BIOS Updates forum

I'm developing a application to save and restore the content of the CMOS. Then I'm copying the 128 bytes to a file and later restoring it again. In other BIOSes it works fine, but with AMI I get the error "CMOS Configuration Wrong".

Anyone knows if the AMI has some check that depend on dynamic data?

This is because new BIOSes (not only AMI but also latest version of AWARD 6.00 too) uses 256-bytes length CMOS. Use ports 0x72 and 0x73 (instead 0x70 and 0x71) to access all data in CMOS-memory.

I should read the first 128 bytes using the ports 0x70 and 0x71 then using the ports 0x72 and 0x73 to read the next 128 bytes?
Or may I use the ports 0x72 and 0x73 to read the entire 256 bytes?

thanks by your attention!

Maybe the length would be a problem too. But, I think there is another error. Please take a look at the step I used to test the program:

1 - First, I run my program to save the CMOS to a file.
2 - Next, I reboot the machine and then I make some modifications to the CMOS using the Setup, including the boot sequence.
3 - Next, I run my program again to restore the CMOS from the file previously saved.
4 - Finally, when I reboot the machine I get the error "CMOS Configurations Wrong".

But when I look the Setup again, all configurations was restored, except the boot sequence. Then, I just change the boot sequence, save the Setup and everything works fine. Because this, I'm wondering that AMI has some check related to the boot sequence.

Other stuff: If I save the CMOS to a file and then restore it without make change in the Setup everything works fine. None worth was made, but this shows that the code would be OK. Only when I make changes I get the error.

Have someone any idea?

Thanks in advance!

You should read all data by ports 72h/73h.
Try this CMOS editor - i've use it on ASRock K8Upgrade-NF3 (AMI BIOS 8 ) and it works fine:
http://www.rebelshavenforum.com/sisubb/ ... 2;t=000086

I had saved to the CMOS using the ports 72h/73h. I really can modify its configurations, but the error still remain. I see that all configuration was saved but the boot sequence, that always appear with the floppy disk in the first place. I think this is causing the message "CMOS Settings Wrong". The same code works fine in Award BIOSes but fail with the AMI BIOS.

Maybe CMOS is larger than 256 bytes on your motherboard? Try to read/write 384 or 512 bytes... Maybe this is the key...