I have a need to be able to flash a BIOS via a PXE boot. My PXE boot image is a standard MS DOS 6.22 disk with the flash util and binary on it. I will apologize for the length but I thought being thorough would be best:
The PXE boot image is the same image that I use via floppy. If I boot the floppy image and perform the BIOS uprade it works fine. As soon as I use the image delivered via PXE the BIOS upgrade fails, wiping out the BIOS in the process.
When booting from the floppy and flashing the BIOS, the last 8 blocks never get overwritten (3FE000 and higher), stating that there is no update. This seems to be normal for the operation and the BIOS updates successfully to the newer version.
When performing the same process via PXE, it overwrites those last 8 blocks. After this happens the unit is unbootable and I am prompted by the Award BootBlock notice stating that there is a BIOS ROM Checksum error. This doesnt make any sense since I am using the identical image as the floppy.
I am using the award 823b flash utility (awfl823b.exe) which is suggested by the manufacturer of the motherboard (Via).
I believe the issue centers around memory management. Here are the contents of my config.sys and autoexec.bat files:
shell=a:\command.com /E:512 /P
I understand that EMM386 is bad when performing BIOS flashes, but this is something that predates me at this company and it has worked successfully in the past.
Here is what I have tried:
1) removing the autoexec.bat and config.sys files - This would perform the BIOS upgrade but list 4 blocks as "write failed" and so it would not perform the update
2) removing EMM386 from config.sys - same results as #1
3) removing himem.sys and emm386 from congig.sys - same results as #1
4) I have tried flashing the BIOS with the switch that prevents writing the boot block. No change. If emm386 and himem are loaded it wipes out the BIOS, if not then it gives the same results as #1
I have to admit I am stumped. Any suggestions from you gurus out there that might have run into this? I am currently looking into a different DOS as well as a different flashing utility but so far I haven't met with any success (I haven't spent much time on it to be fair).
Any help would be appreciated.