[U-Boot] still weird problems (linker/debug?) on MCF5445x
Wolfgang Wegner
wolfgang at leila.ping.de
Tue Mar 2 17:05:13 CET 2010
Hi list,
I had some strange problems in the beginning resulting from bad memory
setup. I fixed the memory setup and now have a linux kernel running
including the user space on top of U-Boot [so would think that the memory
setup should really be OK now], but still have some very weird problems
in U-Boot.
As I really have no clue what might be going wrong I am here again to
ask if anybody has a hint for me.
The behaviour:
When adding code to some functions, the function and sometimes even
completely unrelated other parts of U-Boot fail. The "failure" is a
simple lockup, as I could not yet debug it further. Most of the times
I can "cure" this by adding some code (printf, writing to HW register, ...)
to the failing function - if I figure out which function fails...
(e.g. when adding code to my misc_init_r I had to add some printf()
at the beginning of console_setfile to make U-Boot get past console_setfile
at all.)
While trying to debug this I am running into a somewhat strange
problem with the symbol table relocation for debugging. I added a
printf to board_init_r like this:
printf("gd->reloc_off: 0x%08x\n", gd->reloc_off);
giving me:
gd->reloc_off: 0x07d84000
my TEXT_BASE is 0x40020000, so I set this in my .gdbinit:
define ram
symbol-file
add-symbol-file u-boot 0x47da4000
end
Now in the debugger I do:
(gdb) ram
add symbol table from file "u-boot" at
.text_addr = 0x47da4000
(gdb) b board_init_r
Breakpoint 1 at 0x47da4672: file board.c, line 422.
but the breakpoint is never reached. I tried printing the function
pointer from the code:
printf("%s@%p\n", __FUNCTION__, &board_init_r);
resulting in:
board_init_r at 47da466e
The disassembly shows:
4002066e <board_init_r>:
4002066e: 4e56 ffc0 linkw %fp,#-64
40020672: 202d 0014 movel %a5@(20),%d0
40020676: 48d7 3c3c moveml %d2-%d5/%a2-%a5,%sp@
and in the debugger I can see:
(gdb) print /x *0x47da466e
$1 = 0x4e56ffc0
Can anybody give a hint what I might be doing wrong in debugging (I seem
to remember I already could debug after relocation, and really do not
know I would have changed anything except the symbol table offfset in
between), and what could cause such strange behaviour from U-Boot when
changing the code?
Regards,
Wolfgang
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