From 454e3d90302d52b619e6df7ebbe716964cee016e Mon Sep 17 00:00:00 2001
From: =?utf8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Sun, 11 Sep 2016 22:51:42 +0200
Subject: [PATCH] cmd/fat: Do not crash on write when <bytes> is not specified
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

argc is checked, but is off by one. In case <bytes> is not specified,
create an empty file, which is identical to the ext4write behaviour.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 cmd/fat.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cmd/fat.c b/cmd/fat.c
index 4e207462d9..ad1dc2a49f 100644
--- a/cmd/fat.c
+++ b/cmd/fat.c
@@ -126,7 +126,7 @@ static int do_fat_fswrite(cmd_tbl_t *cmdtp, int flag,
 		return 1;
 	}
 	addr = simple_strtoul(argv[3], NULL, 16);
-	count = simple_strtoul(argv[5], NULL, 16);
+	count = (argc <= 5) ? 0 : simple_strtoul(argv[5], NULL, 16);
 
 	buf = map_sysmem(addr, count);
 	ret = file_fat_write(argv[4], buf, 0, count, &size);
@@ -145,7 +145,7 @@ static int do_fat_fswrite(cmd_tbl_t *cmdtp, int flag,
 U_BOOT_CMD(
 	fatwrite,	6,	0,	do_fat_fswrite,
 	"write file into a dos filesystem",
-	"<interface> <dev[:part]> <addr> <filename> <bytes>\n"
+	"<interface> <dev[:part]> <addr> <filename> [<bytes>]\n"
 	"    - write file 'filename' from the address 'addr' in RAM\n"
 	"      to 'dev' on 'interface'"
 );
-- 
2.39.5