The BootROM uses the Linear mode to access the first 16MB of the QSPI flash to look for the boot image.
There are limitations on where the boot image could be placed if larger than 16MB QSPI flash and RSA Authentication are used.
The following apply only when RSA Authentication is used on larger than 16MB QSPI flashes in single x2 or x4, dual-stacked x4 and dual-parallel x4 configurations.
The boot image cannot be placed at 0x0 offset in the flash when using RSA Authentication in a larger than 16MB QSPI device.
There are three possible work-arounds for this requirement:
NOTE: If RSA is not used, the boot image can be placed at 0x0 even for larger than 16MB QSPI.