Rocket-Chip复位向量的修改

最新推荐文章于 2025-11-12 00:31:02 发布

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最新推荐文章于 2025-11-12 00:31:02 发布 · 2.2k 阅读

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#rocket-chip #RISC-V #scala #bootrom #复位向量

本文深入探讨了Rocket-Chip系统启动流程，详细分析了bootrom模块调用过程及复位向量的默认设置。通过修改Rocket-Chip源码，实现了自定义复位向量，使系统启动地址可控。

rocket-chip复位向量的修改

rocket-chip系统复位后是从bootrom中进行启动的，这章我们将详细分析rocket-chip是如何调用bootrom模块的，最后还会对复位向量进行修改，即让rocket-chip不再从bootrom开始启动，而是从我们想要的地址进行启动。

bootrom模块的调用：
首先关注的scala文件是 /src/main/scala/system/ExampleRocketSystem.scala

package freechips.rocketchip.system

import Chisel._
import freechips.rocketchip.config.Parameters
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.tilelink._
import freechips.rocketchip.subsystem._
import freechips.rocketchip.devices.tilelink._
import freechips.rocketchip.util.DontTouch

/** Example Top with periphery devices and ports, and a Rocket subsystem */
class ExampleRocketSystem(implicit p: Parameters) extends RocketSubsystem
    with HasAsyncExtInterrupts
    with CanHaveMasterAXI4MemPort
    with CanHaveMasterAXI4MMIOPort
    with CanHaveSlaveAXI4Port
    with HasPeripheryBootROM {
  override lazy val module = new ExampleRocketSystemModuleImp(this)

  // Error device used for testing and to NACK invalid front port transactions
  val error = LazyModule(new TLError(p(ErrorDeviceKey), sbus.beatBytes))
  // always buffer the error device because no one cares about its latency
  sbus.coupleTo("slave_named_error"){ error.node := TLBuffer() := _ }
}

class ExampleRocketSystemModuleImp[+L <: ExampleRocketSystem](_outer: L) extends RocketSubs