SEm-Labos/Libs/RiscV/NEORV32/sw/example/demo_freeRTOS

FreeRTOS Demo for the NEORV32 Processor

This example shows how to run FreeRTOS on the NEORV32 processor. It features the default "blinky_demo" and the more sophisticated "full_demo" demo applications. See the comments in main.c and the according source files for more information.

The chip-specific extensions folder (chip_specific_extensions/neorv32) should be in $(FREERTOS_HOME)/Source/portable/GCC/RISC-V/chip_specific_extensions, but is placed in this source directory for simplicity.

Hardware Requirements

• DMEM/IMEM requriements depend on the actual application (for example: 8kB DMEM and 16kB IMEM for blinky_demo)
• MTIME (machine timer) + UART + GPIO
• Zicsr CPU extension

Instructions

Download FreeRTOS from the official GitHub repository or from the its official homepage.

$ git clone https://github.com/FreeRTOS/FreeRTOS.git

Open the makefile from this example folder and configure the FREERTOS_HOME variable to point to your FreeRTOS home folder.

FREERTOS_HOME ?= /mnt/n/Projects/FreeRTOSv10.4.1

Compile the NEORV32 executable. Do not forget the RUN_FREERTOS_DEMO switch.

$ make USER_FLAGS+=-DRUN_FREERTOS_DEMO clean_all exe

Note: The *.c sources and the FreeRTOS-specific part of the makefile have (include) guards that test if RUN_FREERTOS_DEMO is defined. This has no pratical usage for the user - it is just a work-around for the NEORV32 CI environment.

Upload the executable (neorv32_exe.bin) to the processor via the bootloader and execute it.

Awaiting neorv32_exe.bin... OK
CMD:> e
Booting...

FreeRTOS V10.4.1
Blink
Blink
Blink

FreeRTOS Plus

To automatically add source and include files from FreeRTOS plus extensions add one (or more) of the following arguments when invoking make:

• FreeRTOS-Plus-CLI: USER_FLAGS+=-FREERTOS_PLUS_CLI
• FreeRTOS-Plus-TCP: USER_FLAGS+=-FREERTOS_PLUS_TCP

Example:

$ make USER_FLAGS+=-DRUN_FREERTOS_DEMO USER_FLAGS+=-FREERTOS_PLUS_TCP clean_all exe

Notes

The onfiguration of the FreeRTOS home folder (via FREERTOS_HOME) is corrupted if the compiler shows the following error:

main.c:36:10: fatal error: FreeRTOS.h: No such file or directory
   36 | #include <FreeRTOS.h>
      |          ^~~~~~~~~~~~
compilation terminated.
make: *** [makefile:203: main.c.o] Error 1