Please... read my OP carefully.
I see @Rachit Rawat and @[Nut} have successfully add recovery to stock rom Jb 4.2 for xperia L and Xperia Z too with locked bootloader condition.
May i try to explain, with this method we just hijack the boot process of stock kernel, stock ramdisk to boot our custom boot script to launch the recovery. just like that. and about the unmout -l (lazy unmout) its to unmount every mountpoint that was mounted by original ramdisk so before the recovery launch its clean from mountpoint of original ramdisk.
Please check @Rachit Rawat thread here
Xperia L stock recovery
http://xdaforums.com/xperia-l/orig-development/cwm-recovery-installer-t2589320
thanks for you reply.
I know what you're trying to do, I can read source code. And I didn't say that it's impossible. I said that you're gonna have a bad time.