SPRADU1 September   2026 AM62A3 , AM62A7

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Boot Process
    1. 2.1 SPL Boot Process
      1. 2.1.1 R5 SPL
      2. 2.1.2 TF-A+OPTEE+A53 SPL
      3. 2.1.3 U-Boot
      4. 2.1.4 Linux and User Mode
    2. 2.2 SPL Falcon Mode
      1. 2.2.1 Steps
        1. 2.2.1.1 Installing Linux SDK
        2. 2.2.1.2 Adding Falcon Script
        3. 2.2.1.3 Compiling Linux Device Tree
        4. 2.2.1.4 Creating tispl.bin
        5. 2.2.1.5 Creating a Bootable Card
    3. 2.3 Replacing SPL With SBL
      1. 2.3.1 Falcon Boot in SBL
  6. 3Boot Media
  7. 4Operating System Boot Optimization
    1. 4.1 Trimming Operating System
      1. 4.1.1 Using Preset Trimming Configuration
      2. 4.1.2 Custom Trimming
    2. 4.2 Reducing Log Output
  8. 5Userspace Optimization
    1. 5.1 Customizing Boot Services Using Systemd
  9. 6Minimizing Boot Services Using init Script
  10. 7Conclusion
  11. 8References

4.1 Trimming Operating System

An operating system has two impacts on boot: affecting the image movement speed through the image size and requiring quite a long time to run the initialization code for some kernel modules. Therefore, trimming the operating system helps speed up image movement and kernel startup.

To do so, the main approach is to disable some kernel modules or change them to dynamically loaded ones. This can be controlled by directly modifying the definition in the arch/arm64/configs/defconfig file or using the Linux configuration tool.