[UEFILDR] Add support for Apple Screen Info Protocol for old Macs

Author: DistroHopper39B

boot/freeldr/freeldr/arch/uefi/uefivid.c

@@ -16,6 +16,7 @@ DBG_DEFAULT_CHANNEL(UI);
 extern EFI_SYSTEM_TABLE* GlobalSystemTable;
 extern EFI_HANDLE GlobalImageHandle;
 EFI_GUID EfiGraphicsOutputProtocol = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+EFI_GUID AppleScreenInfoProtocol = APPLE_SCREEN_INFO_PROTOCOL_GUID;
 
 ULONG_PTR VramAddress;
 ULONG VramSize;
@@ -52,8 +53,9 @@ static EFI_PIXEL_BITMASK EfiPixelMasks[] =
 
 #endif /* UEFI */
 
+static
 EFI_STATUS
-UefiInitializeVideo(VOID)
+UefiInitializeGop(VOID)
 {
     EFI_STATUS Status;
     EFI_GRAPHICS_OUTPUT_PROTOCOL* gop = NULL;
@@ -128,6 +130,84 @@ UefiInitializeVideo(VOID)
     return Status;
 }
 
+static
+EFI_STATUS
+UefiInitializeAppleScreen(VOID)
+{
+    EFI_STATUS Status;
+    APPLE_SCREEN_INFO_PROTOCOL *AppleScreen = NULL;
+    EFI_PIXEL_BITMASK* pPixelBitmask;
+    
+    UINT64 BaseAddress, FrameBufferSize;
+    UINT32 BytesPerRow, Width, Height, Depth;
+    
+    Status = GlobalSystemTable->BootServices->LocateProtocol(&AppleScreenInfoProtocol, 0, (VOID**)&AppleScreen);
+    if (Status != EFI_SUCCESS)
+    {
+        ERR("Failed to find Apple Screen Info with status %d\n", Status);
+        return Status;
+    }
+    
+    Status = AppleScreen->GetInfo(AppleScreen,
+                                  &BaseAddress,
+                                  &FrameBufferSize,
+                                  &BytesPerRow,
+                                  &Width,
+                                  &Height,
+                                  &Depth);
+    
+    if (Status != EFI_SUCCESS)
+    {
+        ERR("Failed to get screen info from Apple Scren Info: %d\n", Status);
+        return Status;
+    }
+    
+    VramAddress = (ULONG_PTR) BaseAddress;
+    VramSize = (ULONG) FrameBufferSize;
+    
+    // All devices requiring Apple Screen Info use PixelBlueGreenRedReserved8BitPerColor.
+    pPixelBitmask = &EfiPixelMasks[PixelBlueGreenRedReserved8BitPerColor];
+    
+    if (!VidFbInitializeVideo(&FrameBufferData,
+                              VramAddress,
+                              VramSize,
+                              Width,
+                              Height,
+                              (BytesPerRow / 4),
+                              Depth,
+                              (PPIXEL_BITMASK)pPixelBitmask))
+    {
+        ERR("Couldn't initialize video framebuffer\n");
+        Status = EFI_UNSUPPORTED;
+    }
+    
+    return Status;
+}
+
+EFI_STATUS
+UefiInitializeVideo(VOID)
+{
+    EFI_STATUS Status;
+    
+    // First, try GOP
+    Status = UefiInitializeGop();
+    if (Status != EFI_SUCCESS)
+    {
+        // Try Apple Screen if that fails
+        TRACE("Cannot find video via GOP, falling back to Apple Screen Info\n");
+        Status = UefiInitializeAppleScreen();
+        if (Status != EFI_SUCCESS)
+        {
+            // Bail out, there's no graphics
+            ERR("Cannot find framebuffer!\n");
+            return Status;
+        }
+    }
+    
+    return EFI_SUCCESS;
+}
+
+
 VOID
 UefiVideoClearScreen(UCHAR Attr)
 {

boot/freeldr/freeldr/include/arch/uefi/uefildr.h

@@ -16,6 +16,7 @@
 #include <LoadedImage.h>
 #include <GraphicsOutput.h>
 #include <UgaDraw.h>
+#include <AppleScreenInfo.h>
 #include <BlockIo.h>
 #include <Acpi.h>
 #include <GlobalVariable.h>

sdk/include/reactos/edk2/AppleScreenInfo.h

@@ -0,0 +1,26 @@
+/*
+ * PROJECT:     ReactOS UEFI Support 
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Apple Graphics Info Protocol
+ * COPYRIGHT:   Copyright 2026 Sylas Hollander <distrohopper39b.business@gmail.com>
+ */
+ 
+#pragma once
+
+#define APPLE_SCREEN_INFO_PROTOCOL_GUID {0xe316e100, 0x0751, 0x4c49, {0x90, 0x56, 0x48, 0x6c, 0x7e, 0x47, 0x29, 0x03}}
+
+typedef struct _APPLE_SCREEN_INFO_PROTOCOL APPLE_SCREEN_INFO_PROTOCOL;
+
+typedef EFI_STATUS (EFIAPI *GetAppleScreenInfo)(
+    APPLE_SCREEN_INFO_PROTOCOL *This,
+    UINT64 *BaseAddress,
+    UINT64 *FrameBufferSize,
+    UINT32 *BytesPerRow,
+    UINT32 *Width,
+    UINT32 *Height,
+    UINT32 *Depth);
+
+struct _APPLE_SCREEN_INFO_PROTOCOL
+{
+    GetAppleScreenInfo GetInfo;
+};