[LinuxBIOS] RE : Re: VGA bios and i/o access for powerpc

jean-francois simon jfaslist at yahoo.fr
Wed Sep 6 07:47:02 CEST 2006


Hi,
  Maybe there is a way to do without the emulation layer altogether:
  Since in our case we use PCI graphics, I can record all the PCI cycles made by the VGA BIOS to the graphic card on a BIOS based system (using a PCI analyser), put them into a listing, run a perl script on it and include them in the firmware of the non BIOS system....an redo the process whenever we need to use a different graphic which doesn't happen very often 
  -jf simon
   
    I think a sure way is to record all the PCI cycles generated by the VGA BIOS 
jean-francois simon <jfaslist at yahoo.fr> a écrit :
      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
  -jf simon
   
  
 

 		
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