On 07/28/2010 04:29 AM, Michal Simek wrote:Kgdb uses brki r16, 0x18 instruction to callThere is only one place I saw a problem and if you fix it, you can add:
low level _debug_exception function which save
current state to pt_regs and call microblaze_kgdb_break
function. _debug_exception should be called only from
the kernel space. User space calling is not supported
because user application debugging uses different handling.
pt_regs_to_gdb_regs loads additional special registers
which can't be changed
* Enable KGDB in Kconfig
* Remove ancient not-tested KGDB support
* Remove ancient _debug_exception code from entry.S
Only MMU KGDB support is supported.
Acked-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
+
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+ char *remcom_in_buffer, char *remcom_out_buffer,
+ struct pt_regs *regs)
+{
+ char *ptr;
+ unsigned long address;
+ int cpu = smp_processor_id();
+
+ switch (remcom_in_buffer[0]) {
+ case 's':
+ case 'c':
+ /* handle the optional parameter */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &address))
+ regs->pc = address;
+ atomic_set(&kgdb_cpu_doing_single_step, -1);
+ if (remcom_in_buffer[0] == 's')
+ atomic_set(&kgdb_cpu_doing_single_step, cpu);
+
+ return 0;
+ }
As far as I can see there is no code in the arch specific portion to
make use of single stepping. It needs to be implemented using hardware
assist, or a software breakpoint strategy, else you simply omit the 's'
case from statement so that kdb will not enable single stepping at run time.
Example:
switch (remcom_in_buffer[0]) {
case 'c':
/* handle the optional parameter */
ptr = &remcom_in_buffer[1];
if (kgdb_hex2long(&ptr, &address))
regs->pc = address;
return 0;
}
You can also remove the kgdb_cpu_doing_single_step operations because
this arch does not currently implement the kgdb single stepping.
Cheers,
Jason.