AR# 57900

描述

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.

解决方案

There are three possible work-arounds for this requirement:

• Erase the first 32KB of flash and program the boot image at 0x0 + 32KB offset.
  The BootROM will fail booting from 0x0, will fallback and will boot from 0x0 +32KB offset (see UG585 Zynq-7000-TRM for Boot Partition Search).
  
• Program the boot image at 0x0 and Duplicate the Image Header at 0x0 + 16MB offset.
  The BootROM will use the Image Header at 0x0 + 16MB offset and then will boot with the boot image programmed at 0x0.
  
• Use only single x1 QSPI mode.

NOTE: If RSA is not used, the boot image can be placed at 0x0 even for larger than 16MB QSPI.