DUMP_REGS macro
add snprintf to userlib, add user.h, fix linking of userlib in progs
split some basic memory defs out and use them in userlib along with types.h
implement ARM_JUMP24 reloc
add a debugging 'syscall' for dumping logs from 'userspace' to serial port
test the debug syscall
add preliminary ehci module

detects and enumerates port1, loading usb dev descriptor and dumping it