uEnv.txt parameters explained? October 29, 2023 10:14AM |
Registered: 1 year ago Posts: 28 |
Re: uEnv.txt parameters explained? October 29, 2023 02:06PM |
Admin Registered: 13 years ago Posts: 18,994 |
Quote
https://forum.doozan.com/read.php?3,12381
- Ability to customize u-boot envs in a script (uEnv.txt) during boot, without committing changes to NAND (see section C for instruction). This feature also can be used for rescue purpose where the u-boot envs were messed up, or when the NAND envs block is bad.
Quote
https://forum.doozan.com/read.php?3,12381
C. Add uEnv.txt to /boot directory (Optional)
To adjust the default envs to your specific configuration, and not having to permanently alter u-boot envs NAND. Create a text file in /boot directory with the content in the format that u-boot envs are listed.
Examples:
The example below only to demonstrate the syntax in uEnv.txt (they might or might not apply to your current settings):
- Load appropriate DTB file for the kernel to run GoFlex Net box.
- Use SD card, USB and SATA for booting. The kernel and rootfs search order is as they are appeared on the list: mmc, usb, ide.
- Define that there are 8 storage devices (i.e. disk partitions).
- Load the DTB at address 0x2c00000 (u-boot default is 0x1c00000) to allow larger uInitrd.
cat /boot/uEnv.txt
dtb_file=/boot/dts/kirkwood-goflexnet.dtb
devices=mmc usb ide
disks=0 1 2 3 4 5 6 7
load_dtb_addr=0x2c00000
devices=usb sataEach of devices on this list of devices is scanned, if there is no /boot/uEnv.txt in any partition of the USB drives, it will scan SATA partitions.
devices=sata usbIn the example above, u-boot will find the kernel files on SATA drive first, and then if not found find it on USB drives.
devices=sata