Add flag to GBB to allow loading PCI Option ROMs
As shipped, H2C only loads the option ROM for the built-in video, and that
only when it needs display the BIOS warning screens.
By setting a flag in the GBB, you can allow all option ROMs to be loaded:
Note that we'll never enable this ourselves (and there's a factory test to
ensure that*) because it executes non-verified code. But if a customer wants
to void their warranty and set this flag in the read-only flash so they can
install and use other PCI devices, they should be able to do so.
BUG=chrome-os-partner:6148
TEST=none
The only way to test this is to use a BIOS that was compiled with serial
debugging enabled, so there's nothing for QA to do. If you have such a BIOS,
you can see the difference like so:
flashrom -r oldbios.bin
gbb_utility -s --flags=2 oldbios.bin newbios.bin
flashrom -w newbios.bin
<reboot>
When bit 1 of the GBB flags is 0, you'll see these lines in the serial
output:
LoadOpRomImage-->GetSystemConfigurationTable Status = Success
LoadOpRomImage-->GetH2cBootMode Status = Success
When bit 1 of the GBB flags is 1, you'll see these lines in the serial
output:
LoadOpRomImage-->GetSystemConfigurationTable Status = Success
LoadOpRomImage-->GetH2cBootMode Status = Success
LoadOpRomImage-->PCI OpRom on 1.0.0 is allowed!!!
This happens in any boot mode (normal, developer, recovery).
--
*The factory test for GBB zero flags is gft_clear_gbb_flags.sh, in
src/platform/factory_test_tools
Change-Id: I31a10cc9d562b4b83669ca8a114b60e87ae28b0a
Reviewed-on: https://gerrit.chromium.org/gerrit/11505
Tested-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
4 files changed