vboot: Add support for reading GBB flags

This change adds basic support for reading flags from GBB header
located in "GBB" section on SPI flash.

Change-Id: I35ecb5ba964511379baa4e9f458ba2e8c6b74b4e
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/25459
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/src/security/vboot/gbb.h b/src/security/vboot/gbb.h
new file mode 100644
index 0000000000..550548d613
--- /dev/null
+++ b/src/security/vboot/gbb.h
@@ -0,0 +1,39 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __SECURITY_VBOOT_GBB_H__
+#define __SECURITY_VBOOT_GBB_H__
+
+#include <stdint.h>
+
+/* In order to use GBB_FLAG_* macros from vboot, include gbb_header.h. */
+
+/*
+ * Read flags field from GBB header.
+ * Return value:
+ * Success: 32-bit unsigned integer representing flags field from GBB header.
+ * Error  : 0
+ */
+uint32_t gbb_get_flags(void);
+
+/*
+ * Check if given flag is set in the flags field in GBB header.
+ * Return value:
+ * true: Flag is set.
+ * false: Flag is not set or failure to read GBB flags.
+ */
+bool gbb_is_flag_set(uint32_t flag);
+
+#endif /* __SECURITY_VBOOT_GBB_H__ */