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Commit 099e1377 authored by Ian Campbell's avatar Ian Campbell Committed by Ingo Molnar
Browse files

x86: use ELF format in compressed images. 



Signed-off-by: default avatarIan Campbell <ijc@hellion.org.uk>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e0bf0f75

Documentation/i386/boot.txt

+18 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/boot/Makefile

+14 −0
Original line number Diff line number Diff line
@@ -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 \2 0x\1/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)

arch/x86/boot/compressed/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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)

arch/x86/boot/compressed/misc.c

+56 −0
Original line number Diff line number Diff line
@@ -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;

		default: /* Ignore other PT_* */ break;

		}

	}

}



asmlinkage void decompress_kernel(void *rmode, memptr heap,

				  uch *input_data, unsigned long input_len,

				  uch *output)
@@ -408,6 +463,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap, 
	makecrc();

	putstr("\nDecompressing Linux... ");

	gunzip();

	parse_elf(output);

	putstr("done.\nBooting the kernel.\n");

	return;

}

arch/x86/boot/header.S

+6 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <asm/page.h>

#include <asm/setup.h>

#include "boot.h"

#include "offsets.h"



SETUPSECTS	= 4			/* default nr of setup-sectors */

BOOTSEG		= 0x07C0		/* original address of boot-sector */
@@ -223,6 +224,11 @@ hardware_subarch: .long 0 # subarchitecture, added with 2.07 


hardware_subarch_data:	.quad 0



compressed_payload_offset:

			.long input_data

compressed_payload_length:

			.long input_data_end-input_data



# End of setup header #####################################################



	.section ".inittext", "ax"