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efi/loongarch: Add efistub booting support

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This patch adds efistub booting support, which is the standard UEFI boot
protocol for LoongArch to use.

We use generic efistub, which means we can pass boot information (i.e.,
system table, memory map, kernel command line, initrd) via a light FDT
and drop a lot of non-standard code.

We use a flat mapping to map the efi runtime in the kernel's address
space. In efi, VA = PA; in kernel, VA = PA + PAGE_OFFSET. As a result,
flat mapping is not identity mapping, SetVirtualAddressMap() is still
needed for the efi runtime.

Tested-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
[ardb: change fpic to fpie as suggested by Xi Ruoyao]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Huacai Chen 2022-08-19 18:20:37 +08:00 committed by Ard Biesheuvel
parent 568035b01c
commit ead384d956
15 changed files with 275 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/loongarch/Kconfig
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@ -317,6 +317,15 @@ config EFI
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
config EFI_STUB
bool "EFI boot stub support"
default y
depends on EFI
select EFI_GENERIC_STUB
help
This kernel feature allows the kernel to be loaded directly by
EFI firmware without the use of a bootloader.
config SMP
bool "Multi-Processing support"
help

13
arch/loongarch/Makefile
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@ -7,7 +7,11 @@ boot := arch/loongarch/boot
KBUILD_DEFCONFIG := loongson3_defconfig
KBUILD_IMAGE = $(boot)/vmlinux
ifndef CONFIG_EFI_STUB
KBUILD_IMAGE := $(boot)/vmlinux.elf
else
KBUILD_IMAGE := $(boot)/vmlinux.efi
endif
#
# Select the object file format to substitute into the linker script.
@ -75,6 +79,7 @@ endif
head-y := arch/loongarch/kernel/head.o
libs-y += arch/loongarch/lib/
libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
ifeq ($(KBUILD_EXTMOD),)
prepare: vdso_prepare
@ -86,10 +91,10 @@ PHONY += vdso_install
vdso_install:
$(Q)$(MAKE) $(build)=arch/loongarch/vdso $@
all: $(KBUILD_IMAGE)
all: $(notdir $(KBUILD_IMAGE))
$(KBUILD_IMAGE): vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(bootvars-y) $@
vmlinux.elf vmlinux.efi: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(bootvars-y) $(boot)/$@
install:
$(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/vmlinux-$(KERNELRELEASE)

8
arch/loongarch/boot/Makefile
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@ -8,9 +8,13 @@ drop-sections := .comment .note .options .note.gnu.build-id
strip-flags := $(addprefix --remove-section=,$(drop-sections)) -S
OBJCOPYFLAGS_vmlinux.efi := -O binary $(strip-flags)
targets := vmlinux
quiet_cmd_strip = STRIP $@
cmd_strip = $(STRIP) -s -o $@ $<
$(obj)/vmlinux: vmlinux FORCE
targets := vmlinux.elf
$(obj)/vmlinux.elf: vmlinux FORCE
$(call if_changed,strip)
targets += vmlinux.efi
$(obj)/vmlinux.efi: vmlinux FORCE
$(call if_changed,objcopy)

11
arch/loongarch/include/asm/efi.h
View File

@ -17,9 +17,16 @@ void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
#define arch_efi_call_virt_teardown()
#define EFI_ALLOC_ALIGN SZ_64K
#define EFI_RT_VIRTUAL_OFFSET CSR_DMW0_BASE
struct screen_info *alloc_screen_info(void);
void free_screen_info(struct screen_info *si);
static inline struct screen_info *alloc_screen_info(void)
{
return &screen_info;
}
static inline void free_screen_info(struct screen_info *si)
{
}
static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
{

99
arch/loongarch/kernel/efi-header.S Normal file
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@ -0,0 +1,99 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/pe.h>
#include <linux/sizes.h>
.macro __EFI_PE_HEADER
.long PE_MAGIC
.Lcoff_header:
.short IMAGE_FILE_MACHINE_LOONGARCH64 /* Machine */
.short .Lsection_count /* NumberOfSections */
.long 0 /* TimeDateStamp */
.long 0 /* PointerToSymbolTable */
.long 0 /* NumberOfSymbols */
.short .Lsection_table - .Loptional_header /* SizeOfOptionalHeader */
.short IMAGE_FILE_DEBUG_STRIPPED | \
IMAGE_FILE_EXECUTABLE_IMAGE | \
IMAGE_FILE_LINE_NUMS_STRIPPED /* Characteristics */
.Loptional_header:
.short PE_OPT_MAGIC_PE32PLUS /* PE32+ format */
.byte 0x02 /* MajorLinkerVersion */
.byte 0x14 /* MinorLinkerVersion */
.long __inittext_end - .Lefi_header_end /* SizeOfCode */
.long _end - __initdata_begin /* SizeOfInitializedData */
.long 0 /* SizeOfUninitializedData */
.long __efistub_efi_pe_entry - _head /* AddressOfEntryPoint */
.long .Lefi_header_end - _head /* BaseOfCode */
.Lextra_header_fields:
.quad 0 /* ImageBase */
.long PECOFF_SEGMENT_ALIGN /* SectionAlignment */
.long PECOFF_FILE_ALIGN /* FileAlignment */
.short 0 /* MajorOperatingSystemVersion */
.short 0 /* MinorOperatingSystemVersion */
.short LINUX_EFISTUB_MAJOR_VERSION /* MajorImageVersion */
.short LINUX_EFISTUB_MINOR_VERSION /* MinorImageVersion */
.short 0 /* MajorSubsystemVersion */
.short 0 /* MinorSubsystemVersion */
.long 0 /* Win32VersionValue */
.long _end - _head /* SizeOfImage */
/* Everything before the kernel image is considered part of the header */
.long .Lefi_header_end - _head /* SizeOfHeaders */
.long 0 /* CheckSum */
.short IMAGE_SUBSYSTEM_EFI_APPLICATION /* Subsystem */
.short 0 /* DllCharacteristics */
.quad 0 /* SizeOfStackReserve */
.quad 0 /* SizeOfStackCommit */
.quad 0 /* SizeOfHeapReserve */
.quad 0 /* SizeOfHeapCommit */
.long 0 /* LoaderFlags */
.long (.Lsection_table - .) / 8 /* NumberOfRvaAndSizes */
.quad 0 /* ExportTable */
.quad 0 /* ImportTable */
.quad 0 /* ResourceTable */
.quad 0 /* ExceptionTable */
.quad 0 /* CertificationTable */
.quad 0 /* BaseRelocationTable */
/* Section table */
.Lsection_table:
.ascii ".text\0\0\0"
.long __inittext_end - .Lefi_header_end /* VirtualSize */
.long .Lefi_header_end - _head /* VirtualAddress */
.long __inittext_end - .Lefi_header_end /* SizeOfRawData */
.long .Lefi_header_end - _head /* PointerToRawData */
.long 0 /* PointerToRelocations */
.long 0 /* PointerToLineNumbers */
.short 0 /* NumberOfRelocations */
.short 0 /* NumberOfLineNumbers */
.long IMAGE_SCN_CNT_CODE | \
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_EXECUTE /* Characteristics */
.ascii ".data\0\0\0"
.long _end - __initdata_begin /* VirtualSize */
.long __initdata_begin - _head /* VirtualAddress */
.long _edata - __initdata_begin /* SizeOfRawData */
.long __initdata_begin - _head /* PointerToRawData */
.long 0 /* PointerToRelocations */
.long 0 /* PointerToLineNumbers */
.short 0 /* NumberOfRelocations */
.short 0 /* NumberOfLineNumbers */
.long IMAGE_SCN_CNT_INITIALIZED_DATA | \
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_WRITE /* Characteristics */
.set .Lsection_count, (. - .Lsection_table) / 40
.balign 0x10000 /* PECOFF_SEGMENT_ALIGN */
.Lefi_header_end:
.endm

3
arch/loongarch/kernel/efi.c
View File

@ -69,4 +69,7 @@ void __init efi_init(void)
config_tables = early_memremap(efi_config_table, efi_nr_tables * size);
efi_config_parse_tables(config_tables, efi_systab->nr_tables, arch_tables);
early_memunmap(config_tables, efi_nr_tables * size);
if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI)
memblock_reserve(screen_info.lfb_base, screen_info.lfb_size);
}

20
arch/loongarch/kernel/head.S
View File

@ -12,6 +12,26 @@
#include <asm/loongarch.h>
#include <asm/stackframe.h>
#ifdef CONFIG_EFI_STUB
#include "efi-header.S"
__HEAD
_head:
.word MZ_MAGIC /* "MZ", MS-DOS header */
.org 0x3c /* 0x04 ~ 0x3b reserved */
.long pe_header - _head /* Offset to the PE header */
pe_header:
__EFI_PE_HEADER
SYM_DATA(kernel_asize, .long _end - _text);
SYM_DATA(kernel_fsize, .long _edata - _text);
SYM_DATA(kernel_offset, .long kernel_offset - _text);
#endif
__REF
SYM_CODE_START(kernel_entry) # kernel entry point

30
arch/loongarch/kernel/image-vars.h Normal file
View File

@ -0,0 +1,30 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#ifndef __LOONGARCH_KERNEL_IMAGE_VARS_H
#define __LOONGARCH_KERNEL_IMAGE_VARS_H
#ifdef CONFIG_EFI_STUB
__efistub_memcmp = memcmp;
__efistub_memchr = memchr;
__efistub_memcpy = memcpy;
__efistub_memmove = memmove;
__efistub_memset = memset;
__efistub_strcat = strcat;
__efistub_strcmp = strcmp;
__efistub_strlen = strlen;
__efistub_strncat = strncat;
__efistub_strnstr = strnstr;
__efistub_strnlen = strnlen;
__efistub_strrchr = strrchr;
__efistub_kernel_entry = kernel_entry;
__efistub_kernel_asize = kernel_asize;
__efistub_kernel_fsize = kernel_fsize;
__efistub_kernel_offset = kernel_offset;
__efistub_screen_info = screen_info;
#endif
#endif /* __LOONGARCH_KERNEL_IMAGE_VARS_H */

11
arch/loongarch/kernel/setup.c
View File

@ -49,9 +49,7 @@
#define SMBIOS_CORE_PACKAGE_OFFSET 0x23
#define LOONGSON_EFI_ENABLE (1 << 3)
#ifdef CONFIG_VT
struct screen_info screen_info;
#endif
struct screen_info screen_info __section(".data");
unsigned long fw_arg0, fw_arg1;
DEFINE_PER_CPU(unsigned long, kernelsp);
@ -122,16 +120,9 @@ static void __init parse_cpu_table(const struct dmi_header *dm)
static void __init parse_bios_table(const struct dmi_header *dm)
{
int bios_extern;
char *dmi_data = (char *)dm;
bios_extern = *(dmi_data + SMBIOS_BIOSEXTERN_OFFSET);
b_info.bios_size = (*(dmi_data + SMBIOS_BIOSSIZE_OFFSET) + 1) << 6;
if (bios_extern & LOONGSON_EFI_ENABLE)
set_bit(EFI_BOOT, &efi.flags);
else
clear_bit(EFI_BOOT, &efi.flags);
}
static void __init find_tokens(const struct dmi_header *dm, void *dummy)

1
arch/loongarch/kernel/vmlinux.lds.S
View File

@ -12,6 +12,7 @@
#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir)
#include <asm-generic/vmlinux.lds.h>
#include "image-vars.h"
/*
* Max avaliable Page Size is 64K, so we set SectionAlignment

4
drivers/firmware/efi/Kconfig
View File

@ -107,7 +107,7 @@ config EFI_GENERIC_STUB
config EFI_ARMSTUB_DTB_LOADER
bool "Enable the DTB loader"
depends on EFI_GENERIC_STUB && !RISCV
depends on EFI_GENERIC_STUB && !RISCV && !LOONGARCH
default y
help
Select this config option to add support for the dtb= command
@ -124,7 +124,7 @@ config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER
bool "Enable the command line initrd loader" if !X86
depends on EFI_STUB && (EFI_GENERIC_STUB || X86)
default y if X86
depends on !RISCV
depends on !RISCV && !LOONGARCH
help
Select this config option to add support for the initrd= command
line parameter, allowing an initrd that resides on the same volume

10
drivers/firmware/efi/libstub/Makefile
View File

@ -26,6 +26,8 @@ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
$(call cc-option,-mno-single-pic-base)
cflags-$(CONFIG_RISCV) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
-fpic
cflags-$(CONFIG_LOONGARCH) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
-fpie
cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt
@ -70,6 +72,8 @@ lib-$(CONFIG_ARM) += arm32-stub.o
lib-$(CONFIG_ARM64) += arm64-stub.o
lib-$(CONFIG_X86) += x86-stub.o
lib-$(CONFIG_RISCV) += riscv-stub.o
lib-$(CONFIG_LOONGARCH) += loongarch-stub.o
CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
# Even when -mbranch-protection=none is set, Clang will generate a
@ -125,6 +129,12 @@ STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \
--prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_RISCV) := R_RISCV_HI20
# For LoongArch, keep all the symbols in .init section and make sure that no
# absolute symbols references exist.
STUBCOPY_FLAGS-$(CONFIG_LOONGARCH) += --prefix-alloc-sections=.init \
--prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_LOONGARCH) := R_LARCH_MARK_LA
$(obj)/%.stub.o: $(obj)/%.o FORCE
$(call if_changed,stubcopy)

20
drivers/firmware/efi/libstub/efi-stub.c
View File

@ -40,14 +40,22 @@
#ifdef CONFIG_ARM64
# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
#elif defined(CONFIG_RISCV)
#elif defined(CONFIG_RISCV) || defined(CONFIG_LOONGARCH)
# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_MIN
#else
#else /* Only if TASK_SIZE is a constant */
# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
#endif
/*
* Some architectures map the EFI regions into the kernel's linear map using a
* fixed offset.
*/
#ifndef EFI_RT_VIRTUAL_OFFSET
#define EFI_RT_VIRTUAL_OFFSET 0
#endif
static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
static bool flat_va_mapping;
static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
const efi_system_table_t *efi_system_table;
@ -254,8 +262,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
* The easiest way to achieve that is to simply use a 1:1 mapping.
*/
prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
flat_va_mapping = prop_tbl &&
(prop_tbl->memory_protection_attribute &
flat_va_mapping |= prop_tbl &&
(prop_tbl->memory_protection_attribute &
EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
/* force efi_novamap if SetVirtualAddressMap() is unsupported */
@ -338,7 +346,7 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
paddr = in->phys_addr;
size = in->num_pages * EFI_PAGE_SIZE;
in->virt_addr = in->phys_addr;
in->virt_addr = in->phys_addr + EFI_RT_VIRTUAL_OFFSET;
if (efi_novamap) {
continue;
}

60
drivers/firmware/efi/libstub/loongarch-stub.c Normal file
View File

@ -0,0 +1,60 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Author: Yun Liu <liuyun@loongson.cn>
* Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/efi.h>
#include <asm/addrspace.h>
#include "efistub.h"
typedef void __noreturn (*kernel_entry_t)(bool efi, unsigned long fdt);
extern int kernel_asize;
extern int kernel_fsize;
extern int kernel_offset;
extern kernel_entry_t kernel_entry;
efi_status_t check_platform_features(void)
{
return EFI_SUCCESS;
}
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
efi_loaded_image_t *image,
efi_handle_t image_handle)
{
efi_status_t status;
unsigned long kernel_addr = 0;
kernel_addr = (unsigned long)&kernel_offset - kernel_offset;
status = efi_relocate_kernel(&kernel_addr, kernel_fsize, kernel_asize,
PHYSADDR(VMLINUX_LOAD_ADDRESS), SZ_2M, 0x0);
*image_addr = kernel_addr;
*image_size = kernel_asize;
return status;
}
void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, unsigned long fdt_size)
{
kernel_entry_t real_kernel_entry;
/* Config Direct Mapping */
csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0);
csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1);
real_kernel_entry = (kernel_entry_t)
((unsigned long)&kernel_entry - entrypoint + VMLINUX_LOAD_ADDRESS);
if (!efi_novamap)
real_kernel_entry(true, fdt);
else
real_kernel_entry(false, fdt);
}

2
include/linux/pe.h
View File

@ -65,6 +65,8 @@
#define IMAGE_FILE_MACHINE_SH5 0x01a8
#define IMAGE_FILE_MACHINE_THUMB 0x01c2
#define IMAGE_FILE_MACHINE_WCEMIPSV2 0x0169
#define IMAGE_FILE_MACHINE_LOONGARCH32 0x6232
#define IMAGE_FILE_MACHINE_LOONGARCH64 0x6264
/* flags */
#define IMAGE_FILE_RELOCS_STRIPPED 0x0001