isa_fake.hh revision 1817
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 29/** @file 30 * Declaration of a fake device. 31 */ 32 33#ifndef __ISA_FAKE_HH__ 34#define __ISA_FAKE_HH__ 35 36#include "dev/tsunami.hh" 37#include "base/range.hh" 38#include "dev/io_device.hh" 39 40/** 41 * IsaFake is a device that returns -1 on all reads and 42 * accepts all writes. It is meant to be placed at an address range 43 * so that an mcheck doesn't occur when an os probes a piece of hw 44 * that doesn't exist (e.g. UARTs1-3). 45 */ 46class IsaFake : public PioDevice 47{ 48 private: 49 /** The address in memory that we respond to */ 50 Addr addr; 51 52 public: 53 /** 54 * The constructor for Tsunmami Fake just registers itself with the MMU. 55 * @param name name of this device. 56 * @param a address to respond to. 57 * @param mmu the mmu we register with. 58 * @param size number of addresses to respond to 59 */ 60 IsaFake(const std::string &name, Addr a, MemoryController *mmu, 61 HierParams *hier, Bus *bus, Addr size = 0x8); 62 63 /** 64 * This read always returns -1. 65 * @param req The memory request. 66 * @param data Where to put the data. 67 */ 68 virtual Fault read(MemReqPtr &req, uint8_t *data); 69 70 /** 71 * All writes are simply ignored. 72 * @param req The memory request. 73 * @param data the data to not write. 74 */ 75 virtual Fault write(MemReqPtr &req, const uint8_t *data); 76 77 /** 78 * Return how long this access will take. 79 * @param req the memory request to calcuate 80 * @return Tick when the request is done 81 */ 82 Tick cacheAccess(MemReqPtr &req); 83}; 84 85#endif // __ISA_FAKE_HH__ 86