07-08-2021, 09:09 AM
(07-08-2021, 06:39 AM)LMM Wrote: Hello.
Thank you for the reply! Even if it did not exactly answer the question as I posed, it helps towards the requirement indirectly.
You mention that the A72 CPUs show up as 4 and 5 under Linux. Is this because on power-on RK3399 has the A53s as the first CPUs always? If so then somewhere at the start of the boot sequence (e.g. Trustzone BL1 or BL2 stages) I could ensure the A72s remain in reset all the way.
Hi,
the easiest way is :
# get info
cat /proc/cpuinfo
# log root
sudo -s
#disable A72 (cpu 4 & 5)
echo 0 > /sys/devices/system/cpu/cpu4/online
echo 0 > /sys/devices/system/cpu/cpu5/online
# check (ctrl-c to quit)
htop
cat /proc/cpuinfo
to enable again replace 0 by 1
oups I have not read that it should be from power on ! my method does not work then !