On 4/26/06, Christian Sühs chris@suehsi.de wrote:
No, different reason. I guess the ram at 0xc0000 is not visible or writable. The datasheet usually knows how to make that area writable.
Datasheet of which part ?? I have them all :D
I bet access to your video bios cache area is still write protected. Look for something in the CPU or northbridge datasheets (usually northbrdge but the Geode is a bit wierd) that talks about controlling reads and writes to this range. A lot of times its called the c000 segment.
Ah... Nevermind... I just pulled the datasheet. According to what I read I dont think you have a vbios cache. Page 94 Section 3.5.3 ROM Interface.
The CS5530A positively decodes memory addresses 000F0000h-000FFFFFh (64 KB) and FFFC0000h- FFFFFFFFh (256 KB) at reset. These memory cycles cause the CS5530A to claim the cycle, and generate an ISA bus memory cycle with KBROMCS# asserted.
I don't see anywhere that you can enable this section as read from ROM/ write to RAM like you would do for a normal vbios shadow. You can disable the area completely but not on a partial read/write basis.
If this is true then if you can't see your vbios show up at 0xfffc0000 then its not in your ROM image correctly.
This would explain why the user space emulator works but the in-tree dosent.
-- Richard A. Smith