[PATCH 1/3] nandwrite: add stricter sanity checking for blockalign

[David Oberhollenzer]

This patch makes sure that a virtual erase block is always
composed of a postivie number of erase blocks (i.e. 1 or more)
and enforces the block alignment to be a power of two as
suggested by the help text and assumed throughout the program.

Signed-off-by: David Oberhollenzer <david.oberhollenzer at sigma-star.at>
---
 nand-utils/nandwrite.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/nand-utils/nandwrite.c b/nand-utils/nandwrite.c
index 9602a6e..998c68c 100644
--- a/nand-utils/nandwrite.c
+++ b/nand-utils/nandwrite.c
@@ -191,9 +191,13 @@ static void process_options(int argc, char * const argv[])
 		errmsg_die("Can't specify negative device offset with option"
 				" -s: %lld", mtdoffset);
 
-	if (blockalign < 0)
-		errmsg_die("Can't specify negative blockalign with option -b:"
-				" %d", blockalign);
+	if (blockalign <= 0)
+		errmsg_die("Can't specify negative or zero blockalign with "
+				"option -b: %d", blockalign);
+
+	if (!is_power_of_2(blockalign))
+		errmsg_die("Can't specify a non-power-of-two blockalign with "
+				"option -b: %d", blockalign);
 
 	if (autoplace && noecc)
 		errmsg_die("Autoplacement and no-ECC are mutually exclusive");
-- 
2.10.2