imx7d weird boot issue after upgrading eMMC - stuck in factory serial download!

[edwardtyrrell]

Hi All, 

We're experiencing a strange boot issue after replacing the eMMC in a current product. Background - we are trialling a suggested (drop in replacement) Kingston eMMC part as the original is no longer available. Our product has two dip-boot switches fitted that will either put the device into factory serial download mode or normal run mode. Only one is actually used. 

As normal a new unprogrammed imx7d will be in factory serial mode by default until it's been flashed and the OTP fuses set - in our case bank 1 word 3 = 0x10002820, after which the only way to reprogram the product is to use the on-board boot dip switches to force it back into factory serial mode. 

Here's the issue.. with a number of known good working PCBs we had the old eMMC replaced with the new 'suggested' drop-in replacement eMMC to verify that it's OK to use them in production; but the new eMMC are keeping the boards in permanent factory serial mode!

 u-boot detects the new eMMCs fine, the fuse bits are still set to boot as normal (question to clarify - the OTP boot fuse bits are actually in the imx processor correct?) which were actually set when the boards first went in to service, u-boot DFU and UMS work fine. So what could be causing the boards to be stuck in factory serial mode after programming regardless of the dip-boot switch settings?

How can replacing the eMMC cause the boards to be struct in factory serial mode? It's just a slab of memory, all boot fuses are in the imx7.

Kind regards.

[joanxie · Accepted solution]

could you confirm if your new EMMC has available image to boot up? refer to your fuse, the boot mode is 2, refer to the RM, it seems that the boot up from emmc fails, then go to download mode, you can refer to the RM to get further information

[edwardtyrrell]

Hi @joanxie,

Thank you, your information was spot-on! The issue turned out to be the lack of formatting and partitioning typically done via MFGTool or UUU (our test u-boot has no FB ability - that's another NXP ticket). So after some u-boot commands and Linux fdisk type tools we managed to partition the eMMC whilst in u-boot UMS mode. Once that was done it booted in run mode.

Thanks again, appreciated.