read bios dump and disassemble it

[kulkarniniraj]

Hi
I actually want to reverse engineer my ROM BIOS.for that i need to collect memory dump at f000:0000 to f000:ffff and then store it in a file and disassemble it.
So can anyone help me. I tried readinng memory by cat /dev/mem but it gives me whole dump.I need only specific parts.can i try dd? please send me details of this command.

My friend told me that i could disassemble using objdump, but i couldn't figure out how to use it for not-object binaries.Please help me here also.
Thanks in advance

[NathanB]

If you are just wanting to examine the embedded strings and other data, then use a FreeDOS boot floppy [ http://www.fdos.org/bootdisks/ ] and, from here [ http://home.comcast.net/~fbkotler/ ], grab the Seemem (source included) program to view that area of memory. Seemem can be modified to dump to a binary file that can be disassembled, but that is where I stop participating in this discussion [see this forum's TOS].

F/OSS BIOS code is widely available:

http://aebios.com/

http://www.pcengines.ch/tinybios.htm

http://www.openfirmware.info/Welcome_to_OpenBIOS

Hope that helps.

[kulkarniniraj]

Thanx for those links Nathan.
anyway my first problem is solved. Now I can dump memory into a file using dd. Please help me out in disassembling it using OBJDUMP or maybe any other tool