isa_fake.hh revision 2665
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Miguel Serrano 29 * Ali Saidi 30 */ 31 32/** @file 33 * Declaration of a fake device. 34 */ 35 36#ifndef __ISA_FAKE_HH__ 37#define __ISA_FAKE_HH__ 38 39#include "dev/tsunami.hh" 40#include "base/range.hh" 41#include "dev/io_device.hh" 42 43/** 44 * IsaFake is a device that returns -1 on all reads and 45 * accepts all writes. It is meant to be placed at an address range 46 * so that an mcheck doesn't occur when an os probes a piece of hw 47 * that doesn't exist (e.g. UARTs1-3). 48 */ 49class IsaFake : public BasicPioDevice 50{ 51 public: 52 struct Params : public BasicPioDevice::Params 53 { 54 Addr pio_size; 55 }; 56 protected: 57 const Params *params() const { return (const Params*)_params; } 58 59 public: 60 /** 61 * The constructor for Tsunmami Fake just registers itself with the MMU. 62 * @param p params structure 63 */ 64 IsaFake(Params *p); 65 66 /** 67 * This read always returns -1. 68 * @param req The memory request. 69 * @param data Where to put the data. 70 */ 71 virtual Tick read(Packet *pkt); 72 73 /** 74 * All writes are simply ignored. 75 * @param req The memory request. 76 * @param data the data to not write. 77 */ 78 virtual Tick write(Packet *pkt); 79}; 80 81#endif // __TSUNAMI_FAKE_HH__ 82