Archipelago » qemu

/*

 * QEMU NE2000 emulation

 * 

 * Copyright (c) 2003-2004 Fabrice Bellard

 * 

 * 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"

/* debug NE2000 card */

//#define DEBUG_NE2000

#define MAX_ETH_FRAME_SIZE 1514

#define E8390_CMD        0x00  /* The command register (for all pages) */

/* Page 0 register offsets. */

#define EN0_CLDALO        0x01        /* Low byte of current local dma addr  RD */

#define EN0_STARTPG        0x01        /* Starting page of ring bfr WR */

#define EN0_CLDAHI        0x02        /* High byte of current local dma addr  RD */

#define EN0_STOPPG        0x02        /* Ending page +1 of ring bfr WR */

#define EN0_BOUNDARY        0x03        /* Boundary page of ring bfr RD WR */

#define EN0_TSR                0x04        /* Transmit status reg RD */

#define EN0_TPSR        0x04        /* Transmit starting page WR */

#define EN0_NCR                0x05        /* Number of collision reg RD */

#define EN0_TCNTLO        0x05        /* Low  byte of tx byte count WR */

#define EN0_FIFO        0x06        /* FIFO RD */

#define EN0_TCNTHI        0x06        /* High byte of tx byte count WR */

#define EN0_ISR                0x07        /* Interrupt status reg RD WR */

#define EN0_CRDALO        0x08        /* low byte of current remote dma address RD */

#define EN0_RSARLO        0x08        /* Remote start address reg 0 */

#define EN0_CRDAHI        0x09        /* high byte, current remote dma address RD */

#define EN0_RSARHI        0x09        /* Remote start address reg 1 */

#define EN0_RCNTLO        0x0a        /* Remote byte count reg WR */

#define EN0_RCNTHI        0x0b        /* Remote byte count reg WR */

#define EN0_RSR                0x0c        /* rx status reg RD */

#define EN0_RXCR        0x0c        /* RX configuration reg WR */

#define EN0_TXCR        0x0d        /* TX configuration reg WR */

#define EN0_COUNTER0        0x0d        /* Rcv alignment error counter RD */

#define EN0_DCFG        0x0e        /* Data configuration reg WR */

#define EN0_COUNTER1        0x0e        /* Rcv CRC error counter RD */

#define EN0_IMR                0x0f        /* Interrupt mask reg WR */

#define EN0_COUNTER2        0x0f        /* Rcv missed frame error counter RD */

#define EN1_PHYS        0x11

#define EN1_CURPAG      0x17

#define EN1_MULT        0x18

/*  Register accessed at EN_CMD, the 8390 base addr.  */

#define E8390_STOP        0x01        /* Stop and reset the chip */

#define E8390_START        0x02        /* Start the chip, clear reset */

#define E8390_TRANS        0x04        /* Transmit a frame */

#define E8390_RREAD        0x08        /* Remote read */

#define E8390_RWRITE        0x10        /* Remote write  */

#define E8390_NODMA        0x20        /* Remote DMA */

#define E8390_PAGE0        0x00        /* Select page chip registers */

#define E8390_PAGE1        0x40        /* using the two high-order bits */

#define E8390_PAGE2        0x80        /* Page 3 is invalid. */

/* Bits in EN0_ISR - Interrupt status register */

#define ENISR_RX        0x01        /* Receiver, no error */

#define ENISR_TX        0x02        /* Transmitter, no error */

#define ENISR_RX_ERR        0x04        /* Receiver, with error */

#define ENISR_TX_ERR        0x08        /* Transmitter, with error */

#define ENISR_OVER        0x10        /* Receiver overwrote the ring */

#define ENISR_COUNTERS        0x20        /* Counters need emptying */

#define ENISR_RDC        0x40        /* remote dma complete */

#define ENISR_RESET        0x80        /* Reset completed */

#define ENISR_ALL        0x3f        /* Interrupts we will enable */

/* Bits in received packet status byte and EN0_RSR*/

#define ENRSR_RXOK        0x01        /* Received a good packet */

#define ENRSR_CRC        0x02        /* CRC error */

#define ENRSR_FAE        0x04        /* frame alignment error */

#define ENRSR_FO        0x08        /* FIFO overrun */

#define ENRSR_MPA        0x10        /* missed pkt */

#define ENRSR_PHY        0x20        /* physical/multicast address */

#define ENRSR_DIS        0x40        /* receiver disable. set in monitor mode */

#define ENRSR_DEF        0x80        /* deferring */

/* Transmitted packet status, EN0_TSR. */

#define ENTSR_PTX 0x01        /* Packet transmitted without error */

#define ENTSR_ND  0x02        /* The transmit wasn't deferred. */

#define ENTSR_COL 0x04        /* The transmit collided at least once. */

#define ENTSR_ABT 0x08  /* The transmit collided 16 times, and was deferred. */

#define ENTSR_CRS 0x10        /* The carrier sense was lost. */

#define ENTSR_FU  0x20  /* A "FIFO underrun" occurred during transmit. */

#define ENTSR_CDH 0x40        /* The collision detect "heartbeat" signal was lost. */

#define ENTSR_OWC 0x80  /* There was an out-of-window collision. */

#define NE2000_MEM_SIZE 32768

typedef struct NE2000State {

    uint8_t cmd;

    uint32_t start;

    uint32_t stop;

    uint8_t boundary;

    uint8_t tsr;

    uint8_t tpsr;

    uint16_t tcnt;

    uint16_t rcnt;

    uint32_t rsar;

    uint8_t isr;

    uint8_t dcfg;

    uint8_t imr;

    uint8_t phys[6]; /* mac address */

    uint8_t curpag;

    uint8_t mult[8]; /* multicast mask array */

    int irq;

    NetDriverState *nd;

    uint8_t mem[NE2000_MEM_SIZE];

} NE2000State;

static void ne2000_reset(NE2000State *s)

{

    int i;

    s->isr = ENISR_RESET;

    memcpy(s->mem, s->nd->macaddr, 6);

    s->mem[14] = 0x57;

    s->mem[15] = 0x57;

    /* duplicate prom data */

    for(i = 15;i >= 0; i--) {

        s->mem[2 * i] = s->mem[i];

        s->mem[2 * i + 1] = s->mem[i];

    }

}

static void ne2000_update_irq(NE2000State *s)

{

    int isr;

    isr = s->isr & s->imr;

    if (isr)

        pic_set_irq(s->irq, 1);

    else

        pic_set_irq(s->irq, 0);

}

/* return the max buffer size if the NE2000 can receive more data */

static int ne2000_can_receive(void *opaque)

{

    NE2000State *s = opaque;

    int avail, index, boundary;

    if (s->cmd & E8390_STOP)

        return 0;

    index = s->curpag << 8;

    boundary = s->boundary << 8;

    if (index < boundary)

        avail = boundary - index;

    else

        avail = (s->stop - s->start) - (index - boundary);

    if (avail < (MAX_ETH_FRAME_SIZE + 4))

        return 0;

    return MAX_ETH_FRAME_SIZE;

}

#define MIN_BUF_SIZE 60

static void ne2000_receive(void *opaque, const uint8_t *buf, int size)

{

    NE2000State *s = opaque;

    uint8_t *p;

    int total_len, next, avail, len, index;

    uint8_t buf1[60];

#if defined(DEBUG_NE2000)

    printf("NE2000: received len=%d\n", size);

#endif

    /* if too small buffer, then expand it */

    if (size < MIN_BUF_SIZE) {

        memcpy(buf1, buf, size);

        memset(buf1 + size, 0, MIN_BUF_SIZE - size);

        buf = buf1;

        size = MIN_BUF_SIZE;

    }

    index = s->curpag << 8;

    /* 4 bytes for header */

    total_len = size + 4;

    /* address for next packet (4 bytes for CRC) */

    next = index + ((total_len + 4 + 255) & ~0xff);

    if (next >= s->stop)

        next -= (s->stop - s->start);

    /* prepare packet header */

    p = s->mem + index;

    p[0] = ENRSR_RXOK; /* receive status */

    p[1] = next >> 8;

    p[2] = total_len;

    p[3] = total_len >> 8;

    index += 4;

    /* write packet data */

    while (size > 0) {

        avail = s->stop - index;

        len = size;

        if (len > avail)

            len = avail;

        memcpy(s->mem + index, buf, len);

        buf += len;

        index += len;

        if (index == s->stop)

            index = s->start;

        size -= len;

    }

    s->curpag = next >> 8;

    /* now we can signal we have receive something */

    s->isr |= ENISR_RX;

    ne2000_update_irq(s);

}

static void ne2000_ioport_write(void *opaque, uint32_t addr, uint32_t val)

{

    NE2000State *s = opaque;

    int offset, page;

    addr &= 0xf;

#ifdef DEBUG_NE2000

    printf("NE2000: write addr=0x%x val=0x%02x\n", addr, val);

#endif

    if (addr == E8390_CMD) {

        /* control register */

        s->cmd = val;

        if (val & E8390_START) {

            /* test specific case: zero length transfert */

            if ((val & (E8390_RREAD | E8390_RWRITE)) &&

                s->rcnt == 0) {

                s->isr |= ENISR_RDC;

                ne2000_update_irq(s);

            }

            if (val & E8390_TRANS) {

                net_send_packet(s->nd, s->mem + (s->tpsr << 8), s->tcnt);

                /* signal end of transfert */

                s->tsr = ENTSR_PTX;

                s->isr |= ENISR_TX;

                ne2000_update_irq(s);

            }

        }

    } else {

        page = s->cmd >> 6;

        offset = addr | (page << 4);

        switch(offset) {

        case EN0_STARTPG:

            s->start = val << 8;

            break;

        case EN0_STOPPG:

            s->stop = val << 8;

            break;

        case EN0_BOUNDARY:

            s->boundary = val;

            break;

        case EN0_IMR:

            s->imr = val;

            ne2000_update_irq(s);

            break;

        case EN0_TPSR:

            s->tpsr = val;

            break;

        case EN0_TCNTLO:

            s->tcnt = (s->tcnt & 0xff00) | val;

            break;

        case EN0_TCNTHI:

            s->tcnt = (s->tcnt & 0x00ff) | (val << 8);

            break;

        case EN0_RSARLO:

            s->rsar = (s->rsar & 0xff00) | val;

            break;

        case EN0_RSARHI:

            s->rsar = (s->rsar & 0x00ff) | (val << 8);

            break;

        case EN0_RCNTLO:

            s->rcnt = (s->rcnt & 0xff00) | val;

            break;

        case EN0_RCNTHI:

            s->rcnt = (s->rcnt & 0x00ff) | (val << 8);

            break;

        case EN0_DCFG:

            s->dcfg = val;

            break;

        case EN0_ISR:

            s->isr &= ~val;

            ne2000_update_irq(s);

            break;

        case EN1_PHYS ... EN1_PHYS + 5:

            s->phys[offset - EN1_PHYS] = val;

            break;

        case EN1_CURPAG:

            s->curpag = val;

            break;

        case EN1_MULT ... EN1_MULT + 7:

            s->mult[offset - EN1_MULT] = val;

            break;

        }

    }

}

static uint32_t ne2000_ioport_read(void *opaque, uint32_t addr)

{

    NE2000State *s = opaque;

    int offset, page, ret;

    addr &= 0xf;

    if (addr == E8390_CMD) {

        ret = s->cmd;

    } else {

        page = s->cmd >> 6;

        offset = addr | (page << 4);

        switch(offset) {

        case EN0_TSR:

            ret = s->tsr;

            break;

        case EN0_BOUNDARY:

            ret = s->boundary;

            break;

        case EN0_ISR:

            ret = s->isr;

            break;

        case EN1_PHYS ... EN1_PHYS + 5:

            ret = s->phys[offset - EN1_PHYS];

            break;

        case EN1_CURPAG:

            ret = s->curpag;

            break;

        case EN1_MULT ... EN1_MULT + 7:

            ret = s->mult[offset - EN1_MULT];

            break;

        default:

            ret = 0x00;

            break;

        }

    }

#ifdef DEBUG_NE2000

    printf("NE2000: read addr=0x%x val=%02x\n", addr, ret);

#endif

    return ret;

}

static void ne2000_asic_ioport_write(void *opaque, uint32_t addr, uint32_t val)

{

    NE2000State *s = opaque;

    uint8_t *p;

#ifdef DEBUG_NE2000

    printf("NE2000: asic write val=0x%04x\n", val);

#endif

    p = s->mem + s->rsar;

    if (s->dcfg & 0x01) {

        /* 16 bit access */

        p[0] = val;

        p[1] = val >> 8;

        s->rsar += 2;

        s->rcnt -= 2;

    } else {

        /* 8 bit access */

        p[0] = val;

        s->rsar++;

        s->rcnt--;

    }

    /* wrap */

    if (s->rsar == s->stop)

        s->rsar = s->start;

    if (s->rcnt == 0) {

        /* signal end of transfert */

        s->isr |= ENISR_RDC;

        ne2000_update_irq(s);

    }

}

static uint32_t ne2000_asic_ioport_read(void *opaque, uint32_t addr)

{

    NE2000State *s = opaque;

    uint8_t *p;

    int ret;

    p = s->mem + s->rsar;

    if (s->dcfg & 0x01) {

        /* 16 bit access */

        ret = p[0] | (p[1] << 8);

        s->rsar += 2;

        s->rcnt -= 2;

    } else {

        /* 8 bit access */

        ret = p[0];

        s->rsar++;

        s->rcnt--;

    }

    /* wrap */

    if (s->rsar == s->stop)

        s->rsar = s->start;

    if (s->rcnt == 0) {

        /* signal end of transfert */

        s->isr |= ENISR_RDC;

        ne2000_update_irq(s);

    }

#ifdef DEBUG_NE2000

    printf("NE2000: asic read val=0x%04x\n", ret);

#endif

    return ret;

}

static void ne2000_reset_ioport_write(void *opaque, uint32_t addr, uint32_t val)

{

    /* nothing to do (end of reset pulse) */

}

static uint32_t ne2000_reset_ioport_read(void *opaque, uint32_t addr)

{

    NE2000State *s = opaque;

    ne2000_reset(s);

    return 0;

}

void ne2000_init(int base, int irq, NetDriverState *nd)

{

    NE2000State *s;

    s = qemu_mallocz(sizeof(NE2000State));

    if (!s)

        return;

    register_ioport_write(base, 16, 1, ne2000_ioport_write, s);

    register_ioport_read(base, 16, 1, ne2000_ioport_read, s);

    register_ioport_write(base + 0x10, 1, 1, ne2000_asic_ioport_write, s);

    register_ioport_read(base + 0x10, 1, 1, ne2000_asic_ioport_read, s);

    register_ioport_write(base + 0x10, 2, 2, ne2000_asic_ioport_write, s);

    register_ioport_read(base + 0x10, 2, 2, ne2000_asic_ioport_read, s);

    register_ioport_write(base + 0x1f, 1, 1, ne2000_reset_ioport_write, s);

    register_ioport_read(base + 0x1f, 1, 1, ne2000_reset_ioport_read, s);

    s->irq = irq;

    s->nd = nd;

    ne2000_reset(s);

    qemu_add_fd_read_handler(nd->fd, ne2000_can_receive, ne2000_receive, s);

}