SPRAD09A
December 2021 – July 2022
DRA821U
,
DRA821U-Q1
Abstract
Trademarks
1
Hardware and Software Required Stuff
2
DRA821U Boot Mode With Fast Boot Method
3
Detailed Steps
3.1
Step1: Patch and Build/Copy the u-boot
3.2
Step2: Optimizations by Switching to xSPI Boot: Copy Bootloaders to xSPI
3.3
Step 3: Optimize the DTSI by Disabling Nodes not Mandatory for Linux Boot
3.4
Step 4: Create Bootable SD Card, Switch to TinyFS
3.5
Step 5: Switch to eMMC Filesystem
3.6
Step 6: Optimizations With Bootargs
3.7
Step 7: Hijack the init
4
Debug Commands
4.1
SF Probe
4.2
mmcblk
4.3
How to Check Mounted Devices?
4.4
How to Check Your Partitions?
4.5
How to Restore Your Boot Setting?
5
Fast Boot Result Review
6
References
7
Revision History
4.3
How to Check Mounted Devices?
Cmds:
cat /proc/mtd
Figure 4-3
Jacinto DRA821U Check Mounted Devices