LPC4088 QSB 'No ACK received'

[tux19]

I want to use platformio to develop the LPC4088. It has an onboard CMSIS-DAP debug probe. I was unable to debug with platformio. Not sure what the root cause was, I opened a thread at platformio. I was able to narrow the issues down to pyOCD.

As mentioned here only older versions of pyOCD are able to successfully debug these LPC chips. I tried pyOCD 0.8.0 successfully, but it is really akward/hacky to use python2 for some tasks whereas the rest of platformio has to run with python3.

Is there a way to get pyOCD to support the LPC17xx/LPC40xx family with on board probes again?

I am happy to help, but I am unsure how/where to start.

Below the log output from my debug attempt with pyOCD 1.29

❯ python .\pyocd-gdbserver.py -t lpc4088
0000506:WARNING:gdb_server:pyocd-gdbserver is deprecated; please use the new combined pyocd tool.
Waiting for a debug probe to be connected...
0009486:INFO:board:Target type is lpc4088
0009539:INFO:dap:DP IDR = 0x2ba01477 (v1 rev2)
0009597:INFO:ap:AHB-AP#0 IDR = 0x24770011 (AHB-AP var1 rev2)
0009654:INFO:rom_table:AHB-AP#0 Class 0x1 ROM table #0 @ 0xe00ff000 (designer=43b part=4c4)
0009663:INFO:rom_table:[0]<e000e000:SCS-M4 class=14 designer=43b part=00c>
0009668:INFO:rom_table:[1]<e0001000:DWT class=14 designer=43b part=002>
0009674:INFO:rom_table:[2]<e0002000:FPB class=14 designer=43b part=003>
0009680:INFO:rom_table:[3]<e0000000:ITM class=14 designer=43b part=001>
0009686:INFO:rom_table:[4]<e0040000:TPIU-M4 class=9 designer=43b part=9a1 devtype=11 archid=0000 devid=ca1:0:0>
0009692:INFO:rom_table:[5]<e0041000:ETM-M4 class=9 designer=43b part=925 devtype=13 archid=0000 devid=0:0:0>
0009695:INFO:cortex_m:CPU core #0 is Cortex-M4 r0p1
0009705:INFO:cortex_m:FPU present: FPv4-SP-D16-M
0009710:INFO:dwt:4 hardware watchpoints
0009714:INFO:fpb:6 hardware breakpoints, 4 literal comparators
0009737:INFO:server:Semihost server started on port 4444 (core 0)
0009748:INFO:gdbserver:GDB server started on port 3333 (core 0)
0275145:INFO:gdbserver:Client connected to port 3333!
0275186:INFO:gdbserver:Attempting to load argon
0275187:INFO:gdbserver:Attempting to load freertos
0275187:INFO:gdbserver:Attempting to load rtx5
0275187:INFO:gdbserver:Attempting to load zephyr
[====================] 100%
0285430:INFO:loader:Erased 4096 bytes (1 sector), programmed 4096 bytes (8 pages), skipped 159744 bytes (312 pages) at 15.66 kB/s
0286813:ERROR:gdbserver:Unhandled exception in handle_message: No ACK received
Traceback (most recent call last):
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\cmsis_dap_probe.py", line 238, in flush
    self._link.flush()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\utility\concurrency.py", line 28, in _locking
    return func(self, *args, **kwargs)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 672, in flush
    self._read_packet()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\utility\concurrency.py", line 28, in _locking
    return func(self, *args, **kwargs)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 932, in _read_packet
    decoded_data = cmd.decode_data(raw_data)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 452, in decode_data
    data = self._decode_transfer_data(data)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 359, in _decode_transfer_data
    self._check_response(data[2])
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 342, in _check_response
    raise DAPAccessIntf.TransferError("No ACK received")
pyocd.probe.pydapaccess.dap_access_api.DAPAccessIntf.TransferError: No ACK received

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 427, in handle_message
    reply = handler(msg[msgStart:])
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 675, in v_command
    return self.v_cont(cmd)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 726, in v_cont
    return self.resume(None)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 580, in resume
    self.target.resume()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\cortex_m.py", line 877, in resume
    self.flush()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\core\target.py", line 233, in flush
    self.session.probe.flush()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\cmsis_dap_probe.py", line 240, in flush
    six.raise_from(self._convert_exception(exc), exc)
  File "<string>", line 3, in raise_from
pyocd.core.exceptions.TransferError: No ACK received
0286822:ERROR:gdbserver:Unhandled exception in handle_message: No ACK received
Traceback (most recent call last):
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\cmsis_dap_probe.py", line 286, in read_ap_result_callback
    return result()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 847, in read_reg_cb
    res = transfer.get_result()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 144, in get_result
    self.daplink.flush()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\utility\concurrency.py", line 28, in _locking
    return func(self, *args, **kwargs)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 672, in flush
    self._read_packet()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\utility\concurrency.py", line 28, in _locking
    return func(self, *args, **kwargs)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 932, in _read_packet
    decoded_data = cmd.decode_data(raw_data)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 452, in decode_data
    data = self._decode_transfer_data(data)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 359, in _decode_transfer_data
    self._check_response(data[2])
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\pydapaccess\dap_access_cmsis_dap.py", line 342, in _check_response
    raise DAPAccessIntf.TransferError("No ACK received")
pyocd.probe.pydapaccess.dap_access_api.DAPAccessIntf.TransferError: No ACK received

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 425, in handle_message
    reply = handler()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\gdbserver.py", line 873, in get_registers
    return self.create_rsp_packet(self.target_facade.get_register_context())
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\gdbserver\context_facade.py", line 101, in get_register_context
    vals = self._context.read_core_registers_raw(self._full_reg_num_list)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\debug\cache.py", line 48, in read_core_registers_raw
    return self._regcache.read_core_registers_raw(reg_list)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\cache\register.py", line 96, in read_core_registers_raw
    if self._check_cache():
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\cache\register.py", line 77, in _check_cache
    if self._core.is_running():
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\cortex_m.py", line 861, in is_running
    return self.get_state() == Target.State.RUNNING
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\cortex_m.py", line 830, in get_state
    dhcsr = self.read_memory(CortexM.DHCSR)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\cortex_m.py", line 435, in read_memory
    result = self.ap.read_memory(addr, transfer_size, now)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\utility\concurrency.py", line 28, in _locking
    return func(self, *args, **kwargs)
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\ap.py", line 993, in _read_memory
    result = read_mem_cb()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\ap.py", line 972, in read_mem_cb
    res = result_cb()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\coresight\dap.py", line 717, in read_ap_cb
    result = result_cb()
  File "C:\Users\chrigi\.platformio\packages\tool-pyocd\site-packages\py37\pyocd\probe\cmsis_dap_probe.py", line 288, in read_ap_result_callback
    six.raise_from(self._convert_exception(error), error)
  File "<string>", line 3, in raise_from
pyocd.core.exceptions.TransferError: No ACK received

[tux19]

Any update on this? Even a hint in what direction to look would help... see related issues:

• https://github.com/pyocd/pyOCD/issues/406
• https://github.com/pyocd/pyOCD/issues/745

I plan to look at this in more detail in the next 1-2 months, but since I am not really comfortable with python/virtual envs etc... it might take some effort to get to the point of effective debugging and understanding pyOCD, so any help to get this working is appreciated :)