[U-Boot] Problem accessing MONITOR_BASE in start.S

[Jean-Michel Hautbois]

Hi list,

I was working with an old u-boot on a MPC8541 based board, and I am
currently trying to port it on v2011.09 version of u-boot.
I am facing an issue when debuging with a BDI2000 and I am wondering
what could cause this kind of thing.

Here is the point, I start the board, and it enters start.S :
_start_e500 () at start.S:129
129             mtspr   L1CSR0,r0       /* invalidate d-cache */

I set a breakpoint (hardware) on line 183 which is :
/* Setup interrupt vectors */
    183         lis     r1,CONFIG_SYS_MONITOR_BASE at h
    184         mtspr   IVPR,r1

(gdb) b 183
Breakpoint 1 at 0xfffff07c: file start.S, line 183.

CONFIG_SYS_MONITOR_BASE is set to CONFIG_SYS_TEXT_BASE which is
0xFFF80000 in my config file.

then, I do :
(gdb) c
Continuing.

Breakpoint 1, _start_e500 () at start.S:183
183             lis     r1,CONFIG_SYS_MONITOR_BASE at h
(gdb) stepi
Cannot access memory at address 0xfff80000

This is weird, and I can't understand what could explain this.
I am quite sure it is not a big deal, (gdb) c
Continuing.

Breakpoint 1, _start_e500 () at start.S:183
183             lis     r1,CONFIG_SYS_MONITOR_BASE at h
(gdb) stepi
Cannot access memory at address 0xfff80000

This is weird, and I can't find the answer...

Thanks in advance for any clue !
Regards,
JM