The ST-Link/OpenOCD way

If you stick with ST microcontrollers, the ST-Link is cheap and well supported by open source tools. The ST-Link is embedded on ST discovery boards, which are so cheap that you can afford a board only for the debugger part. The STM32F0 discovery board comes with a ST-Link/v2 for less than 10$. The ST-Link can be used to debug another ST microcontroller using the SWD connector. A long discussion from Andy Brown about the advantage of the ST-Link can be found there [11].

By the way, there are also illegal Chinese copies of the ST-Link (this one does not look very much ST [12] for example), but I can't see the point of supporting Chinese illegal copies when the original is just a few € more.

Example with a STM32F4 discovery board:

How to connect to the standard JTAG connector:

===== === ======
 SWD  <->  JTAG
===== === ======
 VDD  <->  Vref
  -        TDI
SWDIO <->  TMS
SWCLK <->  TCK
  -        TDO
NRST  <-> nTRST
  -       nSRST
 GND  <->  GND
===== === ======

According to a quick probe on the SWCLK (common with JTAG's TCK) clock signal, the adapter appears to run at 1.5MHz.

How to architecture your embedded project?

If you want an all-in-eclipse project, I suggest to follow the 4-part tutorial from Akhmad Hendriawan at [13], [14], [15] and [16]. The problem is, as explained a the beginning of this post, that everything depends on eclipse, which is bad (R)

In addition, I am targetting a bare-metal solution, excluding any compiler start-up and standard C or C++ library (newlib).

Create a new empty project:

By disabling the default build command, all the GNU ARM Ecplise auto build is removed:

For example, the build script could be like this:

#!/bin/sh
# Simple build script

GCC_BIN_PATH=/usr/bin

$GCC_BIN_PATH/arm-none-eabi-g++ -g -std=gnu++0x -fno-exceptions -mcpu=cortex-m3 -mthumb --specs=nosys.specs -I inc/ -T myEmbeddedProject.ld \
myEmbeddedProject.cpp \
-o myEmbeddedProject.elf

# for debug purposes only
$GCC_BIN_PATH/arm-none-eabi-objdump -xmyEmbeddedProject.elf > objdump.log

# convert elf into hex for flashing
$GCC_BIN_PATH/arm-none-eabi-objcopy -O ihex myEmbeddedProject.elf myEmbeddedProject.hex

You can create External Tools Configurations to flash the target, or run the OpenOCD gdb server:

For example, the flash script could be like this:

#!/bin/sh
# Simple flash script

OPENOCD_BIN_PATH=/usr/bin/
OPENOCD_TCL_PATH=/usr/share/openocd/scripts

$OPENOCD_BIN_PATH/openocd -f $OPENOCD_TCL_PATH/interface/stlink-v2.cfg -f $OPENOCD_TCL_PATH/target/stm32f1x_stlink.cfg -c init -c targets -c "halt" -c "flash write_image erase myEmbeddedProject.elf" -c "verify_image myEmbeddedProject.elf" -c "reset run" -c shutdown

The debug configuration for OpenOCD:

For example, the debug script could be like this:

#!/bin/sh
# Simple script for gdb server

OPENOCD_BIN_PATH=/usr/bin/
OPENOCD_TCL_PATH=/usr/share/openocd/scripts

$OPENOCD_BIN_PATH/openocd -f $OPENOCD_TCL_PATH/interface/stlink-v2.cfg -f $OPENOCD_TCL_PATH/target/stm32f1x_stlink.cfg

Result

If you install EmbSysRegister for eclipse, you can have a nice special functions registers (SFR) view matching your microcontroller.

Enjoy programming, flashing and debugging with eclipse, without relying on eclipse in your project!

References