I have an LPC55S69 set up to boot a recovery SB2.1 image from SPI Flash. This recovery image is loaded into SRAM and executes, copying a fallback image from another location in SPI Flash to 0x0 in the internal flash.
If I power-cycle the processor while my recovery image code is copying the fallback image to internal flash, the ROM bootloader does not enter SPI Flash Recovery mode or ISP Mode - it simply hangs until I pull ISP low. As soon as I pull ISP low, it begins SPI Flash Recovery as I would have expected it to do immediately upon power-up.
How can I fix this? I am trying to use the SPI Flash Recovery feature as a way to prevent in-field bricking during a power loss, and requiring the ISP pin to be pulled low to un-brick a device is not acceptable for our application.