Introduction

Generally, both firmware and some data are stored in Flash memory. The SPI Flash Controller (SPIC) is used to transmit/receive data from/to SPI Flash memory in AmebaSmart. In order to protect firmware, the code and data in Flash can be encrypted with Advanced Encryption Standard (AES) algorithm. The Secure Image Protection (RSIP) is mainly used for MMU and image decryption.

The RSIP consists of two parts:

• RSIP-AES: performs Flash decryption on-the-fly.

• RSIP-MMU: used for virtual-to-physical memory address translation.

The detailed explanations are illustrated in the following sections.