Service Name
microcode_ctl
Description
microcode_ctl updates a microcode in IA32 CPU. The microcode is prepared as a file /etc/firmware/microcode.dat. As this service can fix microcode bugs by updating CPU microcode this should be available.m however only for Intel IA32.
Basically, running “service microcode_ctl start” doesn’t start up a daemon, it first checks if the processor is suitable for updating firmware, if it is, then “microcode_ctl” service will insert the module “microcode” into the kernel and creates a device file /dev/cpu/microcode, calls “/sbin/microcode_ctl” to upload the microcode with default data file /etc/firmware/microcode.dat, Then “microcode_ctl” will remove the module “microcode” and device file /dev/cpu/microcode and finally it will report if upload is successful.
The corresponding rpm package is:
microcode_ctl
This is a service not to run any daemon. It uploads microcode to Intel IA32 processor.
Service Control
The microcode update is volatile and needs to be uploaded on each system startup. To control the microcode_ctl service after the next system boot, use the chkconfig utility:
# chkconfig microcode_ctl on # chkconfig --list microcode_ctl microcode_ctl 0:off 1:off 2:on 3:on 4:on 5:on 6:off # chkconfig microcode_ctl off
To control the microcode_ctl service immediately, use the service utility:
# service microcode_ctl
Usage: /etc/init.d/microcode_ctl {start|stop|restart}
The table below describes each of the available commands:
| Command | Description |
|---|---|
| start | Upload the microcode in /etc/firmware/microcode.data to CPU |
| restart | Same as start |
| stop | It removes the lock file /var/lock/subsys/microcode_ctl which is created by command “start” |