diff --git a/qiboot/README b/qiboot/README
index f892773..198507c 100644
--- a/qiboot/README
+++ b/qiboot/README
@@ -54,11 +54,14 @@ Booting Heuristics
 Qi has one or more ways to fetch a kernel depending on the device it finds it is
 running on, for example on GTA02 it can use NAND and SD card devices.  It goes
 through these device-specific storage devices in order and tries to boot the
-first viable kernel it finds, usually /boot/uImage-device>.bin for example
+first viable kernel it finds, usually /boot/<uImage-device>.bin for example
 /boot/uImage-GTA02.bin.
 
 You can disable a rootfs for consideration for boot if you add a file
-/boot/noboot-<device>, eg, /boot/noboot-GTA02.
+/boot/noboot-<device>, eg, /boot/noboot-GTA02.  This differs from renaming or
+deleting the kernel image because updating the kernel package would give you a
+working kernel again and allow boot, whereas the noboot indication will remain
+until you remove it.
 
 The kernel commandline used is associated with the storage device and partition,
 this allows the correct root= line to be arrived at without any work.
diff --git a/qiboot/src/phase2.c b/qiboot/src/phase2.c
index 5a0367b..66d9150 100644
--- a/qiboot/src/phase2.c
+++ b/qiboot/src/phase2.c
@@ -178,6 +178,7 @@ void bootloader_second_phase(void)
 
 		/* is there a commandline append file? */
 
+		commandline_rootfs_append[0] = '\0';
 		read_file(this_board->append, (u8 *)commandline_rootfs_append,
 									   512);