cbfstool: Add way to access entire backing data for a buffer

This is required to handle certain relative-to-flash-start offsets.

BUG=none
BRANCH=tot
TEST=none

Change-Id: I8b30c7b532e330af5db4b8ed65b21774c6cbbd25
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 596ba1aaa62aedb2b214ca55444e3068b9cb1044
Original-Change-Id: Idc9a5279f16951befec4d84aab35117988f7edb7
Original-Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/312220
Original-Commit-Ready: Patrick Georgi <pgeorgi@chromium.org>
Original-Tested-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/12415
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/util/cbfstool/common.h b/util/cbfstool/common.h
index b61c2c0a5e..561a17abe3 100644
--- a/util/cbfstool/common.h
+++ b/util/cbfstool/common.h
@@ -120,6 +120,14 @@ static inline bool buffer_check_magic(const struct buffer *b, const char *magic,
 					memcmp(b->data, magic, magic_len) == 0;
 }
 
+/* Returns the start of the underlying buffer, with the offset undone */
+static inline void *buffer_get_original_backing(const struct buffer *b)
+{
+	if (!b)
+		return NULL;
+	return b->data - b->offset;
+}
+
 /* Creates an empty memory buffer with given size.
  * Returns 0 on success, otherwise non-zero. */
 int buffer_create(struct buffer *buffer, size_t size, const char *name);