How to use RT-Linux in i.MX8MM EVK board

*Apply patches and build new image:
$cd ${YOUR_KERNEL_PATH} and copy the RT_PREEMPT_Patches folder to the kernel path
$git am  RT_PREEMPT_Patches/*.patch
Then rebuild the kenrel
$bitbake –c –f compile linux 
$bitbake –c deploy linux
Note: the new image could be found at your yacto build folder: tmp/deploy/images/imx8mm/
  

*Download image to eMMC:

  1 use uuu to downlaod demo image to i.MX8mm evk board by below cmd:
  copy uuu tool and L4.14.78 demo image to a folder, then open a cmd and switch to this folder, run:
    
    uuu -b emmc_all  imx-boot-imx8mmevk-sd.bin-flash_evk fsl-image-validation-imx-imx8mmevk.sdcard
  
    Note: need to switch to serail download mode before execute above cmd.
  
  2 connecting UART debug cable to i.MX8MM evk board and boot up
  
  3 then can do the Real time test, such as cyclic test

  
  
*How to do cyclictest and stress test:

  1 set cpufreq govern:
 
      echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
  
  2 run cyclictest with cpu stress test
      /home/root/rt-tools/stress -c 4 & /home/root/rt-toos/cyclictest -p 80 -t5 -n                                               
      /home/root/rt-tools/stress -c 4 & /home/root/rt-toos/cyclictest --smp -p 90 -m                                              
      /home/root/rt-tools/stress -c 4 & /home/root/rt-toos/cyclictest -p 90 - m -c 0 -i 200 -n -h 100 -q -l 1000000