OvmfPkg: non-null PcdLib instance for GraphicsConsoleDxe

GraphicsConsoleDxe (a UEFI_DRIVER under MdeModulePkg/Universal/Console)
determines the preferred video resolution from the dynamic PCDs
- gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution
- gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution

In one of the next patches, we'd like to change these PCDs. In order for
GraphicsConsoleDxe to retrieve the new values dynamically,
- it must be linked with the non-null instance of PcdLib,
- OvmfPkg must provide dynamic defaults.

We keep MdeModulePkg's 800x600 default resolution. (The UEFI specification
requires video drivers to support 800x600.)

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@15362 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: introduce gOvmfPlatformConfigGuid

This GUID should become a new "namespace" for UEFI variables that are
specific to OVMF configuration (as opposed to standard UEFI global
variables). We'll also use it as the GUID of the related HII form-set (ie.
the interactive user interface).

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@15363 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: introduce empty PlatformDxe

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
OvmfPkg: PlatformDxe: utility functions for saving / loading configuration

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
OvmfPkg: PlatformDxe: set preferred video resolution from platform config

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
OvmfPkg: PlatformDxe: add an empty HII form

... which opens from the Device Manager window.

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@15367 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: PlatformDxe: introduce state for the main form

We'll need a C language (ie. structure) representation for the state of
the visual elements on the form. We choose the Buffer Storage kind (see
29.2.5.6 "Storage" in UEFI 2.4A), because it's easy to work with.

Note that the structure added in this patch has nothing to do with UEFI
non-volatile variables.

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@15368 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: PlatformDxe: add form widgets for video modes

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
OvmfPkg/PlatformDxe: Silence warning seen with GCC48 IA32

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15370 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: QemuVideoDxe: serialize Start() against callbacks

If Start() succeeds, the callback is only executed when the setup is
complete (on the stack of RestoreTPL()), rather than on the stack of
InstallMultipleProtocolInterfaces(), when the driver setup may yet be
theoretically incomplete.

If Start() fails, the protocol interface will have been uninstalled
(rolled back) by the time the callback runs (again, on the stack of
RestoreTPL()). Since protocol notification callbacks begin with locating
the protocol interface in question, such attempts to locate will fail
immediately and save some work in the callback.

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@15371 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: PlatformDxe: get available resolutions from GOP

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
OvmfPkg: PlatformDxe: add save and discard buttons to the form

The RouteConfig() function is also called now as expected.

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@15373 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: PlatformDxe: connect ExtractConfig() to platform data

Establish the full stack of conversions in retrieving the platform
configuration:

    MultiConfigAltResp       -- form engine / HII communication
            ^
            |
     [BlockToConfig]
            |
     MAIN_FORM_STATE         -- binary representation of form/widget state
            ^
            |
[PlatformConfigToFormState]
            |
     PLATFORM_CONFIG         -- accessible to DXE and UEFI drivers
            ^
            |
   [PlatformConfigLoad]
            |
  UEFI non-volatile variable -- accessible to external utilities

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@15374 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: PlatformDxe: connect RouteConfig() to platform data

Establish the full stack of conversions when modifying the platform
configuration:

       ConfigResp            -- form engine / HII communication
            |
     [ConfigToBlock]
            |
            v
     MAIN_FORM_STATE         -- binary representation of form/widget state
            |
[FormStateToPlatformConfig]
            |
            v
     PLATFORM_CONFIG         -- accessible to DXE and UEFI drivers
            |
   [PlatformConfigSave]
            |
            v
  UEFI non-volatile variable -- accessible to external utilities

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@15375 6f19259b-4bc3-4df7-8a09-765794883524