summaryrefslogtreecommitdiffstats
path: root/hw/ds1225y.c
blob: 44757179d556f34f9df6708b0449b995b1ae5493 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 * QEMU NVRAM emulation for DS1225Y chip
 *
 * Copyright (c) 2007-2008 Hervé Poussineau
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "hw.h"
#include "mips.h"
#include "nvram.h"

//#define DEBUG_NVRAM

typedef struct ds1225y_t
{
    uint32_t chip_size;
    QEMUFile *file;
    uint8_t *contents;
    uint8_t protection;
} ds1225y_t;


static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
{
    ds1225y_t *s = opaque;
    uint32_t val;

    val = s->contents[addr];

#ifdef DEBUG_NVRAM
    printf("nvram: read 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif
    return val;
}

static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)
{
    uint32_t v;
    v = nvram_readb(opaque, addr);
    v |= nvram_readb(opaque, addr + 1) << 8;
    return v;
}

static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)
{
    uint32_t v;
    v = nvram_readb(opaque, addr);
    v |= nvram_readb(opaque, addr + 1) << 8;
    v |= nvram_readb(opaque, addr + 2) << 16;
    v |= nvram_readb(opaque, addr + 3) << 24;
    return v;
}

static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    ds1225y_t *s = opaque;

#ifdef DEBUG_NVRAM
    printf("nvram: write 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif

    s->contents[addr] = val & 0xff;
    if (s->file) {
        qemu_fseek(s->file, addr, SEEK_SET);
        qemu_put_byte(s->file, (int)val);
        qemu_fflush(s->file);
    }
}

static void nvram_writew (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    nvram_writeb(opaque, addr, val & 0xff);
    nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
}

static void nvram_writel (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    nvram_writeb(opaque, addr, val & 0xff);
    nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
    nvram_writeb(opaque, addr + 2, (val >> 16) & 0xff);
    nvram_writeb(opaque, addr + 3, (val >> 24) & 0xff);
}

static void nvram_writeb_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    ds1225y_t *s = opaque;

    if (s->protection != 7) {
#ifdef DEBUG_NVRAM
    printf("nvram: prevent write of 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif
        return;
    }

    nvram_writeb(opaque, addr, val);
}

static void nvram_writew_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    nvram_writeb_protected(opaque, addr, val & 0xff);
    nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
}

static void nvram_writel_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
    nvram_writeb_protected(opaque, addr, val & 0xff);
    nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
    nvram_writeb_protected(opaque, addr + 2, (val >> 16) & 0xff);
    nvram_writeb_protected(opaque, addr + 3, (val >> 24) & 0xff);
}

static CPUReadMemoryFunc *nvram_read[] = {
    &nvram_readb,
    &nvram_readw,
    &nvram_readl,
};

static CPUWriteMemoryFunc *nvram_write[] = {
    &nvram_writeb,
    &nvram_writew,
    &nvram_writel,
};

static CPUWriteMemoryFunc *nvram_write_protected[] = {
    &nvram_writeb_protected,
    &nvram_writew_protected,
    &nvram_writel_protected,
};

/* Initialisation routine */
void *ds1225y_init(target_phys_addr_t mem_base, const char *filename)
{
    ds1225y_t *s;
    int mem_indexRW, mem_indexRP;
    QEMUFile *file;

    s = qemu_mallocz(sizeof(ds1225y_t));
    s->chip_size = 0x2000; /* Fixed for ds1225y chip: 8 KiB */
    s->contents = qemu_mallocz(s->chip_size);
    s->protection = 7;

    /* Read current file */
    file = qemu_fopen(filename, "rb");
    if (file) {
        /* Read nvram contents */
        qemu_get_buffer(file, s->contents, s->chip_size);
        qemu_fclose(file);
    }
    s->file = qemu_fopen(filename, "wb");
    if (s->file) {
        /* Write back contents, as 'wb' mode cleaned the file */
        qemu_put_buffer(s->file, s->contents, s->chip_size);
        qemu_fflush(s->file);
    }

    /* Read/write memory */
    mem_indexRW = cpu_register_io_memory(nvram_read, nvram_write, s);
    cpu_register_physical_memory(mem_base, s->chip_size, mem_indexRW);
    /* Read/write protected memory */
    mem_indexRP = cpu_register_io_memory(nvram_read, nvram_write_protected, s);
    cpu_register_physical_memory(mem_base + s->chip_size, s->chip_size, mem_indexRP);
    return s;
}
OpenPOWER on IntegriCloud