ADLO/Bochs and PCI config write
Richard Smith
rsmith at bitworks.com
Mon Jun 9 15:35:00 CEST 2003
Anyone have any idea why writing to PCI config space while in the middle
of the Bochs BIOS with ADLO is running would cause lockups?
Our board has 2 video chips on the PCI bus and for Xwindows to be able
to use the head I have to init it from the bios. X (even 4.3) has
issues with our setup because there is only one copy of the video bios
for both chips and I haven't been able to make X go look for the bios in
the right location. Plus I need the head to come up early for field
service reasons.
The way we did this under our old COTS bios kit was
enable IO on head 1
call vga bios
disable io on head 1
enable io on head 2
call vga bios
disable io on head 2
enable IO on head 1
Then all is well with X.
I found the vido init part of ADLO/Bochs and ported the
PCI_[WRITE:READ]_CONFIG_DWORD macro from linuxbios but when I call it
the system hangs. Currently I'm down to just re-writing the IO bit in
the config register of the already active head and it still hangs.
Perhaps I don't have my device IDs correct? Can someone verify that if
I want to read and write to the PCI command register and lspci lists my
2 video heads as 0:12.0 and 0:14.0 that the corresponding values I
should load into eax before calling the macros are:
12.0 0x9010
14.0 0xa010
Other than that is there prehaps some freaky 16bit real mode issue thats
busting me?
--
Richard A. Smith
rsmith at bitworks.com
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