Re: [AVaRICE-user] Various patches to AVaRICE

[Cristiano <cri...@ho...>]

On 07/10/2014 11:05 PM, Cristiano wrote:
> Hi, I've applied the patches to  the latest SVN snapshot. I use GDB
 > 7.7.1. Great job! Stepping is now super fast. I'm debugging from
 > Eclipse and the experience is now decent. The patch for the GDB
 > disassemble is here:
 > https://sourceware.org/bugzilla/show_bug.cgi?id=13519
 >
 > Thanks for AVARICE and these patches. -Cristiano
 >
 >> Hello,
 >>
 >> as suggested the patches have been uploaded to the patch tracker!
 >

I'm trying the debugging experience, using the above setup, on a LUFA 
project.
After tweaking a little bit the LUFA makefile and resorting using the 
Atmel AVR toolchain v3.4.5 for Linux, I can confirm the experience is 
still quite good.
Stepping is fast if compared with a vanilla Avarice but...

Sometimes, stepping (gdb `next' or `step' commands) from the return 
statement of a function ends in the __vectors jump table. Another `next' 
from here stops avr-gdb in the USB ISR.

This is somewhat surprising because I launch Avarice with the 
--ignore-intr switch.
Note that interrupts are usually skipped but there are pathological case 
where they are not, systematically.

Returning from the function, from the same return statement above, with 
`finish' or returning through a sequence of `nexti' or `stepi' produces 
the expected result, returning to the function caller.

There must be something wrong with the patches or maybe this is a known 
issue. If I run the same debug session above using a vanilla Avarice 
2.10 (Linux Mint package), with the same options, everything works as 
expected (if you have the patience of waiting 5-10 seconds for a step).

Since these patches make a big difference in debugging (stepping is 5x 
faster) I'd like to help debugging this issue.

Below is the disassembled function. I can provide gdb and avarice logs 
if needed.
Regards,
     Cristiano

           CALLBACK_HID_Device_CreateHIDReport:
000004a6:   push r16
000004a8:   push r17
000004aa:   push r28
000004ac:   push r29
000004ae:   in r28, 0x3d    ; 61
000004b0:   in r29, 0x3e    ; 62
000004b2:   sbiw r28, 0x0f  ; 15
000004b4:   in r0, 0x3f     ; 63
000004b6:   cli
000004b8:   out 0x3e, r29   ; 62
000004ba:   out 0x3f, r0    ; 63
000004bc:   out 0x3d, r28   ; 61
000004be:   std Y+8, r25    ; 0x08
000004c0:   std Y+7, r24    ; 0x07
000004c2:   std Y+10, r23   ; 0x0a
000004c4:   std Y+9, r22    ; 0x09
000004c6:   std Y+11, r20   ; 0x0b
000004c8:   std Y+13, r19   ; 0x0d
000004ca:   std Y+12, r18   ; 0x0c
000004cc:   std Y+15, r17   ; 0x0f
000004ce:   std Y+14, r16   ; 0x0e
167           uint8_t* Data        = (uint8_t*)ReportData;
000004d0:   ldd r24, Y+12   ; 0x0c
000004d2:   ldd r25, Y+13   ; 0x0d
000004d4:   std Y+2, r25    ; 0x02
000004d6:   std Y+1, r24    ; 0x01
168           uint8_t  CurrLEDMask = LEDs_GetLEDs();
000004d8:   call 0x26c      ;  0x26c <LEDs_GetLEDs>
000004dc:   std Y+3, r24    ; 0x03
169           hal_rx_frame_t *frame = NULL;
000004de:   std Y+5, r1     ; 0x05
000004e0:   std Y+4, r1     ; 0x04
171           HAL_ENTER_CRITICAL_REGION();
000004e2:   ldi r24, 0x5F   ; 95
000004e4:   ldi r25, 0x00   ; 0
000004e6:   movw r30, r24
000004e8:   ld r24, Z
000004ea:   std Y+6, r24    ; 0x06
000004ec:   cli
172           frame = (hal_rx_frame_t*) list_pop(hal_rx_frame_queue);
000004ee:   lds r24, 0x0100
000004f2:   lds r25, 0x0101
000004f6:   call 0x14bc     ;  0x14bc <list_pop>
000004fa:   std Y+5, r25    ; 0x05
000004fc:   std Y+4, r24    ; 0x04
173           HAL_LEAVE_CRITICAL_REGION();
000004fe:   ldi r24, 0x5F   ; 95
00000500:   ldi r25, 0x00   ; 0
00000502:   ldd r18, Y+6    ; 0x06
00000504:   movw r30, r24
00000506:   st Z, r18
175           if (frame != NULL) {
00000508:   ldd r24, Y+4    ; 0x04
0000050a:   ldd r25, Y+5    ; 0x05
0000050c:   sbiw r24, 0x00  ; 0
0000050e:   breq .+14       ;  0x51e 
<CALLBACK_HID_Device_CreateHIDReport+120>
177               LEDs_ToggleLEDs(LEDS_LED4);
00000510:   ldi r24, 0x04   ; 4
00000512:   call 0x23c      ;  0x23c <LEDs_ToggleLEDs>
178               hal_rx_frame_free(frame);
00000516:   ldd r24, Y+4    ; 0x04
00000518:   ldd r25, Y+5    ; 0x05
0000051a:   call 0xd98      ;  0xd98 <hal_rx_frame_free>
181           if (changed)
0000051e:   lds r24, 0x0122
00000522:   and r24, r24
00000524:   brne .+2        ;  0x528 
<CALLBACK_HID_Device_CreateHIDReport+130>
00000526:   rjmp .+134      ;  0x5ae 
<CALLBACK_HID_Device_CreateHIDReport+264>
183               changed = false;
00000528:   sts 0x0122, r1
185               Data[0] = ((CurrLEDMask & LEDS_LED1) ? 1 : 0);
0000052c:   ldd r24, Y+3    ; 0x03
0000052e:   adc r24, r24
00000530:   eor r24, r24
00000532:   adc r24, r24
00000534:   mov r18, r24
00000536:   ldd r24, Y+1    ; 0x01
00000538:   ldd r25, Y+2    ; 0x02
0000053a:   movw r30, r24
0000053c:   st Z, r18
186               Data[1] = ((CurrLEDMask & LEDS_LED2) ? 1 : 0);
0000053e:   ldd r24, Y+1    ; 0x01
00000540:   ldd r25, Y+2    ; 0x02
00000542:   adiw r24, 0x01  ; 1
00000544:   ldd r18, Y+3    ; 0x03
00000546:   mov r18, r18
00000548:   ldi r19, 0x00   ; 0
0000054a:   andi r18, 0x20  ; 32
0000054c:   eor r19, r19
0000054e:   ldi r20, 0x01   ; 1
00000550:   cp r18, r1
00000552:   cpc r19, r1
00000554:   brne .+2        ;  0x558 
<CALLBACK_HID_Device_CreateHIDReport+178>
00000556:   ldi r20, 0x00   ; 0
00000558:   mov r18, r20
0000055a:   movw r30, r24
0000055c:   st Z, r18
187               Data[2] = ((CurrLEDMask & LEDS_LED3) ? 1 : 0);
0000055e:   ldd r24, Y+1    ; 0x01
00000560:   ldd r25, Y+2    ; 0x02
00000562:   adiw r24, 0x02  ; 2
00000564:   ldd r18, Y+3    ; 0x03
00000566:   mov r18, r18
00000568:   ldi r19, 0x00   ; 0
0000056a:   andi r18, 0x08  ; 8
0000056c:   eor r19, r19
0000056e:   ldi r20, 0x01   ; 1
00000570:   cp r18, r1
00000572:   cpc r19, r1
00000574:   brne .+2        ;  0x578 
<CALLBACK_HID_Device_CreateHIDReport+210>
00000576:   ldi r20, 0x00   ; 0
00000578:   mov r18, r20
0000057a:   movw r30, r24
0000057c:   st Z, r18
188               Data[3] = ((CurrLEDMask & LEDS_LED4) ? 1 : 0);
0000057e:   ldd r24, Y+1    ; 0x01
00000580:   ldd r25, Y+2    ; 0x02
00000582:   adiw r24, 0x03  ; 3
00000584:   ldd r18, Y+3    ; 0x03
00000586:   mov r18, r18
00000588:   ldi r19, 0x00   ; 0
0000058a:   andi r18, 0x04  ; 4
0000058c:   eor r19, r19
0000058e:   ldi r20, 0x01   ; 1
00000590:   cp r18, r1
00000592:   cpc r19, r1
00000594:   brne .+2        ;  0x598 
<CALLBACK_HID_Device_CreateHIDReport+242>
00000596:   ldi r20, 0x00   ; 0
00000598:   mov r18, r20
0000059a:   movw r30, r24
0000059c:   st Z, r18
190               *ReportSize = GENERIC_REPORT_SIZE;
0000059e:   ldd r24, Y+14   ; 0x0e
000005a0:   ldd r25, Y+15   ; 0x0f
000005a2:   ldi r18, 0x08   ; 8
000005a4:   ldi r19, 0x00   ; 0
000005a6:   movw r30, r24
000005a8:   std Z+1, r19    ; 0x01
000005aa:   st Z, r18
000005ac:   rjmp .+10       ;  0x5b8 
<CALLBACK_HID_Device_CreateHIDReport+274>
193               *ReportSize = 0;
000005ae:   ldd r24, Y+14   ; 0x0e
000005b0:   ldd r25, Y+15   ; 0x0f
000005b2:   movw r30, r24
000005b4:   std Z+1, r1     ; 0x01
000005b6:   st Z, r1
196           return true;
000005b8:   ldi r24, 0x01   ; 1
197       }
000005ba:   adiw r28, 0x0f  ; 15
000005bc:   in r0, 0x3f     ; 63
000005be:   cli
000005c0:   out 0x3e, r29   ; 62
000005c2:   out 0x3f, r0    ; 63
000005c4:   out 0x3d, r28   ; 61
000005c6:   pop r29
000005c8:   pop r28
000005ca:   pop r17
000005cc:   pop r16
000005ce:   ret