How to update linux image file without switching boot mode pins?

[cgperson]

Hi ,

   My i.mx6q mainboard is installed in a box and user can only access it with SD card and USB cable. It requires to update the linux image files on line which means user can not take the box apart. So all the boot mode pins and other cfg pins can not be accessed.

   In normal operating, the system boots from emmc. How to implement this procedure:

connect USB to i.mx6 USB otg inteface(or insert a SD card with new image files) -> start to update new image files to emmc memory -> power off -> power on -> boot from emmc and go to normal operating.

[cgperson]

bmode command in u boot may help to my case, just let me try!

[igorpadykov]

Hi Jie

one can try to erase emmc image and boot from it,

after failing to boot processor will jump to Serial Downloader (USB OTG) mode as

described in Figure 8-1. Boot flow i.MX6DQ Reference Manual

http://www.nxp.com/docs/en/reference-manual/IMX6DQRM.pdf

Best regards
igor
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[cgperson]

Hi

    How to erase emmc image files? Can this be done by mfgtool or uboot?

[wad1]

I ended up using a couple of transistors driven by the SD card detect signal to switch the boot mode between eMMC and external SD card.   If there is a card present in the SD slot, it boots from it.  If there isn't, it boots from eMMC.

[cgperson]

Hi John,

    This is one of the original ideas. But the issue is in normal operation, user uses the SD card to store the data processed by the i.mx6 such as BMP pictures. These is only one SD solt in my application.  

     How do you distinguish between the image file update SD card and normal operation SD card?

[wad1]

In our design, the image update SD card slot is dedicated to factory programming, and not available to the user.  Best of luck with your efforts.