Starting with JLink debugger (ARMv8)

• Debugger: JLink V11
• Target Hardware: raspberry 4b
• Host: Ubuntu 20.04-amd64

Note, the openocd installed by sudo apt-get install openocd is not work on ubuntu 20.04. The error prompted Error: invalid command name "dap". So you shall compile the openocd by yourself. Please refer to the link https://hackaday.io/page/4991... (Though it is targetting for ubuntu 16.04, the 20.04 still follow these build steps.)

1. The Scope

We should use the three command terminals to launch the Jlink debugger. They are openocd/telnet/gbd-multiarch separately.

On the openocd command line, should type the cmd is:

sudo openocd -f jlink.cfg -f raspi4.cfg

On the telnet command line, should type the cmds are:

telnet localhost 4444
> halt
> load_image /home/carlos/work/uncleben/armv8_trainning/lab01/benos.bin 0x80000
> step 0x80000

On the gdb command line, should ytpe the cmds are:

gdb-multiarch --tui benos.elf
> target remote localhost:3333
> b ldr_start
> c
> n
> layout regs