I want to do isolcpus,but i can’t find /etc/default/grub the profile.Where is it?Or is there any solution to achieve isolcpus?

hello 1346825367,

please have a try modify /boot/extlinux/extlinux.conf to add isolcpus in the end of APPEND.

Note that U-Boot is used instead of GRUB, which is why “/boot/extlinux/extlinux.conf”. Anything you see related to GRUB won’t apply to an embedded system.