[U-Boot] [PATCH v6 06/12] arm: add Faraday processor core support

[Kuo-Jung Su <dantesu@gmail.com>]

From: Kuo-Jung Su <dantesu@faraday-tech.com>

This adds i/d-cache control, mmu setup & bootstrap code
for Faraday cores.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
CC: Albert Aribaud <albert.u.boot@aribaud.net>
---
Changes for v6:
   - Nothing updates

Changes for v5:
   - Initial commit which is separated from
     "arm: add Faraday common utilities"

 arch/arm/cpu/faraday/Makefile  |   55 +++++
 arch/arm/cpu/faraday/config.mk |   33 +++
 arch/arm/cpu/faraday/cpu.c     |  343 ++++++++++++++++++++++++++++++++
 arch/arm/cpu/faraday/start.S   |  431 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 862 insertions(+)
 create mode 100644 arch/arm/cpu/faraday/Makefile
 create mode 100644 arch/arm/cpu/faraday/config.mk
 create mode 100644 arch/arm/cpu/faraday/cpu.c
 create mode 100644 arch/arm/cpu/faraday/start.S

diff --git a/arch/arm/cpu/faraday/Makefile b/arch/arm/cpu/faraday/Makefile
new file mode 100644
index 0000000..ecb240a
--- /dev/null
+++ b/arch/arm/cpu/faraday/Makefile
@@ -0,0 +1,55 @@
+#
+# (C) Copyright 2000-2006
+# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	= $(obj)lib$(CPU).o
+
+src-y  := cpu.o
+
+START	= start.o
+COBJS	= $(src-y)
+
+ifdef	CONFIG_SPL_BUILD
+ifdef	CONFIG_SPL_NO_CPU_SUPPORT_CODE
+START	:=
+endif
+endif
+
+SRCS	:= $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))
+START	:= $(addprefix $(obj),$(START))
+
+all:	$(obj).depend $(START) $(LIB)
+
+$(LIB):	$(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/arch/arm/cpu/faraday/config.mk b/arch/arm/cpu/faraday/config.mk
new file mode 100644
index 0000000..f03030a
--- /dev/null
+++ b/arch/arm/cpu/faraday/config.mk
@@ -0,0 +1,33 @@
+#
+# (C) Copyright 2002
+# Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
+
+PLATFORM_CPPFLAGS += -march=armv4
+# =========================================================================
+#
+# Supply options according to compiler version
+#
+# =========================================================================
+PF_RELFLAGS_SLB_AT := $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
+PLATFORM_RELFLAGS += $(PF_RELFLAGS_SLB_AT)
diff --git a/arch/arm/cpu/faraday/cpu.c b/arch/arm/cpu/faraday/cpu.c
new file mode 100644
index 0000000..449bf0d
--- /dev/null
+++ b/arch/arm/cpu/faraday/cpu.c
@@ -0,0 +1,343 @@
+/*
+ * arch/arm/cpu/faraday/cpu.c
+ *
+ * (C) Copyright 2013 Faraday Technology
+ * Dante Su <dantesu@faraday-tech.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * CPU specific code
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <faraday/ftwdt010_wdt.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int cleanup_before_linux(void)
+{
+	/*
+	 * this function is called just before we call linux
+	 * it prepares the processor for linux
+	 *
+	 * we turn off caches etc ...
+	 */
+
+	disable_interrupts();
+
+	/* turn off D-cache */
+	dcache_disable();
+
+	/* flush I-cache */
+	__asm__ __volatile__ (
+		"mov r0, #0\n"
+		"mcr p15, 0, r0, c7, c5, 0\n" /* invalidate i-cache all */
+		:      /* output */
+		:      /* input */
+		: "r0" /* clobber list */
+	);
+
+	return 0;
+}
+
+/*
+ * This arch_preboot_os() overrides the weak function
+ * in "cmd_bootm.c".
+ */
+void arch_preboot_os(void)
+{
+	cleanup_before_linux();
+}
+
+#ifdef CONFIG_SYS_DCACHE_OFF
+
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+#else
+
+void flush_dcache_all(void)
+{
+	__asm__ __volatile__ (
+		"mov r0,#0\n"
+		"mcr p15,0,r0,c7,c14,0\n" /* clean & invalidate d-cache all */
+		"mcr p15,0,r0,c7,c10,4\n" /* drain write buffer */
+		: /* output */
+		: /* input */
+		: "r0" /* clobber list */
+	);
+}
+
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+	unsigned long align = CONFIG_SYS_CACHELINE_SIZE;
+	unsigned long mask  = ~(align - 1);
+
+	/* aligned to cache line */
+	stop  = (stop + (align - 1)) & mask;
+	start = start & mask;
+
+	__asm__ __volatile__ (
+		"1:\n"
+		"mcr p15,0,%0,c7,c14,1\n" /* clean & invalidate d-cache line */
+		"add %0,%0,%2\n"
+		"cmp %0,%1\n"
+		"blo 1b\n"
+		"mov r0,#0\n"
+		"mcr p15,0,r0,c7,c10,4\n" /* drain write buffer */
+		: "+r"(start) /* output */
+		: "r"(stop), "r"(align) /* input */
+		: "r0" /* clobber list */
+	);
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+	unsigned long align = CONFIG_SYS_CACHELINE_SIZE;
+	unsigned long mask  = ~(align - 1);
+
+	/* aligned to cache line */
+	stop  = (stop + (align - 1)) & mask;
+	start = start & mask;
+
+	__asm__ __volatile__ (
+		"1:\n"
+		"mcr p15,0,%0,c7,c6,1\n" /* invalidate cache line */
+		"add %0,%0,%2\n"
+		"cmp %0,%1\n"
+		"blo 1b\n"
+		: "+r"(start) /* output */
+		: "r"(stop), "r"(align) /* input */
+	);
+}
+
+void invalidate_dcache_all(void)
+{
+	__asm__ __volatile__ (
+		"mov r0,#0\n"
+		"mcr p15,0,r0,c7,c6,0\n" /* invalidate d-cache all */
+		: /* output */
+		: /* input */
+		: "r0"/* clobber list */
+	);
+}
+
+void invalidate_icache_all(void)
+{
+	__asm__ __volatile__ (
+		"mov r0,#0\n"
+		"mcr p15,0,r0,c7,c5,0\n" /* invalidate i-cache all */
+		: /* output */
+		: /* input */
+		: "r0" /* clobber list */
+	);
+}
+
+void flush_cache(unsigned long start, unsigned long size)
+{
+	flush_dcache_range(start, start + size);
+}
+
+#endif    /* !defined(CONFIG_SYS_DCACHE_OFF) */
+
+void enable_caches(void)
+{
+	icache_enable();
+
+#if !defined(CONFIG_SYS_DCACHE_OFF)
+	if (gd->arch.cpu_mmu) {
+		puts("MMU:   on\n");
+		dcache_enable();
+	} else
+#endif
+		puts("MMU:   off\n");
+}
+
+#define CPUID_VID(x)        (((x) >> 24) & 0xff)
+#define CPUID_ISA(x)        (((x) >> 16) & 0xff)
+#define CPUID_PID(x)        (((x) >>  4) & 0x0fff)
+#define CPUID_REV(x)        ((x) & 0x0f) /* revision */
+#define CPUID_NOREV(x)      (((x) >>  4) & 0x0fffffff)
+
+/* Vendor ID */
+#define CPUID_VID_ARM       0x41
+#define CPUID_VID_FARADAY   0x66
+
+/* Instruction Set Architecture */
+#define CPUID_ISA_ARMV4     0x01
+#define CPUID_ISA_ARMV5TE   0x05
+#define CPUID_ISA_ARMV5TEJ  0x06
+
+/* Faraday ARMv4 cores */
+#define CPUID_FA526         0x6601526
+#define CPUID_FA626         0x6601626
+
+/* Faraday ARMv5TE cores */
+#define CPUID_FA606TE       0x6605606
+#define CPUID_FA616TE       0x6605616
+#define CPUID_FA626TE       0x6605626
+#define CPUID_FA726TE       0x6605726
+
+#ifdef CONFIG_ARCH_CPU_INIT
+
+int arch_cpu_init(void)
+{
+	unsigned int id, ctr;
+
+	__asm__ __volatile__ (
+		"mrc p15, 0, %0, c0, c0, 0\n"
+		"mrc p15, 0, %1, c0, c0, 1\n"
+		: "=r"(id), "=r"(ctr) /* output */
+		: /* input */
+	);
+
+	gd->arch.cpu_id = id;
+
+	/* MMU/D-Cache */
+	switch (CPUID_NOREV(gd->arch.cpu_id)) {
+	case CPUID_FA606TE: /* FA606TE (no-mmu) */
+		/* Disable MMU/D-Cache */
+		gd->arch.cpu_mmu = 0;
+		break;
+	default:
+		/* Enable MMU/D-Cache */
+		gd->arch.cpu_mmu = 1;
+		break;
+	}
+
+	return 0;
+}
+#endif    /* #ifdef CONFIG_ARCH_CPU_INIT */
+
+#ifdef CONFIG_DISPLAY_CPUINFO
+int print_cpuinfo(void)
+{
+	char cpu_name[32];
+	uint vid = CPUID_VID(gd->arch.cpu_id);
+	uint pid = CPUID_PID(gd->arch.cpu_id);
+
+	/* build cpu_name */
+	switch (vid) {
+	case CPUID_VID_FARADAY:	/* Faraday */
+		switch (CPUID_ISA(gd->arch.cpu_id)) {
+		case CPUID_ISA_ARMV5TE:
+			sprintf(cpu_name, "FA%xTE", pid);
+			break;
+		default:
+			sprintf(cpu_name, "FA%x", pid);
+			break;
+		}
+		break;
+	case CPUID_VID_ARM:	/* ARM */
+		if ((pid & 0xff0) == 0xc00)
+			sprintf(cpu_name, "Cortex-A%u", (pid & 0x00f));
+		else if (pid >= 0xa00)
+			sprintf(cpu_name, "ARM%x", 0x1000 + (pid - 0xa00));
+		else
+			sprintf(cpu_name, "ARM%x", pid);
+		break;
+	default:
+		sprintf(cpu_name, "Unknown");
+		break;
+	}
+
+	/* print cpu_info */
+	printf("CPU:   %s %u MHz\n",
+		cpu_name, (unsigned int)(clock_get_rate(CPU_CLK) / 1000000));
+
+	printf("AHB:   %u MHz\n",
+		(unsigned int)(clock_get_rate(AHB_CLK) / 1000000));
+
+	printf("APB:   %u MHz\n",
+		(unsigned int)(clock_get_rate(APB_CLK) / 1000000));
+
+	return 0;
+}
+#endif /* CONFIG_DISPLAY_CPUINFO */
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+
+#undef  CACHE_SETUP
+#if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
+#define CACHE_SETUP DCACHE_WRITETHROUGH
+#else
+#define CACHE_SETUP DCACHE_WRITEBACK
+#endif
+
+#ifdef CONFIG_USE_IRQ
+static u32 page_table[256] __aligned(1024);
+#endif
+
+/*
+ * This dram_bank_mmu_setup() overrides the weak function
+ * in "cache-cp15.c".
+ */
+void dram_bank_mmu_setup(int bank)
+{
+	u32 pa, *sect_table = (u32 *)gd->arch.tlb_addr;
+	bd_t *bd = gd->bd;
+	int	i;
+
+	for (i = bd->bi_dram[bank].start >> 20;
+	     i < (bd->bi_dram[bank].start + bd->bi_dram[bank].size) >> 20;
+	     i++) {
+		pa = i << 20;
+		sect_table[i] = pa | (3 << 10) | CACHE_SETUP;
+	}
+
+#ifdef CONFIG_USE_IRQ
+	/* only setup exception table when bank == 0 */
+	if (bank)
+		return;
+
+	/* make sure the exception table is mapped to 0x00000000 */
+	sect_table[0] = (u32)page_table | 0x11; /* coarse page */
+	page_table[0] = gd->relocaddr | 0xff2; /* small page (4KB) */
+
+	__asm__ __volatile__ (
+		"mov r0, #0\n"
+		"mcr p15, 0, r0, c8, c7, 0\n" /* invalidate TLB */
+		"mcr p15, 0, r0, c7, c5, 0\n" /* invalidate I Cache */
+		: /* output */
+		: /* input */
+		: "r0" /* clobber list */
+	);
+#endif /* CONFIG_USE_IRQ */
+}
+#endif /* !CONFIG_SYS_DCACHE_OFF */
+
+void reset_cpu(unsigned long ignored)
+{
+#ifdef CONFIG_FTWDT010_BASE
+	struct ftwdt010_wdt *regs = (void __iomem *)CONFIG_FTWDT010_BASE;
+
+	/* Disable WDT */
+	writel(0, &regs->wdcr);
+	/* Timeout in 1000 ticks */
+	writel(1000, &regs->wdload);
+	/* Enable WDT with System Reset Function */
+	writel(FTWDT010_WDCR_ENABLE | FTWDT010_WDCR_RST, &regs->wdcr);
+#endif
+}
diff --git a/arch/arm/cpu/faraday/start.S b/arch/arm/cpu/faraday/start.S
new file mode 100644
index 0000000..916b4a2
--- /dev/null
+++ b/arch/arm/cpu/faraday/start.S
@@ -0,0 +1,431 @@
+/*
+ * u-boot - Startup Code for Faraday CPU-core
+ *
+ * Base is arch/arm/cpu/arm926ejs/start.S
+ *
+ * (C) Copyright 2013 Faraday Technology
+ * Dante Su <dantesu@faraday-tech.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <common.h>
+#include <version.h>
+
+/*
+ *************************************************************************
+ *
+ * Jump vector table as in table 3.1 in [1]
+ *
+ *************************************************************************
+ */
+
+
+#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
+.globl _start
+_start:
+.globl _NOR_BOOT_CFG
+_NOR_BOOT_CFG:
+	.word	CONFIG_SYS_DV_NOR_BOOT_CFG
+	b	reset
+#else
+.globl _start
+_start:
+	b	reset
+#endif
+#ifdef CONFIG_SPL_BUILD
+/* No exception handlers in preloader */
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+
+_hang:
+	.word	do_hang
+/* pad to 64 byte boundary */
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+#else
+	ldr	pc, _undefined_instruction
+	ldr	pc, _software_interrupt
+	ldr	pc, _prefetch_abort
+	ldr	pc, _data_abort
+	ldr	pc, _not_used
+	ldr	pc, _irq
+	ldr	pc, _fiq
+
+_undefined_instruction:
+	.word undefined_instruction
+_software_interrupt:
+	.word software_interrupt
+_prefetch_abort:
+	.word prefetch_abort
+_data_abort:
+	.word data_abort
+_not_used:
+	.word not_used
+_irq:
+	.word irq
+_fiq:
+	.word fiq
+
+#endif	/* CONFIG_SPL_BUILD */
+	.balignl 16,0xdeadbeef
+
+
+/*
+ *************************************************************************
+ *
+ * Startup Code (reset vector)
+ *
+ * do important init only if we don't start from memory!
+ * setup Memory and board specific bits prior to relocation.
+ * relocate armboot to ram
+ * setup stack
+ *
+ *************************************************************************
+ */
+
+.globl _TEXT_BASE
+_TEXT_BASE:
+#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
+	.word	CONFIG_SPL_TEXT_BASE
+#else
+	.word	CONFIG_SYS_TEXT_BASE
+#endif
+
+/*
+ * These are defined in the board-specific linker script.
+ * Subtracting _start from them lets the linker put their
+ * relative position in the executable instead of leaving
+ * them null.
+ */
+.globl _bss_start_ofs
+_bss_start_ofs:
+	.word __bss_start - _start
+
+.globl _bss_end_ofs
+_bss_end_ofs:
+	.word __bss_end - _start
+
+.globl _end_ofs
+_end_ofs:
+	.word _end - _start
+
+#ifdef CONFIG_USE_IRQ
+/* IRQ stack memory (calculated at run-time) */
+.globl IRQ_STACK_START
+IRQ_STACK_START:
+	.word	0x0badc0de
+
+/* IRQ stack memory (calculated at run-time) */
+.globl FIQ_STACK_START
+FIQ_STACK_START:
+	.word 0x0badc0de
+#endif
+
+/* IRQ stack memory (calculated at run-time) + 8 bytes */
+.globl IRQ_STACK_START_IN
+IRQ_STACK_START_IN:
+	.word	0x0badc0de
+
+/*
+ * the actual reset code
+ */
+
+reset:
+	/*
+	 * set the cpu to SVC32 mode
+	 */
+	mrs	r0,cpsr
+	bic	r0,r0,#0x1f
+	orr	r0,r0,#0xd3
+	msr	cpsr,r0
+
+	/*
+	 * we do sys-critical inits only at reboot,
+	 * not when booting from ram!
+	 */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+	bl	cpu_init_crit
+#endif
+
+	/*
+	 * Relocate U-Boot to RAM
+	 * It's copied from the old u-boot release.
+	 */
+#ifndef CONFIG_SPL_BUILD
+	adr r0, _start      /* r0 <- current position of code   */
+	ldr r1, _TEXT_BASE  /* test if we run from flash or RAM */
+	teq r0, r1          /* don't reloc during debug         */
+	bleq rr_exit
+	ldr r2, _end_ofs    /* r2 <- size of u-boot             */
+	add r2, r0, r2      /* r2 <- source end address         */
+
+rr_loop:
+	ldmia r0!, {r3-r10} /* copy from source address [r0]    */
+	stmia r1!, {r3-r10} /* copy to   target address [r1]    */
+	cmp r0, r2          /* until source end addreee [r2]    */
+	blo rr_loop
+
+	/* Adjust the pc to use the correct text address */
+	adr r0, _start
+	ldr r1, _TEXT_BASE
+	sub r2, pc, r0
+	add r2, r2, #4
+	add pc, r1, r2
+
+rr_exit:
+#endif  /* !CONFIG_SPL_BUILD */
+
+	bl	_main
+
+/*---------------------------------------------------------------------------*/
+
+	.globl	c_runtime_cpu_setup
+c_runtime_cpu_setup:
+
+	bx	lr
+
+/*
+ *************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************
+ */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+cpu_init_crit:
+	/*
+	 * flush D cache before disabling it
+	 */
+	mov	r0, #0
+	mcr	p15, 0, r0, c7, c14, 0	/* clean & invalidate D cache */
+	mcr	p15, 0, r0, c8, c7, 0	/* invalidate TLB */
+	mcr	p15, 0, r0, c7, c5, 0	/* invalidate I Cache */
+	mcr	p15, 0, r0, c7, c10, 4	/* drain write buffer */
+
+	/*
+	 * disable MMU and D cache
+	 * enable I cache if CONFIG_SYS_ICACHE_OFF is not defined
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r0, r0, #0x00000300	/* clear bits 9:8 (---- --RS) */
+	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
+#ifdef CONFIG_SYS_EXCEPTION_VECTORS_HIGH
+	orr	r0, r0, #0x00002000	/* set bit 13 (--V- ----) */
+#else
+	bic	r0, r0, #0x00002000	/* clear bit 13 (--V- ----) */
+#endif
+	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
+#ifndef CONFIG_SYS_ICACHE_OFF
+	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
+#endif
+	mcr	p15, 0, r0, c1, c0, 0
+
+	/*
+	 * Go setup Memory and board specific bits prior to relocation.
+	 */
+	mov	ip, lr		/* perserve link reg across call */
+	bl	lowlevel_init	/* go setup pll,mux,memory */
+	mov	lr, ip		/* restore link */
+	mov	pc, lr		/* back to my caller */
+#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
+
+#ifndef CONFIG_SPL_BUILD
+/*
+ *************************************************************************
+ *
+ * Interrupt handling
+ *
+ *************************************************************************
+ */
+
+@
+@ IRQ stack frame.
+@
+#define S_FRAME_SIZE	72
+
+#define S_OLD_R0	68
+#define S_PSR		64
+#define S_PC		60
+#define S_LR		56
+#define S_SP		52
+
+#define S_IP		48
+#define S_FP		44
+#define S_R10		40
+#define S_R9		36
+#define S_R8		32
+#define S_R7		28
+#define S_R6		24
+#define S_R5		20
+#define S_R4		16
+#define S_R3		12
+#define S_R2		8
+#define S_R1		4
+#define S_R0		0
+
+#define MODE_SVC 0x13
+#define I_BIT	 0x80
+
+/*
+ * use bad_save_user_regs for abort/prefetch/undef/swi ...
+ * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
+ */
+
+	.macro	bad_save_user_regs
+	@ carve out a frame on current user stack
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
+	ldr	r2, IRQ_STACK_START_IN
+	@ get values for "aborted" pc and cpsr (into parm regs)
+	ldmia	r2, {r2 - r3}
+	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
+	add	r5, sp, #S_SP
+	mov	r1, lr
+	stmia	r5, {r0 - r3}	@ save sp_SVC, lr_SVC, pc, cpsr
+	mov	r0, sp		@ save current stack into r0 (param register)
+	.endm
+
+	.macro	irq_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}			@ Calling r0-r12
+	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
+	add	r8, sp, #S_PC
+	stmdb	r8, {sp, lr}^		@ Calling SP, LR
+	str	lr, [r8, #0]		@ Save calling PC
+	mrs	r6, spsr
+	str	r6, [r8, #4]		@ Save CPSR
+	str	r0, [r8, #8]		@ Save OLD_R0
+	mov	r0, sp
+	.endm
+
+	.macro	irq_restore_user_regs
+	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
+	mov	r0, r0
+	ldr	lr, [sp, #S_PC]			@ Get PC
+	add	sp, sp, #S_FRAME_SIZE
+	subs	pc, lr, #4		@ return & move spsr_svc into cpsr
+	.endm
+
+	.macro get_bad_stack
+	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
+
+	str	lr, [r13]	@ save caller lr in position 0 of saved stack
+	mrs	lr, spsr	@ get the spsr
+	str	lr, [r13, #4]	@ save spsr in position 1 of saved stack
+	mov	r13, #MODE_SVC	@ prepare SVC-Mode
+	@ msr	spsr_c, r13
+	msr	spsr, r13	@ switch modes, make sure moves will execute
+	mov	lr, pc		@ capture return pc
+	movs	pc, lr		@ jump to next instruction & switch modes.
+	.endm
+
+	.macro get_irq_stack			@ setup IRQ stack
+	ldr	sp, IRQ_STACK_START
+	.endm
+
+	.macro get_fiq_stack			@ setup FIQ stack
+	ldr	sp, FIQ_STACK_START
+	.endm
+#endif	/* CONFIG_SPL_BUILD */
+
+/*
+ * exception handlers
+ */
+#ifdef CONFIG_SPL_BUILD
+	.align	5
+do_hang:
+	ldr	sp, _TEXT_BASE			/* switch to abort stack */
+1:
+	bl	1b				/* hang and never return */
+#else	/* !CONFIG_SPL_BUILD */
+	.align  5
+undefined_instruction:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_undefined_instruction
+
+	.align	5
+software_interrupt:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_software_interrupt
+
+	.align	5
+prefetch_abort:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_prefetch_abort
+
+	.align	5
+data_abort:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_data_abort
+
+	.align	5
+not_used:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_not_used
+
+#ifdef CONFIG_USE_IRQ
+
+	.align	5
+irq:
+	get_irq_stack
+	irq_save_user_regs
+	bl	do_irq
+	irq_restore_user_regs
+
+	.align	5
+fiq:
+	get_fiq_stack
+	/* someone ought to write a more effiction fiq_save_user_regs */
+	irq_save_user_regs
+	bl	do_fiq
+	irq_restore_user_regs
+
+#else
+
+	.align	5
+irq:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_irq
+
+	.align	5
+fiq:
+	get_bad_stack
+	bad_save_user_regs
+	bl	do_fiq
+
+#endif
+#endif	/* CONFIG_SPL_BUILD */
--
1.7.9.5