load 32-bit OS.
> The architecture information will be got through checking FIT image and saved in the os_arch element of spin-table, then the secondary cores will check os_arch and jump to 32-bit OS or 64-bit OS automatically.
>
> PSCI method can also be used for secondary cores to load 32-bit OS.
> As PSCI and secure monitor firmware framework are enabled, loading 32-bit OS is supported in such case. The default target exception level returned to U-Boot is EL2, so the corresponding work to switch to AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware together.
>
> ---------------------------------------
> Changes in v8:
> - Fix the issue when U-Boot is running in EL2 or EL1.
> - Support loading 32-bit OS with PSCI enabled.
>
> Changes in v7:
> - Move the call for armv8_switch_to_el2_m into the first patch.
>
> Changes in v6:
> - Modified armv8_switch_to_el1(). It will always jump to ep when switching to AArch64 or AArch32 modes.
> - Make other platforms compatible with the new armv8_switch_to_el2() and armv8_switch_to_el1().
> - Make secondary_switch_to_el1() always jump to ep when switching to AArch64 or AArch32 modes.
>
> Changes in v5:
> - Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.
> - Make secondary_switch_to_el2() always jump to ep when switching to AArch64 or AArch32 modes.
>
> Changes in v4:
> - Correct config ARM64_SUPPORT_AARCH32.
> - Omit arch and ftaddr arguments.
> - Rename "xreg5" to "tmp".
> - Use xxx_RES1 to combine all RES1 fields in xxx register.
> - Use an immediate cmp directly.
> - Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.
>
> Changes in v3:
> - Comments the functions and the arguments.
> - Rename the real parameters.
> - Use the macros instead of the magic values.
> - Remove the redundant codes.
> - Clean up all of the mess in boot_jump_linux().
> - Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't support AArch32 state.
> - Adjust the arguments for armv8_switch_to_el2_m and armv8_switch_to_el1_m.
>
> Changes in v2:
> - armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
>   to switch to AArch64 EL2 or AArch32 Hyp.
> - armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
>   to switch to AArch64 EL1 or AArch32 SVC.
> - Support to call armv8_switch_to_el2_m and armv8_switch_to_el1_m.
>
> ----------------------------------------------------------------
> Alison Wang (3):
>       armv8: Support loading 32-bit OS in AArch32 execution state

Squashed with Alex Graf's patch "ls2080: efi_loader: Move EL2 switch to 
function call based version".

>       armv8: fsl-layerscape: SMP support for loading 32-bit OS
>       armv8: fsl-layerscape: Support loading 32-bit OS with PSCI enabled
>

This set is applied to fsl-qoriq, awaiting upstream. Thanks.

York

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Ryan Harkin]

Hi Alison,

I wasn't sure where about in this thread to reply to this patch, so I
thought here was as good as any...

I know I tested this commit and it works for me. However, my colleague
Tixy has spotted a recent warning on the kernel dmesg output that only
arrived with an update to u-boot:

[    0.000000] WARNING: x1-x3 nonzero in violation of boot protocol:
[    0.000000]     x1: 0000000000000000
[    0.000000]     x2: 0000000000000000
[    0.000000]     x3: 0000000080080000
[    0.000000] This indicates a broken bootloader or old kernel

This happens on our ARM64 kernels, both the 4.4 based kernel and the
4.9.0 based kernel. They boot, it's with the extra warning.

I bisected it down to the change in this email thread, upstream as
commit ec6617c39741adc6c54952564579e32c3c09c66f in the master repo.

And I can see below in many places that the code is using x3 for the
first time. I'm not sure which one is causing the warning in the
kernel, but I guess we need to reset x3 to zero before jumping to the
kernel?

I'm happy to test any fixes if you wish to send them to me.

Thanks,
Ryan.



On 10 November 2016 at 02:49, Alison Wang <b18965@freescale.com> wrote:
> To support loading a 32-bit OS, the execution state will change from
> AArch64 to AArch32 when jumping to kernel.
>
> The architecture information will be got through checking FIT image,
> then U-Boot will load 32-bit OS or 64-bit OS automatically.
>
> Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
> Signed-off-by: Alison Wang <alison.wang@nxp.com>
> Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
> ---
> Changes in v8:
> - Fix the issue when U-Boot is running in EL2 or EL1.
>
> Changes in v7:
> - Move the call for armv8_switch_to_el2_m into this patch.
>
> Changes in v6:
> - Modified armv8_switch_to_el1(). It will always jump to ep when switching to AArch64 or AArch32 modes.
> - Make other platforms compatible with the new armv8_switch_to_el2() and armv8_switch_to_el1().
>
> Changes in v5:
> - Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.
>
> Changes in v4:
> - Correct config ARM64_SUPPORT_AARCH32.
> - Omit arch and ftaddr arguments.
> - Rename "xreg5" to "tmp".
> - Use xxx_RES1 to combine all RES1 fields in xxx register.
> - Use an immediate cmp directly.
> - Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.
>
> Changes in v3:
> - Comments the functions and the arguments.
> - Rename the real parameters.
> - Use the macros instead of the magic values.
> - Remove the redundant codes.
> - Clean up all of the mess in boot_jump_linux().
> - Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't support AArch32 state.
>
> Changes in v2:
> - armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
>   to switch to AArch64 EL2 or AArch32 Hyp.
> - armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
>   to switch to AArch64 EL1 or AArch32 SVC.
>
>  arch/arm/Kconfig                              |   6 +
>  arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S  |  61 +++++++--
>  arch/arm/cpu/armv8/start.S                    |   8 ++
>  arch/arm/cpu/armv8/transition.S               |  23 +++-
>  arch/arm/include/asm/arch-fsl-layerscape/mp.h |   4 +
>  arch/arm/include/asm/macro.h                  | 176 +++++++++++++++++++-------
>  arch/arm/include/asm/system.h                 | 119 ++++++++++++++++-
>  arch/arm/lib/bootm.c                          |  39 +++++-
>  arch/arm/mach-rmobile/lowlevel_init_gen3.S    |   9 +-
>  common/image-fit.c                            |  19 ++-
>  10 files changed, 396 insertions(+), 68 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index d7a9b11..18c23c0 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -126,6 +126,12 @@ config ENABLE_ARM_SOC_BOOT0_HOOK
>           ARM_SOC_BOOT0_HOOK which contains the required assembler
>           preprocessor code.
>
> +config ARM64_SUPPORT_AARCH32
> +       bool "ARM64 system support AArch32 execution state"
> +       default y if ARM64 && !TARGET_THUNDERX_88XX
> +       help
> +         This ARM64 system supports AArch32 execution state.
> +
>  choice
>         prompt "Target select"
>         default TARGET_HIKEY
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> index 5700b1f..8e6ad4b 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> @@ -13,6 +13,7 @@
>  #ifdef CONFIG_MP
>  #include <asm/arch/mp.h>
>  #endif
> +#include <asm/u-boot.h>
>
>  ENTRY(lowlevel_init)
>         mov     x29, lr                 /* Save LR */
> @@ -339,11 +340,6 @@ ENTRY(secondary_boot_func)
>          gic_wait_for_interrupt_m x0, w1
>  #endif
>
> -       bl secondary_switch_to_el2
> -#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> -       bl secondary_switch_to_el1
> -#endif
> -
>  slave_cpu:
>         wfe
>         ldr     x0, [x11]
> @@ -356,19 +352,64 @@ slave_cpu:
>         tbz     x1, #25, cpu_is_le
>         rev     x0, x0                  /* BE to LE conversion */
>  cpu_is_le:
> -       br      x0                      /* branch to the given address */
> +       ldr     x5, [x11, #24]
> +       ldr     x6, =IH_ARCH_DEFAULT
> +       cmp     x6, x5
> +       b.eq    1f
> +
> +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +       adr     x3, secondary_switch_to_el1
> +       ldr     x4, =ES_TO_AARCH64
> +#else
> +       ldr     x3, [x11]
> +       ldr     x4, =ES_TO_AARCH32
> +#endif
> +       bl      secondary_switch_to_el2
> +
> +1:
> +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +       adr     x3, secondary_switch_to_el1
> +#else
> +       ldr     x3, [x11]
> +#endif
> +       ldr     x4, =ES_TO_AARCH64
> +       bl      secondary_switch_to_el2
> +
>  ENDPROC(secondary_boot_func)
>
>  ENTRY(secondary_switch_to_el2)
> -       switch_el x0, 1f, 0f, 0f
> +       switch_el x5, 1f, 0f, 0f
>  0:     ret
> -1:     armv8_switch_to_el2_m x0
> +1:     armv8_switch_to_el2_m x3, x4, x5
>  ENDPROC(secondary_switch_to_el2)
>
>  ENTRY(secondary_switch_to_el1)
> -       switch_el x0, 0f, 1f, 0f
> +       mrs     x0, mpidr_el1
> +       ubfm    x1, x0, #8, #15
> +       ubfm    x2, x0, #0, #1
> +       orr     x10, x2, x1, lsl #2     /* x10 has LPID */
> +
> +       lsl     x1, x10, #6
> +       ldr     x0, =__spin_table
> +       /* physical address of this cpus spin table element */
> +       add     x11, x1, x0
> +
> +       ldr     x3, [x11]
> +
> +       ldr     x5, [x11, #24]
> +       ldr     x6, =IH_ARCH_DEFAULT
> +       cmp     x6, x5
> +       b.eq    2f
> +
> +       ldr     x4, =ES_TO_AARCH32
> +       bl      switch_to_el1
> +
> +2:     ldr     x4, =ES_TO_AARCH64
> +
> +switch_to_el1:
> +       switch_el x5, 0f, 1f, 0f
>  0:     ret
> -1:     armv8_switch_to_el1_m x0, x1
> +1:     armv8_switch_to_el1_m x3, x4, x5
>  ENDPROC(secondary_switch_to_el1)
>
>         /* Ensure that the literals used by the secondary boot code are
> diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
> index 19c771d..4f5f6d8 100644
> --- a/arch/arm/cpu/armv8/start.S
> +++ b/arch/arm/cpu/armv8/start.S
> @@ -251,9 +251,17 @@ WEAK(lowlevel_init)
>         /*
>          * All slaves will enter EL2 and optionally EL1.
>          */
> +       adr     x3, lowlevel_in_el2
> +       ldr     x4, =ES_TO_AARCH64
>         bl      armv8_switch_to_el2
> +
> +lowlevel_in_el2:
>  #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +       adr     x3, lowlevel_in_el1
> +       ldr     x4, =ES_TO_AARCH64
>         bl      armv8_switch_to_el1
> +
> +lowlevel_in_el1:
>  #endif
>
>  #endif /* CONFIG_ARMV8_MULTIENTRY */
> diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
> index 253a39b..bbccf2b 100644
> --- a/arch/arm/cpu/armv8/transition.S
> +++ b/arch/arm/cpu/armv8/transition.S
> @@ -11,13 +11,24 @@
>  #include <asm/macro.h>
>
>  ENTRY(armv8_switch_to_el2)
> -       switch_el x0, 1f, 0f, 0f
> -0:     ret
> -1:     armv8_switch_to_el2_m x0
> +       switch_el x5, 1f, 0f, 0f
> +0:
> +       /*
> +        * x3 is kernel entry point or switch_to_el1
> +        * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
> +         * When running in EL2 now, jump to the
> +        * address saved in x3.
> +        */
> +       br x3
> +1:     armv8_switch_to_el2_m x3, x4, x5
>  ENDPROC(armv8_switch_to_el2)
>
>  ENTRY(armv8_switch_to_el1)
> -       switch_el x0, 0f, 1f, 0f
> -0:     ret
> -1:     armv8_switch_to_el1_m x0, x1
> +       switch_el x5, 0f, 1f, 0f
> +0:
> +       /* x3 is kernel entry point. When running in EL1
> +        * now, jump to the address saved in x3.
> +        */
> +       br x3
> +1:     armv8_switch_to_el1_m x3, x4, x5
>  ENDPROC(armv8_switch_to_el1)
> diff --git a/arch/arm/include/asm/arch-fsl-layerscape/mp.h b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> index f7306ff..ebf84b6 100644
> --- a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> +++ b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> @@ -36,4 +36,8 @@ void secondary_boot_func(void);
>  int is_core_online(u64 cpu_id);
>  u32 cpu_pos_mask(void);
>  #endif
> +
> +#define IH_ARCH_ARM            2       /* ARM */
> +#define IH_ARCH_ARM64          22      /* ARM64 */
> +
>  #endif /* _FSL_LAYERSCAPE_MP_H */
> diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h
> index 9bb0efa..2553e3e 100644
> --- a/arch/arm/include/asm/macro.h
> +++ b/arch/arm/include/asm/macro.h
> @@ -8,6 +8,11 @@
>
>  #ifndef __ASM_ARM_MACRO_H__
>  #define __ASM_ARM_MACRO_H__
> +
> +#ifdef CONFIG_ARM64
> +#include <asm/system.h>
> +#endif
> +
>  #ifdef __ASSEMBLY__
>
>  /*
> @@ -135,13 +140,21 @@ lr        .req    x30
>  #endif
>  .endm
>
> -.macro armv8_switch_to_el2_m, xreg1
> -       /* 64bit EL2 | HCE | SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1 */
> -       mov     \xreg1, #0x5b1
> -       msr     scr_el3, \xreg1
> +/*
> + * Switch from EL3 to EL2 for ARMv8
> + * @ep:     kernel entry point
> + * @flag:   The execution state flag for lower exception
> + *          level, ES_TO_AARCH64 or ES_TO_AARCH32
> + * @tmp:    temporary register
> + *
> + * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
> + * For loading 64-bit OS, x0 is physical address to the FDT blob.
> + * They will be passed to the guest.
> + */
> +.macro armv8_switch_to_el2_m, ep, flag, tmp
>         msr     cptr_el3, xzr           /* Disable coprocessor traps to EL3 */
> -       mov     \xreg1, #0x33ff
> -       msr     cptr_el2, \xreg1        /* Disable coprocessor traps to EL2 */
> +       mov     \tmp, #CPTR_EL2_RES1
> +       msr     cptr_el2, \tmp          /* Disable coprocessor traps to EL2 */
>
>         /* Initialize Generic Timers */
>         msr     cntvoff_el2, xzr
> @@ -152,45 +165,90 @@ lr        .req    x30
>          * and RES0 bits (31,30,27,26,24,21,20,17,15-13,10-6) +
>          * EE,WXN,I,SA,C,A,M to 0
>          */
> -       mov     \xreg1, #0x0830
> -       movk    \xreg1, #0x30C5, lsl #16
> -       msr     sctlr_el2, \xreg1
> +       ldr     \tmp, =(SCTLR_EL2_RES1 | SCTLR_EL2_EE_LE |\
> +                       SCTLR_EL2_WXN_DIS | SCTLR_EL2_ICACHE_DIS |\
> +                       SCTLR_EL2_SA_DIS | SCTLR_EL2_DCACHE_DIS |\
> +                       SCTLR_EL2_ALIGN_DIS | SCTLR_EL2_MMU_DIS)
> +       msr     sctlr_el2, \tmp
> +
> +       mov     \tmp, sp
> +       msr     sp_el2, \tmp            /* Migrate SP */
> +       mrs     \tmp, vbar_el3
> +       msr     vbar_el2, \tmp          /* Migrate VBAR */
> +
> +       /* Check switch to AArch64 EL2 or AArch32 Hypervisor mode */
> +       cmp     \flag, #ES_TO_AARCH32
> +       b.eq    1f
> +
> +       /*
> +        * The next lower exception level is AArch64, 64bit EL2 | HCE |
> +        * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
> +        */
> +       ldr     \tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
> +                       SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
> +                       SCR_EL3_NS_EN)
> +       msr     scr_el3, \tmp
>
>         /* Return to the EL2_SP2 mode from EL3 */
> -       mov     \xreg1, sp
> -       msr     sp_el2, \xreg1          /* Migrate SP */
> -       mrs     \xreg1, vbar_el3
> -       msr     vbar_el2, \xreg1        /* Migrate VBAR */
> -       mov     \xreg1, #0x3c9
> -       msr     spsr_el3, \xreg1        /* EL2_SP2 | D | A | I | F */
> -       msr     elr_el3, lr
> +       ldr     \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
> +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> +                       SPSR_EL_M_AARCH64 | SPSR_EL_M_EL2H)
> +       msr     spsr_el3, \tmp
> +       msr     elr_el3, \ep
> +       eret
> +
> +1:
> +       /*
> +        * The next lower exception level is AArch32, 32bit EL2 | HCE |
> +        * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
> +        */
> +       ldr     \tmp, =(SCR_EL3_RW_AARCH32 | SCR_EL3_HCE_EN |\
> +                       SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
> +                       SCR_EL3_NS_EN)
> +       msr     scr_el3, \tmp
> +
> +       /* Return to AArch32 Hypervisor mode */
> +       ldr     \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
> +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> +                       SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
> +                       SPSR_EL_M_HYP)
> +       msr     spsr_el3, \tmp
> +       msr     elr_el3, \ep
>         eret
>  .endm
>
> -.macro armv8_switch_to_el1_m, xreg1, xreg2
> +/*
> + * Switch from EL2 to EL1 for ARMv8
> + * @ep:     kernel entry point
> + * @flag:   The execution state flag for lower exception
> + *          level, ES_TO_AARCH64 or ES_TO_AARCH32
> + * @tmp:    temporary register
> + *
> + * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
> + * For loading 64-bit OS, x0 is physical address to the FDT blob.
> + * They will be passed to the guest.
> + */
> +.macro armv8_switch_to_el1_m, ep, flag, tmp
>         /* Initialize Generic Timers */
> -       mrs     \xreg1, cnthctl_el2
> -       orr     \xreg1, \xreg1, #0x3    /* Enable EL1 access to timers */
> -       msr     cnthctl_el2, \xreg1
> +       mrs     \tmp, cnthctl_el2
> +       /* Enable EL1 access to timers */
> +       orr     \tmp, \tmp, #(CNTHCTL_EL2_EL1PCEN_EN |\
> +               CNTHCTL_EL2_EL1PCTEN_EN)
> +       msr     cnthctl_el2, \tmp
>         msr     cntvoff_el2, xzr
>
>         /* Initilize MPID/MPIDR registers */
> -       mrs     \xreg1, midr_el1
> -       mrs     \xreg2, mpidr_el1
> -       msr     vpidr_el2, \xreg1
> -       msr     vmpidr_el2, \xreg2
> +       mrs     \tmp, midr_el1
> +       msr     vpidr_el2, \tmp
> +       mrs     \tmp, mpidr_el1
> +       msr     vmpidr_el2, \tmp
>
>         /* Disable coprocessor traps */
> -       mov     \xreg1, #0x33ff
> -       msr     cptr_el2, \xreg1        /* Disable coprocessor traps to EL2 */
> +       mov     \tmp, #CPTR_EL2_RES1
> +       msr     cptr_el2, \tmp          /* Disable coprocessor traps to EL2 */
>         msr     hstr_el2, xzr           /* Disable coprocessor traps to EL2 */
> -       mov     \xreg1, #3 << 20
> -       msr     cpacr_el1, \xreg1       /* Enable FP/SIMD at EL1 */
> -
> -       /* Initialize HCR_EL2 */
> -       mov     \xreg1, #(1 << 31)              /* 64bit EL1 */
> -       orr     \xreg1, \xreg1, #(1 << 29)      /* Disable HVC */
> -       msr     hcr_el2, \xreg1
> +       mov     \tmp, #CPACR_EL1_FPEN_EN
> +       msr     cpacr_el1, \tmp         /* Enable FP/SIMD at EL1 */
>
>         /* SCTLR_EL1 initialization
>          *
> @@ -199,18 +257,50 @@ lr        .req    x30
>          * UCI,EE,EOE,WXN,nTWE,nTWI,UCT,DZE,I,UMA,SED,ITD,
>          * CP15BEN,SA0,SA,C,A,M to 0
>          */
> -       mov     \xreg1, #0x0800
> -       movk    \xreg1, #0x30d0, lsl #16
> -       msr     sctlr_el1, \xreg1
> +       ldr     \tmp, =(SCTLR_EL1_RES1 | SCTLR_EL1_UCI_DIS |\
> +                       SCTLR_EL1_EE_LE | SCTLR_EL1_WXN_DIS |\
> +                       SCTLR_EL1_NTWE_DIS | SCTLR_EL1_NTWI_DIS |\
> +                       SCTLR_EL1_UCT_DIS | SCTLR_EL1_DZE_DIS |\
> +                       SCTLR_EL1_ICACHE_DIS | SCTLR_EL1_UMA_DIS |\
> +                       SCTLR_EL1_SED_EN | SCTLR_EL1_ITD_EN |\
> +                       SCTLR_EL1_CP15BEN_DIS | SCTLR_EL1_SA0_DIS |\
> +                       SCTLR_EL1_SA_DIS | SCTLR_EL1_DCACHE_DIS |\
> +                       SCTLR_EL1_ALIGN_DIS | SCTLR_EL1_MMU_DIS)
> +       msr     sctlr_el1, \tmp
> +
> +       mov     \tmp, sp
> +       msr     sp_el1, \tmp            /* Migrate SP */
> +       mrs     \tmp, vbar_el2
> +       msr     vbar_el1, \tmp          /* Migrate VBAR */
> +
> +       /* Check switch to AArch64 EL1 or AArch32 Supervisor mode */
> +       cmp     \flag, #ES_TO_AARCH32
> +       b.eq    1f
> +
> +       /* Initialize HCR_EL2 */
> +       ldr     \tmp, =(HCR_EL2_RW_AARCH64 | HCR_EL2_HCD_DIS)
> +       msr     hcr_el2, \tmp
>
>         /* Return to the EL1_SP1 mode from EL2 */
> -       mov     \xreg1, sp
> -       msr     sp_el1, \xreg1          /* Migrate SP */
> -       mrs     \xreg1, vbar_el2
> -       msr     vbar_el1, \xreg1        /* Migrate VBAR */
> -       mov     \xreg1, #0x3c5
> -       msr     spsr_el2, \xreg1        /* EL1_SP1 | D | A | I | F */
> -       msr     elr_el2, lr
> +       ldr     \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
> +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> +                       SPSR_EL_M_AARCH64 | SPSR_EL_M_EL1H)
> +       msr     spsr_el2, \tmp
> +       msr     elr_el2, \ep
> +       eret
> +
> +1:
> +       /* Initialize HCR_EL2 */
> +       ldr     \tmp, =(HCR_EL2_RW_AARCH32 | HCR_EL2_HCD_DIS)
> +       msr     hcr_el2, \tmp
> +
> +       /* Return to AArch32 Supervisor mode from EL2 */
> +       ldr     \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
> +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> +                       SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
> +                       SPSR_EL_M_SVC)
> +       msr     spsr_el2, \tmp
> +       msr     elr_el2, \ep
>         eret
>  .endm
>
> diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
> index c3c88d2..1c3f74d 100644
> --- a/arch/arm/include/asm/system.h
> +++ b/arch/arm/include/asm/system.h
> @@ -18,6 +18,95 @@
>  #define CR_WXN         (1 << 19)       /* Write Permision Imply XN     */
>  #define CR_EE          (1 << 25)       /* Exception (Big) Endian       */
>
> +#define ES_TO_AARCH64          1
> +#define ES_TO_AARCH32          0
> +
> +/*
> + * SCR_EL3 bits definitions
> + */
> +#define SCR_EL3_RW_AARCH64     (1 << 10) /* Next lower level is AArch64     */
> +#define SCR_EL3_RW_AARCH32     (0 << 10) /* Lower lowers level are AArch32  */
> +#define SCR_EL3_HCE_EN         (1 << 8)  /* Hypervisor Call enable          */
> +#define SCR_EL3_SMD_DIS                (1 << 7)  /* Secure Monitor Call disable     */
> +#define SCR_EL3_RES1           (3 << 4)  /* Reserved, RES1                  */
> +#define SCR_EL3_NS_EN          (1 << 0)  /* EL0 and EL1 in Non-scure state  */
> +
> +/*
> + * SPSR_EL3/SPSR_EL2 bits definitions
> + */
> +#define SPSR_EL_END_LE         (0 << 9)  /* Exception Little-endian          */
> +#define SPSR_EL_DEBUG_MASK     (1 << 9)  /* Debug exception masked           */
> +#define SPSR_EL_ASYN_MASK      (1 << 8)  /* Asynchronous data abort masked   */
> +#define SPSR_EL_SERR_MASK      (1 << 8)  /* System Error exception masked    */
> +#define SPSR_EL_IRQ_MASK       (1 << 7)  /* IRQ exception masked             */
> +#define SPSR_EL_FIQ_MASK       (1 << 6)  /* FIQ exception masked             */
> +#define SPSR_EL_T_A32          (0 << 5)  /* AArch32 instruction set A32      */
> +#define SPSR_EL_M_AARCH64      (0 << 4)  /* Exception taken from AArch64     */
> +#define SPSR_EL_M_AARCH32      (1 << 4)  /* Exception taken from AArch32     */
> +#define SPSR_EL_M_SVC          (0x3)     /* Exception taken from SVC mode    */
> +#define SPSR_EL_M_HYP          (0xa)     /* Exception taken from HYP mode    */
> +#define SPSR_EL_M_EL1H         (5)       /* Exception taken from EL1h mode   */
> +#define SPSR_EL_M_EL2H         (9)       /* Exception taken from EL2h mode   */
> +
> +/*
> + * CPTR_EL2 bits definitions
> + */
> +#define CPTR_EL2_RES1          (3 << 12 | 0x3ff)           /* Reserved, RES1 */
> +
> +/*
> + * SCTLR_EL2 bits definitions
> + */
> +#define SCTLR_EL2_RES1         (3 << 28 | 3 << 22 | 1 << 18 | 1 << 16 |\
> +                                1 << 11 | 3 << 4)          /* Reserved, RES1 */
> +#define SCTLR_EL2_EE_LE                (0 << 25) /* Exception Little-endian          */
> +#define SCTLR_EL2_WXN_DIS      (0 << 19) /* Write permission is not XN       */
> +#define SCTLR_EL2_ICACHE_DIS   (0 << 12) /* Instruction cache disabled       */
> +#define SCTLR_EL2_SA_DIS       (0 << 3)  /* Stack Alignment Check disabled   */
> +#define SCTLR_EL2_DCACHE_DIS   (0 << 2)  /* Data cache disabled              */
> +#define SCTLR_EL2_ALIGN_DIS    (0 << 1)  /* Alignment check disabled         */
> +#define SCTLR_EL2_MMU_DIS      (0)       /* MMU disabled                     */
> +
> +/*
> + * CNTHCTL_EL2 bits definitions
> + */
> +#define CNTHCTL_EL2_EL1PCEN_EN (1 << 1)  /* Physical timer regs accessible   */
> +#define CNTHCTL_EL2_EL1PCTEN_EN        (1 << 0)  /* Physical counter accessible      */
> +
> +/*
> + * HCR_EL2 bits definitions
> + */
> +#define HCR_EL2_RW_AARCH64     (1 << 31) /* EL1 is AArch64                   */
> +#define HCR_EL2_RW_AARCH32     (0 << 31) /* Lower levels are AArch32         */
> +#define HCR_EL2_HCD_DIS                (1 << 29) /* Hypervisor Call disabled         */
> +
> +/*
> + * CPACR_EL1 bits definitions
> + */
> +#define CPACR_EL1_FPEN_EN      (3 << 20) /* SIMD and FP instruction enabled  */
> +
> +/*
> + * SCTLR_EL1 bits definitions
> + */
> +#define SCTLR_EL1_RES1         (3 << 28 | 3 << 22 | 1 << 20 |\
> +                                1 << 11) /* Reserved, RES1                   */
> +#define SCTLR_EL1_UCI_DIS      (0 << 26) /* Cache instruction disabled       */
> +#define SCTLR_EL1_EE_LE                (0 << 25) /* Exception Little-endian          */
> +#define SCTLR_EL1_WXN_DIS      (0 << 19) /* Write permission is not XN       */
> +#define SCTLR_EL1_NTWE_DIS     (0 << 18) /* WFE instruction disabled         */
> +#define SCTLR_EL1_NTWI_DIS     (0 << 16) /* WFI instruction disabled         */
> +#define SCTLR_EL1_UCT_DIS      (0 << 15) /* CTR_EL0 access disabled          */
> +#define SCTLR_EL1_DZE_DIS      (0 << 14) /* DC ZVA instruction disabled      */
> +#define SCTLR_EL1_ICACHE_DIS   (0 << 12) /* Instruction cache disabled       */
> +#define SCTLR_EL1_UMA_DIS      (0 << 9)  /* User Mask Access disabled        */
> +#define SCTLR_EL1_SED_EN       (0 << 8)  /* SETEND instruction enabled       */
> +#define SCTLR_EL1_ITD_EN       (0 << 7)  /* IT instruction enabled           */
> +#define SCTLR_EL1_CP15BEN_DIS  (0 << 5)  /* CP15 barrier operation disabled  */
> +#define SCTLR_EL1_SA0_DIS      (0 << 4)  /* Stack Alignment EL0 disabled     */
> +#define SCTLR_EL1_SA_DIS       (0 << 3)  /* Stack Alignment EL1 disabled     */
> +#define SCTLR_EL1_DCACHE_DIS   (0 << 2)  /* Data cache disabled              */
> +#define SCTLR_EL1_ALIGN_DIS    (0 << 1)  /* Alignment check disabled         */
> +#define SCTLR_EL1_MMU_DIS      (0)       /* MMU disabled                     */
> +
>  #ifndef __ASSEMBLY__
>
>  u64 get_page_table_size(void);
> @@ -98,8 +187,34 @@ int __asm_flush_l3_dcache(void);
>  int __asm_invalidate_l3_icache(void);
>  void __asm_switch_ttbr(u64 new_ttbr);
>
> -void armv8_switch_to_el2(void);
> -void armv8_switch_to_el1(void);
> +/*
> + * Switch from EL3 to EL2 for ARMv8
> + *
> + * @args:        For loading 64-bit OS, fdt address.
> + *               For loading 32-bit OS, zero.
> + * @mach_nr:     For loading 64-bit OS, zero.
> + *               For loading 32-bit OS, machine nr
> + * @fdt_addr:    For loading 64-bit OS, zero.
> + *               For loading 32-bit OS, fdt address.
> + * @entry_point: kernel entry point
> + * @es_flag:     execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
> + */
> +void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
> +                        u64 entry_point, u64 es_flag);
> +/*
> + * Switch from EL2 to EL1 for ARMv8
> + *
> + * @args:        For loading 64-bit OS, fdt address.
> + *               For loading 32-bit OS, zero.
> + * @mach_nr:     For loading 64-bit OS, zero.
> + *               For loading 32-bit OS, machine nr
> + * @fdt_addr:    For loading 64-bit OS, zero.
> + *               For loading 32-bit OS, fdt address.
> + * @entry_point: kernel entry point
> + * @es_flag:     execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
> + */
> +void armv8_switch_to_el1(u64 args, u64 mach_nr, u64 fdt_addr,
> +                        u64 entry_point, u64 es_flag);
>  void gic_init(void);
>  void gic_send_sgi(unsigned long sgino);
>  void wait_for_wakeup(void);
> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
> index 53c3141..7015573 100644
> --- a/arch/arm/lib/bootm.c
> +++ b/arch/arm/lib/bootm.c
> @@ -193,10 +193,6 @@ static void do_nonsec_virt_switch(void)
>  {
>         smp_kick_all_cpus();
>         dcache_disable();       /* flush cache before swtiching to EL2 */
> -       armv8_switch_to_el2();
> -#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> -       armv8_switch_to_el1();
> -#endif
>  }
>  #endif
>
> @@ -273,6 +269,24 @@ bool armv7_boot_nonsec(void)
>  }
>  #endif
>
> +#ifdef CONFIG_ARM64
> +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +static void switch_to_el1(void)
> +{
> +       if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
> +           (images.os.arch == IH_ARCH_ARM))
> +               armv8_switch_to_el1(0, (u64)gd->bd->bi_arch_number,
> +                                   (u64)images.ft_addr,
> +                                   (u64)images.ep,
> +                                   ES_TO_AARCH32);
> +       else
> +               armv8_switch_to_el1((u64)images.ft_addr, 0, 0,
> +                                   images.ep,
> +                                   ES_TO_AARCH64);
> +}
> +#endif
> +#endif
> +
>  /* Subcommand: GO */
>  static void boot_jump_linux(bootm_headers_t *images, int flag)
>  {
> @@ -292,7 +306,22 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
>
>         if (!fake) {
>                 do_nonsec_virt_switch();
> -               kernel_entry(images->ft_addr, NULL, NULL, NULL);
> +
> +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +               armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
> +                                   (u64)switch_to_el1, ES_TO_AARCH64);
> +#else
> +               if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
> +                   (images->os.arch == IH_ARCH_ARM))
> +                       armv8_switch_to_el2(0, (u64)gd->bd->bi_arch_number,
> +                                           (u64)images->ft_addr,
> +                                           (u64)images->ep,
> +                                           ES_TO_AARCH32);
> +               else
> +                       armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
> +                                           images->ep,
> +                                           ES_TO_AARCH64);
> +#endif
>         }
>  #else
>         unsigned long machid = gd->bd->bi_arch_number;
> diff --git a/arch/arm/mach-rmobile/lowlevel_init_gen3.S b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> index 88ff56e..11acce0 100644
> --- a/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> +++ b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> @@ -61,11 +61,18 @@ ENTRY(lowlevel_init)
>         /*
>          * All slaves will enter EL2 and optionally EL1.
>          */
> +       adr     x3, lowlevel_in_el2
> +       ldr     x4, =ES_TO_AARCH64
>         bl      armv8_switch_to_el2
> +
> +lowlevel_in_el2:
>  #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> +       adr     x3, lowlevel_in_el1
> +       ldr     x4, =ES_TO_AARCH64
>         bl      armv8_switch_to_el1
> -#endif
>
> +lowlevel_in_el1:
> +#endif
>  #endif /* CONFIG_ARMV8_MULTIENTRY */
>
>         bl      s_init
> diff --git a/common/image-fit.c b/common/image-fit.c
> index 77dc011..ea56d5b 100644
> --- a/common/image-fit.c
> +++ b/common/image-fit.c
> @@ -27,6 +27,7 @@ DECLARE_GLOBAL_DATA_PTR;
>  #include <u-boot/md5.h>
>  #include <u-boot/sha1.h>
>  #include <u-boot/sha256.h>
> +#include <generated/autoconf.h>
>
>  /*****************************************************************************/
>  /* New uImage format routines */
> @@ -1161,11 +1162,18 @@ int fit_image_check_os(const void *fit, int noffset, uint8_t os)
>  int fit_image_check_arch(const void *fit, int noffset, uint8_t arch)
>  {
>         uint8_t image_arch;
> +       int aarch32_support = 0;
> +
> +#ifdef CONFIG_ARM64_SUPPORT_AARCH32
> +       aarch32_support = 1;
> +#endif
>
>         if (fit_image_get_arch(fit, noffset, &image_arch))
>                 return 0;
>         return (arch == image_arch) ||
> -               (arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64);
> +               (arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64) ||
> +               (arch == IH_ARCH_ARM64 && image_arch == IH_ARCH_ARM &&
> +                aarch32_support);
>  }
>
>  /**
> @@ -1614,6 +1622,9 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
>         int type_ok, os_ok;
>         ulong load, data, len;
>         uint8_t os;
> +#ifndef USE_HOSTCC
> +       uint8_t os_arch;
> +#endif
>         const char *prop_name;
>         int ret;
>
> @@ -1697,6 +1708,12 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
>                 return -ENOEXEC;
>         }
>  #endif
> +
> +#ifndef USE_HOSTCC
> +       fit_image_get_arch(fit, noffset, &os_arch);
> +       images->os.arch = os_arch;
> +#endif
> +
>         if (image_type == IH_TYPE_FLATDT &&
>             !fit_image_check_comp(fit, noffset, IH_COMP_NONE)) {
>                 puts("FDT image is compressed");
> --
> 2.1.0.27.g96db324
>

[U-Boot] [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

Hi, Ryan,

	Thanks for your feedback. I will do some investigation and give you my solution.


Best Regards,
Alison Wang

> -----Original Message-----
> From: Ryan Harkin [mailto:ryan.harkin at linaro.org]
> Sent: Wednesday, January 11, 2017 4:59 PM
> To: Alison Wang <b18965@freescale.com>
> Cc: york sun <york.sun@nxp.com>; Alexander Graf <agraf@suse.de>; Scott
> Wood <scott.wood@nxp.com>; Stuart Yoder <stuart.yoder@nxp.com>; Leo Li
> <leoyang.li@nxp.com>; David Feng <fenghua@phytium.com.cn>; Michal Simek
> <monstr@monstr.eu>; thomas.ab at samsung.com; mk7.kang at samsung.com; U-Boot
> ML <u-boot@lists.denx.de>; Alison Wang <alison.wang@nxp.com>; Jason Jin
> <jason.jin@nxp.com>; Jon Medhurst (Tixy) <tixy@linaro.org>
> Subject: Re: [PATCH v8 1/3] armv8: Support loading 32-bit OS in AArch32
> execution state
> 
> Hi Alison,
> 
> I wasn't sure where about in this thread to reply to this patch, so I
> thought here was as good as any...
> 
> I know I tested this commit and it works for me. However, my colleague
> Tixy has spotted a recent warning on the kernel dmesg output that only
> arrived with an update to u-boot:
> 
> [    0.000000] WARNING: x1-x3 nonzero in violation of boot protocol:
> [    0.000000]     x1: 0000000000000000
> [    0.000000]     x2: 0000000000000000
> [    0.000000]     x3: 0000000080080000
> [    0.000000] This indicates a broken bootloader or old kernel
> 
> This happens on our ARM64 kernels, both the 4.4 based kernel and the
> 4.9.0 based kernel. They boot, it's with the extra warning.
> 
> I bisected it down to the change in this email thread, upstream as
> commit ec6617c39741adc6c54952564579e32c3c09c66f in the master repo.
> 
> And I can see below in many places that the code is using x3 for the
> first time. I'm not sure which one is causing the warning in the kernel,
> but I guess we need to reset x3 to zero before jumping to the kernel?
> 
> I'm happy to test any fixes if you wish to send them to me.
> 
> Thanks,
> Ryan.
> 
> 
> 
> On 10 November 2016 at 02:49, Alison Wang <b18965@freescale.com> wrote:
> > To support loading a 32-bit OS, the execution state will change from
> > AArch64 to AArch32 when jumping to kernel.
> >
> > The architecture information will be got through checking FIT image,
> > then U-Boot will load 32-bit OS or 64-bit OS automatically.
> >
> > Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
> > Signed-off-by: Alison Wang <alison.wang@nxp.com>
> > Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
> > ---
> > Changes in v8:
> > - Fix the issue when U-Boot is running in EL2 or EL1.
> >
> > Changes in v7:
> > - Move the call for armv8_switch_to_el2_m into this patch.
> >
> > Changes in v6:
> > - Modified armv8_switch_to_el1(). It will always jump to ep when
> switching to AArch64 or AArch32 modes.
> > - Make other platforms compatible with the new armv8_switch_to_el2()
> and armv8_switch_to_el1().
> >
> > Changes in v5:
> > - Modified armv8_switch_to_el2(). It will always jump to ep when
> switching to AArch64 or AArch32 modes.
> >
> > Changes in v4:
> > - Correct config ARM64_SUPPORT_AARCH32.
> > - Omit arch and ftaddr arguments.
> > - Rename "xreg5" to "tmp".
> > - Use xxx_RES1 to combine all RES1 fields in xxx register.
> > - Use an immediate cmp directly.
> > - Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.
> >
> > Changes in v3:
> > - Comments the functions and the arguments.
> > - Rename the real parameters.
> > - Use the macros instead of the magic values.
> > - Remove the redundant codes.
> > - Clean up all of the mess in boot_jump_linux().
> > - Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system
> doesn't support AArch32 state.
> >
> > Changes in v2:
> > - armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is
> used
> >   to switch to AArch64 EL2 or AArch32 Hyp.
> > - armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is
> used
> >   to switch to AArch64 EL1 or AArch32 SVC.
> >
> >  arch/arm/Kconfig                              |   6 +
> >  arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S  |  61 +++++++--
> >  arch/arm/cpu/armv8/start.S                    |   8 ++
> >  arch/arm/cpu/armv8/transition.S               |  23 +++-
> >  arch/arm/include/asm/arch-fsl-layerscape/mp.h |   4 +
> >  arch/arm/include/asm/macro.h                  | 176
> +++++++++++++++++++-------
> >  arch/arm/include/asm/system.h                 | 119
> ++++++++++++++++-
> >  arch/arm/lib/bootm.c                          |  39 +++++-
> >  arch/arm/mach-rmobile/lowlevel_init_gen3.S    |   9 +-
> >  common/image-fit.c                            |  19 ++-
> >  10 files changed, 396 insertions(+), 68 deletions(-)
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index
> > d7a9b11..18c23c0 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -126,6 +126,12 @@ config ENABLE_ARM_SOC_BOOT0_HOOK
> >           ARM_SOC_BOOT0_HOOK which contains the required assembler
> >           preprocessor code.
> >
> > +config ARM64_SUPPORT_AARCH32
> > +       bool "ARM64 system support AArch32 execution state"
> > +       default y if ARM64 && !TARGET_THUNDERX_88XX
> > +       help
> > +         This ARM64 system supports AArch32 execution state.
> > +
> >  choice
> >         prompt "Target select"
> >         default TARGET_HIKEY
> > diff --git a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> > b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> > index 5700b1f..8e6ad4b 100644
> > --- a/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> > +++ b/arch/arm/cpu/armv8/fsl-layerscape/lowlevel.S
> > @@ -13,6 +13,7 @@
> >  #ifdef CONFIG_MP
> >  #include <asm/arch/mp.h>
> >  #endif
> > +#include <asm/u-boot.h>
> >
> >  ENTRY(lowlevel_init)
> >         mov     x29, lr                 /* Save LR */
> > @@ -339,11 +340,6 @@ ENTRY(secondary_boot_func)
> >          gic_wait_for_interrupt_m x0, w1  #endif
> >
> > -       bl secondary_switch_to_el2
> > -#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > -       bl secondary_switch_to_el1
> > -#endif
> > -
> >  slave_cpu:
> >         wfe
> >         ldr     x0, [x11]
> > @@ -356,19 +352,64 @@ slave_cpu:
> >         tbz     x1, #25, cpu_is_le
> >         rev     x0, x0                  /* BE to LE conversion */
> >  cpu_is_le:
> > -       br      x0                      /* branch to the given
> address */
> > +       ldr     x5, [x11, #24]
> > +       ldr     x6, =IH_ARCH_DEFAULT
> > +       cmp     x6, x5
> > +       b.eq    1f
> > +
> > +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +       adr     x3, secondary_switch_to_el1
> > +       ldr     x4, =ES_TO_AARCH64
> > +#else
> > +       ldr     x3, [x11]
> > +       ldr     x4, =ES_TO_AARCH32
> > +#endif
> > +       bl      secondary_switch_to_el2
> > +
> > +1:
> > +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +       adr     x3, secondary_switch_to_el1
> > +#else
> > +       ldr     x3, [x11]
> > +#endif
> > +       ldr     x4, =ES_TO_AARCH64
> > +       bl      secondary_switch_to_el2
> > +
> >  ENDPROC(secondary_boot_func)
> >
> >  ENTRY(secondary_switch_to_el2)
> > -       switch_el x0, 1f, 0f, 0f
> > +       switch_el x5, 1f, 0f, 0f
> >  0:     ret
> > -1:     armv8_switch_to_el2_m x0
> > +1:     armv8_switch_to_el2_m x3, x4, x5
> >  ENDPROC(secondary_switch_to_el2)
> >
> >  ENTRY(secondary_switch_to_el1)
> > -       switch_el x0, 0f, 1f, 0f
> > +       mrs     x0, mpidr_el1
> > +       ubfm    x1, x0, #8, #15
> > +       ubfm    x2, x0, #0, #1
> > +       orr     x10, x2, x1, lsl #2     /* x10 has LPID */
> > +
> > +       lsl     x1, x10, #6
> > +       ldr     x0, =__spin_table
> > +       /* physical address of this cpus spin table element */
> > +       add     x11, x1, x0
> > +
> > +       ldr     x3, [x11]
> > +
> > +       ldr     x5, [x11, #24]
> > +       ldr     x6, =IH_ARCH_DEFAULT
> > +       cmp     x6, x5
> > +       b.eq    2f
> > +
> > +       ldr     x4, =ES_TO_AARCH32
> > +       bl      switch_to_el1
> > +
> > +2:     ldr     x4, =ES_TO_AARCH64
> > +
> > +switch_to_el1:
> > +       switch_el x5, 0f, 1f, 0f
> >  0:     ret
> > -1:     armv8_switch_to_el1_m x0, x1
> > +1:     armv8_switch_to_el1_m x3, x4, x5
> >  ENDPROC(secondary_switch_to_el1)
> >
> >         /* Ensure that the literals used by the secondary boot code
> > are diff --git a/arch/arm/cpu/armv8/start.S
> > b/arch/arm/cpu/armv8/start.S index 19c771d..4f5f6d8 100644
> > --- a/arch/arm/cpu/armv8/start.S
> > +++ b/arch/arm/cpu/armv8/start.S
> > @@ -251,9 +251,17 @@ WEAK(lowlevel_init)
> >         /*
> >          * All slaves will enter EL2 and optionally EL1.
> >          */
> > +       adr     x3, lowlevel_in_el2
> > +       ldr     x4, =ES_TO_AARCH64
> >         bl      armv8_switch_to_el2
> > +
> > +lowlevel_in_el2:
> >  #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +       adr     x3, lowlevel_in_el1
> > +       ldr     x4, =ES_TO_AARCH64
> >         bl      armv8_switch_to_el1
> > +
> > +lowlevel_in_el1:
> >  #endif
> >
> >  #endif /* CONFIG_ARMV8_MULTIENTRY */
> > diff --git a/arch/arm/cpu/armv8/transition.S
> > b/arch/arm/cpu/armv8/transition.S index 253a39b..bbccf2b 100644
> > --- a/arch/arm/cpu/armv8/transition.S
> > +++ b/arch/arm/cpu/armv8/transition.S
> > @@ -11,13 +11,24 @@
> >  #include <asm/macro.h>
> >
> >  ENTRY(armv8_switch_to_el2)
> > -       switch_el x0, 1f, 0f, 0f
> > -0:     ret
> > -1:     armv8_switch_to_el2_m x0
> > +       switch_el x5, 1f, 0f, 0f
> > +0:
> > +       /*
> > +        * x3 is kernel entry point or switch_to_el1
> > +        * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
> > +         * When running in EL2 now, jump to the
> > +        * address saved in x3.
> > +        */
> > +       br x3
> > +1:     armv8_switch_to_el2_m x3, x4, x5
> >  ENDPROC(armv8_switch_to_el2)
> >
> >  ENTRY(armv8_switch_to_el1)
> > -       switch_el x0, 0f, 1f, 0f
> > -0:     ret
> > -1:     armv8_switch_to_el1_m x0, x1
> > +       switch_el x5, 0f, 1f, 0f
> > +0:
> > +       /* x3 is kernel entry point. When running in EL1
> > +        * now, jump to the address saved in x3.
> > +        */
> > +       br x3
> > +1:     armv8_switch_to_el1_m x3, x4, x5
> >  ENDPROC(armv8_switch_to_el1)
> > diff --git a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> > b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> > index f7306ff..ebf84b6 100644
> > --- a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> > +++ b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
> > @@ -36,4 +36,8 @@ void secondary_boot_func(void);  int
> > is_core_online(u64 cpu_id);
> >  u32 cpu_pos_mask(void);
> >  #endif
> > +
> > +#define IH_ARCH_ARM            2       /* ARM */
> > +#define IH_ARCH_ARM64          22      /* ARM64 */
> > +
> >  #endif /* _FSL_LAYERSCAPE_MP_H */
> > diff --git a/arch/arm/include/asm/macro.h
> > b/arch/arm/include/asm/macro.h index 9bb0efa..2553e3e 100644
> > --- a/arch/arm/include/asm/macro.h
> > +++ b/arch/arm/include/asm/macro.h
> > @@ -8,6 +8,11 @@
> >
> >  #ifndef __ASM_ARM_MACRO_H__
> >  #define __ASM_ARM_MACRO_H__
> > +
> > +#ifdef CONFIG_ARM64
> > +#include <asm/system.h>
> > +#endif
> > +
> >  #ifdef __ASSEMBLY__
> >
> >  /*
> > @@ -135,13 +140,21 @@ lr        .req    x30
> >  #endif
> >  .endm
> >
> > -.macro armv8_switch_to_el2_m, xreg1
> > -       /* 64bit EL2 | HCE | SMD | RES1 (Bits[5:4]) | Non-secure
> EL0/EL1 */
> > -       mov     \xreg1, #0x5b1
> > -       msr     scr_el3, \xreg1
> > +/*
> > + * Switch from EL3 to EL2 for ARMv8
> > + * @ep:     kernel entry point
> > + * @flag:   The execution state flag for lower exception
> > + *          level, ES_TO_AARCH64 or ES_TO_AARCH32
> > + * @tmp:    temporary register
> > + *
> > + * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
> > + * For loading 64-bit OS, x0 is physical address to the FDT blob.
> > + * They will be passed to the guest.
> > + */
> > +.macro armv8_switch_to_el2_m, ep, flag, tmp
> >         msr     cptr_el3, xzr           /* Disable coprocessor traps
> to EL3 */
> > -       mov     \xreg1, #0x33ff
> > -       msr     cptr_el2, \xreg1        /* Disable coprocessor traps
> to EL2 */
> > +       mov     \tmp, #CPTR_EL2_RES1
> > +       msr     cptr_el2, \tmp          /* Disable coprocessor traps
> to EL2 */
> >
> >         /* Initialize Generic Timers */
> >         msr     cntvoff_el2, xzr
> > @@ -152,45 +165,90 @@ lr        .req    x30
> >          * and RES0 bits (31,30,27,26,24,21,20,17,15-13,10-6) +
> >          * EE,WXN,I,SA,C,A,M to 0
> >          */
> > -       mov     \xreg1, #0x0830
> > -       movk    \xreg1, #0x30C5, lsl #16
> > -       msr     sctlr_el2, \xreg1
> > +       ldr     \tmp, =(SCTLR_EL2_RES1 | SCTLR_EL2_EE_LE |\
> > +                       SCTLR_EL2_WXN_DIS | SCTLR_EL2_ICACHE_DIS |\
> > +                       SCTLR_EL2_SA_DIS | SCTLR_EL2_DCACHE_DIS |\
> > +                       SCTLR_EL2_ALIGN_DIS | SCTLR_EL2_MMU_DIS)
> > +       msr     sctlr_el2, \tmp
> > +
> > +       mov     \tmp, sp
> > +       msr     sp_el2, \tmp            /* Migrate SP */
> > +       mrs     \tmp, vbar_el3
> > +       msr     vbar_el2, \tmp          /* Migrate VBAR */
> > +
> > +       /* Check switch to AArch64 EL2 or AArch32 Hypervisor mode */
> > +       cmp     \flag, #ES_TO_AARCH32
> > +       b.eq    1f
> > +
> > +       /*
> > +        * The next lower exception level is AArch64, 64bit EL2 | HCE
> |
> > +        * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
> > +        */
> > +       ldr     \tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
> > +                       SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
> > +                       SCR_EL3_NS_EN)
> > +       msr     scr_el3, \tmp
> >
> >         /* Return to the EL2_SP2 mode from EL3 */
> > -       mov     \xreg1, sp
> > -       msr     sp_el2, \xreg1          /* Migrate SP */
> > -       mrs     \xreg1, vbar_el3
> > -       msr     vbar_el2, \xreg1        /* Migrate VBAR */
> > -       mov     \xreg1, #0x3c9
> > -       msr     spsr_el3, \xreg1        /* EL2_SP2 | D | A | I | F */
> > -       msr     elr_el3, lr
> > +       ldr     \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
> > +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> > +                       SPSR_EL_M_AARCH64 | SPSR_EL_M_EL2H)
> > +       msr     spsr_el3, \tmp
> > +       msr     elr_el3, \ep
> > +       eret
> > +
> > +1:
> > +       /*
> > +        * The next lower exception level is AArch32, 32bit EL2 | HCE
> |
> > +        * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
> > +        */
> > +       ldr     \tmp, =(SCR_EL3_RW_AARCH32 | SCR_EL3_HCE_EN |\
> > +                       SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
> > +                       SCR_EL3_NS_EN)
> > +       msr     scr_el3, \tmp
> > +
> > +       /* Return to AArch32 Hypervisor mode */
> > +       ldr     \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
> > +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> > +                       SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
> > +                       SPSR_EL_M_HYP)
> > +       msr     spsr_el3, \tmp
> > +       msr     elr_el3, \ep
> >         eret
> >  .endm
> >
> > -.macro armv8_switch_to_el1_m, xreg1, xreg2
> > +/*
> > + * Switch from EL2 to EL1 for ARMv8
> > + * @ep:     kernel entry point
> > + * @flag:   The execution state flag for lower exception
> > + *          level, ES_TO_AARCH64 or ES_TO_AARCH32
> > + * @tmp:    temporary register
> > + *
> > + * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
> > + * For loading 64-bit OS, x0 is physical address to the FDT blob.
> > + * They will be passed to the guest.
> > + */
> > +.macro armv8_switch_to_el1_m, ep, flag, tmp
> >         /* Initialize Generic Timers */
> > -       mrs     \xreg1, cnthctl_el2
> > -       orr     \xreg1, \xreg1, #0x3    /* Enable EL1 access to
> timers */
> > -       msr     cnthctl_el2, \xreg1
> > +       mrs     \tmp, cnthctl_el2
> > +       /* Enable EL1 access to timers */
> > +       orr     \tmp, \tmp, #(CNTHCTL_EL2_EL1PCEN_EN |\
> > +               CNTHCTL_EL2_EL1PCTEN_EN)
> > +       msr     cnthctl_el2, \tmp
> >         msr     cntvoff_el2, xzr
> >
> >         /* Initilize MPID/MPIDR registers */
> > -       mrs     \xreg1, midr_el1
> > -       mrs     \xreg2, mpidr_el1
> > -       msr     vpidr_el2, \xreg1
> > -       msr     vmpidr_el2, \xreg2
> > +       mrs     \tmp, midr_el1
> > +       msr     vpidr_el2, \tmp
> > +       mrs     \tmp, mpidr_el1
> > +       msr     vmpidr_el2, \tmp
> >
> >         /* Disable coprocessor traps */
> > -       mov     \xreg1, #0x33ff
> > -       msr     cptr_el2, \xreg1        /* Disable coprocessor traps
> to EL2 */
> > +       mov     \tmp, #CPTR_EL2_RES1
> > +       msr     cptr_el2, \tmp          /* Disable coprocessor traps
> to EL2 */
> >         msr     hstr_el2, xzr           /* Disable coprocessor traps
> to EL2 */
> > -       mov     \xreg1, #3 << 20
> > -       msr     cpacr_el1, \xreg1       /* Enable FP/SIMD at EL1 */
> > -
> > -       /* Initialize HCR_EL2 */
> > -       mov     \xreg1, #(1 << 31)              /* 64bit EL1 */
> > -       orr     \xreg1, \xreg1, #(1 << 29)      /* Disable HVC */
> > -       msr     hcr_el2, \xreg1
> > +       mov     \tmp, #CPACR_EL1_FPEN_EN
> > +       msr     cpacr_el1, \tmp         /* Enable FP/SIMD at EL1 */
> >
> >         /* SCTLR_EL1 initialization
> >          *
> > @@ -199,18 +257,50 @@ lr        .req    x30
> >          * UCI,EE,EOE,WXN,nTWE,nTWI,UCT,DZE,I,UMA,SED,ITD,
> >          * CP15BEN,SA0,SA,C,A,M to 0
> >          */
> > -       mov     \xreg1, #0x0800
> > -       movk    \xreg1, #0x30d0, lsl #16
> > -       msr     sctlr_el1, \xreg1
> > +       ldr     \tmp, =(SCTLR_EL1_RES1 | SCTLR_EL1_UCI_DIS |\
> > +                       SCTLR_EL1_EE_LE | SCTLR_EL1_WXN_DIS |\
> > +                       SCTLR_EL1_NTWE_DIS | SCTLR_EL1_NTWI_DIS |\
> > +                       SCTLR_EL1_UCT_DIS | SCTLR_EL1_DZE_DIS |\
> > +                       SCTLR_EL1_ICACHE_DIS | SCTLR_EL1_UMA_DIS |\
> > +                       SCTLR_EL1_SED_EN | SCTLR_EL1_ITD_EN |\
> > +                       SCTLR_EL1_CP15BEN_DIS | SCTLR_EL1_SA0_DIS |\
> > +                       SCTLR_EL1_SA_DIS | SCTLR_EL1_DCACHE_DIS |\
> > +                       SCTLR_EL1_ALIGN_DIS | SCTLR_EL1_MMU_DIS)
> > +       msr     sctlr_el1, \tmp
> > +
> > +       mov     \tmp, sp
> > +       msr     sp_el1, \tmp            /* Migrate SP */
> > +       mrs     \tmp, vbar_el2
> > +       msr     vbar_el1, \tmp          /* Migrate VBAR */
> > +
> > +       /* Check switch to AArch64 EL1 or AArch32 Supervisor mode */
> > +       cmp     \flag, #ES_TO_AARCH32
> > +       b.eq    1f
> > +
> > +       /* Initialize HCR_EL2 */
> > +       ldr     \tmp, =(HCR_EL2_RW_AARCH64 | HCR_EL2_HCD_DIS)
> > +       msr     hcr_el2, \tmp
> >
> >         /* Return to the EL1_SP1 mode from EL2 */
> > -       mov     \xreg1, sp
> > -       msr     sp_el1, \xreg1          /* Migrate SP */
> > -       mrs     \xreg1, vbar_el2
> > -       msr     vbar_el1, \xreg1        /* Migrate VBAR */
> > -       mov     \xreg1, #0x3c5
> > -       msr     spsr_el2, \xreg1        /* EL1_SP1 | D | A | I | F */
> > -       msr     elr_el2, lr
> > +       ldr     \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
> > +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> > +                       SPSR_EL_M_AARCH64 | SPSR_EL_M_EL1H)
> > +       msr     spsr_el2, \tmp
> > +       msr     elr_el2, \ep
> > +       eret
> > +
> > +1:
> > +       /* Initialize HCR_EL2 */
> > +       ldr     \tmp, =(HCR_EL2_RW_AARCH32 | HCR_EL2_HCD_DIS)
> > +       msr     hcr_el2, \tmp
> > +
> > +       /* Return to AArch32 Supervisor mode from EL2 */
> > +       ldr     \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
> > +                       SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
> > +                       SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
> > +                       SPSR_EL_M_SVC)
> > +       msr     spsr_el2, \tmp
> > +       msr     elr_el2, \ep
> >         eret
> >  .endm
> >
> > diff --git a/arch/arm/include/asm/system.h
> > b/arch/arm/include/asm/system.h index c3c88d2..1c3f74d 100644
> > --- a/arch/arm/include/asm/system.h
> > +++ b/arch/arm/include/asm/system.h
> > @@ -18,6 +18,95 @@
> >  #define CR_WXN         (1 << 19)       /* Write Permision Imply XN
> */
> >  #define CR_EE          (1 << 25)       /* Exception (Big) Endian
> */
> >
> > +#define ES_TO_AARCH64          1
> > +#define ES_TO_AARCH32          0
> > +
> > +/*
> > + * SCR_EL3 bits definitions
> > + */
> > +#define SCR_EL3_RW_AARCH64     (1 << 10) /* Next lower level is
> AArch64     */
> > +#define SCR_EL3_RW_AARCH32     (0 << 10) /* Lower lowers level are
> AArch32  */
> > +#define SCR_EL3_HCE_EN         (1 << 8)  /* Hypervisor Call enable
> */
> > +#define SCR_EL3_SMD_DIS                (1 << 7)  /* Secure Monitor
> Call disable     */
> > +#define SCR_EL3_RES1           (3 << 4)  /* Reserved, RES1
> */
> > +#define SCR_EL3_NS_EN          (1 << 0)  /* EL0 and EL1 in Non-scure
> state  */
> > +
> > +/*
> > + * SPSR_EL3/SPSR_EL2 bits definitions  */
> > +#define SPSR_EL_END_LE         (0 << 9)  /* Exception Little-endian
> */
> > +#define SPSR_EL_DEBUG_MASK     (1 << 9)  /* Debug exception masked
> */
> > +#define SPSR_EL_ASYN_MASK      (1 << 8)  /* Asynchronous data abort
> masked   */
> > +#define SPSR_EL_SERR_MASK      (1 << 8)  /* System Error exception
> masked    */
> > +#define SPSR_EL_IRQ_MASK       (1 << 7)  /* IRQ exception masked
> */
> > +#define SPSR_EL_FIQ_MASK       (1 << 6)  /* FIQ exception masked
> */
> > +#define SPSR_EL_T_A32          (0 << 5)  /* AArch32 instruction set
> A32      */
> > +#define SPSR_EL_M_AARCH64      (0 << 4)  /* Exception taken from
> AArch64     */
> > +#define SPSR_EL_M_AARCH32      (1 << 4)  /* Exception taken from
> AArch32     */
> > +#define SPSR_EL_M_SVC          (0x3)     /* Exception taken from SVC
> mode    */
> > +#define SPSR_EL_M_HYP          (0xa)     /* Exception taken from HYP
> mode    */
> > +#define SPSR_EL_M_EL1H         (5)       /* Exception taken from
> EL1h mode   */
> > +#define SPSR_EL_M_EL2H         (9)       /* Exception taken from
> EL2h mode   */
> > +
> > +/*
> > + * CPTR_EL2 bits definitions
> > + */
> > +#define CPTR_EL2_RES1          (3 << 12 | 0x3ff)           /*
> Reserved, RES1 */
> > +
> > +/*
> > + * SCTLR_EL2 bits definitions
> > + */
> > +#define SCTLR_EL2_RES1         (3 << 28 | 3 << 22 | 1 << 18 | 1 <<
> 16 |\
> > +                                1 << 11 | 3 << 4)          /*
> Reserved, RES1 */
> > +#define SCTLR_EL2_EE_LE                (0 << 25) /* Exception
> Little-endian          */
> > +#define SCTLR_EL2_WXN_DIS      (0 << 19) /* Write permission is not
> XN       */
> > +#define SCTLR_EL2_ICACHE_DIS   (0 << 12) /* Instruction cache
> disabled       */
> > +#define SCTLR_EL2_SA_DIS       (0 << 3)  /* Stack Alignment Check
> disabled   */
> > +#define SCTLR_EL2_DCACHE_DIS   (0 << 2)  /* Data cache disabled
> */
> > +#define SCTLR_EL2_ALIGN_DIS    (0 << 1)  /* Alignment check disabled
> */
> > +#define SCTLR_EL2_MMU_DIS      (0)       /* MMU disabled
> */
> > +
> > +/*
> > + * CNTHCTL_EL2 bits definitions
> > + */
> > +#define CNTHCTL_EL2_EL1PCEN_EN (1 << 1)  /* Physical timer regs
> accessible   */
> > +#define CNTHCTL_EL2_EL1PCTEN_EN        (1 << 0)  /* Physical counter
> accessible      */
> > +
> > +/*
> > + * HCR_EL2 bits definitions
> > + */
> > +#define HCR_EL2_RW_AARCH64     (1 << 31) /* EL1 is AArch64
> */
> > +#define HCR_EL2_RW_AARCH32     (0 << 31) /* Lower levels are AArch32
> */
> > +#define HCR_EL2_HCD_DIS                (1 << 29) /* Hypervisor Call
> disabled         */
> > +
> > +/*
> > + * CPACR_EL1 bits definitions
> > + */
> > +#define CPACR_EL1_FPEN_EN      (3 << 20) /* SIMD and FP instruction
> enabled  */
> > +
> > +/*
> > + * SCTLR_EL1 bits definitions
> > + */
> > +#define SCTLR_EL1_RES1         (3 << 28 | 3 << 22 | 1 << 20 |\
> > +                                1 << 11) /* Reserved, RES1
> */
> > +#define SCTLR_EL1_UCI_DIS      (0 << 26) /* Cache instruction
> disabled       */
> > +#define SCTLR_EL1_EE_LE                (0 << 25) /* Exception
> Little-endian          */
> > +#define SCTLR_EL1_WXN_DIS      (0 << 19) /* Write permission is not
> XN       */
> > +#define SCTLR_EL1_NTWE_DIS     (0 << 18) /* WFE instruction disabled
> */
> > +#define SCTLR_EL1_NTWI_DIS     (0 << 16) /* WFI instruction disabled
> */
> > +#define SCTLR_EL1_UCT_DIS      (0 << 15) /* CTR_EL0 access disabled
> */
> > +#define SCTLR_EL1_DZE_DIS      (0 << 14) /* DC ZVA instruction
> disabled      */
> > +#define SCTLR_EL1_ICACHE_DIS   (0 << 12) /* Instruction cache
> disabled       */
> > +#define SCTLR_EL1_UMA_DIS      (0 << 9)  /* User Mask Access
> disabled        */
> > +#define SCTLR_EL1_SED_EN       (0 << 8)  /* SETEND instruction
> enabled       */
> > +#define SCTLR_EL1_ITD_EN       (0 << 7)  /* IT instruction enabled
> */
> > +#define SCTLR_EL1_CP15BEN_DIS  (0 << 5)  /* CP15 barrier operation
> disabled  */
> > +#define SCTLR_EL1_SA0_DIS      (0 << 4)  /* Stack Alignment EL0
> disabled     */
> > +#define SCTLR_EL1_SA_DIS       (0 << 3)  /* Stack Alignment EL1
> disabled     */
> > +#define SCTLR_EL1_DCACHE_DIS   (0 << 2)  /* Data cache disabled
> */
> > +#define SCTLR_EL1_ALIGN_DIS    (0 << 1)  /* Alignment check disabled
> */
> > +#define SCTLR_EL1_MMU_DIS      (0)       /* MMU disabled
> */
> > +
> >  #ifndef __ASSEMBLY__
> >
> >  u64 get_page_table_size(void);
> > @@ -98,8 +187,34 @@ int __asm_flush_l3_dcache(void);  int
> > __asm_invalidate_l3_icache(void);  void __asm_switch_ttbr(u64
> > new_ttbr);
> >
> > -void armv8_switch_to_el2(void);
> > -void armv8_switch_to_el1(void);
> > +/*
> > + * Switch from EL3 to EL2 for ARMv8
> > + *
> > + * @args:        For loading 64-bit OS, fdt address.
> > + *               For loading 32-bit OS, zero.
> > + * @mach_nr:     For loading 64-bit OS, zero.
> > + *               For loading 32-bit OS, machine nr
> > + * @fdt_addr:    For loading 64-bit OS, zero.
> > + *               For loading 32-bit OS, fdt address.
> > + * @entry_point: kernel entry point
> > + * @es_flag:     execution state flag, ES_TO_AARCH64 or
> ES_TO_AARCH32
> > + */
> > +void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
> > +                        u64 entry_point, u64 es_flag);
> > +/*
> > + * Switch from EL2 to EL1 for ARMv8
> > + *
> > + * @args:        For loading 64-bit OS, fdt address.
> > + *               For loading 32-bit OS, zero.
> > + * @mach_nr:     For loading 64-bit OS, zero.
> > + *               For loading 32-bit OS, machine nr
> > + * @fdt_addr:    For loading 64-bit OS, zero.
> > + *               For loading 32-bit OS, fdt address.
> > + * @entry_point: kernel entry point
> > + * @es_flag:     execution state flag, ES_TO_AARCH64 or
> ES_TO_AARCH32
> > + */
> > +void armv8_switch_to_el1(u64 args, u64 mach_nr, u64 fdt_addr,
> > +                        u64 entry_point, u64 es_flag);
> >  void gic_init(void);
> >  void gic_send_sgi(unsigned long sgino);  void wait_for_wakeup(void);
> > diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c index
> > 53c3141..7015573 100644
> > --- a/arch/arm/lib/bootm.c
> > +++ b/arch/arm/lib/bootm.c
> > @@ -193,10 +193,6 @@ static void do_nonsec_virt_switch(void)  {
> >         smp_kick_all_cpus();
> >         dcache_disable();       /* flush cache before swtiching to
> EL2 */
> > -       armv8_switch_to_el2();
> > -#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > -       armv8_switch_to_el1();
> > -#endif
> >  }
> >  #endif
> >
> > @@ -273,6 +269,24 @@ bool armv7_boot_nonsec(void)  }  #endif
> >
> > +#ifdef CONFIG_ARM64
> > +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +static void switch_to_el1(void)
> > +{
> > +       if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
> > +           (images.os.arch == IH_ARCH_ARM))
> > +               armv8_switch_to_el1(0, (u64)gd->bd->bi_arch_number,
> > +                                   (u64)images.ft_addr,
> > +                                   (u64)images.ep,
> > +                                   ES_TO_AARCH32);
> > +       else
> > +               armv8_switch_to_el1((u64)images.ft_addr, 0, 0,
> > +                                   images.ep,
> > +                                   ES_TO_AARCH64); } #endif #endif
> > +
> >  /* Subcommand: GO */
> >  static void boot_jump_linux(bootm_headers_t *images, int flag)  { @@
> > -292,7 +306,22 @@ static void boot_jump_linux(bootm_headers_t *images,
> > int flag)
> >
> >         if (!fake) {
> >                 do_nonsec_virt_switch();
> > -               kernel_entry(images->ft_addr, NULL, NULL, NULL);
> > +
> > +#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +               armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
> > +                                   (u64)switch_to_el1,
> > +ES_TO_AARCH64); #else
> > +               if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
> > +                   (images->os.arch == IH_ARCH_ARM))
> > +                       armv8_switch_to_el2(0, (u64)gd->bd-
> >bi_arch_number,
> > +                                           (u64)images->ft_addr,
> > +                                           (u64)images->ep,
> > +                                           ES_TO_AARCH32);
> > +               else
> > +                       armv8_switch_to_el2((u64)images->ft_addr, 0,
> 0,
> > +                                           images->ep,
> > +                                           ES_TO_AARCH64); #endif
> >         }
> >  #else
> >         unsigned long machid = gd->bd->bi_arch_number; diff --git
> > a/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> > b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> > index 88ff56e..11acce0 100644
> > --- a/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> > +++ b/arch/arm/mach-rmobile/lowlevel_init_gen3.S
> > @@ -61,11 +61,18 @@ ENTRY(lowlevel_init)
> >         /*
> >          * All slaves will enter EL2 and optionally EL1.
> >          */
> > +       adr     x3, lowlevel_in_el2
> > +       ldr     x4, =ES_TO_AARCH64
> >         bl      armv8_switch_to_el2
> > +
> > +lowlevel_in_el2:
> >  #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
> > +       adr     x3, lowlevel_in_el1
> > +       ldr     x4, =ES_TO_AARCH64
> >         bl      armv8_switch_to_el1
> > -#endif
> >
> > +lowlevel_in_el1:
> > +#endif
> >  #endif /* CONFIG_ARMV8_MULTIENTRY */
> >
> >         bl      s_init
> > diff --git a/common/image-fit.c b/common/image-fit.c index
> > 77dc011..ea56d5b 100644
> > --- a/common/image-fit.c
> > +++ b/common/image-fit.c
> > @@ -27,6 +27,7 @@ DECLARE_GLOBAL_DATA_PTR;  #include <u-boot/md5.h>
> > #include <u-boot/sha1.h>  #include <u-boot/sha256.h>
> > +#include <generated/autoconf.h>
> >
> >
> >
> /*********************************************************************
> > ********/
> >  /* New uImage format routines */
> > @@ -1161,11 +1162,18 @@ int fit_image_check_os(const void *fit, int
> > noffset, uint8_t os)  int fit_image_check_arch(const void *fit, int
> > noffset, uint8_t arch)  {
> >         uint8_t image_arch;
> > +       int aarch32_support = 0;
> > +
> > +#ifdef CONFIG_ARM64_SUPPORT_AARCH32
> > +       aarch32_support = 1;
> > +#endif
> >
> >         if (fit_image_get_arch(fit, noffset, &image_arch))
> >                 return 0;
> >         return (arch == image_arch) ||
> > -               (arch == IH_ARCH_I386 && image_arch ==
> IH_ARCH_X86_64);
> > +               (arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64)
> ||
> > +               (arch == IH_ARCH_ARM64 && image_arch == IH_ARCH_ARM
> &&
> > +                aarch32_support);
> >  }
> >
> >  /**
> > @@ -1614,6 +1622,9 @@ int fit_image_load(bootm_headers_t *images,
> ulong addr,
> >         int type_ok, os_ok;
> >         ulong load, data, len;
> >         uint8_t os;
> > +#ifndef USE_HOSTCC
> > +       uint8_t os_arch;
> > +#endif
> >         const char *prop_name;
> >         int ret;
> >
> > @@ -1697,6 +1708,12 @@ int fit_image_load(bootm_headers_t *images,
> ulong addr,
> >                 return -ENOEXEC;
> >         }
> >  #endif
> > +
> > +#ifndef USE_HOSTCC
> > +       fit_image_get_arch(fit, noffset, &os_arch);
> > +       images->os.arch = os_arch;
> > +#endif
> > +
> >         if (image_type == IH_TYPE_FLATDT &&
> >             !fit_image_check_comp(fit, noffset, IH_COMP_NONE)) {
> >                 puts("FDT image is compressed");
> > --
> > 2.1.0.27.g96db324
> >