Does kernel Image file contains the elf format information ?

[horse_rivers]

At 2012-11-27 13:10:37,"Kumar amit mehta" <gmate.amit at gmail.com> wrote:
>On Tue, Nov 27, 2012 at 12:44:45PM +0800, horse_rivers wrote:
>> hi,
>>    when we compile kernel,gcc will put elf format information into the target file ,then we use build-tools construct the kernel Image,
>> 
>>   during this procedure,will elf information be copyed into Image file ?
>> 
>Yes, it does but as you know that the kernel image will be in the compressed
>format, therefore you'll have to decompress it first. I tried following with my
>kernel image and then I was able to use the 'readelf' and 'objdump' on the
>extracted elf:
>
   and  this  file can  boot inux os ?  if I put this file into  floppy ,and boot from floppy ,can I boot this kernel ?

thanks!

>amit at ubuntu:/tmp$ cp /boot/vmlinuz-3.7.0-rc3-next-20121029 /tmp/
>amit at ubuntu:/tmp$ od -A d -t x1 vmlinuz-3.7.0-rc3-next-20121029 | grep '1f 8b 08
>00'
>0016992 f3 a5 fc 5e 8d 83 b4 91 4f 00 ff e0 1f 8b 08 00
>                             
>amit at ubuntu:/tmp$ dd if=vmlinuz bs=1 skip=17004 | zcat > vmlinux
>
>How did i calculated 17004 ?
>0016992 + offset of GZ signature(1f 8b 08 00), i.e.
>0016992 + 12
>
>amit at ubuntu:/tmp$ dd if=vmlinuz-3.7.0-rc3-next-20121029 bs=1 skip=17004 | 
>zcat > vmlinux
>5233764+0 records in
>5233764+0 records out
>5233764 bytes (5.2 MB) copied
>
>amit at ubuntu:/tmp$ file vmlinux
>vmlinux: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically
>linked, BuildID[sha1]=0xb874d61ffd40167270bdc1a95274976200223cc0, stripped
>
>amit at ubuntu:/tmp$ objdump -f vmlinux
>
>vmlinux:     file format elf32-i386
>architecture: i386, flags 0x00000102:
>EXEC_P, D_PAGED
>start address 0x01000000
>
>For more information check the link [1] below.
>
>- Amit
>
>[1] http://forums.codeguru.com/showthread.php?415186-convert-vmlinuz-to-vmlinux