Archipelago » qemu

/*

 * QEMU M48T08 NVRAM emulation for Sparc platform

 * 

 * Copyright (c) 2003-2004 Jocelyn Mayer

 * 

 * 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 "vl.h"

#include "m48t08.h"

//#define DEBUG_NVRAM

#if defined(DEBUG_NVRAM)

#define NVRAM_PRINTF(fmt, args...) do { printf(fmt , ##args); } while (0)

#else

#define NVRAM_PRINTF(fmt, args...) do { } while (0)

#endif

#define NVRAM_MAX_MEM 0x1ff0

#define NVRAM_MAXADDR 0x1fff

struct m48t08_t {

    /* RTC management */

    time_t   time_offset;

    time_t   stop_time;

    /* NVRAM storage */

    uint8_t *buffer;

};

/* Fake timer functions */

/* Generic helpers for BCD */

static inline uint8_t toBCD (uint8_t value)

{

    return (((value / 10) % 10) << 4) | (value % 10);

}

static inline uint8_t fromBCD (uint8_t BCD)

{

    return ((BCD >> 4) * 10) + (BCD & 0x0F);

}

/* RTC management helpers */

static void get_time (m48t08_t *NVRAM, struct tm *tm)

{

    time_t t;

    t = time(NULL) + NVRAM->time_offset;

#ifdef _WIN32

    memcpy(tm,localtime(&t),sizeof(*tm));

#else

    localtime_r (&t, tm) ;

#endif

}

static void set_time (m48t08_t *NVRAM, struct tm *tm)

{

    time_t now, new_time;

    new_time = mktime(tm);

    now = time(NULL);

    NVRAM->time_offset = new_time - now;

}

/* Direct access to NVRAM */

void m48t08_write (m48t08_t *NVRAM, uint32_t addr, uint8_t val)

{

    struct tm tm;

    int tmp;

    addr &= NVRAM_MAXADDR;

    switch (addr) {

    case 0x1FF8:

        /* control */

        NVRAM->buffer[0x1FF8] = (val & ~0xA0) | 0x90;

        break;

    case 0x1FF9:

        /* seconds (BCD) */

        tmp = fromBCD(val & 0x7F);

        if (tmp >= 0 && tmp <= 59) {

            get_time(NVRAM, &tm);

            tm.tm_sec = tmp;

            set_time(NVRAM, &tm);

        }

        if ((val & 0x80) ^ (NVRAM->buffer[0x1FF9] & 0x80)) {

            if (val & 0x80) {

                NVRAM->stop_time = time(NULL);

            } else {

                NVRAM->time_offset += NVRAM->stop_time - time(NULL);

                NVRAM->stop_time = 0;

            }

        }

        NVRAM->buffer[0x1FF9] = val & 0x80;

        break;

    case 0x1FFA:

        /* minutes (BCD) */

        tmp = fromBCD(val & 0x7F);

        if (tmp >= 0 && tmp <= 59) {

            get_time(NVRAM, &tm);

            tm.tm_min = tmp;

            set_time(NVRAM, &tm);

        }

        break;

    case 0x1FFB:

        /* hours (BCD) */

        tmp = fromBCD(val & 0x3F);

        if (tmp >= 0 && tmp <= 23) {

            get_time(NVRAM, &tm);

            tm.tm_hour = tmp;

            set_time(NVRAM, &tm);

        }

        break;

    case 0x1FFC:

        /* day of the week / century */

        tmp = fromBCD(val & 0x07);

        get_time(NVRAM, &tm);

        tm.tm_wday = tmp;

        set_time(NVRAM, &tm);

        NVRAM->buffer[0x1FFC] = val & 0x40;

        break;

    case 0x1FFD:

        /* date */

        tmp = fromBCD(val & 0x1F);

        if (tmp != 0) {

            get_time(NVRAM, &tm);

            tm.tm_mday = tmp;

            set_time(NVRAM, &tm);

        }

        break;

    case 0x1FFE:

        /* month */

        tmp = fromBCD(val & 0x1F);

        if (tmp >= 1 && tmp <= 12) {

            get_time(NVRAM, &tm);

            tm.tm_mon = tmp - 1;

            set_time(NVRAM, &tm);

        }

        break;

    case 0x1FFF:

        /* year */

        tmp = fromBCD(val);

        if (tmp >= 0 && tmp <= 99) {

            get_time(NVRAM, &tm);

            tm.tm_year = fromBCD(val);

            set_time(NVRAM, &tm);

        }

        break;

    default:

        NVRAM->buffer[addr] = val & 0xFF;

        break;

    }

}

uint8_t m48t08_read (m48t08_t *NVRAM, uint32_t addr)

{

    struct tm tm;

    uint8_t retval = 0xFF;

    addr &= NVRAM_MAXADDR;

    switch (addr) {

    case 0x1FF8:

        /* control */

        goto do_read;

    case 0x1FF9:

        /* seconds (BCD) */

        get_time(NVRAM, &tm);

        retval = (NVRAM->buffer[0x1FF9] & 0x80) | toBCD(tm.tm_sec);

        break;

    case 0x1FFA:

        /* minutes (BCD) */

        get_time(NVRAM, &tm);

        retval = toBCD(tm.tm_min);

        break;

    case 0x1FFB:

        /* hours (BCD) */

        get_time(NVRAM, &tm);

        retval = toBCD(tm.tm_hour);

        break;

    case 0x1FFC:

        /* day of the week / century */

        get_time(NVRAM, &tm);

        retval = NVRAM->buffer[0x1FFC] | tm.tm_wday;

        break;

    case 0x1FFD:

        /* date */

        get_time(NVRAM, &tm);

        retval = toBCD(tm.tm_mday);

        break;

    case 0x1FFE:

        /* month */

        get_time(NVRAM, &tm);

        retval = toBCD(tm.tm_mon + 1);

        break;

    case 0x1FFF:

        /* year */

        get_time(NVRAM, &tm);

        retval = toBCD(tm.tm_year);

        break;

    default:

    do_read:

        retval = NVRAM->buffer[addr];

        break;

    }

    return retval;

}

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

{

    m48t08_t *NVRAM = opaque;

    m48t08_write(NVRAM, addr, value);

}

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

{

    m48t08_t *NVRAM = opaque;

    m48t08_write(NVRAM, addr, value);

    m48t08_write(NVRAM, addr + 1, value >> 8);

}

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

{

    m48t08_t *NVRAM = opaque;

    m48t08_write(NVRAM, addr, value);

    m48t08_write(NVRAM, addr + 1, value >> 8);

    m48t08_write(NVRAM, addr + 2, value >> 16);

    m48t08_write(NVRAM, addr + 3, value >> 24);

}

static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)

{

    m48t08_t *NVRAM = opaque;

    uint32_t retval = 0;

    retval = m48t08_read(NVRAM, addr);

    return retval;

}

static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)

{

    m48t08_t *NVRAM = opaque;

    uint32_t retval = 0;

    retval = m48t08_read(NVRAM, addr) << 8;

    retval |= m48t08_read(NVRAM, addr + 1);

    return retval;

}

static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)

{

    m48t08_t *NVRAM = opaque;

    uint32_t retval = 0;

    retval = m48t08_read(NVRAM, addr) << 24;

    retval |= m48t08_read(NVRAM, addr + 1) << 16;

    retval |= m48t08_read(NVRAM, addr + 2) << 8;

    retval |= m48t08_read(NVRAM, addr + 3);

    return retval;

}

static CPUWriteMemoryFunc *nvram_write[] = {

    &nvram_writeb,

    &nvram_writew,

    &nvram_writel,

};

static CPUReadMemoryFunc *nvram_read[] = {

    &nvram_readb,

    &nvram_readw,

    &nvram_readl,

};

static void nvram_save(QEMUFile *f, void *opaque)

{

    m48t08_t *s = opaque;

    qemu_put_be32s(f, (uint32_t *)&s->time_offset);

    qemu_put_be32s(f, (uint32_t *)&s->stop_time);

    qemu_put_buffer(f, s->buffer, 0x2000);

}

static int nvram_load(QEMUFile *f, void *opaque, int version_id)

{

    m48t08_t *s = opaque;

    if (version_id != 1)

        return -EINVAL;

    qemu_get_be32s(f, (uint32_t *)&s->time_offset);

    qemu_get_be32s(f, (uint32_t *)&s->stop_time);

    qemu_get_buffer(f, s->buffer, 0x2000);

    return 0;

}

static void m48t08_reset(void *opaque)

{

    m48t08_t *s = opaque;

    s->time_offset = 0;

    s->stop_time = 0;

}

/* Initialisation routine */

m48t08_t *m48t08_init(uint32_t mem_base, uint16_t size)

{

    m48t08_t *s;

    int mem_index;

    s = qemu_mallocz(sizeof(m48t08_t));

    if (!s)

        return NULL;

    s->buffer = qemu_mallocz(size);

    if (!s->buffer) {

        qemu_free(s);

        return NULL;

    }

    if (mem_base != 0) {

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

        cpu_register_physical_memory(mem_base, 0x2000, mem_index);

    }

    register_savevm("nvram", mem_base, 1, nvram_save, nvram_load, s);

    qemu_register_reset(m48t08_reset, s);

    return s;

}

#if 0

struct idprom

{

        unsigned char   id_format;      /* Format identifier (always 0x01) */

        unsigned char   id_machtype;    /* Machine type */

        unsigned char   id_ethaddr[6];  /* Hardware ethernet address */

        long            id_date;        /* Date of manufacture */

        unsigned int    id_sernum:24;   /* Unique serial number */

        unsigned char   id_cksum;       /* Checksum - xor of the data bytes */

        unsigned char   reserved[16];

};

#endif