While trying to use the soft reset via AIRCR (CMSIS function: NVIC_SystemReset) on the AN521 FVP it was noticed that the bootloader would immediately crash. After debugging it was found that the reboot would work if it was done before the configuration of the MPC/PPC/MPU (appears to be any of the three that causes the issue). This appears to indicate that the security hardware is not being properly reset.
When tested on the MPS2 AN521, this issue did not occur. The reboot proceeds fine, and this is therefore probably a bug with the FVP