cpu command

Synopsis

cpu list
cpu detail
cpu release <core ID> <addr>

Description

The cpu command prints information about the CPUs, and release a CPU core to a given address to run applications.

cpu list

The ‘list’ subcommand lists and prints brief information of all the CPU cores, the CPU information is provided by vendors’ CPU driver.

cpu detail

The ‘detail’ subcommand prints more details about the CPU cores, including CPU ID, core frequency and feature list.

cpu release

The ‘release’ subcommand is used to release a CPU core to run a baremetal or RTOS applications. The parameter <core ID> is the sequence number of the CPU core to release. The parameter <addr> is the address to run of the specified core after release.

Examples

cpu list

This example lists all the CPU cores On i.MX8M Plus EVK:

u-boot=> cpu list
  0: cpu@0      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
  1: cpu@1      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 30C
  2: cpu@2      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
  3: cpu@3      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C

cpu detail

This example prints the details of the CPU cores On i.MX8M Plus EVK:

u-boot=> cpu detail
  0: cpu@0      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
        ID = 0, freq = 1.2 GHz: L1 cache, MMU
  1: cpu@1      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 30C
        ID = 0, freq = 1.2 GHz: L1 cache, MMU
  2: cpu@2      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
        ID = 0, freq = 1.2 GHz: L1 cache, MMU
  3: cpu@3      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
        ID = 0, freq = 1.2 GHz: L1 cache, MMU

cpu release

This example shows release the LAST CPU core to run a RTOS application, on i.MX8M Plus EVK:

u-boot=> load mmc 1:2 c0000000 /hello_world.bin
66008 bytes read in 5 ms (12.6 MiB/s)
u-boot=> dcache flush; icache flush
u-boot=> cpu release 3 c0000000
Released CPU core (mpidr: 0x3) to address 0xc0000000

Configuration

The cpu command is available if CONFIG_CMD_CPU=y.

Return code

The return value $? is set to 0 (true) if the command is successful, 1 (false) otherwise.