Create a new boot/ directory

Quite a lot of the code in common/relates to booting and images. Before
adding more it seems like a good time to move the code into its own
directory.

Most files with 'boot' or 'image' in them are moved, except:

- autoboot.c which relates to U-Boot automatically running a script
- bootstage.c which relates to U-Boot timing

Drop the removal of boot* files from the output directory, since this
interfers with the symlinks created by tools and there does not appear
to be any such file from my brief testing.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
Tested-by: Artem Lapkin <email2tema@gmail.com>

boot/bootretry.c

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ */
+
+#include <common.h>
+#include <bootretry.h>
+#include <cli.h>
+#include <env.h>
+#include <errno.h>
+#include <time.h>
+#include <watchdog.h>
+
+#ifndef CONFIG_BOOT_RETRY_MIN
+#define CONFIG_BOOT_RETRY_MIN CONFIG_BOOT_RETRY_TIME
+#endif
+
+static uint64_t endtime;  /* must be set, default is instant timeout */
+static int      retry_time = -1; /* -1 so can call readline before main_loop */
+
+/***************************************************************************
+ * initialize command line timeout
+ */
+void bootretry_init_cmd_timeout(void)
+{
+	char *s = env_get("bootretry");
+
+	if (s != NULL)
+		retry_time = (int)simple_strtol(s, NULL, 10);
+	else
+		retry_time = CONFIG_BOOT_RETRY_TIME;
+
+	if (retry_time >= 0 && retry_time < CONFIG_BOOT_RETRY_MIN)
+		retry_time = CONFIG_BOOT_RETRY_MIN;
+}
+
+/***************************************************************************
+ * reset command line timeout to retry_time seconds
+ */
+void bootretry_reset_cmd_timeout(void)
+{
+	endtime = endtick(retry_time);
+}
+
+int bootretry_tstc_timeout(void)
+{
+	while (!tstc()) {	/* while no incoming data */
+		if (retry_time >= 0 && get_ticks() > endtime)
+			return -ETIMEDOUT;
+		WATCHDOG_RESET();
+	}
+
+	return 0;
+}
+
+void bootretry_dont_retry(void)
+{
+	retry_time = -1;
+}