Load video option ROM which is not embedded in system firmware image.

Load video option ROM which is not embedded in system firmware image.

QEMU will automatically fill the video BIOS image into memory at the
legacy video BIOS memory location (0xc0000).  This code will look
there for a EFI option rom image, and load it if it found.  This
allows the video option ROM to be separated out from the main system
firmware image.

QEMU does not appear to emulate the PCI rom expansion method
for making the video BIOS available to the system.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8942 6f19259b-4bc3-4df7-8a09-765794883524