From: Ard Biesheuvel <ardb@kernel.org> To: linux-efi@vger.kernel.org Cc: Ard Biesheuvel <ardb@kernel.org>, Atish Patra <atish.patra@wdc.com>, Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, Albert Ou <aou@eecs.berkeley.edu>, linux-riscv@lists.infradead.org Subject: [PATCH v5 7/7] RISC-V: Add EFI stub support. Date: Wed, 22 Apr 2020 19:24:14 +0200 [thread overview] Message-ID: <20200422172414.6662-8-ardb@kernel.org> (raw) In-Reply-To: <20200422172414.6662-1-ardb@kernel.org> From: Atish Patra <atish.patra@wdc.com> Add a RISC-V architecture specific stub code that actually copies the actual kernel image to a valid address and jump to it after boot services are terminated. Enable UEFI related kernel configs as well for RISC-V. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com [ardb: - move hartid fetch into check_platform_features() - use image_size not reserve_size - moved asm/efi.h addition into separate patch ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/riscv/Kconfig | 20 ++++ arch/riscv/Makefile | 1 + arch/riscv/configs/defconfig | 1 + drivers/firmware/efi/Kconfig | 4 +- drivers/firmware/efi/libstub/Makefile | 10 ++ drivers/firmware/efi/libstub/riscv-stub.c | 109 ++++++++++++++++++++ 6 files changed, 143 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index f05dd09acd48..54c78cafcd35 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -379,10 +379,30 @@ config CMDLINE_FORCE endchoice +config EFI_STUB + bool + +config EFI + bool "UEFI runtime support" + depends on OF + select LIBFDT + select UCS2_STRING + select EFI_PARAMS_FROM_FDT + select EFI_STUB + select EFI_GENERIC_STUB + default y + help + This option provides support for runtime services provided + by UEFI firmware (such as non-volatile variables, realtime + clock, and platform reset). A UEFI stub is also provided to + allow the kernel to be booted as an EFI application. This + is only useful on systems that have UEFI firmware. + endmenu menu "Power management options" source "kernel/power/Kconfig" +source "drivers/firmware/Kconfig" endmenu diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index fb6e37db836d..079435804d6d 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -80,6 +80,7 @@ head-y := arch/riscv/kernel/head.o core-y += arch/riscv/ libs-y += arch/riscv/lib/ +core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a PHONY += vdso_install vdso_install: diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig index 4da4886246a4..ae69e12d306a 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -129,3 +129,4 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y # CONFIG_RUNTIME_TESTING_MENU is not set CONFIG_MEMTEST=y # CONFIG_SYSFS_SYSCALL is not set +CONFIG_EFI=y diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 4e788dd55b03..8bfc17381b29 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -111,7 +111,7 @@ config EFI_GENERIC_STUB config EFI_ARMSTUB_DTB_LOADER bool "Enable the DTB loader" - depends on EFI_GENERIC_STUB + depends on EFI_GENERIC_STUB && !RISCV default y help Select this config option to add support for the dtb= command @@ -126,7 +126,7 @@ config EFI_ARMSTUB_DTB_LOADER config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER bool "Enable the command line initrd loader" - depends on EFI_GENERIC_STUB + depends on EFI_GENERIC_STUB && !RISCV default y help Select this config option to add support for the initrd= command diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75cb2c3a1519..a4fd1b048e8c 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -22,6 +22,8 @@ cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) +cflags-$(CONFIG_RISCV) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ + -fpic cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt @@ -56,6 +58,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o fdt.o string.o \ lib-$(CONFIG_ARM) += arm32-stub.o lib-$(CONFIG_ARM64) += arm64-stub.o lib-$(CONFIG_X86) += x86-stub.o +lib-$(CONFIG_RISCV) += riscv-stub.o CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) @@ -80,6 +83,13 @@ STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS +# For RISC-V, we don't need anything special other than arm64. Keep all the +# symbols in .init section and make sure that no absolute symbols references +# doesn't exist. +STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \ + --prefix-symbols=__efistub_ +STUBCOPY_RELOC-$(CONFIG_RISCV) := R_RISCV_HI20 + $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,stubcopy) diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c new file mode 100644 index 000000000000..349646928e9b --- /dev/null +++ b/drivers/firmware/efi/libstub/riscv-stub.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + */ + +#include <linux/efi.h> +#include <linux/libfdt.h> + +#include <asm/efi.h> +#include <asm/sections.h> + +#include "efistub.h" + +/* + * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and + * 4MB for 32 bit. + */ +#ifdef CONFIG_64BIT +#define MIN_KIMG_ALIGN SZ_2M +#else +#define MIN_KIMG_ALIGN SZ_4M +#endif + +typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long); + +static u32 hartid; + +static u32 get_boot_hartid_from_fdt(void) +{ + const void *fdt; + int chosen_node, len; + const fdt32_t *prop; + + fdt = get_efi_config_table(DEVICE_TREE_GUID); + if (!fdt) + return U32_MAX; + + chosen_node = fdt_path_offset(fdt, "/chosen"); + if (chosen_node < 0) + return U32_MAX; + + prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len); + if (!prop || len != sizeof(u32)) + return U32_MAX; + + return fdt32_to_cpu(*prop); +} + +efi_status_t check_platform_features(void) +{ + hartid = get_boot_hartid_from_fdt(); + if (hartid == U32_MAX) { + pr_efi_err("/chosen/boot-hartid missing or invalid!\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + +void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, + unsigned long fdt_size) +{ + unsigned long kernel_entry = entrypoint + (unsigned long)stext_offset; + jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry; + + /* + * Jump to real kernel here with following constraints. + * 1. MMU should be disabled. + * 2. a0 should contain hartid + * 3. a1 should DT address + */ + csr_write(CSR_SATP, 0); + jump_kernel(hartid, fdt); +} + +efi_status_t handle_kernel_image(unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long dram_base, + efi_loaded_image_t *image) +{ + unsigned long kernel_size = 0; + unsigned long preferred_addr; + efi_status_t status; + + kernel_size = _edata - _start; + *image_addr = (unsigned long)_start; + *image_size = kernel_size + (_end - _edata); + + /* + * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical + * address where kernel is booted. That's why kernel should boot from + * as low as possible to avoid wastage of memory. Currently, dram_base + * is occupied by the firmware. So the preferred address for kernel to + * boot is next aligned address. If preferred address is not available, + * relocate_kernel will fall back to efi_low_alloc_above to allocate + * lowest possible memory region as long as the address and size meets + * the alignment constraints. + */ + preferred_addr = round_up(dram_base, MIN_KIMG_ALIGN) + MIN_KIMG_ALIGN; + status = efi_relocate_kernel(image_addr, kernel_size, *image_size, + preferred_addr, MIN_KIMG_ALIGN, dram_base); + + if (status != EFI_SUCCESS) { + pr_efi_err("Failed to relocate kernel\n"); + *image_size = 0; + } + return status; +} -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org> To: linux-efi@vger.kernel.org Cc: Albert Ou <aou@eecs.berkeley.edu>, Atish Patra <atish.patra@wdc.com>, Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, linux-riscv@lists.infradead.org, Ard Biesheuvel <ardb@kernel.org> Subject: [PATCH v5 7/7] RISC-V: Add EFI stub support. Date: Wed, 22 Apr 2020 19:24:14 +0200 [thread overview] Message-ID: <20200422172414.6662-8-ardb@kernel.org> (raw) In-Reply-To: <20200422172414.6662-1-ardb@kernel.org> From: Atish Patra <atish.patra@wdc.com> Add a RISC-V architecture specific stub code that actually copies the actual kernel image to a valid address and jump to it after boot services are terminated. Enable UEFI related kernel configs as well for RISC-V. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com [ardb: - move hartid fetch into check_platform_features() - use image_size not reserve_size - moved asm/efi.h addition into separate patch ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/riscv/Kconfig | 20 ++++ arch/riscv/Makefile | 1 + arch/riscv/configs/defconfig | 1 + drivers/firmware/efi/Kconfig | 4 +- drivers/firmware/efi/libstub/Makefile | 10 ++ drivers/firmware/efi/libstub/riscv-stub.c | 109 ++++++++++++++++++++ 6 files changed, 143 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index f05dd09acd48..54c78cafcd35 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -379,10 +379,30 @@ config CMDLINE_FORCE endchoice +config EFI_STUB + bool + +config EFI + bool "UEFI runtime support" + depends on OF + select LIBFDT + select UCS2_STRING + select EFI_PARAMS_FROM_FDT + select EFI_STUB + select EFI_GENERIC_STUB + default y + help + This option provides support for runtime services provided + by UEFI firmware (such as non-volatile variables, realtime + clock, and platform reset). A UEFI stub is also provided to + allow the kernel to be booted as an EFI application. This + is only useful on systems that have UEFI firmware. + endmenu menu "Power management options" source "kernel/power/Kconfig" +source "drivers/firmware/Kconfig" endmenu diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index fb6e37db836d..079435804d6d 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -80,6 +80,7 @@ head-y := arch/riscv/kernel/head.o core-y += arch/riscv/ libs-y += arch/riscv/lib/ +core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a PHONY += vdso_install vdso_install: diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig index 4da4886246a4..ae69e12d306a 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -129,3 +129,4 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y # CONFIG_RUNTIME_TESTING_MENU is not set CONFIG_MEMTEST=y # CONFIG_SYSFS_SYSCALL is not set +CONFIG_EFI=y diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 4e788dd55b03..8bfc17381b29 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -111,7 +111,7 @@ config EFI_GENERIC_STUB config EFI_ARMSTUB_DTB_LOADER bool "Enable the DTB loader" - depends on EFI_GENERIC_STUB + depends on EFI_GENERIC_STUB && !RISCV default y help Select this config option to add support for the dtb= command @@ -126,7 +126,7 @@ config EFI_ARMSTUB_DTB_LOADER config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER bool "Enable the command line initrd loader" - depends on EFI_GENERIC_STUB + depends on EFI_GENERIC_STUB && !RISCV default y help Select this config option to add support for the initrd= command diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75cb2c3a1519..a4fd1b048e8c 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -22,6 +22,8 @@ cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) +cflags-$(CONFIG_RISCV) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ + -fpic cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt @@ -56,6 +58,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o fdt.o string.o \ lib-$(CONFIG_ARM) += arm32-stub.o lib-$(CONFIG_ARM64) += arm64-stub.o lib-$(CONFIG_X86) += x86-stub.o +lib-$(CONFIG_RISCV) += riscv-stub.o CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) @@ -80,6 +83,13 @@ STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS +# For RISC-V, we don't need anything special other than arm64. Keep all the +# symbols in .init section and make sure that no absolute symbols references +# doesn't exist. +STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \ + --prefix-symbols=__efistub_ +STUBCOPY_RELOC-$(CONFIG_RISCV) := R_RISCV_HI20 + $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,stubcopy) diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c new file mode 100644 index 000000000000..349646928e9b --- /dev/null +++ b/drivers/firmware/efi/libstub/riscv-stub.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + */ + +#include <linux/efi.h> +#include <linux/libfdt.h> + +#include <asm/efi.h> +#include <asm/sections.h> + +#include "efistub.h" + +/* + * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and + * 4MB for 32 bit. + */ +#ifdef CONFIG_64BIT +#define MIN_KIMG_ALIGN SZ_2M +#else +#define MIN_KIMG_ALIGN SZ_4M +#endif + +typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long); + +static u32 hartid; + +static u32 get_boot_hartid_from_fdt(void) +{ + const void *fdt; + int chosen_node, len; + const fdt32_t *prop; + + fdt = get_efi_config_table(DEVICE_TREE_GUID); + if (!fdt) + return U32_MAX; + + chosen_node = fdt_path_offset(fdt, "/chosen"); + if (chosen_node < 0) + return U32_MAX; + + prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len); + if (!prop || len != sizeof(u32)) + return U32_MAX; + + return fdt32_to_cpu(*prop); +} + +efi_status_t check_platform_features(void) +{ + hartid = get_boot_hartid_from_fdt(); + if (hartid == U32_MAX) { + pr_efi_err("/chosen/boot-hartid missing or invalid!\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + +void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, + unsigned long fdt_size) +{ + unsigned long kernel_entry = entrypoint + (unsigned long)stext_offset; + jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry; + + /* + * Jump to real kernel here with following constraints. + * 1. MMU should be disabled. + * 2. a0 should contain hartid + * 3. a1 should DT address + */ + csr_write(CSR_SATP, 0); + jump_kernel(hartid, fdt); +} + +efi_status_t handle_kernel_image(unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long dram_base, + efi_loaded_image_t *image) +{ + unsigned long kernel_size = 0; + unsigned long preferred_addr; + efi_status_t status; + + kernel_size = _edata - _start; + *image_addr = (unsigned long)_start; + *image_size = kernel_size + (_end - _edata); + + /* + * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical + * address where kernel is booted. That's why kernel should boot from + * as low as possible to avoid wastage of memory. Currently, dram_base + * is occupied by the firmware. So the preferred address for kernel to + * boot is next aligned address. If preferred address is not available, + * relocate_kernel will fall back to efi_low_alloc_above to allocate + * lowest possible memory region as long as the address and size meets + * the alignment constraints. + */ + preferred_addr = round_up(dram_base, MIN_KIMG_ALIGN) + MIN_KIMG_ALIGN; + status = efi_relocate_kernel(image_addr, kernel_size, *image_size, + preferred_addr, MIN_KIMG_ALIGN, dram_base); + + if (status != EFI_SUCCESS) { + pr_efi_err("Failed to relocate kernel\n"); + *image_size = 0; + } + return status; +} -- 2.17.1
next prev parent reply other threads:[~2020-04-22 17:24 UTC|newest] Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-22 17:24 [PATCH v5 0/7] Add UEFI support for RISC-V Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` [PATCH v5 1/7] efi/libstub: Move arm-stub to a common file Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` [PATCH v5 2/7] efi/libstub: Make initrd file loader configurable Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-06-16 7:55 ` Geert Uytterhoeven 2020-06-16 7:55 ` Geert Uytterhoeven 2020-06-16 8:16 ` Ard Biesheuvel 2020-06-16 8:16 ` Ard Biesheuvel 2020-06-23 15:10 ` Geert Uytterhoeven 2020-06-23 15:10 ` Geert Uytterhoeven 2020-04-22 17:24 ` [PATCH v5 3/7] efi/libstub/riscv: add arch specific efi.h header file Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` [PATCH v5 4/7] include: pe.h: Add RISC-V related PE definition Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` [PATCH v5 5/7] RISC-V: Define fixmap bindings for generic early ioremap support Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` [PATCH v5 6/7] RISC-V: Add PE/COFF header for EFI stub Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel 2020-04-22 17:24 ` Ard Biesheuvel [this message] 2020-04-22 17:24 ` [PATCH v5 7/7] RISC-V: Add EFI stub support Ard Biesheuvel 2020-04-22 18:48 ` Atish Patra 2020-04-22 18:48 ` Atish Patra 2020-04-23 11:15 ` Ard Biesheuvel 2020-04-23 11:15 ` Ard Biesheuvel 2020-04-23 11:49 ` Ard Biesheuvel 2020-04-23 11:49 ` Ard Biesheuvel 2020-04-22 17:25 ` [PATCH v5 0/7] Add UEFI support for RISC-V Ard Biesheuvel 2020-04-22 17:25 ` Ard Biesheuvel 2020-04-22 18:50 ` Atish Patra 2020-04-22 18:50 ` Atish Patra 2020-04-23 22:43 ` Palmer Dabbelt 2020-04-23 22:43 ` Palmer Dabbelt 2020-04-24 11:08 ` Ard Biesheuvel 2020-04-24 11:08 ` Ard Biesheuvel
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