[U-Boot] Problem with u-boot debugging

[mouse1]

Hi!

I would like to port the U-Boot to a custom developed port with an 
Au1200 chip. I'm using the ELDK as toolchain.
I successfully compiled the U-Boot. I'm trying to debug it with a 
BDI-3000, through GDB. But anywhere I put a breakpoint (e.g. to the 
board_init_f), the program stops at line 234 in the start.s: mtc0 zero, 
CP0_WATCHLO, and it writes out:

Program received signal SIGABRT, Aborted.
reset () at start.S:234
234        mtc0    zero, CP0_WATCHLO


After I continue program running, the BDI writes out:

*** TARGET: all hardware breakpoints in use

and the gdb:

(gdb) c
Continuing.
Warning:
Cannot insert breakpoint 2.
Error accessing memory address 0xbfc01030: Unknown error 4294967295.

Contrarily, I can use the BDI's TI command, so from terminal, I can 
single step the program.
Any idea?

Here's the full gdb output:

(gdb) target remote bdi:2001
Remote debugging using bdi:2001
_start () at start.S:64
64        RVECENT(reset,0)    /* U-boot entry point */
(gdb) b board_init_f
Note: breakpoint 2 also set at pc 0xbfc01030.
Breakpoint 3 at 0xbfc01030: file board.c, line 202.
(gdb) c
Continuing.

Program received signal SIGABRT, Aborted.
reset () at start.S:234
234        mtc0    zero, CP0_WATCHLO
(gdb) c
Continuing.
Warning:
Cannot insert breakpoint -5.
Error accessing memory address 0xbfc00000: Ismeretlen hiba 4294967295.