SPRAD09A December   2021  – July 2022 DRA821U , DRA821U-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Hardware and Software Required Stuff
  4. 2DRA821U Boot Mode With Fast Boot Method
  5. 3Detailed Steps
    1. 3.1 Step1: Patch and Build/Copy the u-boot
    2. 3.2 Step2: Optimizations by Switching to xSPI Boot: Copy Bootloaders to xSPI
    3. 3.3 Step 3: Optimize the DTSI by Disabling Nodes not Mandatory for Linux Boot
    4. 3.4 Step 4: Create Bootable SD Card, Switch to TinyFS
    5. 3.5 Step 5: Switch to eMMC Filesystem
    6. 3.6 Step 6: Optimizations With Bootargs
    7. 3.7 Step 7: Hijack the init
  6. 4Debug Commands
    1. 4.1 SF Probe
    2. 4.2 mmcblk
    3. 4.3 How to Check Mounted Devices?
    4. 4.4 How to Check Your Partitions?
    5. 4.5 How to Restore Your Boot Setting?
  7. 5Fast Boot Result Review
  8. 6References
  9. 7Revision History

4.5 How to Restore Your Boot Setting?

When you are doing the boot debug, if boot failed and as long as your SD card contain is not broken, switch your Boot setting to the SD card, and do the following cmd. Your DRA821U will be boot-able again.

Cmds:

  • env default -f –a
  • setenv board_name j7200
  • setenv default_device_tree k3-j7200-common-proc-board.dtb