FreeRtos Examples

Pre-Built Demo applications

• cl-som-imx8

  • hello_world.bin

  • igpio_led_output.bin

  • rpmsg_lite_str_echo_rtos_imxcm4.bin

  • rpmsg_lite_pingpong_rtos_linux_remote.bin

• ucm-imx8m-mini

  • hello_world.bin

  • igpio_led_output.bin

  • rpmsg_lite_str_echo_rtos_imxcm4.bin

  • rpmsg_lite_pingpong_rtos_linux_remote.bin

• iot-gate-imx8

  • hello_world.bin

  • igpio_led_output.bin

  • rpmsg_lite_str_echo_rtos_imxcm4.bin

  • rpmsg_lite_pingpong_rtos_linux_remote.bin

• mcm-imx8m-mini

  • hello_world.bin

  • igpio_led_output.bin

Basic setup

The demo applications are loaded from MMC to TCM.

• U-Boot environment:

  setenv m4_loadaddr 0x7e0000
  setenv m4_start 'load mmc 1 0x48000000 ${m4_file}; cp.b 0x48000000 ${m4_loadaddr} 0x20000; dcache flush; bootaux ${m4_loadaddr}'
  saveenv

• UART1 configured as the M4 debug console.

  • cl-som-imx8

    SB-iMX8M P20 header is in use.
    P20.P19 - UART1_TXD
    P20.P21 - UART1_RXD
    P20.P33 - GND

  • ucm-imx8m-mini

    SB-UCM-iMX8 P16 connector is in use.

  • mcm-imx8m-mini

    SB-MCM-iMX8-Mini P20 header is in use.
    P20.P9  - UART1_TXD
    P20.P11 - UART1_RXD
    P20.P31 - GND

• UART2 configured as the M4 debug console.

  • iot-gate-imx8

    • The IED-BASE module should be installed on the SB-IOTGIMX8 base board.

    • IED-RS232 should be installed in socket A of the IE-BASE module.

      IED-BASE P2 header is in use.
      P2.P1 - UART2_TXD
      P2.P3 - UART2_RXD
      P2.P2 - GND

Demo Applications How To

• hello_world.bin

  • U-Boot

    setenv m4_file hello_world.bin; run m4_start

  • M4 console

    hello world.

• igpio_led_output.bin

  • U-Boot

    setenv m4_file igpio_led_output.bin; run m4_start

  • M4 console

    GPIO Driver example
    The LED is blinking.
    GPIO_DR& 0x30200000 ; PIN# 12

• rpmsg_lite_str_echo_rtos_imxcm4.bin

  • U-Boot

    setenv m4_file rpmsg_lite_str_echo_rtos_imxcm4.bin; run m4_start; boot

  • M4 console

    RPMSG String Echo FreeRTOS RTOS API Demo...
    Nameservice sent, ready for incoming messages...

  • OS

    dmesg -c > /dev/null
    modprobe imx_rpmsg_tty
    dmesg
    [   41.088386] imx_rpmsg_tty virtio0.rpmsg-virtual-tty-channel-1.-1.30: new channel: 0x400 -> 0x1e!
    [   41.099673] Install rpmsg tty driver!
    [   41.108472] rpmsg_tty_cb68 65 6c 6c 6f 20 77 6f 72 6c 64 21              hello world!

  • M4 console

    Get Message From Master Side : "hello world!" [len : 12]

• rpmsg_lite_pingpong_rtos_linux_remote.bin

  • U-Boot

    setenv m4_file rpmsg_lite_pingpong_rtos_linux_remote.bin; run m4_start; boot

  • M4 console

    RPMSG Ping-Pong FreeRTOS RTOS API Demo...
    RPMSG Share Base Addr is 0xb8000000
    Link is up!
    Nameservice announce sent.

  • OS

    • maunal load

      dmesg -c > /dev/null
      modprobe imx_rpmsg_pingpong
      dmesg
      [   30.420794] imx_rpmsg_pingpong virtio0.rpmsg-openamp-demo-channel.-1.30: new channel: 0x400 -> 0x1e!
      [   30.433498] get 1 (src: 0x1e)
       ....
      [   30.665919] get 101 (src: 0x1e)
      [   30.669131] imx_rpmsg_pingpong virtio0.rpmsg-openamp-demo-channel.-1.30: goodbye!

    • auto load

      # This approach shows how to make the system load the driver automatically at the boot time.
      # It is up to the user to prepare the boot environment that loads an m4-ping-pong demo before starting kernel.
      cat << eof > /etc/modules-load.d/imx_rpmsg_pingpong.conf
      imx_rpmsg_pingpong
      eof
      reboot

  • M4 console

    Waiting for ping...
    Sending pong...
     ....
    Ping pong done, deinitializing...
    Looping forever...

JTAG Debugging

• Requirements:

  • HW: Bus Blaster v3

  • SW: OpenOCD

  • Integration and configuration: Open Source JTAG Debugging

• How to:

  • Target is a ucm-imx8m-mini SOC.

    • U-Boot console:

      setenv m4_file hello_world.bin; run m4_start

  • Host is a development Linux machine.

    • BackEnd

      sudo openocd -f ~/openocd/tcl/interface/ftdi/dp_busblaster.cfg -f ~/openocd/tcl/board/nxp_mcimx8m-evk.cfg

    • Monitor

      • get connected to the openocd:4444, switch to the imx8mq.m4 and examine:

        telnet localhost 4444
        > targets imx8mq.m4
        > imx8mq.m4 arp_examine
        imx8mq.m4: hardware has 6 breakpoints, 4 watchpoints
        > targets
            TargetName         Type       Endian TapName            State
        --  ------------------ ---------- ------ ------------------ ------------
         0  imx8mq.a53.0       aarch64    little imx8mq.cpu         running
         1  imx8mq.a53.1       aarch64    little imx8mq.cpu         examine deferred
         2  imx8mq.a53.2       aarch64    little imx8mq.cpu         examine deferred
         3  imx8mq.a53.3       aarch64    little imx8mq.cpu         examine deferred
         4* imx8mq.m4          cortex_m   little imx8mq.cpu         running
         5  imx8mq.ahb         mem_ap     little imx8mq.cpu         running

    • Front End

      • get connected to the openocd:3334, resume the m4:

        ${CROSS_COMPILE}gdb /path/to/igpio_led_output.elf
        (gdb) target remote :3334
        Remote debugging using :3334
        delay () at /path/to/rtos/freertos/imx8mm/boards/ucm-imx8m-mini/driver_examples/gpio/led_output/gpio_led_output.c:41
        41          for (i = 0; i < EXAMPLE_DELAY_COUNT; ++i)
        (gdb) continue
        Continuing.