How to configure uniprocessor mode
This article explains how to switch from a SMP (symmetric multiprocessing) Linux® kernel configuration to a UP (uniprocessor) Linux kernel configuration.
Considering that STMicroelectronics Linux kernel is configured in SMP mode by default, single Arm Cortex-A core users may wish to disable this configuration in order to avoid trying to start the second core at every boot. Please note that keeping the SMP mode enabled on a single processor does not have any performance impact on the kernel in most use cases, so this change is not mandatory.
3 Modify kernel configuration
To switch to UP configuration, disable SMP configuration. To do that, search SMP in kernel menuconfig and disable the option.