cmd/fat: Do not crash on write when <bytes> is not specified

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>

diff --git a/cmd/fat.c b/cmd/fat.c
index 4e207462d93e9a1301d32b2a379e29149251a351..ad1dc2a49f1162ce52eaab706817bbbec5aeef8e 100644 (file)
--- 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'"
 );