OpenOCD + BusBlaster v4

OpenOCD+BusBlasterv4.md

Setup

1. Install OpenOCD.
2. Plug the JTAG cable into the Bus Blaster's adapter board and the target.
3. Run

arm-none-eabi-gdb path/to/firmware.elf -ex 'target remote | openocd -c "gdb_port pipe;" -f ../jtag/busblaster.cfg'

(adjust paths as appropriate) to launch gdb.

GDB commands

Basics

• c - continue
• ctrl-c - stop
• p expr - print the value of the C expression expr
• bt - stack backtrace
• s - step instruction, goes into calls
• n - next instruction, skips over calls
• fin - run until return from function
• break function - break at the beginning of a function (can also pass file.c:line)
• delete 1 - delete the first breakpoint
• tbreak - break only once

Hardware

• mon reset - Reset cpu and all on-chip peripherals (like the reset button)
• mon soft_reset_halt - Reset the CPU only

Bus Blaster

adapter driver ftdi
adapter speed 1000
ftdi_device_desc "Dual RS232-HS"
ftdi_vid_pid 0x0403 0x6010

ftdi_layout_init 0x0c08 0x0f1b
ftdi_layout_signal nTRST -data 0x0100 -noe 0x0400
ftdi_layout_signal nSRST -data 0x0200 -noe 0x0800

reset_config srst_only

transport select jtag
#the other option is swd - this bit I had to look up