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U-boot bootargs don't work

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I try send parameters to Kernel via U-boot, but that is not worked.
From U-boot command line:
setenv bootargs 'isolcpus=0'

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


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



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

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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.

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