Archipelago » qemu

/*

 * QEMU NVRAM emulation for DS1225Y chip

 * 

 * Copyright (c) 2007 Herv? Poussineau

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "hw.h"

#include "mips.h"

#include "nvram.h"

typedef enum

{

    none = 0,

    readmode,

    writemode,

} nvram_open_mode;

struct ds1225y_t

{

    target_phys_addr_t mem_base;

    uint32_t capacity;

    const char *filename;

    QEMUFile *file;

    nvram_open_mode open_mode;

};

static int ds1225y_set_to_mode(ds1225y_t *NVRAM, nvram_open_mode mode, const char *filemode)

{

    if (NVRAM->open_mode != mode)

    {

        if (NVRAM->file)

            qemu_fclose(NVRAM->file);

        NVRAM->file = qemu_fopen(NVRAM->filename, filemode);

        NVRAM->open_mode = mode;

    }

    return (NVRAM->file != NULL);

}

static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)

{

    ds1225y_t *NVRAM = opaque;

    int64_t pos;

    pos = addr - NVRAM->mem_base;

    if (addr >= NVRAM->capacity)

        addr -= NVRAM->capacity;

    if (!ds1225y_set_to_mode(NVRAM, readmode, "rb"))

        return 0;

    qemu_fseek(NVRAM->file, pos, SEEK_SET);

    return (uint32_t)qemu_get_byte(NVRAM->file);

}

static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)

{

    ds1225y_t *NVRAM = opaque;

    int64_t pos;

    pos = addr - NVRAM->mem_base;

    if (ds1225y_set_to_mode(NVRAM, writemode, "wb"))

    {

        qemu_fseek(NVRAM->file, pos, SEEK_SET);

        qemu_put_byte(NVRAM->file, (int)value);

    }

}

static CPUReadMemoryFunc *nvram_read[] = {

    &nvram_readb,

    NULL,

    NULL,

};

static CPUWriteMemoryFunc *nvram_write[] = {

    &nvram_writeb,

    NULL,

    NULL,

};

static CPUWriteMemoryFunc *nvram_none[] = {

    NULL,

    NULL,

    NULL,

};

/* Initialisation routine */

ds1225y_t *ds1225y_init(target_phys_addr_t mem_base, const char *filename)

{

    ds1225y_t *s;

    int mem_index1, mem_index2;

    s = qemu_mallocz(sizeof(ds1225y_t));

    if (!s)

        return NULL;

    s->mem_base = mem_base;

    s->capacity = 0x2000; /* Fixed for ds1225y chip: 8K */

    s->filename = filename;

    /* Read/write memory */

    mem_index1 = cpu_register_io_memory(0, nvram_read, nvram_write, s);

    cpu_register_physical_memory(mem_base, s->capacity, mem_index1);

    /* Read-only memory */

    mem_index2 = cpu_register_io_memory(0, nvram_read, nvram_none, s);

    cpu_register_physical_memory(mem_base + s->capacity, s->capacity, mem_index2);

    return s;

}