[PATCH] bbu: command: update via TFTP if no image given

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Booting barebox over TFTP is a common operation that even has a default
boot target: `boot bnet`.

Once, a chainloaded barebox was tested to work, it may need to be
persisted, which needs a cumbersome:

  barebox_update /mnt/tftp/${global.user}-barebox-${global.hostname}

Make this more straight-forward by interpreting barebox_update called
without any non-option argument to mean just that.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 commands/barebox-update.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/commands/barebox-update.c b/commands/barebox-update.c
index 4b23433e84f2..59db315e5650 100644
--- a/commands/barebox-update.c
+++ b/commands/barebox-update.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <command.h>
 #include <libfile.h>
+#include <globalvar.h>
 #include <getopt.h>
 #include <malloc.h>
 #include <errno.h>
@@ -20,6 +21,7 @@ static void print_handlers_list(void)
 
 static int do_barebox_update(int argc, char *argv[])
 {
+	char pathbuf[PATH_MAX];
 	int opt, ret, repair = 0;
 	struct bbu_data data = {};
 	struct bbu_handler *handler;
@@ -82,14 +84,17 @@ static int do_barebox_update(int argc, char *argv[])
 
 	if (argc - optind > 0) {
 		data.imagefile = argv[optind];
+	} else if (!repair) {
+		snprintf(pathbuf, sizeof(pathbuf), "/mnt/tftp/%s-barebox-%s",
+			 globalvar_get("user"), globalvar_get("hostname"));
+		data.imagefile = pathbuf;
+	}
 
+	if (data.imagefile) {
 		image = read_file(data.imagefile, &data.len);
 		if (!image)
 			return -errno;
 		data.image = image;
-	} else {
-		if (!repair)
-			return COMMAND_ERROR_USAGE;
 	}
 
 	ret = barebox_update(&data, handler);
-- 
2.39.2