[PATCH v2 5/5] OvmfPkg/QemuVideoDxe: parse edid blob, detect display resolution

["Gerd Hoffmann" <kraxel@redhat.com>]

Check whenever an EDID blob is present.  In case it is get the display
resolution from it.  Unless PcdVideoResolutionSource indicates the
display resolution has been set already update
PcdVideoHorizontalResolution and PcdVideoVerticalResolution accordingly.
Also add the resolution to the mode list.

This will make OVMF boot up with the display resolution configured by
QEMU, which is 1024x768 by default.  The resolution can be set using the
xres and yres properties.  Here is an example for FullHD:

qemu-system-x86_64 -device VGA,xres=1920,yres=1080

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3778
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1749250
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf |   3 +
 OvmfPkg/QemuVideoDxe/Qemu.h           |   2 +
 OvmfPkg/QemuVideoDxe/Initialize.c     | 102 +++++++++++++++++++++++++-
 3 files changed, 105 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
index fe8befd51d3c..43a6e07faa88 100644
--- a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+++ b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
@@ -63,4 +63,7 @@ [Protocols]
 
 [Pcd]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
+  gUefiOvmfPkgTokenSpaceGuid.PcdVideoResolutionSource
   gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
+  gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution
+  gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution
diff --git a/OvmfPkg/QemuVideoDxe/Qemu.h b/OvmfPkg/QemuVideoDxe/Qemu.h
index 1e6507f44caa..57341a0bbfc4 100644
--- a/OvmfPkg/QemuVideoDxe/Qemu.h
+++ b/OvmfPkg/QemuVideoDxe/Qemu.h
@@ -115,6 +115,8 @@ typedef struct {
   FRAME_BUFFER_CONFIGURE          *FrameBufferBltConfigure;
   UINTN                           FrameBufferBltConfigureSize;
   UINT8                           FrameBufferVramBarIndex;
+
+  UINT8                           Edid[128];
 } QEMU_VIDEO_PRIVATE_DATA;
 
 ///
diff --git a/OvmfPkg/QemuVideoDxe/Initialize.c b/OvmfPkg/QemuVideoDxe/Initialize.c
index 8c5c9176ad21..2a3cbc65c32a 100644
--- a/OvmfPkg/QemuVideoDxe/Initialize.c
+++ b/OvmfPkg/QemuVideoDxe/Initialize.c
@@ -284,6 +284,88 @@ QemuVideoBochsAddMode (
   Private->MaxMode++;
 }
 
+STATIC
+VOID
+QemuVideoBochsEdid (
+  QEMU_VIDEO_PRIVATE_DATA  *Private,
+  UINT32                   *XRes,
+  UINT32                   *YRes
+  )
+{
+  EFI_STATUS  Status;
+
+  if (Private->Variant != QEMU_VIDEO_BOCHS_MMIO) {
+    return;
+  }
+
+  Status = Private->PciIo->Mem.Read (
+                                 Private->PciIo,
+                                 EfiPciIoWidthUint8,
+                                 PCI_BAR_IDX2,
+                                 0,
+                                 sizeof (Private->Edid),
+                                 Private->Edid
+                                 );
+  if (Status != EFI_SUCCESS) {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: mmio read failed\n",
+      __FUNCTION__
+      ));
+    return;
+  }
+
+  if ((Private->Edid[0] != 0x00) ||
+      (Private->Edid[1] != 0xff))
+  {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: magic check failed\n",
+      __FUNCTION__
+      ));
+    return;
+  }
+
+  DEBUG ((
+    DEBUG_INFO,
+    "%a: blob found (extensions: %d)\n",
+    __FUNCTION__,
+    Private->Edid[126]
+    ));
+
+  if ((Private->Edid[54] == 0x00) &&
+      (Private->Edid[55] == 0x00))
+  {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: no detailed timing descriptor\n",
+      __FUNCTION__
+      ));
+    return;
+  }
+
+  *XRes = Private->Edid[56] | ((Private->Edid[58] & 0xf0) << 4);
+  *YRes = Private->Edid[59] | ((Private->Edid[61] & 0xf0) << 4);
+  DEBUG ((
+    DEBUG_INFO,
+    "%a: default resolution: %dx%d\n",
+    __FUNCTION__,
+    *XRes,
+    *YRes
+    ));
+
+  if (PcdGet8 (PcdVideoResolutionSource) == 0) {
+    Status = PcdSet32S (PcdVideoHorizontalResolution, *XRes);
+    ASSERT_RETURN_ERROR (Status);
+    Status = PcdSet32S (PcdVideoVerticalResolution, *YRes);
+    ASSERT_RETURN_ERROR (Status);
+    Status = PcdSet8S (PcdVideoResolutionSource, 2);
+    ASSERT_RETURN_ERROR (Status);
+  }
+
+  // TODO: register edid as gEfiEdidDiscoveredProtocolGuid ?
+}
+
 EFI_STATUS
 QemuVideoBochsModeSetup (
   QEMU_VIDEO_PRIVATE_DATA  *Private,
@@ -291,7 +373,7 @@ QemuVideoBochsModeSetup (
   )
 {
   UINT32  AvailableFbSize;
-  UINT32  Index;
+  UINT32  Index, XRes = 0, YRes = 0;
 
   //
   // Fetch the available framebuffer size.
@@ -374,13 +456,29 @@ QemuVideoBochsModeSetup (
   // Setup Video Modes
   //
   Private->ModeData = AllocatePool (
-                        sizeof (Private->ModeData[0]) * QEMU_VIDEO_BOCHS_MODE_COUNT
+                        sizeof (Private->ModeData[0]) * (QEMU_VIDEO_BOCHS_MODE_COUNT+1)
                         );
   if (Private->ModeData == NULL) {
     return EFI_OUT_OF_RESOURCES;
   }
 
+  QemuVideoBochsEdid (Private, &XRes, &YRes);
+  if (XRes && YRes) {
+    QemuVideoBochsAddMode (
+      Private,
+      AvailableFbSize,
+      XRes,
+      YRes
+      );
+  }
+
   for (Index = 0; Index < QEMU_VIDEO_BOCHS_MODE_COUNT; Index++) {
+    if ((QemuVideoBochsModes[Index].Width == XRes) &&
+        (QemuVideoBochsModes[Index].Height == YRes))
+    {
+      continue; // duplicate with edid resolution
+    }
+
     QemuVideoBochsAddMode (
       Private,
       AvailableFbSize,
-- 
2.34.1