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
  29 typedef struct {
  30     MemoryRegion iomem;
  31     uint32_t chip_size;
  32     char *filename;
  33     FILE *file;
  34     uint8_t *contents;
  35 } NvRamState;
  36
  37 static 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
  47 static 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
  63 static 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
  73 static 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
  95 static 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
 110 typedef struct {
 111     SysBusDevice parent_obj;
 112
 113     NvRamState nvram;
 114 } SysBusNvRamState;
 115
 116 static 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
 142 static 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
 148 static 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
 158 static 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
 165 static void nvram_register_types(void)
 166 {
 167     type_register_static(&nvram_sysbus_info);
 168 }
 169
 170 type_init(nvram_register_types)