he BIOS emulator in the board's firmware can only run real 16bit x86 code but QEMU vgabios is compiled for 16bit mode of an i386 CPU which has some opcodes that cannot be run so it will fail to init display with a BIOS emulation exception (seen on serial output) and no screen output will be produced. Even the VGA_FIXUP_ASM config option of vgabios which is supposed to work around problems with x86emu does not seem to help. This problem affects both pegasos2 and sam460ex firmwares. A work around is to use a real mode vgabios (or no vgabios let the OS init the card which means firmware output is only over serial until the OS starts and may not work with all drivers that depend on the card being init by firware ROM). Fortunately the VGABIOS-lgpl-latest.bin Plex86/Bochs LGPL VGABios from http://www.nongnu.org/vgabios/ does not have this problem and is a suitable replacement. One can use these via command line options, e.g. for cirrus VGA: -vga none -device cirrus-vga,romfile=VGABIOS-lgpl-latest.cirrus.bin with BIOS from same VGABios page that works better with SmartFirmware (although still producing some different errors) but guests may not have a cirrus driver so that needs further changes in the guest OS. The same problem also happens with ati-vga where similar workaround is to just disable rom with romfile="" or use a real card ROM but that may not work with the emulated card.
Fork
he BIOS emulator in the board's firmware can only run real 16bit x86 code but QEMU vgabios is compiled for 16bit mode of an i386 CPU which has some opcodes that cannot be run so it will fail to init display with a BIOS emulation exception (seen on serial output) and no screen output will be produced. Even the VGA_FIXUP_ASM config option of vgabios which is supposed to work around problems with x86emu does not seem to help. This problem affects both pegasos2 and sam460ex firmwares. A work around is to use a real mode vgabios (or no vgabios let the OS init the card which means firmware output is only over serial until the OS starts and may not work with all drivers that depend on the card being init by firware ROM). Fortunately the VGABIOS-lgpl-latest.bin Plex86/Bochs LGPL VGABios from http://www.nongnu.org/vgabios/ does not have this problem and is a suitable replacement. One can use these via command line options, e.g. for cirrus VGA: -vga none -device cirrus-vga,romfile=VGABIOS-lgpl-latest.cirrus.bin with BIOS from same VGABios page that works better with SmartFirmware (although still producing some different errors) but guests may not have a cirrus driver so that needs further changes in the guest OS. The same problem also happens with ati-vga where similar workaround is to just disable rom with romfile="" or use a real card ROM but that may not work with the emulated card.