[U-Boot] [PATCH v3] cmd_fat: add FAT write command

[Donggeun Kim]

Once CONFIG_FAT_WRITE is defined,
users can invoke 'fatwrite' command that saves data in RAM as a FAT file.

By removing variable of 'part_size' in fs/fat.c,
compile error occurs when enabling FAT write feature.
The variable should be declared only when CONFIG_FAT_WRITE is defined.
This patch also removes compile error when FAT write is enabled and
compile warning when FAT write is disabled.

Signed-off-by: Donggeun Kim <dg77.kim at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
Changes for v3:
   - use cmd_usage function
Changes for v2:
   - merge the patch that fixes compile error when enabling FAT write
   - change do_fat_fswrite to be static function

 common/cmd_fat.c |   57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/fat/fat.c     |    7 ++++++
 2 files changed, 64 insertions(+), 0 deletions(-)

diff --git a/common/cmd_fat.c b/common/cmd_fat.c
index 0220494..fef1c82 100644
--- a/common/cmd_fat.c
+++ b/common/cmd_fat.c
@@ -184,3 +184,60 @@ U_BOOT_CMD(
 	"<interface> <dev[:part]>\n"
 	"    - print information about filesystem from 'dev' on 'interface'"
 );
+
+#ifdef CONFIG_FAT_WRITE
+static int do_fat_fswrite(cmd_tbl_t *cmdtp, int flag,
+		int argc, char * const argv[])
+{
+	long size;
+	unsigned long addr;
+	unsigned long count;
+	block_dev_desc_t *dev_desc = NULL;
+	int dev = 0;
+	int part = 1;
+	char *ep;
+
+	if (argc < 5)
+		return cmd_usage(cmdtp);
+
+	dev = (int)simple_strtoul(argv[2], &ep, 16);
+	dev_desc = get_dev(argv[1], dev);
+	if (dev_desc == NULL) {
+		puts("\n** Invalid boot device **\n");
+		return 1;
+	}
+	if (*ep) {
+		if (*ep != ':') {
+			puts("\n** Invalid boot device, use `dev[:part]' **\n");
+			return 1;
+		}
+		part = (int)simple_strtoul(++ep, NULL, 16);
+	}
+	if (fat_register_device(dev_desc, part) != 0) {
+		printf("\n** Unable to use %s %d:%d for fatwrite **\n",
+			argv[1], dev, part);
+		return 1;
+	}
+	addr = simple_strtoul(argv[3], NULL, 16);
+	count = simple_strtoul(argv[5], NULL, 16);
+
+	size = file_fat_write(argv[4], (void *)addr, count);
+	if (size == -1) {
+		printf("\n** Unable to write \"%s\" from %s %d:%d **\n",
+			argv[4], argv[1], dev, part);
+		return 1;
+	}
+
+	printf("%ld bytes write\n", size);
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	fatwrite,	6,	0,	do_fat_fswrite,
+	"write file into a dos filesystem",
+	"<interface> <dev[:part]> <addr> <filename> <bytes>\n"
+	"    - write file 'filename' from the address 'addr' in RAM\n"
+	"      to 'dev' on 'interface'"
+);
+#endif
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 9a29458..40c0538 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -47,6 +47,10 @@ static block_dev_desc_t *cur_dev = NULL;
 
 static unsigned long part_offset = 0;
 
+#ifdef CONFIG_FAT_WRITE
+static unsigned long part_size;
+#endif
+
 static int cur_part = 1;
 
 #define DOS_PART_TBL_OFFSET	0x1be
@@ -101,6 +105,9 @@ int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
 		if (!get_partition_info(dev_desc, part_no, &info)) {
 			part_offset = info.start;
 			cur_part = part_no;
+#ifdef CONFIG_FAT_WRITE
+			part_size = info.size;
+#endif
 		} else if ((strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET],
 				    "FAT", 3) == 0) ||
 			   (strncmp((char *)&buffer[DOS_FS32_TYPE_OFFSET],
-- 
1.7.4.1