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 "hw/sysbus.h"
  26 #include "trace.h"
  27
  28 typedef struct {
  29     MemoryRegion iomem;
  30     uint32_t chip_size;
  31     char *filename;
  32     FILE *file;
  33     uint8_t *contents;
  34 } NvRamState;
  35
  36 static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
  37 {
  38     NvRamState *s = opaque;
  39     uint32_t val;
  40
  41     val = s->contents[addr];
  42     trace_nvram_read(addr, val);
  43     return val;
  44 }
  45
  46 static void nvram_write(void *opaque, hwaddr addr, uint64_t val,
  47                         unsigned size)
  48 {
  49     NvRamState *s = opaque;
  50
  51     val &= 0xff;
  52     trace_nvram_write(addr, s->contents[addr], val);
  53
  54     s->contents[addr] = val;
  55     if (s->file) {
  56         fseek(s->file, addr, SEEK_SET);
  57         fputc(val, s->file);
  58         fflush(s->file);
  59     }
  60 }
  61
  62 static const MemoryRegionOps nvram_ops = {
  63     .read = nvram_read,
  64     .write = nvram_write,
  65     .impl = {
  66         .min_access_size = 1,
  67         .max_access_size = 1,
  68     },
  69     .endianness = DEVICE_LITTLE_ENDIAN,
  70 };
  71
  72 static int nvram_post_load(void *opaque, int version_id)
  73 {
  74     NvRamState *s = opaque;
  75
  76     /* Close file, as filename may has changed in load/store process */
  77     if (s->file) {
  78         fclose(s->file);
  79     }
  80
  81     /* Write back nvram contents */
  82     s->file = fopen(s->filename, "wb");
  83     if (s->file) {
  84         /* Write back contents, as 'wb' mode cleaned the file */
  85         if (fwrite(s->contents, s->chip_size, 1, s->file) != 1) {
  86             printf("nvram_post_load: short write\n");
  87         }
  88         fflush(s->file);
  89     }
  90
  91     return 0;
  92 }
  93
  94 static const VMStateDescription vmstate_nvram = {
  95     .name = "nvram",
  96     .version_id = 0,
  97     .minimum_version_id = 0,
  98     .post_load = nvram_post_load,
  99     .fields = (VMStateField[]) {
 100         VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
 101                               vmstate_info_uint8, uint8_t),
 102         VMSTATE_END_OF_LIST()
 103     }
 104 };
 105
 106 #define TYPE_DS1225Y "ds1225y"
 107 #define DS1225Y(obj) OBJECT_CHECK(SysBusNvRamState, (obj), TYPE_DS1225Y)
 108
 109 typedef struct {
 110     SysBusDevice parent_obj;
 111
 112     NvRamState nvram;
 113 } SysBusNvRamState;
 114
 115 static int nvram_sysbus_initfn(SysBusDevice *dev)
 116 {
 117     SysBusNvRamState *sys = DS1225Y(dev);
 118     NvRamState *s = &sys->nvram;
 119     FILE *file;
 120
 121     s->contents = g_malloc0(s->chip_size);
 122
 123     memory_region_init_io(&s->iomem, OBJECT(s), &nvram_ops, s,
 124                           "nvram", s->chip_size);
 125     sysbus_init_mmio(dev, &s->iomem);
 126
 127     /* Read current file */
 128     file = fopen(s->filename, "rb");
 129     if (file) {
 130         /* Read nvram contents */
 131         if (fread(s->contents, s->chip_size, 1, file) != 1) {
 132             printf("nvram_sysbus_initfn: short read\n");
 133         }
 134         fclose(file);
 135     }
 136     nvram_post_load(s, 0);
 137
 138     return 0;
 139 }
 140
 141 static Property nvram_sysbus_properties[] = {
 142     DEFINE_PROP_UINT32("size", SysBusNvRamState, nvram.chip_size, 0x2000),
 143     DEFINE_PROP_STRING("filename", SysBusNvRamState, nvram.filename),
 144     DEFINE_PROP_END_OF_LIST(),
 145 };
 146
 147 static void nvram_sysbus_class_init(ObjectClass *klass, void *data)
 148 {
 149     DeviceClass *dc = DEVICE_CLASS(klass);
 150     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 151
 152     k->init = nvram_sysbus_initfn;
 153     dc->vmsd = &vmstate_nvram;
 154     dc->props = nvram_sysbus_properties;
 155 }
 156
 157 static const TypeInfo nvram_sysbus_info = {
 158     .name          = TYPE_DS1225Y,
 159     .parent        = TYPE_SYS_BUS_DEVICE,
 160     .instance_size = sizeof(SysBusNvRamState),
 161     .class_init    = nvram_sysbus_class_init,
 162 };
 163
 164 static void nvram_register_types(void)
 165 {
 166     type_register_static(&nvram_sysbus_info);
 167 }
 168
 169 type_init(nvram_register_types)