AN 709: HPS SoC Boot Guide - Cyclone V SoC Development Kit

ID 683265
Date 1/27/2016
Public

1.2.1.2. Preloader

Typically, the main responsibilities of the Preloader are:

  • Perform additional HPS initialization
  • Bring up SDRAM
  • Load the next boot stage from Flash to SDRAM and jump to it

Currently, two different Preloader options are available:

  • SPL – part of U-Boot. Provided with SoC EDS under GPL (Open Source) License
  • MPL – provided with SoC EDS as an example using the HWLibs (Altera bare-metal libraries). Uses BSD license.
Note: The Preloader requires a special header to be placed at the beginning of the next stage boot image. Also, the header contains a CRC value used to validate the image. The header can be attached to an image by using the mkimage utility that is included with the SoC EDS.