GPY J-Link debugging

  • Hi all,
    I'm trying to use a J-Link debugger with openocd to debug an external c-module i'm making for the gpy, but it doesn't give any output(JTAG scan chain interrogation failed: all zeroes). I hooked it up like this:
    TDO -> pin 4
    TCLK -> pin 10
    TMS -> pin 23
    TDI -> pin 9

    My openocd setup is the following:

    interface jlink 
    transport select jtag
    adapter_khz 200
    set ESP32_RTOS none
    set ESP32_FLASH_VOLTAGE 3.3
    source [find $OPENOCD_SCRIPTS/target/esp32.cfg]

    If I try running openocd -f debug.cfg it gives the following output:

    Open On-Chip Debugger  v0.10.0-esp32-20190313 (2019-03-13-09:52)
    Licensed under GNU GPL v2
    For bug reports, read
    adapter speed: 200 kHz
    Info : Configured 2 cores
    esp32 interrupt mask on
    Info : Listening on port 6666 for tcl connections
    Info : Listening on port 4444 for telnet connections
    Info : J-Link V10 compiled Oct  5 2020 14:56:16
    Info : Hardware version: 10.10
    Info : VTarget = 3.328 V
    Info : clock speed 200 kHz
    Error: JTAG scan chain interrogation failed: all zeroes
    Error: Check JTAG interface, timings, target power, etc.
    Error: Trying to use configured scan chain anyway...
    Error: esp32.cpu0: IR capture error; saw 0x00 not 0x01
    Warn : Bypassing JTAG setup events due to errors
    Info : Listening on port 3333 for gdb connections

    What can I try to make j-link find the gpy?

  • I found the solution, I need to set the BTYPE=debug flag when building the firmware.

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