I am working on Sabre auto board. There are 4 cpus running on linux kernel.
In Bootargs i set maxcpus as 1 at Uboot. So that during initial boot time kernel boots with single CPU to reduce 300ms boot time.
Later after mounting the file system using sysfs i tried to enable the rest of CPU's. But rest of 3 CPU's were not enabled.
Scrip ran :
echo 1 > /sys/devices/system/cpu/cpu/online
Verified with :