LXR qemu/hw/nvram/ds1225y.c

   1/*
   2 * QEMU NVRAM emulation for DS1225Y chip
   3 *
   4 * Copyright (c) 2007-2008 Hervé Poussineau
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "qemu/osdep.h"
  26#include "hw/sysbus.h"
  27#include "trace.h"
  28
  29typedef struct {
  30    MemoryRegion iomem;
  31    uint32_t chip_size;
  32    char *filename;
  33    FILE *file;
  34    uint8_t *contents;
  35} NvRamState;
  36
  37static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
  38{
  39    NvRamState *s = opaque;
  40    uint32_t val;
  41
  42    val = s->contents[addr];
  43    trace_nvram_read(addr, val);
  44    return val;
  45}
  46
  47static void nvram_write(void *opaque, hwaddr addr, uint64_t val,
  48                        unsigned size)
  49{
  50    NvRamState *s = opaque;
  51
  52    val &= 0xff;
  53    trace_nvram_write(addr, s->contents[addr], val);
  54
  55    s->contents[addr] = val;
  56    if (s->file) {
  57        fseek(s->file, addr, SEEK_SET);
  58        fputc(val, s->file);
  59        fflush(s->file);
  60    }
  61}
  62
  63static const MemoryRegionOps nvram_ops = {
  64    .read = nvram_read,
  65    .write = nvram_write,
  66    .impl = {
  67        .min_access_size = 1,
  68        .max_access_size = 1,
  69    },
  70    .endianness = DEVICE_LITTLE_ENDIAN,
  71};
  72
  73static int nvram_post_load(void *opaque, int version_id)
  74{
  75    NvRamState *s = opaque;
  76
  77    /* Close file, as filename may has changed in load/store process */
  78    if (s->file) {
  79        fclose(s->file);
  80    }
  81
  82    /* Write back nvram contents */
  83    s->file = fopen(s->filename, "wb");
  84    if (s->file) {
  85        /* Write back contents, as 'wb' mode cleaned the file */
  86        if (fwrite(s->contents, s->chip_size, 1, s->file) != 1) {
  87            printf("nvram_post_load: short write\n");
  88        }
  89        fflush(s->file);
  90    }
  91
  92    return 0;
  93}
  94
  95static const VMStateDescription vmstate_nvram = {
  96    .name = "nvram",
  97    .version_id = 0,
  98    .minimum_version_id = 0,
  99    .post_load = nvram_post_load,
 100    .fields = (VMStateField[]) {
 101        VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
 102                              vmstate_info_uint8, uint8_t),
 103        VMSTATE_END_OF_LIST()
 104    }
 105};
 106
 107#define TYPE_DS1225Y "ds1225y"
 108#define DS1225Y(obj) OBJECT_CHECK(SysBusNvRamState, (obj), TYPE_DS1225Y)
 109
 110typedef struct {
 111    SysBusDevice parent_obj;
 112
 113    NvRamState nvram;
 114} SysBusNvRamState;
 115
 116static int nvram_sysbus_initfn(SysBusDevice *dev)
 117{
 118    SysBusNvRamState *sys = DS1225Y(dev);
 119    NvRamState *s = &sys->nvram;
 120    FILE *file;
 121
 122    s->contents = g_malloc0(s->chip_size);
 123
 124    memory_region_init_io(&s->iomem, OBJECT(s), &nvram_ops, s,
 125                          "nvram", s->chip_size);
 126    sysbus_init_mmio(dev, &s->iomem);
 127
 128    /* Read current file */
 129    file = fopen(s->filename, "rb");
 130    if (file) {
 131        /* Read nvram contents */
 132        if (fread(s->contents, s->chip_size, 1, file) != 1) {
 133            printf("nvram_sysbus_initfn: short read\n");
 134        }
 135        fclose(file);
 136    }
 137    nvram_post_load(s, 0);
 138
 139    return 0;
 140}
 141
 142static Property nvram_sysbus_properties[] = {
 143    DEFINE_PROP_UINT32("size", SysBusNvRamState, nvram.chip_size, 0x2000),
 144    DEFINE_PROP_STRING("filename", SysBusNvRamState, nvram.filename),
 145    DEFINE_PROP_END_OF_LIST(),
 146};
 147
 148static void nvram_sysbus_class_init(ObjectClass *klass, void *data)
 149{
 150    DeviceClass *dc = DEVICE_CLASS(klass);
 151    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 152
 153    k->init = nvram_sysbus_initfn;
 154    dc->vmsd = &vmstate_nvram;
 155    dc->props = nvram_sysbus_properties;
 156}
 157
 158static const TypeInfo nvram_sysbus_info = {
 159    .name          = TYPE_DS1225Y,
 160    .parent        = TYPE_SYS_BUS_DEVICE,
 161    .instance_size = sizeof(SysBusNvRamState),
 162    .class_init    = nvram_sysbus_class_init,
 163};
 164
 165static void nvram_register_types(void)
 166{
 167    type_register_static(&nvram_sysbus_info);
 168}
 169
 170type_init(nvram_register_types)
 171