In Tech Ref Figure 19-1 "Boot Flow" it seems to imply that SPI boot will support redundancy. However, 19.4.8 indiactes it might not, PERSIST_SECONDARY_BOOT, "Used only for boot modes that support redundant boot." Further, 18.104.22.168 says "The device ROM supports redundant boot for expansion device." It APPEARS that "expansion device" is limited to SD/MMC which concerns me (SPI not included as an "expansion device").
So...the question is, if I set RCON for SPI Boot and my primary image is corrupt (authentication fails), will it attempt to boot from the secondary SPI image?
Also, I can't find any mention of the authentication process itself. Could you describe it?