Bug#124117: boot-floppies: udbootstrap exits after base install

[Philip Blundell <philb@gnu.org>]

I checked in some code to give a primitive register dump if a segmentation
fault happens in debugging mode.  Maybe that will help find out where the
crash is happening.  Anybody want to try it out?

You should see something like this on the screen when a segfault happens:

*** Segmentation fault
Registers:
  EAX: 00000000  EBX: 401ad1f0  ECX: bffff840  EDX: 00000000
  EDI: bffffb94  ESI: 4001530c  EBP: bffffb68  ESP: bffff9a4

  EIP: 0805521a  EFLAGS: 00210296

  Trap: 0000000e  Code: 00000006
*** Press RETURN to continue

The EIP number is the most important one, being the address of the instruction
that caused the fault.

p.