cmd: Add pause command

This command is being introduced with the goal of allowing user-friendly
"generic use case" U-Boot builds to pause until user input under some
situations.

The main use case would be when a boot failure happens, to pause until
the user has had time to acknowledge the current state.

Tested using:

    make && ./u-boot -v -T -c 'ut lib lib_test_hush_pause'

Signed-off-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Cc: Simon Glass <sjg@chromium.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/cmd/pause.c b/cmd/pause.c
new file mode 100644
index 00000000000..c97833c0d70
--- /dev/null
+++ b/cmd/pause.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * Samuel Dionne-Riel <samuel@dionne-riel.com>
+ */
+
+#include <command.h>
+#include <stdio.h>
+
+static int do_pause(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	char *message = "Press any key to continue...";
+
+	if (argc == 2)
+		message = argv[1];
+
+	/* No newline, so it sticks to the bottom of the screen */
+	printf("%s", message);
+
+	/* Wait on "any" key... */
+	(void) getchar();
+
+	/* Since there was no newline, we need it now */
+	printf("\n");
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(pause, 2, 1, do_pause,
+	"delay until user input",
+	"[prompt] - Wait until users presses any key. [prompt] can be used to customize the message.\n"
+);