[linuxsh-dev] ??? How to debug the kernel ???

[Fabio G. <fg...@ti...>]

Hi everyone,
To make running on my board the sh-boot-cvs-25-03-2002 I wrote my
config.h
config.mk
init-mycard.S (for BSC initialization)

I modified
Makefile
sh-sci.c

and I modified enrty.S in the following way

#if defined(CONFIG_MYCARD)
INITIAL_SR:
        .long   0x500000f0      /* MD=1, RD=0, BL=1 I3,I2,I1,I0 = 1, 
interrupt masked */
#else
INITIAL_SR:
        .long   0x50000000      /* MD=1, RD=0, BL=1 */
#endif

What are the side effect of this modification?

The following is the output of my sh-linux-gnu-gdb: 


bash-2.05# sh-linux-gnu-gdb /root/sh/linux/vmlinux
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
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=sh-linux-gnu"...
(gdb) set endian little
The target is assumed to be little endian
(gdb) set remotebaud 115200
(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
0x800022c6 in ?? ()
warning: shared library handler failed to enable breakpoint
(gdb) load
Loading section .empty_zero_page, size 0x1000 lma 0x8c001000
Loading section .text, size 0x71594 lma 0x8c002000
Loading section .rodata, size 0x847c lma 0x8c073594
Loading section __ex_table, size 0x1468 lma 0x8c07ba10
Loading section .data, size 0x3f48 lma 0x8c07ce78
Loading section .data.init_task, size 0x2000 lma 0x8c082000
Loading section .text.init, size 0x6440 lma 0x8c084000
Loading section .data.init, size 0x3bc lma 0x8c08a440
Loading section .setup.init, size 0xa0 lma 0x8c08a800
Loading section .initcall.init, size 0x50 lma 0x8c08a8a0
Loading section .data.cacheline_aligned, size 0xb70 lma 0x8c08b000
Start address 0x8c002000, load size 561692
Transfer rate: 59913 bits/sec, 149 bytes/write.
(gdb) cont
Continuing.

and now everything is stopped.

Some questions:
1)
warning: shared library handler failed to enable breakpoint
Is this dangerous for corretly running of the kernel using the upper 
procedure?

2) How and where I have to put the breakpoints which is written about in 
http://linuxsh.sourceforge.net/docs/gdb.php3

>> (gdb) load 
>>
>>
>> GDB will print a line of output as each section of the ELF file is loaded. 
>>This can take several minutes. 
>>
>> Once the kernel has been loaded you can set any breakpoints required, as 
>>normal. Finally start the kernel running: 
>>
>>cont

3) How can I easily debug why my kernel doesn't work?

Attached my config file and my kernel is 2.4.18.

Thanks a lot.