From dba1ca186dfd0a8bfc06a3f40dec9218df41516d Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@devjustinian.com>
Date: Tue, 3 Jan 2017 08:03:07 -0800
Subject: [PATCH] Discover and set the best video mode supported by the UEFI
 graphics driver

---
 Makefile               |  5 +++++
 src/arch/x86_64/main.c | 45 +++++++++++++++++++++++++++++++++++++-----
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 5d4ad1f..ec3e3a2 100644
--- a/Makefile
+++ b/Makefile
@@ -144,6 +144,11 @@ $(BUILD_D)/fs.img: $(BUILD_D)/kernel.efi
 	rm $(TEMPFILE)
 	mv $@.tmp $@
 
+$(BUILD_D)/fs.iso: $(BUILD_D)/fs.img
+	mkdir -p $(BUILD_D)/iso
+	cp $< $(BUILD_D)/iso/
+	xorriso -as mkisofs -R -f -e fs.img -no-emul-boot -o $@ $(BUILD_D)/iso
+
 qemu: $(BUILD_D)/fs.img
 	"$(QEMU)" $(QEMUOPTS)
 
diff --git a/src/arch/x86_64/main.c b/src/arch/x86_64/main.c
index e9a15b0..6f42fcc 100644
--- a/src/arch/x86_64/main.c
+++ b/src/arch/x86_64/main.c
@@ -12,11 +12,46 @@ efi_main (EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 
 	InitializeLib(ImageHandle, SystemTable);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
-	status = ST->ConOut->OutputString(ST->ConOut, L"Hello from UEFI\n\r");
-#pragma GCC diagnostic pop
-	check_status(status, L"OutputString");
+	Print(L"Popcorn OS " GIT_VERSION L" booting...\n");
+
+	Print(L"Setting console display mode... ");
+
+	EFI_GRAPHICS_OUTPUT_PROTOCOL *gfx_out_proto;
+	EFI_GUID gfx_out_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+	status = SystemTable->BootServices->LocateProtocol(&gfx_out_guid, NULL, (void**)&gfx_out_proto);
+	check_status(status, "LocateProtocol gfx");
+
+	const uint32_t modes = gfx_out_proto->Mode->MaxMode;
+	uint32_t res =
+		gfx_out_proto->Mode->Info->HorizontalResolution *
+		gfx_out_proto->Mode->Info->VerticalResolution;
+	uint32_t best = (uint32_t)-1;
+
+	for (uint32_t i = 0; i < modes; ++i) {
+		UINTN size = 0;
+		EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info = NULL;
+		status = gfx_out_proto->QueryMode(gfx_out_proto, i, &size, &info);
+		check_status(status, "QueryMode");
+
+		const uint32_t new_res =
+			info->HorizontalResolution *
+			info->VerticalResolution;
+
+		if (new_res > res) {
+			best = i;
+			res = new_res;
+		}
+	}
+
+	if (best != (uint32_t)-1) {
+		status = gfx_out_proto->SetMode(gfx_out_proto, best);
+		check_status(status, "SetMode");
+		Print(L"*");
+	}
+	Print(L"%ux%u\n",
+		gfx_out_proto->Mode->Info->HorizontalResolution,
+		gfx_out_proto->Mode->Info->VerticalResolution);
+
 
 	Print(L" SystemTable: %x\n", SystemTable);
 	if (SystemTable)