[Feature Request]: Flash via JTAG _without_ serial (VSC-1575)

[karlp]

Is your feature request related to a problem? Please describe.
I have a board that has only a jtag header. (2x5pin, I'm not talking about Using command line tools, I can flash and debug, using openocd, and "mon program_esp ...."
However, if I try and flash in vscode, it always attempts to open a serial port with esptool. This is despite having "flash method JTAG" set ("idf.flashType": "JTAG")

It seems that #183 really only applies to flashing via the built in usb-jtag? at least, it certainly doesn't seem to help

It's perhaps demonstrated by this diagram: https://docs.espressif.com/projects/vscode-esp-idf-extension/en/latest/debugproject.html#debugging-process-overview where it shows that flashing is always via the uart.

I very much want to avoid having to use a second cable, just for vscode.

Describe alternatives you've considered
Adding a serial connection jsut for flashing does work, but... seriously?

I've tried using the explist tasks "ESP-IDF:Flash (with jtag)" option as well, both with and without openocd started before hand.

Additional context
maybe I'm just missing how to configure this?

I'm not very good at reading typescript, but it almost appears as if the jtag code got detached somewhere. flashcmd.ts will error if a port isn't set, and in flashtask, https://github.com/espressif/vscode-esp-idf-extension/blob/master/src/flash/flashTask.ts#L111-L119 it seems to just... not handle the jtag case?

My openocd.cfg file

source [find interface/cmsis-dap.cfg]
adapter speed 8000
transport select jtag
bindto 0.0.0.0
set ESP32_FLASH_VOLTAGE 3.3
# Source the ESP32 configuration file
source [find target/esp32.cfg]

My settings.json

{
        "C_Cpp.intelliSenseEngine": "default",
        "idf.espIdfPath": "/home/karlp/src/esp-idf",
        "idf.toolsPath": "/home/karlp/tools/esp-idf",
        "idf.openOcdConfigs": [
                "openocd.cfg",
        ],
        "idf.openOcdDebugLevel": "3",
        "idf.flashType": "JTAG"
}

ESP-IDF plugin version: 1.9.0