[PATCH 4/6] membuf: Add an easy way to set up a buffer with data

[Simon Glass]

In some cases it is useful to set up a buffer with some data to read,
e.g. when reading lines from a text file. Add a helper for this.

Tidy up the comment for membuf_init() while we are here.

Signed-off-by: Simon Glass <s...@chromium.org>
---

 include/membuf.h | 15 ++++++++++++++-
 lib/membuf.c     |  8 ++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/include/membuf.h b/include/membuf.h
index b495a72652b..f5c474cf730 100644
--- a/include/membuf.h
+++ b/include/membuf.h
@@ -222,7 +222,9 @@ int membuf_readline(struct membuf *mb, char *str, int 
maxlen, int minch,
 int membuf_extend_by(struct membuf *mb, int by, int max);
 
 /**
- * membuf_init() - set up a new membuff using an existing membuff
+ * membuf_init() - set up a new membuff using an existing buffer
+ *
+ * The buffer is initially empty
  *
  * @mb: membuff to set up
  * @buff: Address of buffer
@@ -230,6 +232,17 @@ int membuf_extend_by(struct membuf *mb, int by, int max);
  */
 void membuf_init(struct membuf *mb, char *buff, int size);
 
+/**
+ * membuf_init_with_data() - set up a new membuff using existing data
+ *
+ * The buffer is set up to contain the provided data
+ *
+ * @mb: membuff to set up
+ * @buff: Address of buffer
+ * @size: Size of buffer
+ */
+void membuf_init_with_data(struct membuf *mb, char *buff, int size);
+
 /**
  * membuf_uninit() - clear a membuff so it can no longer be used
  *
diff --git a/lib/membuf.c b/lib/membuf.c
index 016430ae988..347c92e3326 100644
--- a/lib/membuf.c
+++ b/lib/membuf.c
@@ -405,6 +405,14 @@ void membuf_init(struct membuf *mb, char *buff, int size)
        membuf_purge(mb);
 }
 
+void membuf_init_with_data(struct membuf *mb, char *buff, int size)
+{
+       char *data;
+
+       membuf_init(mb, buff, size);
+       membuf_putraw(mb, size, true, &data);
+}
+
 int membuf_new(struct membuf *mb, int size)
 {
        mb->start = malloc(size);
-- 
2.43.0