It's a UINT8 (enum) PCD telling where the PcdVideoHorizontalResolution
and PcdVideoVerticalResolution values are coming from. It can be:
0 (unset aka default from dsc file), or
1 (from PlatformConfig), or
2 (set by Video Driver).
It will be used by video drivers to avoid overriding PlatformConfig
values, or override each others values in case multiple display devices
are present.
The underlying problem this tries to solve is that the GOP protocol has
no way to indicate the preferred video mode. On physical hardware this
isn't much of a problem because using the highest resolution available
works just fine as that is typically the native display resolution
But in a virtual machine you don't want come up with a huge 4k window by
default just because the virtual vga is able to handle that. Cutting
down the video mode list isn't a great solution either as that would
also remove the modes from the platform configuration so the user
wouldn't be able to pick a resolution higher than the default any more.
So with patch drivers can use use PcdVideoHorizontalResolution and
PcdVideoVerticalResolution to indicate what the preferred display
resolution is, without overwriting the user preferences from
PlatformConfig if present.
A possible alternative approach would be to extend the GOP protocol, but
I'm not sure this is a good plan given this is mostly a problem for
virtual machines and using PCDs allows to keep this local to OvmfPkg.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
The header file declares the PlatformConfigSave() and PlatformConfigLoad()
functions (and defines related types and macros). The functions are
defined in "PlatformConfig.c" and called from "Platform.c".
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Suggested-by: Michael Kinney <michael.d.kinney@intel.com>
Ref: http://mid.mail-archive.com/E92EE9817A31E24EB0585FDF735412F56327F7D3@ORSMSX113.amr.corp.intel.com
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
The header file defines HII-related macros and types that are shared
between the form description in "PlatformForms.vfr" and the HII driver
logic "Platform.c".
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Suggested-by: Michael Kinney <michael.d.kinney@intel.com>
Ref: http://mid.mail-archive.com/E92EE9817A31E24EB0585FDF735412F56327F7D3@ORSMSX113.amr.corp.intel.com
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Generate the options for the drop-down list from the GOP resolutions.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15372 6f19259b-4bc3-4df7-8a09-765794883524
In this patch we populate the form with the two widgets related to video
resolution:
- A read-only string field displaying the preference for the next boot.
- A drop-down list offering choices for changing the setting. This list is
implemented with dynamically generated IFR opcodes.
(In general, the current preference may be missing, or it may be invalid
for the available video RAM size. The list of possible new settings is
filtered with the video RAM size.)
Because the form now becomes able to receive input, we must also implement
ExtractConfig(). This function tells the HII engine about the state of the
widgets.
For now we set up both widgets with static data only:
- The current preference always says "Unset". The driver code is still
isolated from the backend (the UEFI variable store).
- The list of possible resolutions offers 800x600 only. We don't
interrogate the GOP yet.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15369 6f19259b-4bc3-4df7-8a09-765794883524
The GraphicsConsoleDxe driver (in MdeModulePkg/Universal/Console)
determines the preferred video resolution from the dynamic PCDs
- gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution
- gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution
Setting the graphics resolution during boot is useful when the guest OS
(for lack of a dedicated display driver) continues to work with the
original GOP resolution and framebuffer.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15366 6f19259b-4bc3-4df7-8a09-765794883524
The two functions introduced here allow the saving and loading of platform
configuration to/from the non-volatile variable store.
The PLATFORM_CONFIG structure and the two functions that take it / return
it are generally meant for any DXE or UEFI driver that needs to access
platform configuration. For now we keep this small "library" internal to
PlatformDxe.
The PLATFORM_CONFIG wire format is intended only to grow over time (as
long as the variable GUID remains unchanged). At the introduction of new
fields, new feature flags must be added, and recognized in
PlatformConfigLoad().
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15365 6f19259b-4bc3-4df7-8a09-765794883524
This DXE driver will load/save persistent values for OVMF's config knobs,
plus expose those knobs via HII.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15364 6f19259b-4bc3-4df7-8a09-765794883524