[coreboot] Extracting an image created with mkelfImage

[Brian Luckau]

Thanks!    

It is an initramfs but it was compressed (must just be very large in relative terms.)  After using your strategy to determine what to put into dd, I was able to use cpio and gzip to do the rest.

--Brian
________________________________________
From: coreboot-bounces at coreboot.org [coreboot-bounces at coreboot.org] on behalf of Brian Luckau [bluckau at sgi.com]
Sent: Monday, January 09, 2012 3:00 PM
To: Peter Stuge; coreboot at coreboot.org
Subject: Re: [coreboot] Extracting an image created with mkelfImage

Hi,

I'm not sure if I'm using the correct paramters but here is some of the information you requested.

# objdump -x -s -D Compute.ebi

Compute.ebi:     file format elf32-i386
Compute.ebi
architecture: i386, flags 0x00000102:
EXEC_P, D_PAGED
start address 0x00010000

Program Header:
    NOTE off    0x000000d4 vaddr 0x00000000 paddr 0x00000000 align 2**0
         filesz 0x000000a4 memsz 0x000000a4 flags rwx
    LOAD off    0x00000178 vaddr 0x00010000 paddr 0x00010000 align 2**0
         filesz 0x00001288 memsz 0x00005524 flags rwx
    LOAD off    0x00001400 vaddr 0x00020000 paddr 0x00020000 align 2**0
         filesz 0x00000000 memsz 0x00001070 flags rwx
    LOAD off    0x00001400 vaddr 0x00100000 paddr 0x00100000 align 2**0
         filesz 0x0020029c memsz 0x00700000 flags rwx
    LOAD off    0x0020169c vaddr 0x02800000 paddr 0x02800000 align 2**0
         filesz 0x007dbdc6 memsz 0x007dbdc6 flags rwx

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
SYMBOL TABLE:
no symbols

root at admin cache]# readelf -a Compute.ebi
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           Intel 80386
  Version:                           0x1
  Entry point address:               0x10000
  Start of program headers:          52 (bytes into file)
  Start of section headers:          0 (bytes into file)
  Flags:                             0x0
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         5
  Size of section headers:           0 (bytes)
  Number of section headers:         0
  Section header string table index: 0

There are no sections in this file.

There are no sections in this file.

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  NOTE           0x0000d4 0x00000000 0x00000000 0x000a4 0x000a4 RWE 0
  LOAD           0x000178 0x00010000 0x00010000 0x01288 0x05524 RWE 0
  LOAD           0x001400 0x00020000 0x00020000 0x00000 0x01070 RWE 0
  LOAD           0x001400 0x00100000 0x00100000 0x20029c 0x700000 RWE 0
  LOAD           0x20169c 0x02800000 0x02800000 0x7dbdc6 0x7dbdc6 RWE 0

There is no dynamic section in this file.

There are no relocations in this file.

There are no unwind sections in this file.

No version information found in this file.
__________________________
From: coreboot-bounces at coreboot.org [coreboot-bounces at coreboot.org] on behalf of Peter Stuge [peter at stuge.se]
Sent: Monday, January 09, 2012 2:30 PM
To: coreboot at coreboot.org
Subject: Re: [coreboot] Extracting an image created with mkelfImage

Hi Brian,

Brian Luckau wrote:
> I have an elf netowrk bootable image for linux that was created
> with mkelfImage.  How can I extract the file to view its contents
> (which kernel modules were included in the file, etc. )

The image may or may not include initrd, if yes it will quite likely
be compressed. What does readelf and/or objdump say about the file?

There's no pre-made tool for taking apart those ELF images. You can
of course always peruse the mkelfImage source code to find out all
details.

http://www.coreboot.org/Mkelfimage
svn co svn://coreboot.org/coreboot/trunk/util/mkelfImage


//Peter

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