LiteOS-Reading/src/targets/realview-pbx-a9

Cortex-A9 Running LiteOS in QEMU

Installing QEMU

• QEMU is an open-source tool. For details about QEMU, visit https://github.com/qemu/qemu.

• Ubuntu Linux is used in this example. If QEMU is not installed, run the following commands to download and install it:

  apt-get install qemu
  apt-get install qemu-system
  

Building PBX A9 in Symmetric Multi-Processors (SMP) Mode on Linux

• Change the .config file required for building to the default configuration file of the PBX A9.

  cp tools/build/config/realview-pbx-a9.config .config
  

• Use make for building. Kernel SMP is enabled by default.

  make clean; make -j
  

• Use QEMU to start the guest VM and run LiteOS.

  qemu-system-arm -machine realview-pbx-a9 -smp 4 -m 512M -kernel out/realview-pbx-a9/Huawei_LiteOS.bin -nographic
  

  You can run the qemu-system-arm --help command to view the description of QEMU command parameters. The parameters in the preceding command are described as follows:

  Parameter	Description
  -machine	Specifies the type of a VM to be emulated by QEMU.
  -smp	Specifies the number of CPUs of the guest VM.
  -m	Specifies the memory reserved for the guest VM. If this parameter is not specified, the default value 128M is used.
  -kernel	Specifies the path of an image file to run.
  -nographic	Specifies that the non-graphical interface is started.

• After Kernel SMP is enabled, the following information is displayed when LiteOS is started:

  ********Hello Huawei LiteOS********
  
  Processor   : Cortex-A9 * 4
  Run Mode    : SMP
  GIC Rev     : unknown
  build time  : Dec  1 2020 04:17:44
  
  **********************************
  
  main core booting up...
  osAppInit
  releasing 3 secondary cores
  cpu 0 entering scheduler
  cpu 1 entering scheduler
  cpu 3 entering scheduler
  cpu 2 entering scheduler
  app_init
  
  Huawei LiteOS #
  

Building PBX A9 in Uni-Processor (UP) Mode on Linux

• Kernel SMP is enabled by default. To disable SMP, you can disable LOSCFG_KERNEL_SMP in make menuconfig. The configuration is as follows:

  Kernel --> Enable Kernel SMP
  

• After the build, run the following command to run QEMU:

  qemu-system-arm -machine realview-pbx-a9 -kernel out/realview-pbx-a9/Huawei_LiteOS.bin -nographic
  

• After Kernel SMP is disabled, the following information is displayed when LiteOS is started:

  ********Hello Huawei LiteOS********
  
  Processor   : Cortex-A9
  Run Mode    : UP
  GIC Rev     : unknown
  build time  : Dec  1 2020 04:26:08
  
  **********************************
  
  main core booting up...
  osAppInit
  cpu 0 entering scheduler
  app_init
  
  Huawei LiteOS #