sandbox: Allow Ctrl-C to work in sandbox

It is useful for Cltl-C to be handled by U-Boot as it is on other boards.
But it is also useful to be able to terminate U-Boot with Ctrl-C.

Add an option to enable signals while in raw mode, and make this the
default. Add an option to leave the terminal cooked, which is useful for
redirecting output.

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 35 insertions, 6 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 52e1096f3..9de71bb2b 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -104,21 +104,22 @@ void os_exit(int exit_code)
 
 /* Restore tty state when we exit */
 static struct termios orig_term;
+static bool term_setup;
 
 static void os_fd_restore(void)
 {
-	tcsetattr(0, TCSANOW, &orig_term);
+	if (term_setup)
+		tcsetattr(0, TCSANOW, &orig_term);
 }
 
 /* Put tty into raw mode so <tab> and <ctrl+c> work */
-void os_tty_raw(int fd)
+void os_tty_raw(int fd, bool allow_sigs)
 {
-	static int setup = 0;
 	struct termios term;
 
-	if (setup)
+	if (term_setup)
 		return;
-	setup = 1;
+	term_setup = true;
 
 	/* If not a tty, don't complain */
 	if (tcgetattr(fd, &orig_term))
@@ -128,7 +129,7 @@ void os_tty_raw(int fd)
 	term.c_iflag = IGNBRK | IGNPAR;
 	term.c_oflag = OPOST | ONLCR;
 	term.c_cflag = CS8 | CREAD | CLOCAL;
-	term.c_lflag = 0;
+	term.c_lflag = allow_sigs ? ISIG : 0;
 	if (tcsetattr(fd, TCSANOW, &term))
 		return;
 
diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 4d5569e64..36dfc0a40 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -184,6 +184,34 @@ static int sandbox_cmdline_cb_show_lcd(struct sandbox_state *state,
 SANDBOX_CMDLINE_OPT_SHORT(show_lcd, 'l', 0,
 			  "Show the sandbox LCD display");
 
+static const char *term_args[STATE_TERM_COUNT] = {
+	"raw-with-sigs",
+	"raw",
+	"cooked",
+};
+
+static int sandbox_cmdline_cb_terminal(struct sandbox_state *state,
+				       const char *arg)
+{
+	int i;
+
+	for (i = 0; i < STATE_TERM_COUNT; i++) {
+		if (!strcmp(arg, term_args[i])) {
+			state->term_raw = i;
+			return 0;
+		}
+	}
+
+	printf("Unknown terminal setting '%s' (", arg);
+	for (i = 0; i < STATE_TERM_COUNT; i++)
+		printf("%s%s", i ? ", " : "", term_args[i]);
+	puts(")\n");
+
+	return 1;
+}
+SANDBOX_CMDLINE_OPT_SHORT(terminal, 't', 1,
+			  "Set terminal to raw/cooked mode");
+
 int main(int argc, char *argv[])
 {
 	struct sandbox_state *state;