Re: [Qemu-devel] [edk2] [edk2 PATCH] OvmfPkg: split the variable store to a separate file

[Paolo Bonzini]

Il 22/11/2013 12:46, Laszlo Ersek ha scritto:
>> Also, I see a command line compatibility problem, especially if one
>> > wants OVMF.fd to become the default firmware.
> I don't understand. If you use the un-split build, you use the original
> command line (single -pflash or -drive if=pflash option).
> 
> If you use the split build, then you:
> - extend the first -drive if=pflash option with ",readonly" -- this is
> optional but recommended,
> - you add a second option after the first, pointing it to NVVARSTORE.fd
> (ie. its VM-specific, private copy).

Suppose OVMF.fd is already the default.  To add a non-volatile store,
you would have to do one of the following:

* -pflash /path/to/OVMF.fd -pflash NVVARSTORE.fd


Or alternatively, pc and q35 could use the current semantics forever.
UEFI-by-default will be tied to a separate machine type (pc-uefi, or
q35-uefi, or a different chipset) where -bios will also create a
cfi_pflash01 device and all pflash drives will be mapped below the
BIOS's.  So you would have one of the following:

* -M pc -pflash /path/to/OVMF.fd -pflash NVVARSTORE.fd

* -M pc-uefi -pflash NVVARSTORE.fd

> You don't specify OVMF.fd twice.

I meant the first time is inside QEMU, the second is on the command line.

> I think I don't fully understand your point.

I probably didn't express it well, also because I have no real idea to
offer (I don't like the "-M pc-uefi" either).

Paolo