backdoor.hh revision 4762 
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 * Authors: Nathan Binkert
29 */
30
31/** @file
32 * System Console Interface
33 */
34
35#ifndef __ALPHA_CONSOLE_HH__
36#define __ALPHA_CONSOLE_HH__
37
38#include "base/range.hh"
39#include "dev/alpha/access.h"
40#include "dev/io_device.hh"
41#include "params/AlphaConsole.hh"
42#include "sim/host.hh"
43#include "sim/sim_object.hh"
44
45class BaseCPU;
46class SimConsole;
47class AlphaSystem;
48class SimpleDisk;
49
50/**
51 * Memory mapped interface to the system console. This device
52 * represents a shared data region between the OS Kernel and the
53 * System Console.
54 *
55 * The system console is a small standalone program that is initially
56 * run when the system boots.  It contains the necessary code to
57 * access the boot disk, to read/write from the console, and to pass
58 * boot parameters to the kernel.
59 *
60 * This version of the system console is very different from the one
61 * that would be found in a real system.  Many of the functions use
62 * some sort of backdoor to get their job done.  For example, reading
63 * from the boot device on a real system would require a minimal
64 * device driver to access the disk controller, but since we have a
65 * simulator here, we are able to bypass the disk controller and
66 * access the disk image directly.  There are also some things like
67 * reading the kernel off the disk image into memory that are normally
68 * taken care of by the console that are now taken care of by the
69 * simulator.
70 *
71 * These shortcuts are acceptable since the system console is
72 * primarily used doing boot before the kernel has loaded its device
73 * drivers.
74 */
75class AlphaConsole : public BasicPioDevice
76{
77  protected:
78    struct Access : public AlphaAccess
79    {
80        void serialize(std::ostream &os);
81        void unserialize(Checkpoint *cp, const std::string &section);
82    };
83
84    union {
85        Access *alphaAccess;
86        uint8_t *consoleData;
87    };
88
89    /** the disk must be accessed from the console */
90    SimpleDisk *disk;
91
92    /** the system console (the terminal) is accessable from the console */
93    SimConsole *console;
94
95    /** a pointer to the system we are running in */
96    AlphaSystem *system;
97
98    /** a pointer to the CPU boot cpu */
99    BaseCPU *cpu;
100
101  public:
102    typedef AlphaConsoleParams Params;
103    AlphaConsole(const Params *p);
104
105    const Params *
106    params() const
107    {
108        return dynamic_cast<const Params *>(_params);
109    }
110
111    virtual void startup();
112
113    /**
114     * memory mapped reads and writes
115     */
116    virtual Tick read(PacketPtr pkt);
117    virtual Tick write(PacketPtr pkt);
118
119    /**
120     * standard serialization routines for checkpointing
121     */
122    virtual void serialize(std::ostream &os);
123    virtual void unserialize(Checkpoint *cp, const std::string &section);
124};
125
126#endif // __ALPHA_CONSOLE_HH__
127