From e425501ea7af0e2cf0397b46bf65f9275f2a5659 Mon Sep 17 00:00:00 2001
From: Joursoir <chat@joursoir.net>
Date: Fri, 25 Mar 2022 17:02:48 +0300
Subject: main: locate graphics output protocol

---
 UefiMonitorTest/UefiMonitorTest.c | 47 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/UefiMonitorTest/UefiMonitorTest.c b/UefiMonitorTest/UefiMonitorTest.c
index f7c9f04..7cdff88 100644
--- a/UefiMonitorTest/UefiMonitorTest.c
+++ b/UefiMonitorTest/UefiMonitorTest.c
@@ -10,6 +10,45 @@
 
 #include <Protocol/GraphicsOutput.h>
 
+STATIC
+EFI_GRAPHICS_OUTPUT_PROTOCOL *
+GetGraphicsOutputProtocol (
+  VOID
+  )
+{
+  EFI_STATUS                            Status;
+  EFI_GRAPHICS_OUTPUT_PROTOCOL          *Gop;
+  EFI_GRAPHICS_OUTPUT_MODE_INFORMATION  *ModeInfo;
+  UINTN                                 SizeOfInfo;
+
+  Status = gBS->LocateProtocol (
+                  &gEfiGraphicsOutputProtocolGuid,
+                  NULL,
+                  (VOID **)&Gop
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "Unable to locate GOP\n"));
+    return NULL;
+  }
+
+  Status = Gop->QueryMode (
+                  Gop,
+                  (Gop->Mode == NULL) ? 0 : Gop->Mode->Mode,
+                  &SizeOfInfo,
+                  &ModeInfo
+                  );
+  if (Status == EFI_NOT_STARTED) {
+    Status = Gop->SetMode (Gop, 0);
+  }
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "Unable to get native mode\n"));
+    return NULL;
+  }
+
+  // TODO: free ModeInfo
+  return Gop;
+}
+
 EFI_STATUS
 EFIAPI
 UefiMain (
@@ -17,5 +56,13 @@ UefiMain (
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
 {
+  EFI_GRAPHICS_OUTPUT_PROTOCOL  *Gop;
+
+  Gop = GetGraphicsOutputProtocol ();
+  if (Gop == NULL) {
+    Print (L"Error: Getting a Graphical Output Protocol is failed\n");
+    return EFI_NOT_FOUND;
+  }
+
   return EFI_SUCCESS;
 }
-- 
cgit v1.2.3-18-g5258