hw/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 "sysbus.h"
  26 #include "trace.h"
  27
  28 typedef struct {
  29     DeviceState qdev;
  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, target_phys_addr_t 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, target_phys_addr_t 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     .minimum_version_id_old = 0,
 100     .post_load = nvram_post_load,
 101     .fields = (VMStateField[]) {
 102         VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
 103                               vmstate_info_uint8, uint8_t),
 104         VMSTATE_END_OF_LIST()
 105     }
 106 };
 107
 108 typedef struct {
 109     SysBusDevice busdev;
 110     NvRamState nvram;
 111 } SysBusNvRamState;
 112
 113 static int nvram_sysbus_initfn(SysBusDevice *dev)
 114 {
 115     NvRamState *s = &FROM_SYSBUS(SysBusNvRamState, dev)->nvram;
 116     FILE *file;
 117
 118     s->contents = g_malloc0(s->chip_size);
 119
 120     memory_region_init_io(&s->iomem, &nvram_ops, s, "nvram", s->chip_size);
 121     sysbus_init_mmio(dev, &s->iomem);
 122
 123     /* Read current file */
 124     file = fopen(s->filename, "rb");
 125     if (file) {
 126         /* Read nvram contents */
 127         if (fread(s->contents, s->chip_size, 1, file) != 1) {
 128             printf("nvram_sysbus_initfn: short read\n");
 129         }
 130         fclose(file);
 131     }
 132     nvram_post_load(s, 0);
 133
 134     return 0;
 135 }
 136
 137 static SysBusDeviceInfo nvram_sysbus_info = {
 138     .qdev.name  = "ds1225y",
 139     .qdev.size  = sizeof(SysBusNvRamState),
 140     .qdev.vmsd  = &vmstate_nvram,
 141     .init       = nvram_sysbus_initfn,
 142     .qdev.props = (Property[]) {
 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
 149 static void nvram_register(void)
 150 {
 151     sysbus_register_withprop(&nvram_sysbus_info);
 152 }
 153
 154 device_init(nvram_register)