== DF-3854: IGP board, ROM unreadable -> rdev->bios == NULL ==
r100_init: pre-AVIVO, radeon_get_bios() failed, driver continues
radeon_combios_i2c_init / connector table fallback engaged; first ext-TMDS modeset reaches radeon_combios_external_tmds_setup()

combios_get_table_offset(TMDS_POWER_ON) = 0x0000 (NULL bios -> 0, radeon_combios.c:131)
executing radeon_combios.c:2890:  rev = RBIOS8(offset);  i.e. bios[0] with bios == 0x0 ...
Segmentation fault (core dumped)
harness exit=139 (139=128+11 SIGSEGV => in-kernel: page fault on NULL -> panic)