feat(fwu): add basic definitions for GUID handling

The FWU metadata structure uses GUID's to identify the updatable
firmware images. Add some basic helper functions and
macros that would be used for working with the GUID datatype.

With the FWU feature enabled, these would then be used for image
identification and booting of images from a particular
bank(partition).

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Change-Id: Ia54c0402d72b503d6abd1d94bc751cc14602cd39
diff --git a/include/drivers/partition/efi.h b/include/drivers/partition/efi.h
new file mode 100644
index 0000000..e463f96
--- /dev/null
+++ b/include/drivers/partition/efi.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2021, Linaro Limited
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef DRIVERS_PARTITION_EFI_H
+#define DRIVERS_PARTITION_EFI_H
+
+#include <string.h>
+
+#include <tools_share/uuid.h>
+
+#define EFI_NAMELEN		36
+
+static inline int guidcmp(const void *g1, const void *g2)
+{
+	return memcmp(g1, g2, sizeof(struct efi_guid));
+}
+
+static inline void *guidcpy(void *dst, const void *src)
+{
+	return memcpy(dst, src, sizeof(struct efi_guid));
+}
+
+#define EFI_GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \
+	{ (a) & 0xffffffff,		\
+	  (b) & 0xffff,			\
+	  (c) & 0xffff,			\
+	  { (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } }
+
+#define NULL_GUID \
+	EFI_GUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, \
+		 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
+
+#endif /* DRIVERS_PARTITION_EFI_H */