I have a board here that uses an XGI Volari Z9s integrated graphics device. The board boots under coreboot and loads Linux, but if I add the appropriate VGA option ROM (extracted from the vendor BIOS) SeaBIOS hangs:
SeaBIOS (version rel-1.7.5-150-g301dd09-20150126_124858-apollo) Found mainboard ASUS KFSN4-DRE Relocating init from 0x000e6fe0 to 0x3ff95800 (size 42816) Found CBFS header at 0xfffffc80 CPU Mhz=2311 Found 26 PCI devices (max PCI bus is 05) Copying MPTABLE from 0x3ffe0400/3ffe0410 to 0x000f1550 Copying ACPI RSDP from 0x3ffe1400 to 0x000f1520 Copying SMBIOS entry point from 0x3ffec800 to 0x000f1500 Using pmtimer, ioport 0x2008 Scan for VGA option rom Running option rom at c000:0003
The Volari graphics initialise and work properly once Linux has booted and loaded the appropriate device drivers. For now I have been using SGABIOS for VGA emulation, however I would like to see the native VGA work on boot.