U-Boot

U-Boot runs at 0x8002,0000 and works in S mode. It contains basic file system and commonly used peripheral drivers (such as GMAC, UART, QSPI, USB, SDIO etc.). U-Boot can load the kernel image through ETH, UART, QSPI, SDIO or USB.

The following example describes how to load Linux 5.10 kernel image from SDIO.

Note:
  • The example assumes the installation of Ubuntu 18.04.
  • Press Enter to confirm the operation or for the next command.

Steps:

  1. SD card partition. The following is an example:
    Figure 1. SD Card Partition Command Explanation
  2. Format the partition. The following is an example:
    Figure 2. Format the Partition
  3. Generate image.fit from Freelight U SDK. Refer to the detailed guidelines in the link.
  4. Copy the boot file. The following is an example:
    Figure 3. Copying the Boot File
  5. Load the kernel (Linux 5.10 as an example).
    Figure 4. Loading the Kernel
Note: The addresses 0x80200000, 0x86100000 and 0x86000000 have been specified when compiling and generating image.fit and cannot be modified.