AnsweredAssumed Answered

imx7s emmc ( boot ) fuse bits - no u-boot

Question asked by Edward Tyrrell on Dec 14, 2016
Latest reply on Dec 16, 2016 by igorpadykov


I'm having some issues getting a new custom board to boot off u-boot. It's close to the warp7 and came out of production with a blank emmc ( apparently one big user partition ).  According to fsl support I can't use the mgftool as yocto ( krogoth ) lacks the initramfs package in which mfgtool requires.  Here's what I can do:


1) Using imx_usb load u-boot into ram ( manufacturing switch = 1 )

2) Using u-boot and "ums 0 mmc 0" I managed to get a virtual SD card pop up.

3) I formatted this virtual SD card and partitioned it as close to a normal Linux SD card as possible.

4) I can dd kernel on to the virtual card and it remains after I reset my board ( manufacturing sw = 0 ).

5) What I can't do is flash u-boot permanently. After returning the manufacturing sw to 0 u-boot never runs from power up.

6) What else is odd that in run mode ( sw=0), the board is still actually in manufacturing mode. I can prove this by running imx_usb and loading u-boot back into ram. If I let the ram u-boot run I get my previously flashed kernel loading.


Could this be due to fuse bits; caused by doing things ( partitioning ) manually? Things seem to be ignoring the manufacturing sw and preferring OTG manufacturing mode. So perhaps u-boot IS flashed in but due to the fuse bits it's getting ignored?


How do I check and set these fuse bits if needed?


Any help would be appreciated.