[U-Boot] u-boot USB question

[Bo Shen]

Hi Lance,

On 5/17/2013 06:32, Lance Beck wrote:
> We are using u-boot on an AT91SAM9G20 platform with NAND Flash and running Linux.  Is there a means to update the kernel and root fs image by reading them from a USB memory device and writing the new images to flash?  I have built the fw_printenv tool thinking I might be able to use this to somehow trigger that action.

Yes. Please take the following example (using the mainline 
u-boot-2013.04) for updating related image from USB disk.

1. connect usb to board and power up
U-boot> usb start
(Re)start USB...
USB:   scanning bus for devices... 2 USB Device(s) found
        scanning bus for storage devices... 1 Storage Device(s) found
U-boot> fatls usb 0
...
2396352 uImage
...
U-boot> fatload usb 0 0x20000000 uImage
U-boot> nand erase 0x200000 0x600000
U-boot> nand write 0x20000000 0x200000 <uImage_size>

If all steps are successfully, then you have updated linux kernel uImage.

BTW, the fw_printenv is used with Linux file system to access u-boot 
environment.

> Not sure where to go from here...
>
> Thanks,
>
> Lance

Best Regards,
Bo Shen