To try Emgo you need first download it. You can probably use go get but preffered way is to clone this repository:
git clone https://github.com/ziutek/emgo.git
Next you need to build and install egc (Emgo compiler):
cd emgo/egc
go install
All examples are for ARM Cortex-M based MCUs. To build them, you need to install ARM toolchain. You have two options: install a package included in your OS distribution (in case of Debian/Ubuntu Linux):
apt-get install gcc-arm-none-eabi
or better go to the GNU ARM Embedded Toolchain website and download most recent toolchain (this is preffered version of toolchain, try use it before report any bug with compilation).
Installed toolchain contains set of arm-none-eabi-* binaries. Find their location and set required enviroment variables:
export EGCC=path_to_arm_gcc # eg. /usr/local/arm/bin/arm-none-eabi-gcc
export EGLD=path_to_arm_linekr # eg. /usr/local/arm/bin/arm-none-eabi-ld
export EGAR=path_to_arm_archiver # eg. /usr/local/arm/bin/arm-none-eabi-ar
export EGROOT=path_to_egroot_directory # eg. $HOME/emgo/egroot
export EGPATH=path_to_egpath_directory # eg. $HOME/emgo/egpath
Now you are ready to compile some example code. There are two directories that contain examples:
Use one that contains example for your MCU/devboard.
For example, to build blinky for STM32 NUCLEO-F411RE board:
cd $EGPATH/src/stm32/examples/nucleo-f411re/blinky
../build.sh
First compilation may take some time because egc must process all required libraries and runtime. If everything went well you obtain cortexm4.elf binary.
Compilation can produce two kind of binaries: binaries that should be loaded to RAM or to Flash of your MCU.
Load into RAM is useful in case of small programs, during working on the code and debuging. Loading into RAM is faster, allows unlimited number of breakpoints, allows to modify constants and even the code from debuger and saves your Flash, which has big but limited number of erase cycles.
To run program loaded to RAM you must change MCU boot option. In case of most STM32 MCUs you simply need to set high BOOT0 and BOOT1 pins.
But eventually your program should be loaded to Flash. Sometimes you simply can not load to RAM: program is too big, your MCU does not provide easy way to run program loaded to RAM (eg. nRF51). At last, some bugs may only appear when program runs from Flash.
To program your MCU using binary built to run from RAM:
../load.sh # This uses st-util.
or
../load-oocd.sh # This uses openocd.
To load binary built to run from flash (this erases Flash and programs it with new firmware):
../load.sh flash
or
../load-oocd.sh flash
To change this RAM/Flash build option you need to edit script.ld file and change the line:
INCLUDE stm32/loadram
to
INCLUDE stm32/loadflash
or vice versa. More editing is need for STM32F1xx series.
There are also scripts for Black Magic Probe: load-bmp.sh, debug-bmp.sh.
