LS1028 flashing memories by boot ROM?

[rdr3e]

Considering the LS1028-based SoM, equipped with either eMMC or NOR flash onboard, how can one initiate the initial flashing or reflash the storage in scenarios where the processor is unable to exit a boot ROM, for instance, due to corrupted eMMC or NOR flash memory? Is JTAG the primary option for achieving this task, or are there alternative methods available? Is there any fallback mode that LS1028 enters when it is not able to load RCW and the rest of the required binaries? Can it somehow reprogram memories from using other media like USB?

Can somebody point me to a manual where I could read something more about this?

[kenli]

This is a recurrent question, and considering that the LS1028 and other Layerscape platforms share similar characteristics, the following content applies to Layerscape as well.

Generally, Layerscape platforms can determine the RCW boot source through the cfg_rcw_src pin sampling. This is the first point where customization can be made. During the design process, it is recommended to incorporate more than one boot medium, as the probability of both media failing is relatively low. For example, sd/emmc,sd/nor etc. can be considered.

It is strongly recommended to locate the SD card slot near the edge of the board, as it facilitates system recovery. If a customer opts for a single boot source, such as eMMC, and a hardware issue arises with the eMMC, the system may encounter difficulties if both RCW and PBI loading fail. In such cases, the only options available are to use JTAG with CW or replace the faulty eMMC with a new one containing a valid image.

Of course, hardware redundancy designs can also be implemented, but we will not delve into that here.