Who's good with Hexidecimal?

[Topcat]

Ok, a BIOS modding that I can't figure out..... I need to convert a bin file from a 1mbit (128k) to a 2mbit (256k) filesize. It's for a retro build that has onboard SCSI, and I want to add some option ROM's (scsi RAID abilities) to the bin, but its too small and I can not add any more.....so increasing the file size (which increases its capacity) and using a 2mbit eprom will fix this.....but the problem is, I've exhausted all my BIOS hacking tricks (unsuccessfully) to do this..... The file is attached, so feel free to take a crack at it!! There could be an e-cookie in it for someone who can figure this out!!!

[stj]

Re: Who's good with Hexidecimal?

open a dos-box and
"copy /b rom.bin+rom.bin rom2.bin"

or in Linux:
"cat rom.bin rom.bin > rom2.bin"

[Curious.George]

Re: Who's good with Hexadecimal?

open a dos-box and
"copy /b rom.bin+rom.bin rom2.bin"

or in Linux:
"cat rom.bin rom.bin > rom2.bin"

This just appends a second copy of the first ROM image to the end of the first copy and stores it as a new file.

I would assume there are other "structures" in the ROM image that tell the BIOS where to find stuff, what range of addresses to examine when computing a checksum, where the checksum is stored, etc.?

[Topcat]

Re: Who's good with Hexidecimal?

^
Yes. The extra space I'd guess would just be zero filled, ASSuming that the structure remains intact, and modbin & cbrom simply see it as a 2mbit .bin. The original .bin contains the motherboard parameters, so naturally, they can't be removed or readdressed. I did try taking a 2mbit 4.51 compatible .bin, removing the ROM's in it, and inserting the ROM's for this .bin with cbrom, that didn't work either....

[Sparkey55]

Re: Who's good with Hexidecimal?

Ok, a BIOS modding that I can't figure out..... I need to convert a bin file from a 1mbit (128k) to a 2mbit (256k) filesize. It's for a retro build that has onboard SCSI, and I want to add some option ROM's (scsi RAID abilities) to the bin, but its too small and I can not add any more.....so increasing the file size (which increases its capacity) and using a 2mbit eprom will fix this.....but the problem is, I've exhausted all my BIOS hacking tricks (unsuccessfully) to do this..... The file is attached, so feel free to take a crack at it!! There could be an e-cookie in it for someone who can figure this out!!!

http://warp9-systems.proboards.com/

Get in contact with Mr.Scott He is very smart about BIOS modding and such.

[stj]

Re: Who's good with Hexidecimal?

you make 2 because you dont know if the host expects it to be aligned with the start of the flash, or the end.

[Dan81]

Re: Who's good with Hexidecimal?

The easiest method I came up with:

1. Download Uniflash (the one made by Rainbow)
2. Put it on a bootable DOS media (HDD would be the best given it's a old 586 board)
3. Put your BIOS file on the same media
4. Boot to the DOS prompt
5. While at DOS, hotflash a 2Mb EEPROM in the DIP32 socket
6. Write this on the prompt: uniflash -e yourbiosfilename.bin
7. Uniflash should at this point ignore the fact that you are trying to flash a 1Mb file on a 2Mb EEPROM
8. Once the flash finishes successfully (no red blocks), then start Uniflash again, this time with no switches
9. Select the first option called "Write backup BIOS image to file" then input the filename you want to save it with.
10. Connect the drive you just saved the BIOS to the PC you have CBROM on and check the BIOS image integrity and filesize.

[Topcat]

Re: Who's good with Hexidecimal?

The easiest method I came up with:

1. Download Uniflash (the one made by Rainbow)
2. Put it on a bootable DOS media (HDD would be the best given it's a old 586 board)
3. Put your BIOS file on the same media
4. Boot to the DOS prompt
5. While at DOS, hotflash a 2Mb EEPROM in the DIP32 socket
6. Write this on the prompt: uniflash -e yourbiosfilename.bin
7. Uniflash should at this point ignore the fact that you are trying to flash a 1Mb file on a 2Mb EEPROM
8. Once the flash finishes successfully (no red blocks), then start Uniflash again, this time with no switches
9. Select the first option called "Write backup BIOS image to file" then input the filename you want to save it with.
10. Connect the drive you just saved the BIOS to the PC you have CBROM on and check the BIOS image integrity and filesize.

This got real close. Board post'd just fine off step 6 (hotflashed to 2mbit eprom). Dumped it back off, file size is correct (256k). CBROM sees everything as it should be. attempted to edit with modbin, brick wall....'corrupt header' errors. Any attempt to rewrite (even unmodified), write appears to go (no red blocks), but verification fails, and no POST. Hmmmm....but hey, this is the closest I've gotten so far!! I had to move this off the bench to work on some other stuff, but I'll get back to it. Thanks for the info!!