On Tue, 2006-09-05 at 20:02 +0200, jean-francois simon wrote: > Those legacy IO ports are NOT necessary mapped to the PCI IO > address. > Some VGA card does and some others come with some kind of > remapping > or offset. Your system chipset should have a way to map legacy > VGA IO > ports to memory address. You have to read the doc to the PPC > chipset > carefully to find it out. > > I have read the chipset doc and there is no such VGA support. > But could you plse explain more on the different ways for VGA cards to > map the VGA registers? Since the registers are located on a PCI agent > (the graphic card), there must be a way to access them by generating > PCI cycles? > Thanks
I don't know how exactly those legacy IO address is implemented by the HW and/or the bus protocol. But the Appendix G of PCI sepc says it is possible for PCI device to decode those legacy ports independent of the base address register. Ollie > -- linuxbios mailing list [email protected] http://www.openbios.org/mailman/listinfo/linuxbios
