Comment 2 for bug 607794

The missing detail in this bug report is that you only get the segfault if the CPSR register is being changed via the gdb stub interface. This happens because we try to use cpu_single_env as the env to pass to cpu_abort(), and if you've got to bank_number() via the gdb stub then cpu_single_env is NULL. I'm going to submit some patches which (a) fix this and (b) change behaviour to ignore bogus mode setting attempts rather than aborting.