[OpenBIOS] PIC Passthough( VGA )
mark.cave-ayland at ilande.co.uk
Sun Dec 17 10:51:50 CET 2017
On 15/12/17 22:39, Programmingkid wrote:
> If someone wanted to enhance OpenBIOS to load a FCode ROM from a video card, what would need to be changed?
> My theory is this line in the pci.c file's vga_config_cb() function would need this line changed:
> feval("['] vga-driver-fcode 2 cells + 1 byte-load");
> I think the vga-driver-fcode word is what points to the generic driver. Would this be a correct assumption?
Yes, that's correct - the above Forth finds the address of
vga-driver-fcode (which is the target of the compiled VGA driver FCode),
adds 2 cells to skip the CFA/LFA and then executes byte-load on the
What really needs to be done is to generate a proper PCI option ROM and
then include the binary in QEMU as similar to the QEMU,cgthree and
QEMU,tcx FCode ROMs. The main reason it was done this way was until now
no-one was no other user other than QEMU so it didn't really matter that
much (and it's easier to get code changes merged into OpenBIOS than QEMU).
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