backdoor.hh revision 2512 
1/*
2 * Copyright (c) 2001-2005 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 * System Console Interface
31 */
32
33#ifndef __ALPHA_CONSOLE_HH__
34#define __ALPHA_CONSOLE_HH__
35
36#include "base/range.hh"
37#include "dev/alpha_access.h"
38#include "dev/io_device.hh"
39#include "sim/host.hh"
40#include "sim/sim_object.hh"
41
42class BaseCPU;
43class SimConsole;
44class AlphaSystem;
45class SimpleDisk;
46class MemoryController;
47
48/**
49 * Memory mapped interface to the system console. This device
50 * represents a shared data region between the OS Kernel and the
51 * System Console.
52 *
53 * The system console is a small standalone program that is initially
54 * run when the system boots.  It contains the necessary code to
55 * access the boot disk, to read/write from the console, and to pass
56 * boot parameters to the kernel.
57 *
58 * This version of the system console is very different from the one
59 * that would be found in a real system.  Many of the functions use
60 * some sort of backdoor to get their job done.  For example, reading
61 * from the boot device on a real system would require a minimal
62 * device driver to access the disk controller, but since we have a
63 * simulator here, we are able to bypass the disk controller and
64 * access the disk image directly.  There are also some things like
65 * reading the kernel off the disk image into memory that are normally
66 * taken care of by the console that are now taken care of by the
67 * simulator.
68 *
69 * These shortcuts are acceptable since the system console is
70 * primarily used doing boot before the kernel has loaded its device
71 * drivers.
72 */
73class AlphaConsole : public BasePioDevice
74{
75  protected:
76    struct Access : public AlphaAccess
77    {
78        void serialize(std::ostream &os);
79        void unserialize(Checkpoint *cp, const std::string &section);
80    };
81
82    union {
83        Access *alphaAccess;
84        uint8_t *consoleData;
85    };
86
87    /** the disk must be accessed from the console */
88    SimpleDisk *disk;
89
90    /** the system console (the terminal) is accessable from the console */
91    SimConsole *console;
92
93    /** a pointer to the system we are running in */
94    AlphaSystem *system;
95
96    /** a pointer to the CPU boot cpu */
97    BaseCPU *cpu;
98
99  public:
100    struct Params : public BasePioDevice::Params
101    {
102        SimConsole *cons;
103        SimpleDisk *disk;
104        AlphaSystem *sys;
105        BaseCpu *cpu;
106    };
107  protected:
108    const Params *params() const {return (const Params *)_params; }
109
110  public:
111
112    /** Standard Constructor */
113    AlphaConsole(Params *p);
114
115    virtual void startup();
116
117    /**
118     * memory mapped reads and writes
119     */
120    virtual Tick read(Packet &pkt);
121    virtual Tick write(Packet &pkt);
122
123    /**
124     * standard serialization routines for checkpointing
125     */
126    virtual void serialize(std::ostream &os);
127    virtual void unserialize(Checkpoint *cp, const std::string &section);
128
129  public:
130    Tick cacheAccess(MemReqPtr &req);
131};
132
133#endif // __ALPHA_CONSOLE_HH__
134