backdoor.hh revision 56 
1/*
2 * Copyright (c) 2003 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 "sim/host.hh"
37#include "dev/alpha_access.h"
38#include "mem/functional_mem/mmap_device.hh"
39
40class BaseCPU;
41class SimConsole;
42class System;
43class TlaserClock;
44class SimpleDisk;
45
46/*
47 * Memory mapped interface to the system console. This device
48 * represents a shared data region between the OS Kernel and the
49 * System Console.
50 *
51 * The system console is a small standalone program that is initially
52 * run when the system boots.  It contains the necessary code to
53 * access the boot disk, to read/write from the console, and to pass
54 * boot parameters to the kernel.
55 *
56 * This version of the system console is very different from the one
57 * that would be found in a real system.  Many of the functions use
58 * some sort of backdoor to get their job done.  For example, reading
59 * from the boot device on a real system would require a minimal
60 * device driver to access the disk controller, but since we have a
61 * simulator here, we are able to bypass the disk controller and
62 * access the disk image directly.  There are also some things like
63 * reading the kernel off the disk image into memory that are normally
64 * taken care of by the console that are now taken care of by the
65 * simulator.
66 *
67 * These shortcuts are acceptable since the system console is
68 * primarily used doing boot before the kernel has loaded its device
69 * drivers.
70 */
71class AlphaConsole : public MmapDevice
72{
73  protected:
74    union {
75        AlphaAccess *alphaAccess;
76        uint8_t *consoleData;
77    };
78
79    /** the disk must be accessed from the console */
80    SimpleDisk *disk;
81
82    /** the system console (the terminal) is accessable from the console */
83    SimConsole *console;
84
85  public:
86    /** Standard Constructor */
87    AlphaConsole(const std::string &name, SimConsole *cons,
88                 SimpleDisk *d, int size,
89                 System *system, BaseCPU *cpu,
90                 TlaserClock *clock, int num_cpus,
91                 Addr addr, Addr mask, MemoryController *mmu);
92
93  public:
94    /**
95     * memory mapped reads and writes
96     */
97    virtual Fault read(MemReqPtr req, uint8_t *data);
98    virtual Fault write(MemReqPtr req, const uint8_t *data);
99
100    /**
101     * standard serialization routines for checkpointing
102     */
103    virtual void serialize();
104    virtual void unserialize(IniFile &db, const std::string &category,
105                             ConfigNode *node);
106};
107
108#endif // __ALPHA_CONSOLE_HH__
109