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AMIBIOS docs - checksum
Posted: Tue Nov 16, 2004 5:08 pm
by Borg Number One
Hi
Does anybody know where to get documents about AMIBIOS?
( AMIBIOS core ...,6, 7, 8,...)
"Where" is/are the checksum/s inside AMIBIOS file(s)?
( AMIBIOS core ...,6, 7, 8,...)
Posted: Wed Nov 17, 2004 10:57 pm
by Amiboot
For AMIBIOS core 6 and 7 there's no official documentation available anymore. I contacted AMI about it and they told me only AMIBIOS core 8 is documentated right now.
The main BIOS ROM image chekcsum looks like this:
AMIBIOSC0XYZ (XYZ are variables describing the core version).
It can be found when opening the complete image with an hex editor.
Search for above string "AMIBIOSC" and you'll get the AMIBIOS Checksum (AMIBIOSC).
Ofcourse there are more checksums. Inside the runtime (BIOS06xx,07xx, hex id: 02) several checksums can be found. Also the POST (BIOS06xx,07xx,hex id:00) contains one or more checksums.
Also other modules like the Device Initializiation Manager (DIM, BIOS06xx,07xx,hex id:03) may contain various checksums.
Last item is the Boot Block BIOS (by AMIBCP called "INIT), which contains an internal checksum to verify its code.
The place where all those internal checksums can be found differs per BIOS compilation and core version. The checksums are probably generated with the special building software, used to make those BIOS compilations.
Posted: Thu Nov 18, 2004 12:09 am
by Borg Number One
"AMIBIOSC0700" would mean the BIOSCore-Version and Checksum at the same time????
Not really! Is not it?
You want kid me.
Posted: Thu Nov 18, 2004 10:07 am
by Amiboot
Neither I, nor AMI want to kid you. AMIBIOSC is shortened for AMIBIOS main ROM Checksum. 0700 is the core version number that's part of the main ROM checksum.
If you don't believe, check it yourself. Change one of the characters of AMIBIOS0700 (for example AMIBIOS0900) and you'll see the ROM image seems to be corrupted immediatly (until you change it back to it's original values, but I guess you knew that already).
Posted: Thu Nov 18, 2004 10:12 am
by Amiboot
P.S.: the 0700 message is just a number, indicating the core version. Please note that it's actually not the core version itself. The core itself is "in" the ROM structure, runtime/INIT/POST code, etc. (the BIOS core is not just a few numbers).
