Re: kgdb errors with serial console

From: Elvis Dowson
Date: Fri Oct 08 2010 - 18:34:26 EST


Hi Jason,
Some good news. I switch the GDB command set from mi to mi1, and it seems to be working now.

What I did is added the kgdbwait command to the bootargs as follows (not sure if it was necessary, but will try once again without it)

setenv mmcargs 'setenv bootargs console=${console} vram=12M omapfb.vram=0:4M omapfb.mode=dvi:${dvimode} omapdss.def_disp=${defaultdisplay} root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait kgdb=${console} kgdboc=${console} kgdbwait'

Then I launched the debugger, and it did something, and resumed normally.

Then I manually went to the console and activated kgdb by typing

echo g > /proc/sysrq-trigger

This caused the debugger on the Eclipse side to process something, and then it stopped in file kgdb.c at the call to arch_kgdb_breakpoint(), in the following method:

void kgdb_breakpoint(void)
{
atomic_set(&kgdb_setting_breakpoint, 1);
wmb(); /* Sync point before breakpoint */
arch_kgdb_breakpoint();
wmb(); /* Sync point after breakpoint */
atomic_set(&kgdb_setting_breakpoint, 0);
}

I can now clearly see all the registers and variables in Eclipse.

Question 02: sys_sync doesn't seem to be called in the ARM arch files, it only exists for x86 and sparc architectures.

Is there any other kernel file I can set a break-point into, to be able to check if everything is working ok?

For example, if I type a normal cd or ls command?

Best regards,

Elvis

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