[PATCH v2 1/3] tools: kwboot: Allow to specify custom baudrate only in supported operations

["Pali Rohár" <pali@kernel.org>]

Custom baudrate different than 115200 may be specified only when kwboot is
not going to send boot/debug message pattern or when it is going to send
boot message pattern with image file (in which case baudrate change happens
after sending kwbimage header). BootROM detects boot/debug message pattern
only at baudrate 115200.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 tools/kwboot.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 69d1be0f4823..986f27c2012a 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -2133,6 +2133,12 @@ main(int argc, char **argv)
 	if (optind != argc)
 		goto usage;
 
+	/* boot and debug message use baudrate 115200 */
+	if (((bootmsg && !imgpath) || debugmsg) && baudrate != 115200) {
+		fprintf(stderr, "Baudrate other than 115200 cannot be used for this operation.\n");
+		goto usage;
+	}
+
 	tty = kwboot_open_tty(ttypath, imgpath ? 115200 : baudrate);
 	if (tty < 0) {
 		perror(ttypath);
-- 
2.20.1