Re: [PATCH 0/4] Add QemuRamfbDxe driver

[Laszlo Ersek <lersek@redhat.com>]

On 06/08/18 13:39, Gerd Hoffmann wrote:
> This is the efi driver for qemu ramfb, a simple boot framebuffer.
> Qemu patches just have been posted to qemu-devel.
> 
> Gerd Hoffmann (4):
>   OvmfPkg: add QEMU_RAMFB_GUID
>   OvmfPkg: add QemuRamfbDxe
>   OvmfPkg: add QemuRamfb to platform console
>   ArmVirtPkg: add QemuRamfbDxe
> 
>  OvmfPkg/Include/Guid/QemuRamfb.h                   |  25 ++
>  .../Library/PlatformBootManagerLib/PlatformData.c  |  44 +++
>  OvmfPkg/QemuRamfbDxe/QemuRamfb.c                   | 308 +++++++++++++++++++++
>  ArmVirtPkg/ArmVirtQemu.dsc                         |   2 +
>  ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc               |   1 +
>  ArmVirtPkg/ArmVirtQemuKernel.dsc                   |   2 +
>  OvmfPkg/OvmfPkg.dec                                |   1 +
>  OvmfPkg/OvmfPkgIa32.dsc                            |   1 +
>  OvmfPkg/OvmfPkgIa32.fdf                            |   1 +
>  OvmfPkg/OvmfPkgIa32X64.dsc                         |   1 +
>  OvmfPkg/OvmfPkgIa32X64.fdf                         |   1 +
>  OvmfPkg/OvmfPkgX64.dsc                             |   1 +
>  OvmfPkg/OvmfPkgX64.fdf                             |   1 +
>  OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf              |  34 +++
>  14 files changed, 423 insertions(+)
>  create mode 100644 OvmfPkg/Include/Guid/QemuRamfb.h
>  create mode 100644 OvmfPkg/QemuRamfbDxe/QemuRamfb.c
>  create mode 100644 OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
> 

Some testing related questions:

- What happens in the UEFI shell if you do recursive connect/disconnect
cycles for all handles in the system? (Preferably initiated from serial.)

- What happens if you locate the parent handle (with the VenHw node)
and/or the child handle (with the GOP on it), and try to disconnect them?

- Have you tested mode changes with the MODE command?

Expected results:

- recursive connect / disconnect should not break, as far as the entire
system is concerned; the procedure should simply skip ramfb.

- targeted connect / disconnect for ramfb should fail (produce an error
message), but nothing should crash or stop working.

- mode changes should work.

I expect the first two behaviors because the driver is a platform DXE
driver, not a UEFI driver that conforms to the UEFI driver model -- we
don't install an EFI_DRIVER_BINDING_PROTOCOL instance, hence the driver
should be "invisible" to the connect / disconnect UEFI shell commands
(they should fail gracefully).

Thanks,
Laszlo