Running FreeRTOS Command Linux Interface

This application note explains the interactive Command Line Interface (CLI) implemented by the FreeRTOS BSP.

Understanding FreeRTOS Command Line Interface

FreeRTOS CLI Purpose

The FreeRTOS test application integrates implementation of a FreeRTOS Command Line Interface (CLI). The CLI provides an interactive user interface on the serial console, allowing the user to run various commands from the FreeRTOS test application in interactive mode.

The FreeRTOS test application is enhanced to provide various custom CLI commands, used to validate and demonstrate the features supported by the FreeRTOS BSP. These custom CLI commands are documented in the other application notes available on the site.

FreeRTOS CLI UART Port

The FreeRTOS BSP is enhanced to implement a serial console interface on the STM32H7 USART1 port.

The serial console is configured to run at 115200 rate.

FreeRTOS CLI Source Files

Implementation of the serial console interface can be found in the Applications/FreeRTOS/freertos_stm32h750/Src/console.[ch] source files.

FreeRTOS CLI C-Binding API

The serial console interface will implement the following C-binding API:

Function	Description	Comments
int console_init(void)	Initialise the serial console interface	Serial console available on USART1, at 115200 rate
void console_putc(char c)	Print a character to the serial console	Can be called from multiple parallel threads
void console_puts(char * str)	Print a string to the serial console	Can be called from multiple parallel threads
char console_getc(void)	Get a character from the serial console	Implementation is interrupt-driven. Use shall be limited to a single thread

FreeRTOS CLI Sample Session

The following is a FreeRTOS sample session:

$ picocom -b 115200 /dev/ttyUSB1
picocom v3.1

port is        : /dev/ttyUSB1
flowcontrol    : none
baudrate is    : 115200
parity is      : none
databits are   : 8
stopbits are   : 1
escape is      : C-a
local echo is  : no
noinit is      : no
noreset is     : no
hangup is      : no
nolock is      : no
send_cmd is    : sz -vv
receive_cmd is : rz -vv -E
imap is        :
omap is        :
emap is        : crcrlf,delbs,
logfile is     : none
initstring     : none
exit_after is  : not set
exit is        : no

Type [C-a] [C-h] to see available commands
Terminal ready

U-Boot SPL 2019.04-gb41e2dbf49-dirty (Mar 14 2023 - 01:00:44 +0300)
Hit 's' key to enter spl shell:
Trying to boot from SPI


U-Boot 2019.04-gb41e2dbf49-dirty (Mar 14 2023 - 01:00:44 +0300)

Model: STMicroelectronics STM32H7 SOM
DRAM:  32 MiB
SF: Detected n25q512ax3 with page size 256 Bytes, erase size 4 KiB, total 64 MiB
Flash: 128 KiB
MMC:   STM32 SDMMC2: 0
Loading Environment from UBI... ubi0: default fastmap pool size: 190
ubi0: default fastmap WL pool size: 95
ubi0: attaching mtd2
ubi0: scanning is finished
ubi0: attached mtd2 (name "system", size 15 MiB)
ubi0: PEB size: 4096 bytes (4 KiB), LEB size: 3968 bytes
ubi0: min./max. I/O unit sizes: 1/256, sub-page size 1
ubi0: VID header offset: 64 (aligned 64), data offset: 128
ubi0: good PEBs: 3840, bad PEBs: 0, corrupted PEBs: 0
ubi0: user volume: 5, internal volumes: 1, max. volumes count: 23
ubi0: max/mean erase counter: 2/1, WL threshold: 4096, image sequence number: 0
ubi0: available PEBs: 1145, total reserved PEBs: 2695, PEBs reserved for 
bad PEB handling: 0
Read 16384 bytes from volume env1 to d1e72960
Read 16384 bytes from volume env2 to d1e76980
OK
In:    serial
Out:   serial
Err:   serial
No size specified -> Using max size (2099072)
Read 2099072 bytes from volume splash to d0400000
Net:   Net Initialization Skipped
No ethernet found.
Hit any key to stop autoboot:  0
Booting Image #1
No size specified -> Using max size (4198144)
Read 4198144 bytes from volume rtos1 to d0400000
## Loading kernel from FIT Image at d0400000 ...
   Using 'config-1' configuration
   Verifying Hash Integrity ... sha1,rsa2048:dev+ OK
   Trying 'kernel' kernel subimage
     Description:  FreeRTOS Image
     Type:         Kernel Image
     Compression:  uncompressed
     Data Start:   0xd04000d0
     Data Size:    77376 Bytes = 75.6 KiB
     Architecture: ARM
     OS:           Linux
     Load Address: 0xd0600000
     Entry Point:  0xd0610279
     Hash algo:    sha1
     Hash value:   413d02bfc42ad673db4f077d8f84dd4e48d2de79
   Verifying Hash Integrity ... sha1+ OK
   Loading Kernel Image ... OK

Starting kernel ...

STM32H7 SOM FreeRTOS CLI, www.emcraft.com
Type help to view a list of available commands.
CLI> help

help:
 Lists all the registered commands

i2c_scan <bus>
i2c_read  <bus> <i2c_addr> <addr_data> <cnt>
i2c_write <bus> <i2c_addr> <addr_data> <data>   
rtc_get_date
rtc_set_date <date>
wdt_stop
sdram_test  <ptrn> <cnt>
uart_test <port> <baudrate> <cnt>
lcdtest
pwm_start <tim> <chnl> <period> <duty>
pwm_stop <tim> <chnl>
adc_se <nadc> <chnl>
spi_flash_test <spi_bus>
timer_cnt
ubipart <mtdpart>
ubifsmount <vol>
ubifsumount
ubifsls <path>
ubifsload <path> <addr> <size>
ubifswrite <path> <addr> <size>
ubifsmkdir <path>
ubifsrmdir <path>
ubifsunlink <path>
ubifsstress
usbfatls
uboot_getenv <var>
uboot_setenv <var=val>
uboot_saveenv
sdram_info
reliable_upgrade <image>
CLI>