Esp-prog debugger cannot start or read any flash from ESP32 jtag

mallerya · May 20, 2021, 10:19pm

Problem Summery
I am using an ESP32-S2 board (devkitM-1U) [uses the ‘saola’ board def] with a esp-prog debugger board and I cannot seem to get the two working together. It seems that the esp-prog detects the esp32s2, halts it correctly, but then cannot read any form of flash memory from it. I admit that I am new to the concepts of JTAG, but I am to presume (put simply) that it is a communication interface and the debugger needs the memory mapped before the program starts to be able to set watches or pretty much do anything.

Enviroment:
Windows 10 pro x64 bit.
VScode 1.56.2
PlatformIO core 5.1.1
PlatformIO home 3.3.4
esp framework version in the debug log. It is latest as of 5/20/21

Troubleshooting attempts:
I have followed the standard steps from the espressif website and even followed the popular referenced video tutorial on youtube (I forget the authors name). I have the FTDI VCP Drivers installed, along with the Zadig WinUSB drivers on both interface 0 and 1 (debugger/programmer channels). I restarted the computer to ensure the drivers were initializing correctly. The S2 revision of the board has different JTAG pins and so I made sure to find and connect them all (GPIO 39-42). I verified these connections multiple times with the online documentation. The jumpers on the esp prog are set to 5v for both boards (prog/esp).

The Test:
For the test, I wanted to run the debugger on my program. The program compiles and runs correctly, but there is a pointer variable that is being reset and I cannot source the problem for it. Hence, the debugger would help here.

I heard that inserting breakpoints in app_main() can be finicky or cause problems, so instead, I put a breakpoint a bit deeper in the source where other stuff is happening. Regardless of where I put it though, this does not seem to matter much if the esp-prog cannot read the chip’s flash memory.

platformio.ini:

[env:esp32-s2-saola-1]
platform = espressif32
board = esp32-s2-saola-1
framework = espidf
monitor_speed = 115200
upload_port = COM4

debug_tool = esp-prog

This is the Debug Console output when run:

Processing esp32-s2-saola-1 (platform: espressif32; board: esp32-s2-saola-1; framework: espidf)
--------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/espressif32/esp32-s2-saola-1.html
PLATFORM: Espressif 32 (3.2.0) > Espressif ESP32-S2-Saola-1
HARDWARE: ESP32S2 240MHz, 320KB RAM, 4MB Flash
DEBUG: Current (esp-prog) External (esp-prog, iot-bus-jtag, jlink, minimodule, olimex-arm-usb-ocd, olimex-arm-usb-ocd-h, olimex-arm-usb-tiny-h, olimex-jtag-tiny, tumpa)
PACKAGES:
 - framework-espidf 3.40200.210118 (4.2.0)
 - tool-cmake 3.16.4
 - tool-esptoolpy 1.30000.201119 (3.0.0)
 - tool-idf 1.0.1
 - tool-mconf 1.4060000.20190628 (406.0.0)
 - tool-ninja 1.9.0
 - toolchain-esp32s2ulp 1.22851.191205 (2.28.51)
 - toolchain-xtensa32s2 1.80400.210211 (8.4.0)
Reading CMake configuration...
LDF: Library Dependency Finder -> http://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 1 compatible libraries
Scanning dependencies...
Dependency Graph
|-- <StepperDriver>
Building in debug mode
Generating project linker script .pio\build\esp32-s2-saola-1\esp32s2.project.ld
Linking .pio\build\esp32-s2-saola-1\firmware.elf
Retrieving maximum program size .pio\build\esp32-s2-saola-1\firmware.elf
Checking size .pio\build\esp32-s2-saola-1\firmware.elf
Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM:   [          ]   2.9% (used 9648 bytes from 327680 bytes)
Flash: [=         ]  14.1% (used 147722 bytes from 1048576 bytes)
========================= [SUCCESS] Took 28.60 seconds =========================
Reading symbols from C:\Users\admin\Documents\Github\C++\ESP32-S2-Saola\ESP32_S2_Saola1\.pio\build\esp32-s2-saola-1\firmware.elf...
done.
PlatformIO Unified Debugger -> http://bit.ly/pio-debug
PlatformIO: debug_tool = esp-prog
PlatformIO: Initializing remote target...
Open On-Chip Debugger  v0.10.0-esp32-20201202 (2020-12-02-17:38)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
adapter speed: 20000 kHz

Info : FreeRTOS creation
adapter speed: 5000 kHz

Info : tcl server disabled
Info : telnet server disabled
Info : clock speed 5000 kHz
Info : JTAG tap: esp32s2.cpu tap/device found: 0x120034e5 (mfg: 0x272 (Tensilica), part: 0x2003, ver: 0x1)
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Core was reset.
Info : accepting 'gdb' connection from pipe
Warn : No symbols for FreeRTOS!
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Target halted, PC=0x40016102, debug_reason=00000000
Info : Detected ESP32-S2 chip
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Warn : Empty flash mapping!
Warn : Failed to get flash mappings (0)!
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Info : Auto-detected flash bank 'esp32s2.flash' size 4096 KB
Info : Using flash bank 'esp32s2.flash' size 4096 KB
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Warn : Empty flash mapping!
Warn : Failed to get flash mappings (0)!
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Info : Using flash bank 'esp32s2.irom' size 0 KB
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Warn : Empty flash mapping!
Warn : Failed to get flash mappings (0)!
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Core was reset.
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Core was reset.
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Core was reset.
Info : esp32s2: Debug controller was reset.
Error: Target not examined yet
Error: Failed to wait algorithm (-4)!
Error: Target not examined yet
Error: failed to restore 28 bytes of working area at address 0x400314a4
Error: Target not examined yet
Error: failed to restore 1024 bytes of working area at address 0x3ffe007c
Error: Target not examined yet
Error: failed to restore 5284 bytes of working area at address 0x40030000
Error: Target not examined yet
Error: failed to restore 124 bytes of working area at address 0x3ffe0000
Error: Algorithm run failed (-4)!
Error: Failed to run flasher stub (-4)!
Info : Using flash bank 'esp32s2.drom' size 0 KB
0x400314a4 in ?? ()
Warn : Target not HALTED!
Error: Target not examined yet
Error: Could not read FreeRTOS thread count from target!
Error: Target not examined yet
Info : JTAG tap: esp32s2.cpu tap/device found: 0x120034e5 (mfg: 0x272 (Tensilica), part: 0x2003, ver: 0x1)
Info : esp32s2: Debug controller was reset.
JTAG tap: esp32s2.cpu tap/device found: 0x120034e5 (mfg: 0x272 (Tensilica), part: 0x2003, ver: 0x1)
Info : esp32s2: Core was reset.
esp32s2: Debug controller was reset.
esp32s2: Core was reset.
Info : esp32s2: Target halted, PC=0x40016102, debug_reason=00000000
esp32s2: Target halted, PC=0x40016102, debug_reason=00000000
Info : esp32s2: Debug controller was reset.
Info : esp32s2: Core was reset.
Info : esp32s2: Target halted, PC=0x40012734, debug_reason=00000000
esp32s2: Debug controller was reset.
esp32s2: Core was reset.
esp32s2: Target halted, PC=0x40012734, debug_reason=00000000
Info : esp32s2: Core was reset.
esp32s2: Core was reset.
Info : esp32s2: Target halted, PC=0x40000400, debug_reason=00000000
esp32s2: Target halted, PC=0x40000400, debug_reason=00000000
** Programming Started **
** Programming Started **
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
** Programming Finished **
** Verify Started **
** Programming Finished **
** Verify Started **
Info : esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
esp32s2: Target halted, PC=0x400314BA, debug_reason=00000001
** Verified OK **
** Verified OK **
.pioinit:12: Error in sourced command file:
Remote communication error.  Target disconnected.: Success.

maxgerhardt · May 21, 2021, 3:21am

Does a lower JTAG clock make a difference? Write

debug_speed = 1000

(docs) to use 1000kHz.

If that does not make a difference, open an issue at https://github.com/platformio/platform-espressif32/.It’s clear that that is not a wiring issue since it can read JTAG tap: esp32s2.cpu tap/device found: 0x120034e5 but still something may wrong, maybe in OpenOCD or the way it’s invoked.

mallerya · May 22, 2021, 5:40am

Actually, yes. This fixed it.

It seems strange that lowering the speed from whatever the default is resolved the issue. I would think that the default configuration for a probe such as the esp-prog would be set at something more stable.

By default does it run at the speed of the microcontrollers baud rate? I notice that the drivers you need to install actually have settings within the windows driver menu in the device manager. If I remember correctly, it was set to 9600.

So 1khz works, but it is actually very slow when stepping over code. What do you think is safe/stable to run at if I were to attempt something higher?

Edit: it seems that even at 1khz it is sometimes hit-or-miss. I may have to reinitialize debugging because for some reason it does not insert the first hardware breakpoint in app_main() due to some memory not being available or something. I’ve read reports of this with other esp32-s2 boards as well and debugging with this method can be finicky for some reason.

I don’t necessarily need it to stop in app_main or use a hardware breakpoint. Is there a way to bypass the debugger from stopping there by default?