Look in known directories for OVMF

Makefile

@@ -1,7 +0,0 @@
-.PHONY: all
-all:
-	@./rscons
-
-.PHONY: run
-run: all
-	qemu-system-x86_64 -bios OVMF.fd -hdb build/e.1/efi-loader.img

Rsconscript

@@ -1,13 +1,14 @@
 configure do
   check_program "mformat"
   check_program "x86_64-w64-mingw32-gcc"
+  check_cfg package: "gnu-efi", use: false
 end
 
 class Image < Builder
   def run(options)
     unless @cache.up_to_date?(@target, nil, @sources, @env)
       print_run_message("Image <target>#{@target}<reset>", nil)
-      system(*%W[dd if=/dev/zero of=#{@target} bs=1k count=1440])
+      File.binwrite(@target, "\0" * (1440 * 1024))
       system(*%W[mformat -i #{@target} -f 1440 ::])
       system(*%W[mmd -i #{@target} ::/EFI])
       system(*%W[mmd -i #{@target} ::/EFI/BOOT])
@@ -18,14 +19,24 @@ class Image < Builder
   end
 end
 
-env do |env|
+uefi_env = env "uefi" do |env|
   env.add_builder(Image)
   env["CC"] = "x86_64-w64-mingw32-gcc"
   env["CPPPATH"] += %w[/usr/include/efi /usr/include/efi/x86_64]
   env["CFLAGS"] += %w[-ffreestanding]
   env["LDFLAGS"] += %w[-nostdlib -Wl,-dll -shared -Wl,--subsystem,10 -e efi_main]
   env["LIBS"] += %w[gcc]
-  env["sources"] = glob("*.c")
+  env["sources"] = glob("src/**/*.c")
   env.Program("^/BOOTX64.EFI", "${sources}")
   env.Image("^/efi-loader.img", "^/BOOTX64.EFI")
 end
+
+task "run" do
+  ovmf = "OVMF.fd"
+  if File.exist?("/usr/share/edk2/x64/OVMF.fd")
+    ovmf = "/usr/share/edk2/x64/OVMF.fd"
+  elsif File.exist?("/usr/share/edk2/x64/OVMF.4m.fd")
+    ovmf = "/usr/share/edk2/x64/OVMF.4m.fd"
+  end
+	sh %W[qemu-system-x86_64 -bios #{ovmf} -drive file=#{uefi_env.expand("^/efi-loader.img")},format=raw]
+end

src/main.c

@@ -38,8 +38,19 @@ static void write_hex64(size_t n)
     write_string(s);
 }
 
+static void wait_key(void)
+{
+    EFI_INPUT_KEY key;
+    write_string(L"Press any key...\r\n");
+    while (g_system_table->ConIn->ReadKeyStroke(g_system_table->ConIn, &key) == EFI_NOT_READY)
+    {
+    }
+}
+
 static void check_gop_handle(EFI_HANDLE handle)
 {
+    write_string(L"Going to check GOP handle...\r\n");
+    wait_key();
     EFI_HANDLE interface = NULL;
     EFI_STATUS status = g_system_table->BootServices->HandleProtocol(handle,
             &(EFI_GUID)EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID,
@@ -63,6 +74,32 @@ static void check_gop_handle(EFI_HANDLE handle)
     write_string(L"\r\n");
 
     EFI_GRAPHICS_OUTPUT_PROTOCOL * gop = (EFI_GRAPHICS_OUTPUT_PROTOCOL *)interface;
+    UINTN info_size;
+    EFI_GRAPHICS_OUTPUT_MODE_INFORMATION * info;
+    for (uint32_t mode_number = 0u;
+         (status = gop->QueryMode(gop, mode_number, &info_size, &info)) == EFI_SUCCESS;
+         mode_number++)
+    {
+        write_string(L"Mode ");
+        write_uint(mode_number);
+        write_string(L": ");
+        write_uint(info->HorizontalResolution);
+        write_string(L"x");
+        write_uint(info->VerticalResolution);
+        write_string(L" f=");
+        write_uint(info->PixelFormat);
+        write_string(L" s=");
+        write_uint(info->PixelsPerScanLine);
+        write_string(L"\r\n");
+        g_system_table->BootServices->FreePool(info);
+        if ((mode_number % 20) == 19)
+        {
+            wait_key();
+        }
+    }
+    write_string(L"Error ");
+    write_uint(status);
+    write_string(L" from QueryMode\r\n");
 }
 
 static void dump_memory_map(void)
@@ -73,7 +110,7 @@ static void dump_memory_map(void)
     UINTN descriptor_size;
     UINT32 descriptor_version;
     EFI_STATUS status = g_system_table->BootServices->GetMemoryMap(&memory_map_size,
-            memory_map_buffer,
+            (EFI_MEMORY_DESCRIPTOR *)memory_map_buffer,
             &map_key,
             &descriptor_size,
             &descriptor_version);
@@ -114,10 +151,11 @@ EFI_STATUS
 efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE * system_table)
 {
     EFI_STATUS status;
-    EFI_INPUT_KEY key;
 
     g_system_table = system_table;
 
+    system_table->ConOut->ClearScreen(system_table->ConOut);
+
     write_string(L"My first EFI loader\r\n");
 
     status = system_table->ConIn->Reset(system_table->ConIn, FALSE);
@@ -149,10 +187,7 @@ efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE * system_table)
         check_gop_handle(buffer[i]);
     }
 
-    write_string(L"Press any key...\r\n");
+    wait_key();
-    while ((status = system_table->ConIn->ReadKeyStroke(system_table->ConIn, &key)) == EFI_NOT_READY)
-    {
-    }
 
     return status;
 }