Flashing with jtag on ESP32_WROOM module for the first time resets indefinitely

[CKiamy]

Hello everyone,

I have made a custom board that uses the esp32-wroom-32ue module. The way I flash this guys is by using the JTAG connections, a jlink and the openocd script:

openocd -f interface/jlink.cfg -f board/esp-wroom-32.cfg -c "program_esp build/myCode.bin 0x50000"

This works on devices that have been previously flashed via UART. Nevertheless devices that are "out of the box" and have never been flashed display a weird behaviour when flashing via JTAG. Once the devices are flashed, the program will not run. After plugging UART to the device and opening up the terminal, the following message is displayed multiple times per second.

Code: [Select all] [Expand/Collapse]

1. rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
2. configsip: 0, SPIWP:0xee
3. clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
4. mode:DIO, clock div:2
5. load:0x3fffeba4,len:4
6. load:0x4009f000,len:3248
7. entry 0x4009f574
8. �OHAI�ets Jul 29 2019 12:21:46

GeSHi © Codebox Plus Extension

The only way to make the device actually work is by flashing it first via UART, and then jtag becomes usable again. Why is this? I would like to use the jtag connections only right out of the box.

[ESP_Sprite]

Looks like you're not programming the 2nd stage bootloader binary.

[CKiamy]

Looks like you're not programming the 2nd stage bootloader binary.

Where can I find/generate the .bin file for the 2nd stage bootloader? And to which offset should I flash it to the esp32?

[ESP_Sprite]

It depends, bootloaders can be customized and have different versions. Easiest way may just to install ESP32 Arduino, flash 'Hello world' or another example application, and then flash your binary over that like you did before.