[build] Copy uefi headers into project

Eventually the UEFI headers should be brought in from their own project,
but for now, like the other projects under external/, these are being
copied into this repository.

Tags: boot uefi

external/uefi/protos/simple_file_system.h

@@ -0,0 +1,36 @@
+#pragma once
+#ifndef _uefi_protos_simple_file_system_h_
+#define _uefi_protos_simple_file_system_h_
+
+// This file was auto generated by the j6-uefi-headers project. Please see
+// https://github.com/justinian/j6-uefi-headers for more information.
+
+#include <uefi/guid.h>
+#include <uefi/types.h>
+#include <uefi/protos/file.h>
+
+namespace uefi {
+namespace protos {
+struct simple_file_system;
+
+struct simple_file_system
+{
+    static constexpr uefi::guid guid{ 0x0964e5b22,0x6459,0x11d2,{0x8e,0x39,0x00,0xa0,0xc9,0x69,0x72,0x3b} };
+
+    inline uefi::status open_volume(uefi::protos::file ** root) {
+        return _open_volume(this, root);
+    }
+
+    uint64_t revision;
+
+protected:
+    using _open_volume_def = uefi::status (*)(uefi::protos::simple_file_system *, uefi::protos::file **);
+    _open_volume_def _open_volume;
+
+public:
+};
+
+} // namespace protos
+} // namespace uefi
+
+#endif // _uefi_protos_simple_file_system_h_