Hi,

I try send parameters to Kernel via U-boot, but that is not worked.
From U-boot command line:

setenv bootargs 'isolcpus=0'
saveenv
boot

After Linux boot I don't see system changes, for test 

cat /proc/cmdline

How to send bootargs 'isolcpus=0' to Kernel?

My system image Armbian_5.12_Lime2_Debian_jessie_4.5.5

 

Add it to the boot script /boot/boot.cmd & convert to boot.scr after you are done.

Great Igor, how to convert boot.cmd to boot.scr?

 

UPDATE

Need run script mkimage -C none -A arm -T script -d boot.cmd boot.scr

I tried /boot/armbianEnv.txt ... did not work.

 

I have inserted isolcpus=2,3 in /boot/boot.cmd in the middle of the line like

 

setenv bootargs "root=${rootdev} rootwait rootfstype=${rootfstype} ${consoleargs} hdmi.audio=EDID:0 disp.screen0_output_mode=${disp_mode} panic=10 consoleblank=0 loglevel=${verbosity} ubootpart=${partuuid} ubootsource=${devtype} usb-storage.quirks=${usbstoragequirks} ${extraargs} ${extraboardargs}"

 

and ran the command given at the very end of /boot/boot.cmd

 

mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr

 

reboot, and it's working for me.

 

To check it's working, run top, press 1 to expand the CPU view, and launch four times this command in parallel:

 

cat /dev/urandom >/dev/null

 

It's a CPU eating task, but not yet a fork bomb. Isolated core should keep iddle between 99 and 100%

 

OxFF you should avoid to isolate core 0 because it's the prefered core for kernel; running kernel on an other core may lead to bugs; this heavily depends on the platform, kernel version, kernel taste (features like process migration) ... and which drivers you are using. Isolate core #0 only if you are sure it will let the kernel run on core #0, and only prevent normal process from running on it.