Re: [Qemu-devel] Re: Re: NE2K PCI and Windows 98SE & Cirrus Logic

[Fabrice Bellard <fabrice@bellard.org>]

Derek Fawcus wrote:
> On Tue, Jun 08, 2004 at 10:15:05AM +0100, Antony T Curtis wrote:
> 
>>I am still having problems with WinXP ... it appears to be trying to to
>>vram to vram color-expand pattern bitblts starting from the first byte
>>after the end of the current display
> 
> 
> ... and this is why I was suggesting a simple BitBLT capable chip,  so
> as to prevent the OS from trying to do the above.

5446 _is_ a simple BitBLT capable chip. IMHO, it will be difficult to 
find a simpler PCI chip.

The only drawback I see in this chip is that it has some ISA legacy 
which complicates a bit the VGA memory access. In particular, the mode 4 
and mode 5 will accur a serious performance loss if they are ever used. 
Moreover, Windows does not use the separate 16 MB data region for the 
bitblt data, which will also slow down a bit the optimized version of 
the driver (I want to suppress the memory callback functions in the most 
common cases).

SIS6326 would be better in that respect. Now, thanks to the work done to 
integrate the Cirrus VGA driver, the QEMU VGA subsystem is more generic 
so anyone is free to add new VGA cards :-)

Fabrice.