From 49a2d8cbf5191efd5c2709acd1a1e64f0d9599de Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 17 Jan 2022 10:58:17 +0100
Subject: OvmfPkg/QemuVideoDxe: parse edid blob, detect display resolution

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 1280x800 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>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
---
 OvmfPkg/QemuVideoDxe/Initialize.c     | 102 +++++++++++++++++++++++++++++++++-
 OvmfPkg/QemuVideoDxe/Qemu.h           |   2 +
 OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf |   3 +
 3 files changed, 105 insertions(+), 2 deletions(-)

(limited to 'OvmfPkg/QemuVideoDxe')

diff --git a/OvmfPkg/QemuVideoDxe/Initialize.c b/OvmfPkg/QemuVideoDxe/Initialize.c
index 8c5c9176ad..2a3cbc65c3 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,
diff --git a/OvmfPkg/QemuVideoDxe/Qemu.h b/OvmfPkg/QemuVideoDxe/Qemu.h
index 1e6507f44c..57341a0bbf 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/QemuVideoDxe.inf b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
index fe8befd51d..43a6e07faa 100644
--- a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+++ b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
@@ -63,4 +63,7 @@
 
 [Pcd]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
+  gUefiOvmfPkgTokenSpaceGuid.PcdVideoResolutionSource
   gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
+  gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution
+  gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution
-- 
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