cmd: introduce 'write' command

It's almost no extra code to hook up a buddy to the 'read' command. In
fact, since the command is passed its own 'struct cmd_tbl', we can use
the exact same callback, and let it figure out for itself whether it
was invoked as "read" or "write".

Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Rasmus Villemoes <[email protected]>

Author: Rasmus Villemoes

cmd/Kconfig

@@ -1562,6 +1562,11 @@ config CMD_WDT
 	help
 	  This provides commands to control the watchdog timer devices.
 
+config CMD_WRITE
+	bool "write - Write binary data to a partition"
+	help
+	  Provides low-level write access to a partition.
+
 config CMD_AXI
 	bool "axi"
 	depends on AXI

cmd/Makefile

@@ -140,6 +140,7 @@ obj-$(CONFIG_CMD_PXE) += pxe.o
 obj-$(CONFIG_CMD_WOL) += wol.o
 obj-$(CONFIG_CMD_QFW) += qfw.o
 obj-$(CONFIG_CMD_READ) += read.o
+obj-$(CONFIG_CMD_WRITE) += read.o
 obj-$(CONFIG_CMD_REGINFO) += reginfo.o
 obj-$(CONFIG_CMD_REISER) += reiser.o
 obj-$(CONFIG_CMD_REMOTEPROC) += remoteproc.o

cmd/read.c

@@ -13,14 +13,14 @@
 #include <mapmem.h>
 #include <part.h>
 
-int do_read(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+static int
+do_rw(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	struct blk_desc *dev_desc = NULL;
 	struct disk_partition part_info;
 	ulong offset, limit;
+	uint blk, cnt, res;
 	void *addr;
-	uint blk;
-	uint cnt;
 	int part;
 
 	if (argc != 6) {
@@ -47,20 +47,35 @@ int do_read(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	}
 
 	if (cnt + blk > limit) {
-		printf("Read out of range\n");
+		printf("%s out of range\n", cmdtp->name);
 		return 1;
 	}
 
-	if (blk_dread(dev_desc, offset + blk, cnt, addr) != cnt) {
-		printf("Error reading blocks\n");
+	if (IS_ENABLED(CONFIG_CMD_WRITE) && !strcmp(cmdtp->name, "write"))
+		res = blk_dwrite(dev_desc, offset + blk, cnt, addr);
+	else
+		res = blk_dread(dev_desc, offset + blk, cnt, addr);
+
+	if (res != cnt) {
+		printf("%s error\n", cmdtp->name);
 		return 1;
 	}
 
 	return 0;
 }
 
+#ifdef CONFIG_CMD_READ
 U_BOOT_CMD(
-	read,	6,	0,	do_read,
+	read,	6,	0,	do_rw,
 	"Load binary data from a partition",
 	"<interface> <dev[:part|#partname]> addr blk# cnt"
 );
+#endif
+
+#ifdef CONFIG_CMD_WRITE
+U_BOOT_CMD(
+	write,	6,	0,	do_rw,
+	"Store binary data to a partition",
+	"<interface> <dev[:part|#partname]> addr blk# cnt"
+);
+#endif