mips-big-elf craches

[Johan Rydberg <jrydberg at night dot trouble dot net>]

I get the following crash when I try to run against my own developed
simulator (http://www.nongnu.org/guss).  It seems that the "get_next_frame"
fn returns NULL for some reason.

Transcript:

(top-gdb) run
Starting program: /home/jrydberg/g2/src/b/gdb/./gdb 
GNU gdb 2003-02-13-cvs
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
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Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "--host=i686-pc-linux-gnu --target=mips-big-elf".
Setting up the environment for debugging gdb.
.gdbinit:5: Error in sourced command file:
No symbol table is loaded.  Use the "file" command.
(gdb) set debug remote 1          
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
Sending packet: $Hc-1#09...Ack
Packet received: OK
Sending packet: $qC#b4...Ack
Packet received: 
Sending packet: $qOffsets#4b...Ack
Packet received: 
Sending packet: $?#3f...Ack
Packet received: S05
Sending packet: $Hg0#df...Ack
Packet received: OK
Sending packet: $g#67...Ack
Packet received: 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800ffffc00000000000000000000000000000000000000000000000000000000bfc000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b6d20040346b014028c313400100000000000000d8f6ffbf9db2234093e10c080060274000ca0d08aa920408c43414400000000088d01508f8f6ffbf28f7ffbf50d40040

Breakpoint 1, internal_error (file=0x81c7649 "../../gdb/frame.c", line=187, string=0x8190c62 "%s%sAssertion `%s' failed.") at ../../gdb/utils.c:800
800	  va_start (ap, string);
(top-gdb) bt
#0  internal_error (file=0x81c7649 "../../gdb/frame.c", line=187, string=0x8190c62 "%s%sAssertion `%s' failed.") at ../../gdb/utils.c:800
#1  0x080f9702 in frame_register_unwind (frame=0x0, regnum=29, optimizedp=0xbfffed8c, lvalp=0xbfffed90, addrp=0xbfffed94, realnump=0xbfffed98, bufferp=0xbfffed70) at ../../gdb/frame.c:187
#2  0x080c6cf4 in read_next_frame_reg (fi=0x0, regno=29) at ../../gdb/mips-tdep.c:1592
#3  0x080c7720 in heuristic_proc_desc (start_pc=0, limit_pc=3217031168, next_frame=0x0, cur_frame=1) at ../../gdb/mips-tdep.c:2140
#4  0x080c7e1a in find_proc_desc (pc=3217031168, next_frame=0x0, cur_frame=1) at ../../gdb/mips-tdep.c:2403
#5  0x080c7f94 in mips_init_extra_frame_info (fromleaf=0, fci=0x821f498) at ../../gdb/mips-tdep.c:2477
#6  0x080bcc80 in gdbarch_init_extra_frame_info (gdbarch=0x8221da8, fromleaf=0, frame=0x821f498) at ../../gdb/gdbarch.c:4436
#7  0x080facdf in get_prev_frame (next_frame=0x821f450) at ../../gdb/frame.c:1321
#8  0x080f9f2e in unwind_to_current_frame (ui_out=0x8221678, args=0x821f450) at ../../gdb/frame.c:496
#9  0x080f442e in catcher (func=0x80f9f20 <unwind_to_current_frame>, func_uiout=0x8221678, func_args=0x821f450, func_val=0xbfffefe0, func_caught=0xbfffefe4, errstring=0x0, mask=2) at ../../gdb/top.c:424
#10 0x080f44da in catch_exceptions (uiout=0x8221678, func=0x80f9f20 <unwind_to_current_frame>, func_args=0x821f450, errstring=0x0, mask=2) at ../../gdb/top.c:474
#11 0x080f9fc7 in get_current_frame () at ../../gdb/frame.c:518
#12 0x080ad8b8 in normal_stop () at ../../gdb/infrun.c:2986
...