Re: [PATCH V9 21/24] LoongArch: Add zboot (compressed kernel) support

From: Huacai Chen
Date: Sun May 01 2022 - 01:22:45 EST

Hi, Arnd,

On Sat, Apr 30, 2022 at 7:02 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Sat, Apr 30, 2022 at 11:05 AM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
> >
> > This patch adds zboot (self-extracting compressed kernel) support, all
> > existing in-kernel compressing algorithm and efistub are supported.
> >
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
>
> I have no objections to adding a decompressor in principle, and
> the implementation seems reasonable. However, I think we should try to
> be consistent between architectures. On both arm64 and riscv, the
> maintainers decided to not include a decompressor and instead leave
> it up to the boot loader to decompress the kernel and enter it from there.
X86, ARM32 and MIPS already support self-extracting kernel, and in
5.17 we even support self-extracting modules. So I think a
self-extracting kernel is better than a pure compressed kernel.

>
> As I understand it, this is not part of the UEFI boot flow though, so it
> means that you don't get any compressed kernel images at all when
> booting using UEFI (let me know if that is wrong). I assume this is why
> you decided to include the decompressor here after all.
>
> I think we should first aim for consistency here, and handle this the
> same way across the modern architectures, either leaving the
> decompressor code out, or adding it consistently. Maybe it would
> even be possible to have the decompressor code as part of the
> EFI stub and share it between the three architectures (x86 and
> 32-bit arm already support loading compressed kernels using EFI).
>
> Adding the arm64, risc-v and uefi maintainers for further discussion here,
> see full below.
Keeping consistency across architectures (support self-extracting for
all modern architectures) looks good to me, but can we do that after
this series? I think that needs a long time to discuss and develop.

Huacai
>
> Arnd
>
> > ---
> > arch/loongarch/Kbuild | 2 +-
> > arch/loongarch/Kconfig | 11 ++
> > arch/loongarch/Makefile | 26 ++-
> > arch/loongarch/boot/Makefile | 55 ++++++
> > arch/loongarch/boot/boot.lds.S | 64 +++++++
> > arch/loongarch/boot/decompress.c | 98 +++++++++++
> > arch/loongarch/boot/string.c | 166 ++++++++++++++++++
> > arch/loongarch/boot/zheader.S | 100 +++++++++++
> > arch/loongarch/boot/zkernel.S | 99 +++++++++++
> > arch/loongarch/tools/Makefile | 15 ++
> > arch/loongarch/tools/calc_vmlinuz_load_addr.c | 51 ++++++
> > arch/loongarch/tools/elf-entry.c | 66 +++++++
> > 12 files changed, 749 insertions(+), 4 deletions(-)
> > create mode 100644 arch/loongarch/boot/boot.lds.S
> > create mode 100644 arch/loongarch/boot/decompress.c
> > create mode 100644 arch/loongarch/boot/string.c
> > create mode 100644 arch/loongarch/boot/zheader.S
> > create mode 100644 arch/loongarch/boot/zkernel.S
> > create mode 100644 arch/loongarch/tools/Makefile
> > create mode 100644 arch/loongarch/tools/calc_vmlinuz_load_addr.c
> > create mode 100644 arch/loongarch/tools/elf-entry.c
> >
> > diff --git a/arch/loongarch/Kbuild b/arch/loongarch/Kbuild
> > index ab5373d0a24f..d907fdd7ca08 100644
> > --- a/arch/loongarch/Kbuild
> > +++ b/arch/loongarch/Kbuild
> > @@ -3,4 +3,4 @@ obj-y += mm/
> > obj-y += vdso/
> >
> > # for cleaning
> > -subdir- += boot
> > +subdir- += boot tools
> > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> > index 55225ee5f868..6c1042746b2d 100644
> > --- a/arch/loongarch/Kconfig
> > +++ b/arch/loongarch/Kconfig
> > @@ -107,6 +107,7 @@ config LOONGARCH
> > select PERF_USE_VMALLOC
> > select RTC_LIB
> > select SPARSE_IRQ
> > + select SYS_SUPPORTS_ZBOOT
> > select SYSCTL_EXCEPTION_TRACE
> > select SWIOTLB
> > select TRACE_IRQFLAGS_SUPPORT
> > @@ -143,6 +144,16 @@ config LOCKDEP_SUPPORT
> > bool
> > default y
> >
> > +config SYS_SUPPORTS_ZBOOT
> > + bool
> > + select HAVE_KERNEL_GZIP
> > + select HAVE_KERNEL_BZIP2
> > + select HAVE_KERNEL_LZ4
> > + select HAVE_KERNEL_LZMA
> > + select HAVE_KERNEL_LZO
> > + select HAVE_KERNEL_XZ
> > + select HAVE_KERNEL_ZSTD
> > +
> > config MACH_LOONGSON32
> > def_bool 32BIT
> >
> > diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
> > index d88a792dafbe..1ed5b8466565 100644
> > --- a/arch/loongarch/Makefile
> > +++ b/arch/loongarch/Makefile
> > @@ -5,12 +5,31 @@
> >
> > boot := arch/loongarch/boot
> >
> > +ifndef CONFIG_SYS_SUPPORTS_ZBOOT
> > +
> > ifndef CONFIG_EFI_STUB
> > KBUILD_IMAGE = $(boot)/vmlinux
> > else
> > KBUILD_IMAGE = $(boot)/vmlinux.efi
> > endif
> >
> > +else
> > +
> > +ifndef CONFIG_EFI_STUB
> > +KBUILD_IMAGE = $(boot)/vmlinuz
> > +else
> > +KBUILD_IMAGE = $(boot)/vmlinuz.efi
> > +endif
> > +
> > +endif
> > +
> > +load-y = 0x9000000000200000
> > +bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y)
> > +
> > +archscripts: scripts_basic
> > + $(Q)$(MAKE) $(build)=arch/loongarch/tools elf-entry
> > + $(Q)$(MAKE) $(build)=arch/loongarch/tools calc_vmlinuz_load_addr
> > +
> > #
> > # Select the object file format to substitute into the linker script.
> > #
> > @@ -55,9 +74,6 @@ KBUILD_CFLAGS_MODULE += -fplt -Wa,-mla-global-with-abs,-mla-local-with-abs
> > cflags-y += -ffreestanding
> > cflags-y += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
> >
> > -load-y = 0x9000000000200000
> > -bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y)
> > -
> > drivers-$(CONFIG_PCI) += arch/loongarch/pci/
> >
> > KBUILD_AFLAGS += $(cflags-y)
> > @@ -99,7 +115,11 @@ $(KBUILD_IMAGE): vmlinux
> > $(Q)$(MAKE) $(build)=$(boot) $(bootvars-y) $@
> >
> > install:
> > +ifndef CONFIG_SYS_SUPPORTS_ZBOOT
> > $(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/vmlinux-$(KERNELRELEASE)
> > +else
> > + $(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/vmlinuz-$(KERNELRELEASE)
> > +endif
> > $(Q)install -D -m 644 .config $(INSTALL_PATH)/config-$(KERNELRELEASE)
> > $(Q)install -D -m 644 System.map $(INSTALL_PATH)/System.map-$(KERNELRELEASE)
> >
> > diff --git a/arch/loongarch/boot/Makefile b/arch/loongarch/boot/Makefile
> > index 66f2293c34b2..c26a36004ae2 100644
> > --- a/arch/loongarch/boot/Makefile
> > +++ b/arch/loongarch/boot/Makefile
> > @@ -21,3 +21,58 @@ quiet_cmd_eficopy = OBJCOPY $@
> >
> > $(obj)/vmlinux.efi: $(obj)/vmlinux FORCE
> > $(call if_changed,eficopy)
> > +
> > +# zboot
> > +extra-y += boot.lds
> > +$(obj)/boot.lds: $(obj)/vmlinux.bin FORCE
> > +CPPFLAGS_boot.lds = $(KBUILD_CPPFLAGS) -DVMLINUZ_LOAD_ADDRESS=$(zload-y)
> > +
> > +entry-y = $(shell $(objtree)/arch/loongarch/tools/elf-entry $(obj)/vmlinux)
> > +zload-y = $(shell $(objtree)/arch/loongarch/tools/calc_vmlinuz_load_addr \
> > + $(obj)/vmlinux.bin $(VMLINUX_LOAD_ADDRESS))
> > +
> > +BOOT_HEAP_SIZE := 0x400000
> > +BOOT_STACK_SIZE := 0x002000
> > +
> > +KBUILD_AFLAGS := $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
> > + -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
> > + -DBOOT_STACK_SIZE=$(BOOT_STACK_SIZE)
> > +
> > +KBUILD_CFLAGS := $(KBUILD_CFLAGS) -fpic -D__KERNEL__ \
> > + -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
> > + -DBOOT_STACK_SIZE=$(BOOT_STACK_SIZE)
> > +
> > +targets += vmlinux.bin
> > +OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary $(strip-flags)
> > +$(obj)/vmlinux.bin: $(obj)/vmlinux FORCE
> > + $(call if_changed,objcopy)
> > +
> > +tool_$(CONFIG_KERNEL_GZIP) = gzip
> > +tool_$(CONFIG_KERNEL_BZIP2) = bzip2_with_size
> > +tool_$(CONFIG_KERNEL_LZ4) = lz4_with_size
> > +tool_$(CONFIG_KERNEL_LZMA) = lzma_with_size
> > +tool_$(CONFIG_KERNEL_LZO) = lzo_with_size
> > +tool_$(CONFIG_KERNEL_XZ) = xzkern_with_size
> > +tool_$(CONFIG_KERNEL_ZSTD) = zstd22_with_size
> > +
> > +targets += vmlinux.bin.z
> > +$(obj)/vmlinux.bin.z: $(obj)/vmlinux.bin FORCE
> > + $(call if_changed,$(tool_y))
> > +
> > +targets += $(notdir $(vmlinuzobjs-y))
> > +vmlinuzobjs-y := $(obj)/zkernel.o $(obj)/decompress.o $(obj)/string.o
> > +vmlinuzobjs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
> > +$(obj)/zkernel.o: $(obj)/vmlinux.bin.z
> > +AFLAGS_zkernel.o = $(KBUILD_AFLAGS) -DVMLINUZ_LOAD_ADDRESS=$(zload-y) -DKERNEL_ENTRY=$(entry-y)
> > +
> > +quiet_cmd_zld = LD $@
> > + cmd_zld = $(LD) $(KBUILD_LDFLAGS) -T $< $(vmlinuzobjs-y) -o $@
> > +
> > +targets += vmlinuz
> > +$(obj)/vmlinuz: $(src)/boot.lds $(vmlinuzobjs-y) FORCE
> > + $(call if_changed,zld)
> > + $(call if_changed,strip)
> > +
> > +targets += vmlinuz.efi
> > +$(obj)/vmlinuz.efi: $(obj)/vmlinuz FORCE
> > + $(call if_changed,eficopy)
> > diff --git a/arch/loongarch/boot/boot.lds.S b/arch/loongarch/boot/boot.lds.S
> > new file mode 100644
> > index 000000000000..23e698782afd
> > --- /dev/null
> > +++ b/arch/loongarch/boot/boot.lds.S
> > @@ -0,0 +1,64 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * ld.script for compressed kernel support of LoongArch
> > + *
> > + * Author: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> > + */
> > +
> > +#include "../kernel/image-vars.h"
> > +
> > +/*
> > + * Max avaliable Page Size is 64K, so we set SectionAlignment
> > + * field of EFI application to 64K.
> > + */
> > +PECOFF_FILE_ALIGN = 0x200;
> > +PECOFF_SEGMENT_ALIGN = 0x10000;
> > +
> > +OUTPUT_ARCH(loongarch)
> > +ENTRY(kernel_entry)
> > +PHDRS {
> > + text PT_LOAD FLAGS(7); /* RWX */
> > +}
> > +SECTIONS
> > +{
> > + . = VMLINUZ_LOAD_ADDRESS;
> > +
> > + _text = .;
> > + .head.text : {
> > + *(.head.text)
> > + }
> > +
> > + .text : {
> > + *(.text)
> > + *(.init.text)
> > + *(.rodata)
> > + }: text
> > +
> > + . = ALIGN(PECOFF_SEGMENT_ALIGN);
> > + _data = .;
> > + .data : {
> > + *(.data)
> > + *(.init.data)
> > + /* Put the compressed image here */
> > + __image_begin = .;
> > + *(.image)
> > + __image_end = .;
> > + CONSTRUCTORS
> > + . = ALIGN(PECOFF_FILE_ALIGN);
> > + }
> > + _edata = .;
> > +
> > + .bss : {
> > + *(.bss)
> > + *(.init.bss)
> > + }
> > + . = ALIGN(PECOFF_SEGMENT_ALIGN);
> > + _end = .;
> > +
> > + /DISCARD/ : {
> > + *(.options)
> > + *(.comment)
> > + *(.note)
> > + }
> > +}
> > diff --git a/arch/loongarch/boot/decompress.c b/arch/loongarch/boot/decompress.c
> > new file mode 100644
> > index 000000000000..8f55fcd8f285
> > --- /dev/null
> > +++ b/arch/loongarch/boot/decompress.c
> > @@ -0,0 +1,98 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Author: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> > + */
> > +
> > +#include <linux/types.h>
> > +#include <linux/kernel.h>
> > +#include <linux/string.h>
> > +#include <linux/libfdt.h>
> > +
> > +#include <asm/addrspace.h>
> > +
> > +/*
> > + * These two variables specify the free mem region
> > + * that can be used for temporary malloc area
> > + */
> > +unsigned long free_mem_ptr;
> > +unsigned long free_mem_end_ptr;
> > +
> > +/* The linker tells us where the image is. */
> > +extern unsigned char __image_begin, __image_end;
> > +
> > +#define puts(s) do {} while (0)
> > +#define puthex(val) do {} while (0)
> > +
> > +void error(char *x)
> > +{
> > + puts("\n\n");
> > + puts(x);
> > + puts("\n\n -- System halted");
> > +
> > + while (1)
> > + ; /* Halt */
> > +}
> > +
> > +/* activate the code for pre-boot environment */
> > +#define STATIC static
> > +
> > +#include "../../../../lib/ashldi3.c"
> > +
> > +#ifdef CONFIG_KERNEL_GZIP
> > +#include "../../../../lib/decompress_inflate.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_BZIP2
> > +#include "../../../../lib/decompress_bunzip2.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_LZ4
> > +#include "../../../../lib/decompress_unlz4.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_LZMA
> > +#include "../../../../lib/decompress_unlzma.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_LZO
> > +#include "../../../../lib/decompress_unlzo.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_XZ
> > +#include "../../../../lib/decompress_unxz.c"
> > +#endif
> > +
> > +#ifdef CONFIG_KERNEL_ZSTD
> > +#include "../../../../lib/decompress_unzstd.c"
> > +#endif
> > +
> > +void decompress_kernel(unsigned long boot_heap_start)
> > +{
> > + unsigned long zimage_start, zimage_size;
> > +
> > + zimage_start = (unsigned long)(&__image_begin);
> > + zimage_size = (unsigned long)(&__image_end) -
> > + (unsigned long)(&__image_begin);
> > +
> > + puts("zimage at: ");
> > + puthex(zimage_start);
> > + puts(" ");
> > + puthex(zimage_size + zimage_start);
> > + puts("\n");
> > +
> > + /* This area are prepared for mallocing when decompressing */
> > + free_mem_ptr = boot_heap_start;
> > + free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
> > +
> > + /* Display standard Linux/LoongArch boot prompt */
> > + puts("Uncompressing Linux at load address ");
> > + puthex(VMLINUX_LOAD_ADDRESS);
> > + puts("\n");
> > +
> > + /* Decompress the kernel with according algorithm */
> > + __decompress((char *)zimage_start, zimage_size, 0, 0,
> > + (void *)VMLINUX_LOAD_ADDRESS, 0, 0, error);
> > +
> > + puts("Now, booting the kernel...\n");
> > +}
> > diff --git a/arch/loongarch/boot/string.c b/arch/loongarch/boot/string.c
> > new file mode 100644
> > index 000000000000..3f746e7c2bb5
> > --- /dev/null
> > +++ b/arch/loongarch/boot/string.c
> > @@ -0,0 +1,166 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * arch/loongarch/boot/string.c
> > + *
> > + * Very small subset of simple string routines
> > + */
> > +
> > +#include <linux/types.h>
> > +
> > +void __weak *memset(void *s, int c, size_t n)
> > +{
> > + int i;
> > + char *ss = s;
> > +
> > + for (i = 0; i < n; i++)
> > + ss[i] = c;
> > + return s;
> > +}
> > +
> > +void __weak *memcpy(void *dest, const void *src, size_t n)
> > +{
> > + int i;
> > + const char *s = src;
> > + char *d = dest;
> > +
> > + for (i = 0; i < n; i++)
> > + d[i] = s[i];
> > + return dest;
> > +}
> > +
> > +void __weak *memmove(void *dest, const void *src, size_t n)
> > +{
> > + int i;
> > + const char *s = src;
> > + char *d = dest;
> > +
> > + if (d < s) {
> > + for (i = 0; i < n; i++)
> > + d[i] = s[i];
> > + } else if (d > s) {
> > + for (i = n - 1; i >= 0; i--)
> > + d[i] = s[i];
> > + }
> > +
> > + return dest;
> > +}
> > +
> > +int __weak memcmp(const void *cs, const void *ct, size_t count)
> > +{
> > + int res = 0;
> > + const unsigned char *su1, *su2;
> > +
> > + for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) {
> > + res = *su1 - *su2;
> > + if (res != 0)
> > + break;
> > + }
> > + return res;
> > +}
> > +
> > +int __weak strcmp(const char *str1, const char *str2)
> > +{
> > + int delta = 0;
> > + const unsigned char *s1 = (const unsigned char *)str1;
> > + const unsigned char *s2 = (const unsigned char *)str2;
> > +
> > + while (*s1 || *s2) {
> > + delta = *s1 - *s2;
> > + if (delta)
> > + return delta;
> > + s1++;
> > + s2++;
> > + }
> > + return 0;
> > +}
> > +
> > +size_t __weak strlen(const char *s)
> > +{
> > + const char *sc;
> > +
> > + for (sc = s; *sc != '\0'; ++sc)
> > + /* nothing */;
> > + return sc - s;
> > +}
> > +
> > +size_t __weak strnlen(const char *s, size_t count)
> > +{
> > + const char *sc;
> > +
> > + for (sc = s; count-- && *sc != '\0'; ++sc)
> > + /* nothing */;
> > + return sc - s;
> > +}
> > +
> > +char * __weak strnstr(const char *s1, const char *s2, size_t len)
> > +{
> > + size_t l2;
> > +
> > + l2 = strlen(s2);
> > + if (!l2)
> > + return (char *)s1;
> > + while (len >= l2) {
> > + len--;
> > + if (!memcmp(s1, s2, l2))
> > + return (char *)s1;
> > + s1++;
> > + }
> > + return NULL;
> > +}
> > +
> > +#undef strcat
> > +char * __weak strcat(char *dest, const char *src)
> > +{
> > + char *tmp = dest;
> > +
> > + while (*dest)
> > + dest++;
> > + while ((*dest++ = *src++) != '\0')
> > + ;
> > + return tmp;
> > +}
> > +
> > +char * __weak strncat(char *dest, const char *src, size_t count)
> > +{
> > + char *tmp = dest;
> > +
> > + if (count) {
> > + while (*dest)
> > + dest++;
> > + while ((*dest++ = *src++) != 0) {
> > + if (--count == 0) {
> > + *dest = '\0';
> > + break;
> > + }
> > + }
> > + }
> > + return tmp;
> > +}
> > +
> > +char * __weak strpbrk(const char *cs, const char *ct)
> > +{
> > + const char *sc1, *sc2;
> > +
> > + for (sc1 = cs; *sc1 != '\0'; ++sc1) {
> > + for (sc2 = ct; *sc2 != '\0'; ++sc2) {
> > + if (*sc1 == *sc2)
> > + return (char *)sc1;
> > + }
> > + }
> > + return NULL;
> > +}
> > +
> > +char * __weak strsep(char **s, const char *ct)
> > +{
> > + char *sbegin = *s;
> > + char *end;
> > +
> > + if (sbegin == NULL)
> > + return NULL;
> > +
> > + end = strpbrk(sbegin, ct);
> > + if (end)
> > + *end++ = '\0';
> > + *s = end;
> > + return sbegin;
> > +}
> > diff --git a/arch/loongarch/boot/zheader.S b/arch/loongarch/boot/zheader.S
> > new file mode 100644
> > index 000000000000..4bc50d953ec7
> > --- /dev/null
> > +++ b/arch/loongarch/boot/zheader.S
> > @@ -0,0 +1,100 @@
> > +/* 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
> > +coff_header:
> > + .short IMAGE_FILE_MACHINE_LOONGARCH /* Machine */
> > + .short section_count /* NumberOfSections */
> > + .long 0 /* TimeDateStamp */
> > + .long 0 /* PointerToSymbolTable */
> > + .long 0 /* NumberOfSymbols */
> > + .short section_table - optional_header /* SizeOfOptionalHeader */
> > + .short IMAGE_FILE_DEBUG_STRIPPED | \
> > + IMAGE_FILE_EXECUTABLE_IMAGE | \
> > + IMAGE_FILE_LINE_NUMS_STRIPPED /* Characteristics */
> > +
> > +optional_header:
> > + .short PE_OPT_MAGIC_PE32PLUS /* PE32+ format */
> > + .byte 0x02 /* MajorLinkerVersion */
> > + .byte 0x14 /* MinorLinkerVersion */
> > + .long _data - efi_header_end /* SizeOfCode */
> > + .long _end - _data /* SizeOfInitializedData */
> > + .long 0 /* SizeOfUninitializedData */
> > + .long __efistub_efi_pe_entry - _head /* AddressOfEntryPoint */
> > + .long efi_header_end - _head /* BaseOfCode */
> > +
> > +extra_header_fields:
> > + .quad 0 /* ImageBase */
> > + .long PECOFF_SEGMENT_ALIGN /* SectionAlignment */
> > + .long PECOFF_FILE_ALIGN /* FileAlignment */
> > + .short 0 /* MajorOperatingSystemVersion */
> > + .short 0 /* MinorOperatingSystemVersion */
> > + .short 0 /* MajorImageVersion */
> > + .short 0 /* 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 efi_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 (section_table - .) / 8 /* NumberOfRvaAndSizes */
> > +
> > + .quad 0 /* ExportTable */
> > + .quad 0 /* ImportTable */
> > + .quad 0 /* ResourceTable */
> > + .quad 0 /* ExceptionTable */
> > + .quad 0 /* CertificationTable */
> > + .quad 0 /* BaseRelocationTable */
> > +
> > + /* Section table */
> > +section_table:
> > + .ascii ".text\0\0\0"
> > + .long _data - efi_header_end /* VirtualSize */
> > + .long efi_header_end - _head /* VirtualAddress */
> > + .long _data - efi_header_end /* SizeOfRawData */
> > + .long efi_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 - _data /* VirtualSize */
> > + .long _data - _head /* VirtualAddress */
> > + .long _edata - _data /* SizeOfRawData */
> > + .long _data - _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 */
> > +
> > + .org 0x20e
> > + .word kernel_version - 512 - _head
> > +
> > + .set section_count, (. - section_table) / 40
> > +efi_header_end:
> > + .endm
> > diff --git a/arch/loongarch/boot/zkernel.S b/arch/loongarch/boot/zkernel.S
> > new file mode 100644
> > index 000000000000..13a8a14a2328
> > --- /dev/null
> > +++ b/arch/loongarch/boot/zkernel.S
> > @@ -0,0 +1,99 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/linkage.h>
> > +#include <asm/addrspace.h>
> > +#include <asm/asm.h>
> > +#include <asm/loongarch.h>
> > +#include <asm/regdef.h>
> > +#include <generated/compile.h>
> > +#include <generated/utsrelease.h>
> > +
> > +#ifdef CONFIG_EFI_STUB
> > +
> > +#include "zheader.S"
> > +
> > + __HEAD
> > +
> > +_head:
> > + /* "MZ", MS-DOS header */
> > + .word MZ_MAGIC
> > + .org 0x28
> > + .ascii "Loongson\0"
> > + .org 0x3c
> > + /* Offset to the PE header */
> > + .long pe_header - _head
> > +
> > +pe_header:
> > + __EFI_PE_HEADER
> > +
> > +kernel_asize:
> > + .long _end - _text
> > +
> > +kernel_fsize:
> > + .long _edata - _text
> > +
> > +kernel_vaddr:
> > + .quad VMLINUZ_LOAD_ADDRESS
> > +
> > +kernel_offset:
> > + .long kernel_offset - _text
> > +
> > +kernel_version:
> > + .ascii UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") " UTS_VERSION "\0"
> > +
> > +SYM_L_GLOBAL(kernel_asize)
> > +SYM_L_GLOBAL(kernel_fsize)
> > +SYM_L_GLOBAL(kernel_vaddr)
> > +SYM_L_GLOBAL(kernel_offset)
> > +
> > +#endif
> > +
> > + __INIT
> > +
> > +SYM_CODE_START(kernel_entry)
> > + /* Save boot rom start args */
> > + move s0, a0
> > + move s1, a1
> > + move s2, a2
> > + move s3, a3
> > +
> > + /* Config Direct Mapping */
> > + li.d t0, CSR_DMW0_INIT
> > + csrwr t0, LOONGARCH_CSR_DMWIN0
> > + li.d t0, CSR_DMW1_INIT
> > + csrwr t0, LOONGARCH_CSR_DMWIN1
> > +
> > + /* Clear BSS */
> > + la.abs a0, _edata
> > + la.abs a2, _end
> > +1: st.d zero, a0, 0
> > + addi.d a0, a0, 8
> > + bne a2, a0, 1b
> > +
> > + la.abs a0, .heap /* heap address */
> > + la.abs sp, .stack + 8192 /* stack address */
> > +
> > + la ra, 2f
> > + la t4, decompress_kernel
> > + jirl zero, t4, 0
> > +2:
> > + move a0, s0
> > + move a1, s1
> > + move a2, s2
> > + move a3, s3
> > + PTR_LI t4, KERNEL_ENTRY
> > + jirl zero, t4, 0
> > +3:
> > + b 3b
> > +SYM_CODE_END(kernel_entry)
> > +
> > + .comm .heap, BOOT_HEAP_SIZE, 4
> > + .comm .stack, BOOT_STACK_SIZE, 4
> > +
> > + .align 4
> > + .section .image, "a", %progbits
> > + .incbin "arch/loongarch/boot/vmlinux.bin.z"
> > diff --git a/arch/loongarch/tools/Makefile b/arch/loongarch/tools/Makefile
> > new file mode 100644
> > index 000000000000..8a6181c82a91
> > --- /dev/null
> > +++ b/arch/loongarch/tools/Makefile
> > @@ -0,0 +1,15 @@
> > +#
> > +# arch/loongarch/boot/Makefile
> > +#
> > +# Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> > +#
> > +
> > +hostprogs := elf-entry
> > +PHONY += elf-entry
> > +elf-entry: $(obj)/elf-entry
> > + @:
> > +
> > +hostprogs += calc_vmlinuz_load_addr
> > +PHONY += calc_vmlinuz_load_addr
> > +calc_vmlinuz_load_addr: $(obj)/calc_vmlinuz_load_addr
> > + @:
> > diff --git a/arch/loongarch/tools/calc_vmlinuz_load_addr.c b/arch/loongarch/tools/calc_vmlinuz_load_addr.c
> > new file mode 100644
> > index 000000000000..5e2ca6b4dff6
> > --- /dev/null
> > +++ b/arch/loongarch/tools/calc_vmlinuz_load_addr.c
> > @@ -0,0 +1,51 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> > + */
> > +
> > +#include <errno.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <sys/stat.h>
> > +
> > +int main(int argc, char *argv[])
> > +{
> > + unsigned long long vmlinux_size, vmlinux_load_addr, vmlinuz_load_addr;
> > + struct stat sb;
> > +
> > + if (argc != 3) {
> > + fprintf(stderr, "Usage: %s <pathname> <vmlinux_load_addr>\n", argv[0]);
> > + return EXIT_FAILURE;
> > + }
> > +
> > + if (stat(argv[1], &sb) == -1) {
> > + perror("stat");
> > + return EXIT_FAILURE;
> > + }
> > +
> > + /* Convert hex characters to dec number */
> > + errno = 0;
> > + if (sscanf(argv[2], "%llx", &vmlinux_load_addr) != 1) {
> > + if (errno != 0)
> > + perror("sscanf");
> > + else
> > + fprintf(stderr, "No matching characters\n");
> > +
> > + return EXIT_FAILURE;
> > + }
> > +
> > + vmlinux_size = (uint64_t)sb.st_size;
> > + vmlinuz_load_addr = vmlinux_load_addr + vmlinux_size;
> > +
> > + /*
> > + * Align with 64KB: KEXEC needs load sections to be aligned to PAGE_SIZE,
> > + * which may be as large as 64KB depending on the kernel configuration.
> > + */
> > +
> > + vmlinuz_load_addr += (0x10000 - vmlinux_size % 0x10000);
> > +
> > + printf("0x%llx\n", vmlinuz_load_addr);
> > +
> > + return EXIT_SUCCESS;
> > +}
> > diff --git a/arch/loongarch/tools/elf-entry.c b/arch/loongarch/tools/elf-entry.c
> > new file mode 100644
> > index 000000000000..c80721e0dee1
> > --- /dev/null
> > +++ b/arch/loongarch/tools/elf-entry.c
> > @@ -0,0 +1,66 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#include <elf.h>
> > +#include <inttypes.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +
> > +__attribute__((noreturn))
> > +static void die(const char *msg)
> > +{
> > + fputs(msg, stderr);
> > + exit(EXIT_FAILURE);
> > +}
> > +
> > +int main(int argc, const char *argv[])
> > +{
> > + uint64_t entry;
> > + size_t nread;
> > + FILE *file;
> > + union {
> > + Elf32_Ehdr ehdr32;
> > + Elf64_Ehdr ehdr64;
> > + } hdr;
> > +
> > + if (argc != 2)
> > + die("Usage: elf-entry <elf-file>\n");
> > +
> > + file = fopen(argv[1], "r");
> > + if (!file) {
> > + perror("Unable to open input file");
> > + return EXIT_FAILURE;
> > + }
> > +
> > + nread = fread(&hdr, 1, sizeof(hdr), file);
> > + if (nread != sizeof(hdr)) {
> > + fclose(file);
> > + perror("Unable to read input file");
> > + return EXIT_FAILURE;
> > + }
> > +
> > + if (memcmp(hdr.ehdr32.e_ident, ELFMAG, SELFMAG)) {
> > + fclose(file);
> > + die("Input is not an ELF\n");
> > + }
> > +
> > + switch (hdr.ehdr32.e_ident[EI_CLASS]) {
> > + case ELFCLASS32:
> > + /* Sign extend to form a canonical address */
> > + entry = (int64_t)(int32_t)hdr.ehdr32.e_entry;
> > + break;
> > +
> > + case ELFCLASS64:
> > + entry = hdr.ehdr64.e_entry;
> > + break;
> > +
> > + default:
> > + fclose(file);
> > + die("Invalid ELF class\n");
> > + }
> > +
> > + fclose(file);
> > + printf("0x%016" PRIx64 "\n", entry);
> > +
> > + return EXIT_SUCCESS;
> > +}
> > --
> > 2.27.0
> >