These are the changes I made to get ARM FS working with Ruby.  Most notably, I had to make the memory contiguous by putting the physmem and nvmem together, otherwise Ruby would not handle them correctly.  Details here on the mailing list:  http://permalink.gmane.org/gmane.comp.emulators.m5.users/10440

This required shrinking physmem from 256MB to 172MB, then placing nvmem at address 172MB.  Next, the boot loader has to be recreated with the Makefile under the system directory, changing the address to 0x0C000000.

Hopefully, at the very least, this will help others start testing out ARM FS with Ruby.

Currently, I've tested this successfully with the SPEC CPU2006 libquantum benchmark with the Timing CPU.  I'm still running tests with the ARM O3CPU.  They seem to be hanging during boot at "sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 178956ms".    Note that I have not tested this with Android, only Ubuntu.