SWO driver of RTEMS

the driver and rtems have been tested on stm32f4-discovery board

Use in your app

1. call setup_swo_output() directly
2. then use printf(xxx),you will see the output in swv()

How the driver works

• register the driver as /dev/swo
• use dup2 to replace stdout, so redirect the stdout to swo when use printf

Build

export RTEMS_MAKEFILE_PATH=/path/to/your/rtems/
cd rtems_swo_driver
make
arm-rtems5-objcopy -Obinary ./o-optimize/timer.exe stm32_rtems_swo_timer.bin

Run

1. use your flash program tools to program the flash, if you choose openocd

> flash write_image erase ./rtems_swo_dirver/stm32_rtems_swo_timer.bin 0x8000000
> reset

Get Output / Use OpenOCD as SWV

in the openocd configure:

source [find interface/stlink-v2.cfg]
source [find target/stm32f4x.cfg]

transport select hla_swd
reset_config srst_only
itm port 0 on
tpiu config internal swo.log uart off 16000000 2000000

the 16000000 is the default clock freq(16MHz) set by rtems,200kHz is the freq of st-link on board

after launch openocd -f stm32_swo.cfg

tail -f swo.log and you will watch the output scroll