Oliver Schinagl wrote:
You can do some things also without VSA. VSA is used to create virtual PCI devices for among other things sound and graphics. However, a native graphics driver such as the one in libpayload or xf86-video-geode may not need VSA to drive the graphics hardware.
I suppose I won't even need VSA? I intend on booting Linux only; so as long as that works, i'd be happy?
I think Linux will need VSA to be happy though.
How does this virtual PCI device thing work?
See http://www.amd.com/files/connectivitysolutions/geode/geode_gx/32663C_lx_gx_p...
The VSA blob installs a System Management Mode handler which traps instructions that normally access PCI hardware, and they are instead handled by the VSA code, which responds like PCI hardware would.
Or what should I imagine in that area? My mind draws a blank. I just know that usually your video chips is connected to the PCI bus. How would this all work on a virtual PCI bus?
The Geode is a different architecture, it uses a different bus called GeodeLink, and provides PCI compatibility on top of that.
Drivers that understand GeodeLink directly (such as the X graphics driver) do not need the PCI compat stuff.
If using seabios; would I need the VSA to draw the boot menu selection screen (assuming there exists such a thing even :)
Actually it's even worse. You need a VGA BIOS for the CPU, and I don't know if there is a free one available. There was a GSoC project last year to create one, and there were patches that worked on Geode LX, but I'm not sure about the status on GX2.
Those patches were for the SeaBIOS VGA BIOS "subproject" and I don't know for sure if VSA is needed, but I would guess that it is.
//Peter