Re: [OpenOCD-devel] SAMD issues (was: SWD connect fails with programmed Atmel SAMD20)

[Joerg W. <op...@ur...>]

As Tomas Vanek wrote:

> You can try proposed changes
> http://openocd.zylin.com/2778
> http://openocd.zylin.com/2606
> 
> Check if SRST is connected to RESETN and configure
>      reset_config srst_only
> and you should be able regain debug control after
>      reset halt

I just gave that a try, too (on a homemade SAMD20 board).

Alas, I still have two issues:

* When using the "program" (Tcl?) command, the target does not
automatically run afterwards, but needs a hardware reset.  I do have
this on a SAM4, too, so it's perhaps unrelated.  The command ends up
in

program '"$1"' exit

Do I perhaps need a "reset run" before the exit?

* When pressing the reset button while debugging, OpenOCD cannot
catch up again.  I tried the "[mon] reset halt", but it still
yields:

Open On-Chip Debugger 0.10.0-dev-00036-g48787e1 (2015-10-03-15:03)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
adapter speed: 500 kHz
srst_only separate srst_gates_jtag srst_open_drain connect_deassert_srst
Info : only one transport option; autoselect 'swd'
Warn : Interface already configured, ignoring
srst_only separate srst_gates_jtag srst_open_drain connect_deassert_srst
adapter speed: 400 kHz
cortex_m reset_config sysresetreq
Info : CMSIS-DAP: SWD  Supported
Info : CMSIS-DAP: JTAG Supported
Info : CMSIS-DAP: Interface Initialised (SWD)
Info : CMSIS-DAP: FW Version = 01.16.0041
Info : SWCLK/TCK = 1 SWDIO/TMS = 1 TDI = 1 TDO = 1 nTRST = 0 nRESET = 1
Info : CMSIS-DAP: Interface ready
Info : clock speed 400 kHz
Info : SWD IDCODE 0x0bc11477
Info : at91samd20j18.cpu: hardware has 4 breakpoints, 2 watchpoints
Info : accepting 'gdb' connection on tcp/3333
Info : SAMD MCU: SAMD20J18A (256KB Flash, 32KB RAM)
undefined debug reason 7 - target needs reset
Warn : WARNING! The target is already running. All changes GDB did to registers will be discarded! Waiting for target to halt.
Warn : target at91samd20j18.cpu is not halted
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 100ms
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 300ms
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 700ms
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 1500ms
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 3100ms
Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 6300ms
Info : AP write error, reset will not halt
Error: DP initialisation failed
in procedure 'reset' 
in procedure 'ocd_bouncer'


Polling target at91samd20j18.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 6300ms


-- 
cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/
Never trust an operating system you don't have sources for. ;-)