Page History

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• Ethernet:
  • iperf3 is included with the Krogoth Yocto BSP. With UDP, this command reports much lower bandwidth than expected when compared with iperf command.

• eMMC:

  • Flashing with U-Boot: 
    • fsl-image-gui-imx7d-phyboard-zeta.sdcard image is too large to be loaded into memory (1GB) from u-boot.
    • Workaround: Partition and flash eMMC from Linux instead. See Quickstart for instructions.
• Linux IMX Busfreq driver:
  • Driver disabled by default due to impaired UART console functionality when the system is idle (Low frequency setpoint).

  • For dynamic bus frequency scaling and improved power consumption, the busfreq driver can be enabled in the device tree by removing the "fsl,freq_scaling_disabled" property in imx7-phycore-som.dtsi. It can also be controlled in Linux sysfs: 

    echo 1 > /sys/bus/platform/drivers/imx_busfreq/soc\:busfreq/enable 

    
    

• Kit imx7s-phyboard-zeta-002: 

  • Communication with Cortex-M4: Linux fails to boot when RPMsg is enabled, the RPMSG driver hardcodes the location in memory used for RPMSG to be at the end of 1GB. 

    • Workaround: Fixed in v4.1.15-phy-next branch: the following commits fix the RPMSG driver to support different memory sizes and add a device tree for booting FreeRTOS M4 in parallel with linux Linux on the Cortex-A7.
      • MLK-13279 rpmsg: imx: make vring address configurable by dts
      • IMX7FLY-90 dts: imx7s-phyboard-zeta-002: add dts for running FreeRTOS on M4
        
        

    • Note: RPMSG vring buffers must be modified for 256GB RAM in the M4 kernel as well. For the FreeRTOS NXP release, this is done by changing VRING0_BASE and VRING1_BASE in middleware/multicore/open-amp/porting/imx7d_m4/platform_info.c:

      Code Block
      #define VRING0_BASE 0x8FFF0000 #define VRING1_BASE 0x8FFF8000

      
      

  • 256MB NAND is too small to flash fsl-image-gui filesystem. Booting from NAND was tested with core-image-minimal Yocto image, which is included with release binaries.

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