if (CSR_DRX(s) || CSR_STOP(s) || CSR_SPND(s) || !size)        return;#ifdef PCNET_DEBUG    printf("pcnet_receive size=%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;    }    if (CSR_PROM(s)         || (is_padr=padr_match(s, buf, size))         || (is_bcast=padr_bcast(s, buf, size))        || (is_ladr=ladr_match(s, buf, size))) {        pcnet_rdte_poll(s);        if (!(CSR_CRST(s) & 0x8000) && s->rdra) {            struct pcnet_RMD rmd;            int rcvrc = CSR_RCVRC(s)-1,i;            target_phys_addr_t nrda;            for (i = CSR_RCVRL(s)-1; i > 0; i--, rcvrc--) {                if (rcvrc <= 1)                    rcvrc = CSR_RCVRL(s);                nrda = s->rdra +                    (CSR_RCVRL(s) - rcvrc) *                    (BCR_SWSTYLE(s) ? 16 : 8 );                RMDLOAD(&rmd, PHYSADDR(s,nrda));                                  if (rmd.rmd1.own) {                #ifdef PCNET_DEBUG_RMD                    printf("pcnet - scan buffer: RCVRC=%d PREV_RCVRC=%d\n",                                 rcvrc, CSR_RCVRC(s));#endif                    CSR_RCVRC(s) = rcvrc;                    pcnet_rdte_poll(s);                    break;                }            }        }        if (!(CSR_CRST(s) & 0x8000)) {#ifdef PCNET_DEBUG_RMD            printf("pcnet - no buffer: RCVRC=%d\n", CSR_RCVRC(s));#endif            s->csr[0] |= 0x1000; /* Set MISS flag */            CSR_MISSC(s)++;        } else {            uint8_t *src = &s->buffer[8];            target_phys_addr_t crda = CSR_CRDA(s);            struct pcnet_RMD rmd;            int pktcount = 0;            memcpy(src, buf, size);            #if 1            /* no need to compute the CRC */            src[size] = 0;            src[size + 1] = 0;            src[size + 2] = 0;            src[size + 3] = 0;            size += 4;#else            /* XXX: avoid CRC generation */            if (!CSR_ASTRP_RCV(s)) {                uint32_t fcs = ~0;                uint8_t *p = src;                while (size < 46) {                    src[size++] = 0;                }                                while (p != &src[size]) {                    CRC(fcs, *p++);                }                ((uint32_t *)&src[size])[0] = htonl(fcs);                size += 4; /* FCS at end of packet */            } else size += 4;#endif#ifdef PCNET_DEBUG_MATCH            PRINT_PKTHDR(buf);#endif            RMDLOAD(&rmd, PHYSADDR(s,crda));            /*if (!CSR_LAPPEN(s))*/                rmd.rmd1.stp = 1;#define PCNET_RECV_STORE() do {                                 \    int count = MIN(4096 - rmd.rmd1.bcnt,size);                 \    target_phys_addr_t rbadr = PHYSADDR(s, rmd.rmd0.rbadr);     \    s->phys_mem_write(s->dma_opaque, rbadr, src, count, CSR_BSWP(s));  \    src += count; size -= count;                                \    rmd.rmd2.mcnt = count; rmd.rmd1.own = 0;                    \    RMDSTORE(&rmd, PHYSADDR(s,crda));                           \    pktcount++;                                                 \} while (0)            PCNET_RECV_STORE();            if ((size > 0) && CSR_NRDA(s)) {                target_phys_addr_t nrda = CSR_NRDA(s);                RMDLOAD(&rmd, PHYSADDR(s,nrda));                if (rmd.rmd1.own) {                    crda = nrda;                    PCNET_RECV_STORE();                    if ((size > 0) && (nrda=CSR_NNRD(s))) {                        RMDLOAD(&rmd, PHYSADDR(s,nrda));                        if (rmd.rmd1.own) {                            crda = nrda;                            PCNET_RECV_STORE();                        }                    }                }                            }#undef PCNET_RECV_STORE            RMDLOAD(&rmd, PHYSADDR(s,crda));            if (size == 0) {                rmd.rmd1.enp = 1;                rmd.rmd1.pam = !CSR_PROM(s) && is_padr;                rmd.rmd1.lafm = !CSR_PROM(s) && is_ladr;                rmd.rmd1.bam = !CSR_PROM(s) && is_bcast;            } else {                rmd.rmd1.oflo = 1;                rmd.rmd1.buff = 1;                rmd.rmd1.err = 1;            }            RMDSTORE(&rmd, PHYSADDR(s,crda));            s->csr[0] |= 0x0400;#ifdef PCNET_DEBUG            printf("RCVRC=%d CRDA=0x%08x BLKS=%d\n",                 CSR_RCVRC(s), PHYSADDR(s,CSR_CRDA(s)), pktcount);#endif#ifdef PCNET_DEBUG_RMD            PRINT_RMD(&rmd);#endif                    while (pktcount--) {                if (CSR_RCVRC(s) <= 1)                    CSR_RCVRC(s) = CSR_RCVRL(s);                else                    CSR_RCVRC(s)--;                        }                        pcnet_rdte_poll(s);        }            }    pcnet_poll(s);    pcnet_update_irq(s);    }static void pcnet_transmit(PCNetState *s){    target_phys_addr_t xmit_cxda = 0;    int count = CSR_XMTRL(s)-1;    s->xmit_pos = -1;        if (!CSR_TXON(s)) {        s->csr[0] &= ~0x0008;        return;    }    s->tx_busy = 1;    txagain:    if (pcnet_tdte_poll(s)) {        struct pcnet_TMD tmd;        TMDLOAD(&tmd, PHYSADDR(s,CSR_CXDA(s)));                #ifdef PCNET_DEBUG_TMD        printf("  TMDLOAD 0x%08x\n", PHYSADDR(s,CSR_CXDA(s)));        PRINT_TMD(&tmd);#endif        if (tmd.tmd1.stp) {            s->xmit_pos = 0;                            if (!tmd.tmd1.enp) {                s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tmd0.tbadr),                                 s->buffer, 4096 - tmd.tmd1.bcnt,                                  CSR_BSWP(s));                s->xmit_pos += 4096 - tmd.tmd1.bcnt;            }             xmit_cxda = PHYSADDR(s,CSR_CXDA(s));        }        if (tmd.tmd1.enp && (s->xmit_pos >= 0)) {            s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tmd0.tbadr),                             s->buffer + s->xmit_pos, 4096 - tmd.tmd1.bcnt,                              CSR_BSWP(s));            s->xmit_pos += 4096 - tmd.tmd1.bcnt;#ifdef PCNET_DEBUG            printf("pcnet_transmit size=%d\n", s->xmit_pos);#endif                        if (CSR_LOOP(s))                pcnet_receive(s, s->buffer, s->xmit_pos);            else                qemu_send_packet(s->vc, s->buffer, s->xmit_pos);            s->csr[0] &= ~0x0008;   /* clear TDMD */            s->csr[4] |= 0x0004;    /* set TXSTRT */            s->xmit_pos = -1;        }        tmd.tmd1.own = 0;        TMDSTORE(&tmd, PHYSADDR(s,CSR_CXDA(s)));        if (!CSR_TOKINTD(s) || (CSR_LTINTEN(s) && tmd.tmd1.ltint))            s->csr[0] |= 0x0200;    /* set TINT */        if (CSR_XMTRC(s)<=1)            CSR_XMTRC(s) = CSR_XMTRL(s);        else            CSR_XMTRC(s)--;        if (count--)            goto txagain;    } else     if (s->xmit_pos >= 0) {        struct pcnet_TMD tmd;        TMDLOAD(&tmd, PHYSADDR(s,xmit_cxda));                        tmd.tmd2.buff = tmd.tmd2.uflo = tmd.tmd1.err = 1;        tmd.tmd1.own = 0;        TMDSTORE(&tmd, PHYSADDR(s,xmit_cxda));        s->csr[0] |= 0x0200;    /* set TINT */        if (!CSR_DXSUFLO(s)) {            s->csr[0] &= ~0x0010;        } else        if (count--)          goto txagain;    }    s->tx_busy = 0;}static void pcnet_poll(PCNetState *s){    if (CSR_RXON(s)) {        pcnet_rdte_poll(s);    }    if (CSR_TDMD(s) ||         (CSR_TXON(s) && !CSR_DPOLL(s) && pcnet_tdte_poll(s)))    {        /* prevent recursion */        if (s->tx_busy)            return;        pcnet_transmit(s);    }}static void pcnet_poll_timer(void *opaque){    PCNetState *s = opaque;    qemu_del_timer(s->poll_timer);    if (CSR_TDMD(s)) {        pcnet_transmit(s);    }    pcnet_update_irq(s);        if (!CSR_STOP(s) && !CSR_SPND(s) && !CSR_DPOLL(s)) {        uint64_t now = qemu_get_clock(vm_clock) * 33;        if (!s->timer || !now)            s->timer = now;        else {            uint64_t t = now - s->timer + CSR_POLL(s);            if (t > 0xffffLL) {                pcnet_poll(s);                CSR_POLL(s) = CSR_PINT(s);            } else                CSR_POLL(s) = t;        }        qemu_mod_timer(s->poll_timer,             pcnet_get_next_poll_time(s,qemu_get_clock(vm_clock)));    }}static void pcnet_csr_writew(PCNetState *s, uint32_t rap, uint32_t new_value){    uint16_t val = new_value;#ifdef PCNET_DEBUG_CSR    printf("pcnet_csr_writew rap=%d val=0x%04x\n", rap, val);#endif    switch (rap) {    case 0:        s->csr[0] &= ~(val & 0x7f00); /* Clear any interrupt flags */        s->csr[0] = (s->csr[0] & ~0x0040) | (val & 0x0048);        val = (val & 0x007f) | (s->csr[0] & 0x7f00);        /* IFF STOP, STRT and INIT are set, clear STRT and INIT */        if ((val&7) == 7)          val &= ~3;        if (!CSR_STOP(s) && (val & 4))            pcnet_stop(s);        if (!CSR_INIT(s) && (val & 1))            pcnet_init(s);        if (!CSR_STRT(s) && (val & 2))            pcnet_start(s);        if (CSR_TDMD(s))             pcnet_transmit(s);        return;    case 1:    case 2:    case 8:    case 9:    case 10:    case 11:    case 12:    case 13:    case 14:    case 15:    case 18: /* CRBAL */    case 19: /* CRBAU */    case 20: /* CXBAL */    case 21: /* CXBAU */    case 22: /* NRBAU */    case 23: /* NRBAU */    case 24:    case 25:    case 26:    case 27:    case 28:    case 29:    case 30:    case 31:    case 32:    case 33:    case 34:    case 35:    case 36:    case 37:    case 38:    case 39:    case 40: /* CRBC */    case 41:    case 42: /* CXBC */    case 43:    case 44:    case 45:    case 46: /* POLL */    case 47: /* POLLINT */    case 72:    case 74:    case 76: /* RCVRL */    case 78: /* XMTRL */    case 112:       if (CSR_STOP(s) || CSR_SPND(s))           break;       return;    case 3:        break;    case 4:        s->csr[4] &= ~(val & 0x026a);         val &= ~0x026a; val |= s->csr[4] & 0x026a;        break;    case 5:        s->csr[5] &= ~(val & 0x0a90);         val &= ~0x0a90; val |= s->csr[5] & 0x0a90;        break;    case 16:        pcnet_csr_writew(s,1,val);        return;    case 17:        pcnet_csr_writew(s,2,val);        return;    case 58:        pcnet_bcr_writew(s,BCR_SWS,val);        break;    default:        return;    }    s->csr[rap] = val;}static uint32_t pcnet_csr_readw(PCNetState *s, uint32_t rap){    uint32_t val;    switch (rap) {    case 0:        pcnet_update_irq(s);        val = s->csr[0];        val |= (val & 0x7800) ? 0x8000 : 0;        break;    case 16:        return pcnet_csr_readw(s,1);    case 17:        return pcnet_csr_readw(s,2);    case 58:        return pcnet_bcr_readw(s,BCR_SWS);    case 88:        val = s->csr[89];        val <<= 16;        val |= s->csr[88];        break;    default:        val = s->csr[rap];    }#ifdef PCNET_DEBUG_CSR    printf("pcnet_csr_readw rap=%d val=0x%04x\n", rap, val);#endif    return val;}static void pcnet_bcr_writew(PCNetState *s, uint32_t rap, uint32_t val){    rap &= 127;#ifdef PCNET_DEBUG_BCR    printf("pcnet_bcr_writew rap=%d val=0x%04x\n", rap, val);#endif    switch (rap) {    case BCR_SWS:        if (!(CSR_STOP(s) || CSR_SPND(s)))            return;        val &= ~0x0300;        switch (val & 0x00ff) {        case 0:            val |= 0x0200;            break;        case 1:            val |= 0x0100;            break;        case 2:        case 3:            val |= 0x0300;            break;        default:            printf("Bad SWSTYLE=0x%02x\n", val & 0xff);            val = 0x0200;            break;        }#ifdef PCNET_DEBUG       printf("BCR_SWS=0x%04x\n", val);#endif    case BCR_LNKST:    case BCR_LED1:    case BCR_LED2:    case BCR_LED3:    case BCR_MC:    case BCR_FDC:    case BCR_BSBC:    case BCR_EECAS:    case BCR_PLAT:        s->bcr[rap] = val;        break;    default:        break;    }}static uint32_t pcnet_bcr_readw(PCNetState *s, uint32_t rap){    uint32_t val;    rap &= 127;    switch (rap) {    case BCR_LNKST:    case BCR_LED1:    case BCR_LED2:    case BCR_LED3:        val = s->bcr[rap] & ~0x8000;        val |= (val & 0x017f & s->lnkst) ? 0x8000 : 0;        break;    default:        val = rap < 32 ? s->bcr[rap] : 0;        break;    }#ifdef PCNET_DEBUG_BCR    printf("pcnet_bcr_readw rap=%d val=0x%04x\n", rap, val);#endif    return val;}void pcnet_h_reset(void *opaque){    PCNetState *s = opaque;    int i;    uint16_t checksum;    /* Initialize the PROM */    memcpy(s->prom, s->nd->macaddr, 6);    s->prom[12] = s->prom[13] = 0x00;    s->prom[14] = s->prom[15] = 0x57;