GoflexNet with corrupted init.d/rcS can't boot fully (5 replies)

I was hacking my GoFlexNet pogoplug to install miniDLNA package and somehow I corrupted the /etc/init.d/rcS script file and when I boot, it gets to the point where the rcS script starts to run but it never completes the script. I had ssh access and have now got serial port working. I can break into uboot shell, and I'm hoping there is some way to use the serial port to break into the /bin/sh that is running the rcS script. Here's snippets of the serial port output:

U-Boot 1.1.4 Cloud Engines 1.1.2 (3.4.22) SATA PHYADDR=0
[ 0.880000] Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
[ 0.890000] serial8250.0: ttyS0 at MMIO 0xf1012000 (irq = 33) is a 16550A
[ 7.380000] Freeing init memory: 124K
init started: BusyBox v1.7.0 (2008-02-26 19:25:17 IST)
starting pid 264, tty '': '/etc/init.d/rcS'

My limited linux/unix skills lead me to believe that if I could use the uboot env vars so that the Busybox starts using the serial port so I could break into the shell running rcS. (Maybe I'm wrong that an RS-232 'break' sent to the shell should give me access to the shell so I can fix the corrupted rcS script.)

I'm hoping I can avoid having to flash a new uboot and create a USB flash drive with debian. I don't even know whether such a USB-launched linux can access the mtdblock file systems in the nand so I can edit the original rcS file. If anyone has a suggestion on how to edit the rcS file without creating the USB boot and OS, I would greatly appreciate it. On the other hand, it might be better to install a Debian or Arch on the box so I can more easily add packages.

Thanks in advance

Jerry