可选择的Nios II 引导方法
Alternative Nios II Boot Methods
In any stand-alone embedded system that contains a microprocessor, the processor
runs a small piece of code called a boot copier, or boot loader, after the system resets.
The boot copier locates the appropriate application software in non-volatile memory,
copies it to RAM, initializes critical system components, and branches to the entry
point of the application software image. The block of data in non-volatile memory
that contains the application software is commonly referred to as the boot image. Boot
copiers range in complexity from basic byte-for-byte copy routines to comprehensive
applications that perform rigorous system tests, select among multiple software
applications, and unpack, decompress, and perform error detection on the proper
application.
This document teaches you how to implement your own custom boot copier software
using the Nios® II processor and Nios II software build tools. In addition, this
document provides the basic information needed to externally control the Nios II boot
process.
This document addresses how to implement a custom boot copier for a Nios II
processor already configured in the FPGA. It does not address custom methods of
configuring Altera® FPGAs.
See more an458.pdf。