efi/loongarch: Add efistub booting support
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>
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 4abc9a2..fca106a 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -317,6 +317,15 @@
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
diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index ec3de61..4bc47f4 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -7,7 +7,11 @@
KBUILD_DEFCONFIG := loongson3_defconfig
-KBUILD_IMAGE = $(boot)/vmlinux
+ifndef CONFIG_EFI_STUB
+KBUILD_IMAGE := $(boot)/vmlinux.elf
+else
+KBUILD_IMAGE := $(boot)/vmlinux.efi
+endif
#
# Select the object file format to substitute into the linker script.
@@ -75,6 +79,7 @@
head-y := arch/loongarch/kernel/head.o
libs-y += arch/loongarch/lib/
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
ifeq ($(KBUILD_EXTMOD),)
prepare: vdso_prepare
@@ -86,10 +91,10 @@
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)
diff --git a/arch/loongarch/boot/Makefile b/arch/loongarch/boot/Makefile
index 0125b17..fecf34f 100644
--- a/arch/loongarch/boot/Makefile
+++ b/arch/loongarch/boot/Makefile
@@ -8,9 +8,13 @@
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)
diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/include/asm/efi.h
index 9d44c69..174567b 100644
--- a/arch/loongarch/include/asm/efi.h
+++ b/arch/loongarch/include/asm/efi.h
@@ -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)
{
diff --git a/arch/loongarch/kernel/efi-header.S b/arch/loongarch/kernel/efi-header.S
new file mode 100644
index 0000000..8c1d229
--- /dev/null
+++ b/arch/loongarch/kernel/efi-header.S
@@ -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
diff --git a/arch/loongarch/kernel/efi.c b/arch/loongarch/kernel/efi.c
index a50b60c..1f1f755 100644
--- a/arch/loongarch/kernel/efi.c
+++ b/arch/loongarch/kernel/efi.c
@@ -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);
}
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index c60eb66..01bac62 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -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
diff --git a/arch/loongarch/kernel/image-vars.h b/arch/loongarch/kernel/image-vars.h
new file mode 100644
index 0000000..c901ebb
--- /dev/null
+++ b/arch/loongarch/kernel/image-vars.h
@@ -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 */
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 8f5c2f9..e8714b1 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -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)
diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S
index 69c76f2..36d0427 100644
--- a/arch/loongarch/kernel/vmlinux.lds.S
+++ b/arch/loongarch/kernel/vmlinux.lds.S
@@ -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
