Reference: OpenOCD, GDB

2018-04-18

Cheatsheet/notes about OpenOCD and GDB

OpenOCD Pre-reqs

• Host: Laptop or Beaglebone, with openocd installed, with some USB programmer
• openocd.cfg files: repo

To start OpenOCD, cd to directory with openocd.cfg, run openocd

GDB Commands

• Start GDB, with an ELF file if you want. gdb example.elf
• Should work on the Beaglebone native gdb, because it is ARM, difference is eabihf vs eabi
• (gdb) target remote localhost:3333
• monitor reset , monitor halt , monitor reset halt
• monitor actually issues OpenOCD commands thru GDB.

To verify an ELF file:

monitor verify_image /full/path/to/my.elf

Actually the search path is the directory that OpenOCD started in.

To load an ELF file into flash memory:

monitor flash write_image erase /full/path/to/my.elf

Use the erase parameter, to erase before writing. According to openocd manual, you should assume other flash sectors will be erased too.

• To start gdb connected to remote target: gdb -ex "target remote localhost:3333" ~/my.elf

Telnet Commands

Single Shot Load

v1=copy-paste-your-path-to-elf-here.elf (echo flash write_image erase $(pwd)/$v1 ; sleep 1) | telnet localhost 4444

Load Image Automatically

```

!/bin/bash

fetch_and_load() { echo Starting OpenOCD Server openocd -f ~/openocdconfigs/stm32f4discovery/openocd.cfg & echo Fetching and Loading new firmware: $v1 wget ffn.bootladder.com:9001/$v1

(echo reset halt; sleep 1) | telnet localhost 4444
sleep 2
(echo flash write_image erase $(pwd)/$v1 ; sleep 1) | telnet localhost 4444
sleep 2
(echo reset; sleep 1) | telnet localhost 4444
sleep 2
(echo shutdown; sleep 1) | telnet localhost 4444

}

v1=$(curl ffn.bootladder.com:9001/target/ffnbeagle-woodland-stm32discovery 2>/dev/null) ls $v1 >/dev/null || fetch_and_load ``` This appears to work, but not sure if it works every time. Hence the sleeps.
OpenOCD server is started and stopped for each write_image.
The curl retrieves the contents of the URL, which is a filename * If the local system has that file, don't do anything. * If not, grab that file and load it.

Loop the above to achieve automatic firmware updates while true; do sh fetch-and-load-ffnbeagle-woodland-stm32discovery.sh ; sleep 1; done;

The above works when I only have 1 STM32F4 discovery board.

For my Atmel project, I may have 2 USB debuggers attached to the same host.

At large scale, a host will have many ttyUSB serial ports for bootloading

Hmm, --enable-cmsis-dap not supported in my OpenOCD installation.

Ahh nice, sudo apt install libhidapi-dev , ./configure --enable-cmsis-dap . Props to http://www.signal11.us/oss/