23 lines
1.1 KiB
Plaintext
23 lines
1.1 KiB
Plaintext
Enabling CONFIG_CSM allows SeaBIOS to be built as a Compatibility Support
|
|
Module for use with the OMVF/EDK-II UEFI firmware.
|
|
|
|
It will provide "legacy" BIOS services for booting non-EFI operating
|
|
systems and will also allow OVMF to display on otherwise unsupported
|
|
video hardware by using the traditional VGA BIOS.
|
|
|
|
Windows 2008r2 is known to use INT 10h BIOS calls even when booted via
|
|
EFI, and the presence of a CSM makes this work as expected too.
|
|
|
|
Having built SeaBIOS with CONFIG_CSM, you should be able to drop the
|
|
result (out/Csm16.bin) into your OVMF build tree at
|
|
OvmfPkg/Csm/Csm16/Csm16.bin and then build OVMF with 'build -D
|
|
CSM_ENABLE'. The SeaBIOS binary will be included as a discrete file
|
|
within the 'Flash Volume' which is created, and there are tools which
|
|
will extract it and allow it to be replaced; satisfying the
|
|
requirements of the LGPL licence.
|
|
|
|
A patch to OVMF is required, to prevent it from marking the region from
|
|
0xC0000-0xFFFFF as read-only before invoking our Legacy16Boot method. See
|
|
http://www.sourceforge.net/mailarchive/forum.php?thread_name=50FD7290.9060003%40redhat.com&forum_name=edk2-devel
|
|
|