efi: Use the correct GUID for the SMBIOS table

EFI does not use the 'anchor string' to determine the SMBIOS table
version, instead preferring to have two separate GUIDs. Use the correct
one, depending on the table version.

Call unmap_system() to balance to the use of map_sysmem()

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/efi_api.h b/include/efi_api.h
index 0e92cb8..ab40b1b 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -433,6 +433,10 @@
 	EFI_GUID(0xeb9d2d31, 0x2d88, 0x11d3,  \
 		 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 
+#define SMBIOS3_TABLE_GUID \
+	EFI_GUID(0xf2fd1544, 0x9794, 0x4a2c, \
+		 0x99, 0x2e, 0xe5, 0xbb, 0xcf, 0x20, 0xe3, 0x94)
+
 #define EFI_LOAD_FILE_PROTOCOL_GUID \
 	EFI_GUID(0x56ec3091, 0x954c, 0x11d2, \
 		 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
diff --git a/lib/efi_loader/efi_smbios.c b/lib/efi_loader/efi_smbios.c
index 49adc87..5cbce6d 100644
--- a/lib/efi_loader/efi_smbios.c
+++ b/lib/efi_loader/efi_smbios.c
@@ -14,6 +14,8 @@
 #include <smbios.h>
 #include <linux/sizes.h>
 
+const efi_guid_t smbios3_guid = SMBIOS3_TABLE_GUID;
+
 enum {
 	TABLE_SIZE	= SZ_4K,
 };
@@ -25,8 +27,10 @@
  */
 efi_status_t efi_smbios_register(void)
 {
+	const efi_guid_t *guid;
 	ulong addr;
 	efi_status_t ret;
+	void *buf;
 
 	addr = gd_smbios_start();
 	if (!addr) {
@@ -42,8 +46,12 @@
 	log_debug("EFI using SMBIOS tables at %lx\n", addr);
 
 	/* Install SMBIOS information as configuration table */
-	return efi_install_configuration_table(&smbios_guid,
-					       map_sysmem(addr, 0));
+	buf = map_sysmem(addr, 0);
+	guid = !memcmp(buf, "_SM_", 4) ? &smbios_guid : &smbios3_guid;
+	ret = efi_install_configuration_table(guid, buf);
+	unmap_sysmem(buf);
+
+	return ret;
 }
 
 static int install_smbios_table(void)