At 01:15 08/09/2004, Trellix78@aol.com wrote:
That message is from the original freebios. I was thinking that shadowing is not corretly set up and that maybe the segment is write-protected. After setting up shadowing, the chipset my turn on write protection by default, anyway. I don't know how to turn write protection off specifically for the C00000 segment. So far, the only reference that I can find about write protection is in the Pentium developer's manual. It says to have bit 16 of CR0 be zero to turn off write protection.
On the VIA VT8622/8623 you need to write 0xFF to Device 0, offset 0x61, and this will write enable the shadow RAM area 0xC0000-0xCFFFF. To write protect it afterwards write 0xAA to the same register.
BTW - according to the datasheet both read and write are disabled by default (same goes for all shadow RAM areas)
Cheers
Ian