Hi,
We are considering booting from SPI on our DM8148 custom board to overcome the eMMC boot limitation with capacities over 2GB.
From what I get in the TRM (SPRUGZ8D) the SPI image is simply the binary executable preceded by an 8 byte header with the length and destination and entry point address of the executable. Also, in section 4.7.6 (blocks and sectors search summary), it says that for SPI the first 4 blocks are checked and then one sector searched (table 4-28).
What is not clear is what is considered a "block" in SPI and what is the criteria to determine if an image is present at a searched location, in particular since there appears to be no CRC or any other check protecting the image. Section 4.7.5 is pretty vague.
Our intent is to have a redundant boot image on SPI, but it is not clear from the description how this can be achieved. When booting from NAND it is clear how to obtain this redundancy, but it is not at all clear for SPI.
Can you detail how the SPI boot process works in searching for a valid image and how redundancy can be achieved, if at all?
