> This allows other boot loaders such as the Xen domain builder the
> opportunity to extract the ELF file.
>
> Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
> Cc:
virtualization@lists.linux-foundation.org
> ---
> Documentation/i386/boot.txt | 18 ++++++++++++
> arch/x86/boot/Makefile | 14 +++++++++
> arch/x86/boot/compressed/Makefile | 2 +-
> arch/x86/boot/compressed/misc.c | 56 +++++++++++++++++++++++++++++++++++++
> arch/x86/boot/header.S | 6 ++++
> 5 files changed, 95 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt
> index fc49b79..b5f5ba1 100644
> --- a/Documentation/i386/boot.txt
> +++ b/Documentation/i386/boot.txt
> @@ -170,6 +170,8 @@ Offset Proto Name Meaning
> 0238/4 2.06+ cmdline_size Maximum size of the kernel command line
> 023C/4 2.07+ hardware_subarch Hardware subarchitecture
> 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data
> +0248/4 2.08+ compressed_payload_offset
> +024C/4 2.08+ compressed_payload_length
>
> (1) For backwards compatibility, if the setup_sects field contains 0, the
> real value is 4.
> @@ -512,6 +514,22 @@ Protocol: 2.07+
>
> A pointer to data that is specific to hardware subarch
>
> +Field name: compressed_payload_offset
> +Type: read
> +Offset/size: 0x248/4
> +Protocol: 2.08+
> +
> + If non-zero then this field contains the offset from the end of the
> + real-mode code to the compressed payload. The compression format
> + should be determined using the standard magic number, currently only
> + gzip is used.
> +
> +Field name: compressed_payload_length
> +Type: read
> +Offset/size: 0x24c/4
> +Protocol: 2.08+
> +
> + The length of the compressed payload.
>
> **** THE KERNEL COMMAND LINE
>
> diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
> index f88458e..9695aff 100644
> --- a/arch/x86/boot/Makefile
> +++ b/arch/x86/boot/Makefile
> @@ -94,6 +94,20 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
>
> SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
>
> +sed-offsets := -e 's/^00*/0/' \
> + -e 's/^\([0-9a-fA-F]*\) . \(input_data\|input_data_end\)$$/\#define 0x/p'
> +
> +quiet_cmd_offsets = OFFSETS $@
> + cmd_offsets = $(NM) $< | sed -n $(sed-offsets) > $@
> +
> +$(obj)/offsets.h: $(obj)/compressed/vmlinux FORCE
> + $(call if_changed,offsets)
> +
> +targets += offsets.h
> +
> +AFLAGS_header.o += -I$(obj)
> +$(obj)/header.o: $(obj)/offsets.h
> +
> LDFLAGS_setup.elf := -T
> $(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE
> $(call if_changed,ld)
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index d2b9f3b..92fdd35 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -22,7 +22,7 @@ $(obj)/vmlinux: $(src)/vmlinux_$(BITS).lds $(obj)/head_$(BITS).o $(obj)/misc.o $
> $(call if_changed,ld)
> @:
>
> -OBJCOPYFLAGS_vmlinux.bin := -O binary -R .note -R .comment -S
> +OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
> $(obj)/vmlinux.bin: vmlinux FORCE
> $(call if_changed,objcopy)
>
> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
> index 8182e32..69aec2f 100644
> --- a/arch/x86/boot/compressed/misc.c
> +++ b/arch/x86/boot/compressed/misc.c
> @@ -15,6 +15,10 @@
> * we just keep it from happening
> */
> #undef CONFIG_PARAVIRT
> +#ifdef CONFIG_X86_32
> +#define _ASM_DESC_H_ 1
> +#endif
> +
> #ifdef CONFIG_X86_64
> #define _LINUX_STRING_H_ 1
> #define __LINUX_BITMAP_H 1
> @@ -22,6 +26,7 @@
>
> #include <linux/linkage.h>
> #include <linux/screen_info.h>
> +#include <linux/elf.h>
> #include <asm/io.h>
> #include <asm/page.h>
> #include <asm/boot.h>
> @@ -365,6 +370,56 @@ static void error(char *x)
> asm("hlt");
> }
>
> +static void parse_elf(void *output)
> +{
> +#ifdef CONFIG_X86_64
> + Elf64_Ehdr ehdr;
> + Elf64_Phdr *phdrs, *phdr;
> +#else
> + Elf32_Ehdr ehdr;
> + Elf32_Phdr *phdrs, *phdr;
> +#endif
> + void *dest;
> + int i;
> +
> + memcpy(&ehdr, output, sizeof(ehdr));
> + if(ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
> + ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
> + ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
> + ehdr.e_ident[EI_MAG3] != ELFMAG3)
> + {
> + error("Kernel is not a valid ELF file");
> + return;
> + }
> +
> + putstr("Parsing ELF... ");
> +
> + phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
> + if (!phdrs)
> + error("Failed to allocate space for phdrs");
> +
> + memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
> +
> + for (i=0; i<ehdr.e_phnum; i++) {
> + phdr = &phdrs[i];
> +
> + switch (phdr->p_type) {
> + case PT_LOAD:
> +#ifdef CONFIG_RELOCATABLE
> + dest = output;
> + dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
> +#else
> + dest = (void*)(phdr->p_paddr);
> +#endif
> + memcpy(dest,
> + output + phdr->p_offset,
> + phdr->p_filesz);
> + break;
