Disable serial console clock gating:

touch /mnt/us/DO_NOT_KILL_UART

Disable automatic kernel backup in the case of crc mismatch:

diff --git etc/init.d/ckimage etc/init.d/ckimage
--- /etc/init.d/ckimage
+++ /etc/init.d/ckimage
@@ -79,23 +79,6 @@ perform_check()
 check_kernels()
 {
 	check_curker_info
-	RES=$?
-	if [ ${RES} -eq 2 ]; then
-		msg "backup kernel is out of date - updating" I		
-		flash_unlock $OFDEV
-		dd if=$IFMTD of=$OFMTD bs=128K
-		flash_lock $OFDEV 0 -1
-
-		check_curker_info
-		RES=$?
-		if [ ${RES} -ne 0 ]; then
-			msg "backup kernel still mismatch current kernel" W		
-		else
-			msg "backup kernel is the same as current kernel" I		
-		fi
-	elif [ ${RES} -eq 1 ]; then
-		msg "backup kernel is younger than current kernel : we may be doing an OTA, bailing out" W
-	fi
 }

Disable diagnostics:

diff --git /etc/init.d/filesystems /etc/init.d/filesystems
--- /etc/init.d/filesystems
+++ /etc/init.d/filesystems
@@ -91,7 +91,6 @@ mount_var()
 
 	mount_var_tmp
 	mount_var_local
-	mount_diags
 	wait 
 }