[coreboot-gerrit] Change in ...coreboot[master]: lib/fmap: Add area read/write functions

[T.Michael Turney (Code Review)]

Hello T Michael Turney,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/32287

to review the following change.

Change subject: lib/fmap: Add area read/write functions
......................................................................

lib/fmap: Add area read/write functions

Change-Id: I7669b8dc07b1aa5f00e7d8d0b1305b3de6c5949c
Signed-off-by: T Michael Turney 
---
M src/include/fmap.h
M src/lib/fmap.c
2 files changed, 30 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/87/32287/1

diff --git a/src/include/fmap.h b/src/include/fmap.h
index 5834831..ab7e5ab 100644
--- a/src/include/fmap.h
+++ b/src/include/fmap.h
@@ -40,4 +40,12 @@
  * Return 0 on success, < 0 on error. */
 int fmap_find_region_name(const struct region * const ar,
    char name[FMAP_STRLEN]);
+
+/* Read fmap area into provided buffer.
+ * Return size read on success, < 0 on error. */
+ssize_t fmap_read_area(const char *name, void *buffer, size_t size);
+
+/* Write provided buffer into fmap area.
+ * Return size written on success, < 0 on error. */
+ssize_t fmap_overwrite_area(const char *name, const void *buffer, size_t size);
 #endif
diff --git a/src/lib/fmap.c b/src/lib/fmap.c
index 9602134..e18f406 100644
--- a/src/lib/fmap.c
+++ b/src/lib/fmap.c
@@ -173,3 +173,25 @@

return -1;
 }
+
+ssize_t fmap_read_area(const char *name, void *buffer, size_t size)
+{
+	struct region_device rdev;
+	if (fmap_locate_area_as_rdev(name, &rdev))
+		return -1;
+	return rdev_readat(&rdev, buffer, 0,
+			MIN(size, region_device_sz(&rdev)));
+}
+
+ssize_t fmap_overwrite_area(const char *name, const void *buffer, size_t size)
+{
+	struct region_device rdev;
+
+	if (fmap_locate_area_as_rdev_rw(name, &rdev))
+		return -1;
+	if (size > region_device_sz(&rdev))
+		return -1;
+	if (rdev_eraseat(&rdev, 0, region_device_sz(&rdev)) == -1)
+		return -1;
+	return rdev_writeat(&rdev, (const void *)buffer, 0, size);
+}