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     uint32_t chip_size;
  31     char *filename;
  32     QEMUFile *file;
  33     uint8_t *contents;
  34 } NvRamState;
  35
  36 static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
  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 uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)
  47 {
  48     uint32_t v;
  49     v = nvram_readb(opaque, addr);
  50     v |= nvram_readb(opaque, addr + 1) << 8;
  51     return v;
  52 }
  53
  54 static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)
  55 {
  56     uint32_t v;
  57     v = nvram_readb(opaque, addr);
  58     v |= nvram_readb(opaque, addr + 1) << 8;
  59     v |= nvram_readb(opaque, addr + 2) << 16;
  60     v |= nvram_readb(opaque, addr + 3) << 24;
  61     return v;
  62 }
  63
  64 static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t val)
  65 {
  66     NvRamState *s = opaque;
  67
  68     val &= 0xff;
  69     trace_nvram_write(addr, s->contents[addr], val);
  70
  71     s->contents[addr] = val;
  72     if (s->file) {
  73         qemu_fseek(s->file, addr, SEEK_SET);
  74         qemu_put_byte(s->file, (int)val);
  75         qemu_fflush(s->file);
  76     }
  77 }
  78
  79 static void nvram_writew (void *opaque, target_phys_addr_t addr, uint32_t val)
  80 {
  81     nvram_writeb(opaque, addr, val & 0xff);
  82     nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
  83 }
  84
  85 static void nvram_writel (void *opaque, target_phys_addr_t addr, uint32_t val)
  86 {
  87     nvram_writeb(opaque, addr, val & 0xff);
  88     nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
  89     nvram_writeb(opaque, addr + 2, (val >> 16) & 0xff);
  90     nvram_writeb(opaque, addr + 3, (val >> 24) & 0xff);
  91 }
  92
  93 static CPUReadMemoryFunc * const nvram_read[] = {
  94     &nvram_readb,
  95     &nvram_readw,
  96     &nvram_readl,
  97 };
  98
  99 static CPUWriteMemoryFunc * const nvram_write[] = {
 100     &nvram_writeb,
 101     &nvram_writew,
 102     &nvram_writel,
 103 };
 104
 105 static int nvram_post_load(void *opaque, int version_id)
 106 {
 107     NvRamState *s = opaque;
 108
 109     /* Close file, as filename may has changed in load/store process */
 110     if (s->file) {
 111         qemu_fclose(s->file);
 112     }
 113
 114     /* Write back nvram contents */
 115     s->file = qemu_fopen(s->filename, "wb");
 116     if (s->file) {
 117         /* Write back contents, as 'wb' mode cleaned the file */
 118         qemu_put_buffer(s->file, s->contents, s->chip_size);
 119         qemu_fflush(s->file);
 120     }
 121
 122     return 0;
 123 }
 124
 125 static const VMStateDescription vmstate_nvram = {
 126     .name = "nvram",
 127     .version_id = 0,
 128     .minimum_version_id = 0,
 129     .minimum_version_id_old = 0,
 130     .post_load = nvram_post_load,
 131     .fields = (VMStateField[]) {
 132         VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
 133                               vmstate_info_uint8, uint8_t),
 134         VMSTATE_END_OF_LIST()
 135     }
 136 };
 137
 138 typedef struct {
 139     SysBusDevice busdev;
 140     NvRamState nvram;
 141 } SysBusNvRamState;
 142
 143 static int nvram_sysbus_initfn(SysBusDevice *dev)
 144 {
 145     NvRamState *s = &FROM_SYSBUS(SysBusNvRamState, dev)->nvram;
 146     QEMUFile *file;
 147     int s_io;
 148
 149     s->contents = qemu_mallocz(s->chip_size);
 150
 151     s_io = cpu_register_io_memory(nvram_read, nvram_write, s,
 152                                   DEVICE_NATIVE_ENDIAN);
 153     sysbus_init_mmio(dev, s->chip_size, s_io);
 154
 155     /* Read current file */
 156     file = qemu_fopen(s->filename, "rb");
 157     if (file) {
 158         /* Read nvram contents */
 159         qemu_get_buffer(file, s->contents, s->chip_size);
 160         qemu_fclose(file);
 161     }
 162     nvram_post_load(s, 0);
 163
 164     return 0;
 165 }
 166
 167 static SysBusDeviceInfo nvram_sysbus_info = {
 168     .qdev.name  = "ds1225y",
 169     .qdev.size  = sizeof(SysBusNvRamState),
 170     .qdev.vmsd  = &vmstate_nvram,
 171     .init       = nvram_sysbus_initfn,
 172     .qdev.props = (Property[]) {
 173         DEFINE_PROP_UINT32("size", SysBusNvRamState, nvram.chip_size, 0x2000),
 174         DEFINE_PROP_STRING("filename", SysBusNvRamState, nvram.filename),
 175         DEFINE_PROP_END_OF_LIST(),
 176     },
 177 };
 178
 179 static void nvram_register(void)
 180 {
 181     sysbus_register_withprop(&nvram_sysbus_info);
 182 }
 183
 184 device_init(nvram_register)