--- a/target-utils/pln-ppb-test/mode_entry.c	Sat Dec 02 23:50:07 2023 +0000
+++ b/target-utils/pln-ppb-test/mode_entry.c	Sun Dec 03 00:01:03 2023 +0000
@@ -30,3 +30,24 @@
 	*(volatile u16 *)(addr + 0x554) = 0x55;
 	*(volatile u16 *)(addr + 0xAAA) = mode;
 }
+
+void
+cmd_mode_exit(argbulk)
+	char *argbulk;
+{
+	char *argv[2];
+	u_long addr;
+
+	if (parse_args(argbulk, 1, 1, argv, 0) < 0)
+		return;
+	if (parse_hexarg(argv[0], 8, &addr) < 0) {
+		printf("ERROR: argument must be a valid 32-bit hex address\n");
+		return;
+	}
+	if (addr & 0xFFFF) {
+		printf("ERROR: address is not on 64 KiB boundary\n");
+		return;
+	}
+	*(volatile u16 *)addr = 0x90;
+	*(volatile u16 *)addr = 0x00;
+}