When used with '-drive if=pflash', qemu will store UEFI variables
inside the firmware image file. That is unexpected for a file located in
the sysroot, which should be read-only, while it is normal for image
files in the deploy/images directory. Therefore that directory is a
better place for use with runqemu.
The name was chose so that "runqemu ovmf" can be used as shorthand for
"runqemu <full path>/ovmf.qcow2" by treating "ovmf" as the base name
of the firmware file. "ovmf.secboot.qcow2" is meant to be used for the
Secure Boot enabled firmware.
qcow2 is used because it is needed for "savevm" snapshots of a virtual
machine.
With code and variables stored in the same ovmf.qcow2 it is not
possible to update the firmware code without also overwriting the
variables. For users who care about persistent variables, the code and
variables are also provided as separate files, in ovmf.code.qcow2 and
ovmf.vars.qcow2.
The traditional usage of OVMF via the qemu bios parameter ("biosdir"
and/or "biosfilename" in runqemu) is no longer recommended, and
therefore this recipe no longer provides the bios.bin file. Instead,
OVMF is meant to be used as flash drive in qemu. See the "runqemu:
support UEFI with OVMF firmware" patch for details on how to use OVMF
that way.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
