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

4.1 SF Probe

When issuing the SF probe, you will send this kind of result.

You can see those three uboot files is flashing onto the xSPI flash.

Cmds:

Sf probe

GUID-20211124-SS0I-X8DP-RMLS-DDPQF8TCSTH8-low.png Figure 4-1 Jacinto DRA821U SF Probe in uboot