[uboot] create uboot from github:

repo: https://github.com/u-boot/u-boot
	commit: d80bb749fab53da72c4a0e09b8c2d2aaa3103c91

Change-Id: Ie6434426e1ec15bc08bb1832798e371f3fd5fb29

u-boot-2021.10/cmd/arm/exception.c

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'exception' command can be used for testing exception handling.
+ *
+ * Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
+ */
+
+#include <common.h>
+#include <command.h>
+
+static int do_unaligned(struct cmd_tbl *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	/*
+	 * The LDRD instruction requires the data source to be four byte aligned
+	 * even if strict alignment fault checking is disabled in the system
+	 * control register.
+	 */
+	asm volatile (
+		"MOV r5, sp\n"
+		"ADD r5, #1\n"
+		"LDRD r6, r7, [r5]\n");
+	return CMD_RET_FAILURE;
+}
+
+static int do_breakpoint(struct cmd_tbl *cmdtp, int flag, int argc,
+			 char *const argv[])
+{
+	asm volatile ("BKPT #123\n");
+	return CMD_RET_FAILURE;
+}
+
+static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	/*
+	 * 0xe7f...f.	is undefined in ARM mode
+	 * 0xde..	is undefined in Thumb mode
+	 */
+	asm volatile (".word 0xe7f7defb\n");
+	return CMD_RET_FAILURE;
+}
+
+static struct cmd_tbl cmd_sub[] = {
+	U_BOOT_CMD_MKENT(breakpoint, CONFIG_SYS_MAXARGS, 1, do_breakpoint,
+			 "", ""),
+	U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned,
+			 "", ""),
+	U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
+			 "", ""),
+};
+
+static char exception_help_text[] =
+	"<ex>\n"
+	"  The following exceptions are available:\n"
+	"  breakpoint - prefetch abort\n"
+	"  unaligned  - data abort\n"
+	"  undefined  - undefined instruction\n"
+	;
+
+#include <exception.h>