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 "hw.h"
  26 #include "mips.h"
  27 #include "nvram.h"
  28
  29 //#define DEBUG_NVRAM
  30
  31 typedef struct ds1225y_t
  32 {
  33     uint32_t chip_size;
  34     QEMUFile *file;
  35     uint8_t *contents;
  36     uint8_t protection;
  37 } ds1225y_t;
  38
  39
  40 static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
  41 {
  42     ds1225y_t *s = opaque;
  43     uint32_t val;
  44
  45     val = s->contents[addr];
  46
  47 #ifdef DEBUG_NVRAM
  48     printf("nvram: read 0x%x at " TARGET_FMT_lx "\n", val, addr);
  49 #endif
  50     return val;
  51 }
  52
  53 static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)
  54 {
  55     uint32_t v;
  56     v = nvram_readb(opaque, addr);
  57     v |= nvram_readb(opaque, addr + 1) << 8;
  58     return v;
  59 }
  60
  61 static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)
  62 {
  63     uint32_t v;
  64     v = nvram_readb(opaque, addr);
  65     v |= nvram_readb(opaque, addr + 1) << 8;
  66     v |= nvram_readb(opaque, addr + 2) << 16;
  67     v |= nvram_readb(opaque, addr + 3) << 24;
  68     return v;
  69 }
  70
  71 static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t val)
  72 {
  73     ds1225y_t *s = opaque;
  74
  75 #ifdef DEBUG_NVRAM
  76     printf("nvram: write 0x%x at " TARGET_FMT_lx "\n", val, addr);
  77 #endif
  78
  79     s->contents[addr] = val & 0xff;
  80     if (s->file) {
  81         qemu_fseek(s->file, addr, SEEK_SET);
  82         qemu_put_byte(s->file, (int)val);
  83         qemu_fflush(s->file);
  84     }
  85 }
  86
  87 static void nvram_writew (void *opaque, target_phys_addr_t addr, uint32_t val)
  88 {
  89     nvram_writeb(opaque, addr, val & 0xff);
  90     nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
  91 }
  92
  93 static void nvram_writel (void *opaque, target_phys_addr_t addr, uint32_t val)
  94 {
  95     nvram_writeb(opaque, addr, val & 0xff);
  96     nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
  97     nvram_writeb(opaque, addr + 2, (val >> 16) & 0xff);
  98     nvram_writeb(opaque, addr + 3, (val >> 24) & 0xff);
  99 }
 100
 101 static void nvram_writeb_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
 102 {
 103     ds1225y_t *s = opaque;
 104
 105     if (s->protection != 7) {
 106 #ifdef DEBUG_NVRAM
 107     printf("nvram: prevent write of 0x%x at " TARGET_FMT_lx "\n", val, addr);
 108 #endif
 109         return;
 110     }
 111
 112     nvram_writeb(opaque, addr, val);
 113 }
 114
 115 static void nvram_writew_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
 116 {
 117     nvram_writeb_protected(opaque, addr, val & 0xff);
 118     nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
 119 }
 120
 121 static void nvram_writel_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
 122 {
 123     nvram_writeb_protected(opaque, addr, val & 0xff);
 124     nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
 125     nvram_writeb_protected(opaque, addr + 2, (val >> 16) & 0xff);
 126     nvram_writeb_protected(opaque, addr + 3, (val >> 24) & 0xff);
 127 }
 128
 129 static CPUReadMemoryFunc *nvram_read[] = {
 130     &nvram_readb,
 131     &nvram_readw,
 132     &nvram_readl,
 133 };
 134
 135 static CPUWriteMemoryFunc *nvram_write[] = {
 136     &nvram_writeb,
 137     &nvram_writew,
 138     &nvram_writel,
 139 };
 140
 141 static CPUWriteMemoryFunc *nvram_write_protected[] = {
 142     &nvram_writeb_protected,
 143     &nvram_writew_protected,
 144     &nvram_writel_protected,
 145 };
 146
 147 /* Initialisation routine */
 148 void *ds1225y_init(target_phys_addr_t mem_base, const char *filename)
 149 {
 150     ds1225y_t *s;
 151     int mem_indexRW, mem_indexRP;
 152     QEMUFile *file;
 153
 154     s = qemu_mallocz(sizeof(ds1225y_t));
 155     s->chip_size = 0x2000; /* Fixed for ds1225y chip: 8 KiB */
 156     s->contents = qemu_mallocz(s->chip_size);
 157     s->protection = 7;
 158
 159     /* Read current file */
 160     file = qemu_fopen(filename, "rb");
 161     if (file) {
 162         /* Read nvram contents */
 163         qemu_get_buffer(file, s->contents, s->chip_size);
 164         qemu_fclose(file);
 165     }
 166     s->file = qemu_fopen(filename, "wb");
 167     if (s->file) {
 168         /* Write back contents, as 'wb' mode cleaned the file */
 169         qemu_put_buffer(s->file, s->contents, s->chip_size);
 170         qemu_fflush(s->file);
 171     }
 172
 173     /* Read/write memory */
 174     mem_indexRW = cpu_register_io_memory(0, nvram_read, nvram_write, s);
 175     cpu_register_physical_memory(mem_base, s->chip_size, mem_indexRW);
 176     /* Read/write protected memory */
 177     mem_indexRP = cpu_register_io_memory(0, nvram_read, nvram_write_protected, s);
 178     cpu_register_physical_memory(mem_base + s->chip_size, s->chip_size, mem_indexRP);
 179     return s;
 180 }