Add qemu 2.4.0
[kvmfornfv.git] / qemu / hw / net / pcnet.c
diff --git a/qemu/hw/net/pcnet.c b/qemu/hw/net/pcnet.c
new file mode 100644 (file)
index 0000000..3437376
--- /dev/null
@@ -0,0 +1,1753 @@
+/*
+ * QEMU AMD PC-Net II (Am79C970A) emulation
+ *
+ * Copyright (c) 2004 Antony T Curtis
+ *
+ * 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.
+ */
+
+/* This software was written to be compatible with the specification:
+ * AMD Am79C970A PCnet-PCI II Ethernet Controller Data-Sheet
+ * AMD Publication# 19436  Rev:E  Amendment/0  Issue Date: June 2000
+ */
+
+/*
+ * On Sparc32, this is the Lance (Am7990) part of chip STP2000 (Master I/O), also
+ * produced as NCR89C100. See
+ * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
+ * and
+ * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR92C990.txt
+ */
+
+#include "hw/qdev.h"
+#include "net/net.h"
+#include "qemu/timer.h"
+#include "qemu/sockets.h"
+#include "sysemu/sysemu.h"
+#include "trace.h"
+
+#include "pcnet.h"
+
+//#define PCNET_DEBUG
+//#define PCNET_DEBUG_IO
+//#define PCNET_DEBUG_BCR
+//#define PCNET_DEBUG_CSR
+//#define PCNET_DEBUG_RMD
+//#define PCNET_DEBUG_TMD
+//#define PCNET_DEBUG_MATCH
+
+
+struct qemu_ether_header {
+    uint8_t ether_dhost[6];
+    uint8_t ether_shost[6];
+    uint16_t ether_type;
+};
+
+#define CSR_INIT(S)      !!(((S)->csr[0])&0x0001)
+#define CSR_STRT(S)      !!(((S)->csr[0])&0x0002)
+#define CSR_STOP(S)      !!(((S)->csr[0])&0x0004)
+#define CSR_TDMD(S)      !!(((S)->csr[0])&0x0008)
+#define CSR_TXON(S)      !!(((S)->csr[0])&0x0010)
+#define CSR_RXON(S)      !!(((S)->csr[0])&0x0020)
+#define CSR_INEA(S)      !!(((S)->csr[0])&0x0040)
+#define CSR_BSWP(S)      !!(((S)->csr[3])&0x0004)
+#define CSR_LAPPEN(S)    !!(((S)->csr[3])&0x0020)
+#define CSR_DXSUFLO(S)   !!(((S)->csr[3])&0x0040)
+#define CSR_ASTRP_RCV(S) !!(((S)->csr[4])&0x0800)
+#define CSR_DPOLL(S)     !!(((S)->csr[4])&0x1000)
+#define CSR_SPND(S)      !!(((S)->csr[5])&0x0001)
+#define CSR_LTINTEN(S)   !!(((S)->csr[5])&0x4000)
+#define CSR_TOKINTD(S)   !!(((S)->csr[5])&0x8000)
+#define CSR_DRX(S)       !!(((S)->csr[15])&0x0001)
+#define CSR_DTX(S)       !!(((S)->csr[15])&0x0002)
+#define CSR_LOOP(S)      !!(((S)->csr[15])&0x0004)
+#define CSR_DXMTFCS(S)   !!(((S)->csr[15])&0x0008)
+#define CSR_INTL(S)      !!(((S)->csr[15])&0x0040)
+#define CSR_DRCVPA(S)    !!(((S)->csr[15])&0x2000)
+#define CSR_DRCVBC(S)    !!(((S)->csr[15])&0x4000)
+#define CSR_PROM(S)      !!(((S)->csr[15])&0x8000)
+
+#define CSR_CRBC(S)      ((S)->csr[40])
+#define CSR_CRST(S)      ((S)->csr[41])
+#define CSR_CXBC(S)      ((S)->csr[42])
+#define CSR_CXST(S)      ((S)->csr[43])
+#define CSR_NRBC(S)      ((S)->csr[44])
+#define CSR_NRST(S)      ((S)->csr[45])
+#define CSR_POLL(S)      ((S)->csr[46])
+#define CSR_PINT(S)      ((S)->csr[47])
+#define CSR_RCVRC(S)     ((S)->csr[72])
+#define CSR_XMTRC(S)     ((S)->csr[74])
+#define CSR_RCVRL(S)     ((S)->csr[76])
+#define CSR_XMTRL(S)     ((S)->csr[78])
+#define CSR_MISSC(S)     ((S)->csr[112])
+
+#define CSR_IADR(S)      ((S)->csr[ 1] | ((uint32_t)(S)->csr[ 2] << 16))
+#define CSR_CRBA(S)      ((S)->csr[18] | ((uint32_t)(S)->csr[19] << 16))
+#define CSR_CXBA(S)      ((S)->csr[20] | ((uint32_t)(S)->csr[21] << 16))
+#define CSR_NRBA(S)      ((S)->csr[22] | ((uint32_t)(S)->csr[23] << 16))
+#define CSR_BADR(S)      ((S)->csr[24] | ((uint32_t)(S)->csr[25] << 16))
+#define CSR_NRDA(S)      ((S)->csr[26] | ((uint32_t)(S)->csr[27] << 16))
+#define CSR_CRDA(S)      ((S)->csr[28] | ((uint32_t)(S)->csr[29] << 16))
+#define CSR_BADX(S)      ((S)->csr[30] | ((uint32_t)(S)->csr[31] << 16))
+#define CSR_NXDA(S)      ((S)->csr[32] | ((uint32_t)(S)->csr[33] << 16))
+#define CSR_CXDA(S)      ((S)->csr[34] | ((uint32_t)(S)->csr[35] << 16))
+#define CSR_NNRD(S)      ((S)->csr[36] | ((uint32_t)(S)->csr[37] << 16))
+#define CSR_NNXD(S)      ((S)->csr[38] | ((uint32_t)(S)->csr[39] << 16))
+#define CSR_PXDA(S)      ((S)->csr[60] | ((uint32_t)(S)->csr[61] << 16))
+#define CSR_NXBA(S)      ((S)->csr[64] | ((uint32_t)(S)->csr[65] << 16))
+
+#define PHYSADDR(S,A) \
+  (BCR_SSIZE32(S) ? (A) : (A) | ((0xff00 & (uint32_t)(S)->csr[2])<<16))
+
+struct pcnet_initblk16 {
+    uint16_t mode;
+    uint16_t padr[3];
+    uint16_t ladrf[4];
+    uint32_t rdra;
+    uint32_t tdra;
+};
+
+struct pcnet_initblk32 {
+    uint16_t mode;
+    uint8_t rlen;
+    uint8_t tlen;
+    uint16_t padr[3];
+    uint16_t _res;
+    uint16_t ladrf[4];
+    uint32_t rdra;
+    uint32_t tdra;
+};
+
+struct pcnet_TMD {
+    uint32_t tbadr;
+    int16_t length;
+    int16_t status;
+    uint32_t misc;
+    uint32_t res;
+};
+
+#define TMDL_BCNT_MASK  0x0fff
+#define TMDL_BCNT_SH    0
+#define TMDL_ONES_MASK  0xf000
+#define TMDL_ONES_SH    12
+
+#define TMDS_BPE_MASK   0x0080
+#define TMDS_BPE_SH     7
+#define TMDS_ENP_MASK   0x0100
+#define TMDS_ENP_SH     8
+#define TMDS_STP_MASK   0x0200
+#define TMDS_STP_SH     9
+#define TMDS_DEF_MASK   0x0400
+#define TMDS_DEF_SH     10
+#define TMDS_ONE_MASK   0x0800
+#define TMDS_ONE_SH     11
+#define TMDS_LTINT_MASK 0x1000
+#define TMDS_LTINT_SH   12
+#define TMDS_NOFCS_MASK 0x2000
+#define TMDS_NOFCS_SH   13
+#define TMDS_ADDFCS_MASK TMDS_NOFCS_MASK
+#define TMDS_ADDFCS_SH  TMDS_NOFCS_SH
+#define TMDS_ERR_MASK   0x4000
+#define TMDS_ERR_SH     14
+#define TMDS_OWN_MASK   0x8000
+#define TMDS_OWN_SH     15
+
+#define TMDM_TRC_MASK   0x0000000f
+#define TMDM_TRC_SH     0
+#define TMDM_TDR_MASK   0x03ff0000
+#define TMDM_TDR_SH     16
+#define TMDM_RTRY_MASK  0x04000000
+#define TMDM_RTRY_SH    26
+#define TMDM_LCAR_MASK  0x08000000
+#define TMDM_LCAR_SH    27
+#define TMDM_LCOL_MASK  0x10000000
+#define TMDM_LCOL_SH    28
+#define TMDM_EXDEF_MASK 0x20000000
+#define TMDM_EXDEF_SH   29
+#define TMDM_UFLO_MASK  0x40000000
+#define TMDM_UFLO_SH    30
+#define TMDM_BUFF_MASK  0x80000000
+#define TMDM_BUFF_SH    31
+
+struct pcnet_RMD {
+    uint32_t rbadr;
+    int16_t buf_length;
+    int16_t status;
+    uint32_t msg_length;
+    uint32_t res;
+};
+
+#define RMDL_BCNT_MASK  0x0fff
+#define RMDL_BCNT_SH    0
+#define RMDL_ONES_MASK  0xf000
+#define RMDL_ONES_SH    12
+
+#define RMDS_BAM_MASK   0x0010
+#define RMDS_BAM_SH     4
+#define RMDS_LFAM_MASK  0x0020
+#define RMDS_LFAM_SH    5
+#define RMDS_PAM_MASK   0x0040
+#define RMDS_PAM_SH     6
+#define RMDS_BPE_MASK   0x0080
+#define RMDS_BPE_SH     7
+#define RMDS_ENP_MASK   0x0100
+#define RMDS_ENP_SH     8
+#define RMDS_STP_MASK   0x0200
+#define RMDS_STP_SH     9
+#define RMDS_BUFF_MASK  0x0400
+#define RMDS_BUFF_SH    10
+#define RMDS_CRC_MASK   0x0800
+#define RMDS_CRC_SH     11
+#define RMDS_OFLO_MASK  0x1000
+#define RMDS_OFLO_SH    12
+#define RMDS_FRAM_MASK  0x2000
+#define RMDS_FRAM_SH    13
+#define RMDS_ERR_MASK   0x4000
+#define RMDS_ERR_SH     14
+#define RMDS_OWN_MASK   0x8000
+#define RMDS_OWN_SH     15
+
+#define RMDM_MCNT_MASK  0x00000fff
+#define RMDM_MCNT_SH    0
+#define RMDM_ZEROS_MASK 0x0000f000
+#define RMDM_ZEROS_SH   12
+#define RMDM_RPC_MASK   0x00ff0000
+#define RMDM_RPC_SH     16
+#define RMDM_RCC_MASK   0xff000000
+#define RMDM_RCC_SH     24
+
+#define SET_FIELD(regp, name, field, value)             \
+  (*(regp) = (*(regp) & ~(name ## _ ## field ## _MASK)) \
+             | ((value) << name ## _ ## field ## _SH))
+
+#define GET_FIELD(reg, name, field)                     \
+  (((reg) & name ## _ ## field ## _MASK) >> name ## _ ## field ## _SH)
+
+#define PRINT_TMD(T) printf(                            \
+        "TMD0 : TBADR=0x%08x\n"                         \
+        "TMD1 : OWN=%d, ERR=%d, FCS=%d, LTI=%d, "       \
+        "ONE=%d, DEF=%d, STP=%d, ENP=%d,\n"             \
+        "       BPE=%d, BCNT=%d\n"                      \
+        "TMD2 : BUF=%d, UFL=%d, EXD=%d, LCO=%d, "       \
+        "LCA=%d, RTR=%d,\n"                             \
+        "       TDR=%d, TRC=%d\n",                      \
+        (T)->tbadr,                                     \
+        GET_FIELD((T)->status, TMDS, OWN),              \
+        GET_FIELD((T)->status, TMDS, ERR),              \
+        GET_FIELD((T)->status, TMDS, NOFCS),            \
+        GET_FIELD((T)->status, TMDS, LTINT),            \
+        GET_FIELD((T)->status, TMDS, ONE),              \
+        GET_FIELD((T)->status, TMDS, DEF),              \
+        GET_FIELD((T)->status, TMDS, STP),              \
+        GET_FIELD((T)->status, TMDS, ENP),              \
+        GET_FIELD((T)->status, TMDS, BPE),              \
+        4096-GET_FIELD((T)->length, TMDL, BCNT),        \
+        GET_FIELD((T)->misc, TMDM, BUFF),               \
+        GET_FIELD((T)->misc, TMDM, UFLO),               \
+        GET_FIELD((T)->misc, TMDM, EXDEF),              \
+        GET_FIELD((T)->misc, TMDM, LCOL),               \
+        GET_FIELD((T)->misc, TMDM, LCAR),               \
+        GET_FIELD((T)->misc, TMDM, RTRY),               \
+        GET_FIELD((T)->misc, TMDM, TDR),                \
+        GET_FIELD((T)->misc, TMDM, TRC))
+
+#define PRINT_RMD(R) printf(                            \
+        "RMD0 : RBADR=0x%08x\n"                         \
+        "RMD1 : OWN=%d, ERR=%d, FRAM=%d, OFLO=%d, "     \
+        "CRC=%d, BUFF=%d, STP=%d, ENP=%d,\n       "     \
+        "BPE=%d, PAM=%d, LAFM=%d, BAM=%d, ONES=%d, BCNT=%d\n" \
+        "RMD2 : RCC=%d, RPC=%d, MCNT=%d, ZEROS=%d\n",   \
+        (R)->rbadr,                                     \
+        GET_FIELD((R)->status, RMDS, OWN),              \
+        GET_FIELD((R)->status, RMDS, ERR),              \
+        GET_FIELD((R)->status, RMDS, FRAM),             \
+        GET_FIELD((R)->status, RMDS, OFLO),             \
+        GET_FIELD((R)->status, RMDS, CRC),              \
+        GET_FIELD((R)->status, RMDS, BUFF),             \
+        GET_FIELD((R)->status, RMDS, STP),              \
+        GET_FIELD((R)->status, RMDS, ENP),              \
+        GET_FIELD((R)->status, RMDS, BPE),              \
+        GET_FIELD((R)->status, RMDS, PAM),              \
+        GET_FIELD((R)->status, RMDS, LFAM),             \
+        GET_FIELD((R)->status, RMDS, BAM),              \
+        GET_FIELD((R)->buf_length, RMDL, ONES),         \
+        4096-GET_FIELD((R)->buf_length, RMDL, BCNT),    \
+        GET_FIELD((R)->msg_length, RMDM, RCC),          \
+        GET_FIELD((R)->msg_length, RMDM, RPC),          \
+        GET_FIELD((R)->msg_length, RMDM, MCNT),         \
+        GET_FIELD((R)->msg_length, RMDM, ZEROS))
+
+static inline void pcnet_tmd_load(PCNetState *s, struct pcnet_TMD *tmd,
+                                  hwaddr addr)
+{
+    if (!BCR_SSIZE32(s)) {
+        struct {
+            uint32_t tbadr;
+            int16_t length;
+            int16_t status;
+       } xda;
+        s->phys_mem_read(s->dma_opaque, addr, (void *)&xda, sizeof(xda), 0);
+        tmd->tbadr = le32_to_cpu(xda.tbadr) & 0xffffff;
+        tmd->length = le16_to_cpu(xda.length);
+        tmd->status = (le32_to_cpu(xda.tbadr) >> 16) & 0xff00;
+        tmd->misc = le16_to_cpu(xda.status) << 16;
+        tmd->res = 0;
+    } else {
+        s->phys_mem_read(s->dma_opaque, addr, (void *)tmd, sizeof(*tmd), 0);
+        le32_to_cpus(&tmd->tbadr);
+        le16_to_cpus((uint16_t *)&tmd->length);
+        le16_to_cpus((uint16_t *)&tmd->status);
+        le32_to_cpus(&tmd->misc);
+        le32_to_cpus(&tmd->res);
+        if (BCR_SWSTYLE(s) == 3) {
+            uint32_t tmp = tmd->tbadr;
+            tmd->tbadr = tmd->misc;
+            tmd->misc = tmp;
+        }
+    }
+}
+
+static inline void pcnet_tmd_store(PCNetState *s, const struct pcnet_TMD *tmd,
+                                   hwaddr addr)
+{
+    if (!BCR_SSIZE32(s)) {
+        struct {
+            uint32_t tbadr;
+            int16_t length;
+            int16_t status;
+        } xda;
+        xda.tbadr = cpu_to_le32((tmd->tbadr & 0xffffff) |
+                                ((tmd->status & 0xff00) << 16));
+        xda.length = cpu_to_le16(tmd->length);
+        xda.status = cpu_to_le16(tmd->misc >> 16);
+        s->phys_mem_write(s->dma_opaque, addr, (void *)&xda, sizeof(xda), 0);
+    } else {
+        struct {
+            uint32_t tbadr;
+            int16_t length;
+            int16_t status;
+            uint32_t misc;
+            uint32_t res;
+        } xda;
+        xda.tbadr = cpu_to_le32(tmd->tbadr);
+        xda.length = cpu_to_le16(tmd->length);
+        xda.status = cpu_to_le16(tmd->status);
+        xda.misc = cpu_to_le32(tmd->misc);
+        xda.res = cpu_to_le32(tmd->res);
+        if (BCR_SWSTYLE(s) == 3) {
+            uint32_t tmp = xda.tbadr;
+            xda.tbadr = xda.misc;
+            xda.misc = tmp;
+        }
+        s->phys_mem_write(s->dma_opaque, addr, (void *)&xda, sizeof(xda), 0);
+    }
+}
+
+static inline void pcnet_rmd_load(PCNetState *s, struct pcnet_RMD *rmd,
+                                  hwaddr addr)
+{
+    if (!BCR_SSIZE32(s)) {
+        struct {
+            uint32_t rbadr;
+            int16_t buf_length;
+            int16_t msg_length;
+       } rda;
+        s->phys_mem_read(s->dma_opaque, addr, (void *)&rda, sizeof(rda), 0);
+        rmd->rbadr = le32_to_cpu(rda.rbadr) & 0xffffff;
+        rmd->buf_length = le16_to_cpu(rda.buf_length);
+        rmd->status = (le32_to_cpu(rda.rbadr) >> 16) & 0xff00;
+        rmd->msg_length = le16_to_cpu(rda.msg_length);
+        rmd->res = 0;
+    } else {
+        s->phys_mem_read(s->dma_opaque, addr, (void *)rmd, sizeof(*rmd), 0);
+        le32_to_cpus(&rmd->rbadr);
+        le16_to_cpus((uint16_t *)&rmd->buf_length);
+        le16_to_cpus((uint16_t *)&rmd->status);
+        le32_to_cpus(&rmd->msg_length);
+        le32_to_cpus(&rmd->res);
+        if (BCR_SWSTYLE(s) == 3) {
+            uint32_t tmp = rmd->rbadr;
+            rmd->rbadr = rmd->msg_length;
+            rmd->msg_length = tmp;
+        }
+    }
+}
+
+static inline void pcnet_rmd_store(PCNetState *s, struct pcnet_RMD *rmd,
+                                   hwaddr addr)
+{
+    if (!BCR_SSIZE32(s)) {
+        struct {
+            uint32_t rbadr;
+            int16_t buf_length;
+            int16_t msg_length;
+        } rda;
+        rda.rbadr = cpu_to_le32((rmd->rbadr & 0xffffff) |
+                                ((rmd->status & 0xff00) << 16));
+        rda.buf_length = cpu_to_le16(rmd->buf_length);
+        rda.msg_length = cpu_to_le16(rmd->msg_length);
+        s->phys_mem_write(s->dma_opaque, addr, (void *)&rda, sizeof(rda), 0);
+    } else {
+        struct {
+            uint32_t rbadr;
+            int16_t buf_length;
+            int16_t status;
+            uint32_t msg_length;
+            uint32_t res;
+        } rda;
+        rda.rbadr = cpu_to_le32(rmd->rbadr);
+        rda.buf_length = cpu_to_le16(rmd->buf_length);
+        rda.status = cpu_to_le16(rmd->status);
+        rda.msg_length = cpu_to_le32(rmd->msg_length);
+        rda.res = cpu_to_le32(rmd->res);
+        if (BCR_SWSTYLE(s) == 3) {
+            uint32_t tmp = rda.rbadr;
+            rda.rbadr = rda.msg_length;
+            rda.msg_length = tmp;
+        }
+        s->phys_mem_write(s->dma_opaque, addr, (void *)&rda, sizeof(rda), 0);
+    }
+}
+
+
+#define TMDLOAD(TMD,ADDR) pcnet_tmd_load(s,TMD,ADDR)
+
+#define TMDSTORE(TMD,ADDR) pcnet_tmd_store(s,TMD,ADDR)
+
+#define RMDLOAD(RMD,ADDR) pcnet_rmd_load(s,RMD,ADDR)
+
+#define RMDSTORE(RMD,ADDR) pcnet_rmd_store(s,RMD,ADDR)
+
+#if 1
+
+#define CHECK_RMD(ADDR,RES) do {                \
+    struct pcnet_RMD rmd;                       \
+    RMDLOAD(&rmd,(ADDR));                       \
+    (RES) |= (GET_FIELD(rmd.buf_length, RMDL, ONES) != 15) \
+          || (GET_FIELD(rmd.msg_length, RMDM, ZEROS) != 0); \
+} while (0)
+
+#define CHECK_TMD(ADDR,RES) do {                \
+    struct pcnet_TMD tmd;                       \
+    TMDLOAD(&tmd,(ADDR));                       \
+    (RES) |= (GET_FIELD(tmd.length, TMDL, ONES) != 15); \
+} while (0)
+
+#else
+
+#define CHECK_RMD(ADDR,RES) do {                \
+    switch (BCR_SWSTYLE(s)) {                   \
+    case 0x00:                                  \
+        do {                                    \
+            uint16_t rda[4];                    \
+            s->phys_mem_read(s->dma_opaque, (ADDR), \
+                (void *)&rda[0], sizeof(rda), 0); \
+            (RES) |= (rda[2] & 0xf000)!=0xf000; \
+            (RES) |= (rda[3] & 0xf000)!=0x0000; \
+        } while (0);                            \
+        break;                                  \
+    case 0x01:                                  \
+    case 0x02:                                  \
+        do {                                    \
+            uint32_t rda[4];                    \
+            s->phys_mem_read(s->dma_opaque, (ADDR), \
+                (void *)&rda[0], sizeof(rda), 0); \
+            (RES) |= (rda[1] & 0x0000f000L)!=0x0000f000L; \
+            (RES) |= (rda[2] & 0x0000f000L)!=0x00000000L; \
+        } while (0);                            \
+        break;                                  \
+    case 0x03:                                  \
+        do {                                    \
+            uint32_t rda[4];                    \
+            s->phys_mem_read(s->dma_opaque, (ADDR), \
+                (void *)&rda[0], sizeof(rda), 0); \
+            (RES) |= (rda[0] & 0x0000f000L)!=0x00000000L; \
+            (RES) |= (rda[1] & 0x0000f000L)!=0x0000f000L; \
+        } while (0);                            \
+        break;                                  \
+    }                                           \
+} while (0)
+
+#define CHECK_TMD(ADDR,RES) do {                \
+    switch (BCR_SWSTYLE(s)) {                   \
+    case 0x00:                                  \
+        do {                                    \
+            uint16_t xda[4];                    \
+            s->phys_mem_read(s->dma_opaque, (ADDR), \
+                (void *)&xda[0], sizeof(xda), 0); \
+            (RES) |= (xda[2] & 0xf000)!=0xf000; \
+        } while (0);                            \
+        break;                                  \
+    case 0x01:                                  \
+    case 0x02:                                  \
+    case 0x03:                                  \
+        do {                                    \
+            uint32_t xda[4];                    \
+            s->phys_mem_read(s->dma_opaque, (ADDR), \
+                (void *)&xda[0], sizeof(xda), 0); \
+            (RES) |= (xda[1] & 0x0000f000L)!=0x0000f000L; \
+        } while (0);                            \
+        break;                                  \
+    }                                           \
+} while (0)
+
+#endif
+
+#define PRINT_PKTHDR(BUF) do {                  \
+    struct qemu_ether_header *hdr = (void *)(BUF); \
+    printf("packet dhost=%02x:%02x:%02x:%02x:%02x:%02x, " \
+           "shost=%02x:%02x:%02x:%02x:%02x:%02x, " \
+           "type=0x%04x\n",                     \
+           hdr->ether_dhost[0],hdr->ether_dhost[1],hdr->ether_dhost[2], \
+           hdr->ether_dhost[3],hdr->ether_dhost[4],hdr->ether_dhost[5], \
+           hdr->ether_shost[0],hdr->ether_shost[1],hdr->ether_shost[2], \
+           hdr->ether_shost[3],hdr->ether_shost[4],hdr->ether_shost[5], \
+           be16_to_cpu(hdr->ether_type));       \
+} while (0)
+
+#define MULTICAST_FILTER_LEN 8
+
+static inline uint32_t lnc_mchash(const uint8_t *ether_addr)
+{
+#define LNC_POLYNOMIAL          0xEDB88320UL
+    uint32_t crc = 0xFFFFFFFF;
+    int idx, bit;
+    uint8_t data;
+
+    for (idx = 0; idx < 6; idx++) {
+        for (data = *ether_addr++, bit = 0; bit < MULTICAST_FILTER_LEN; bit++) {
+            crc = (crc >> 1) ^ (((crc ^ data) & 1) ? LNC_POLYNOMIAL : 0);
+            data >>= 1;
+        }
+    }
+    return crc;
+#undef LNC_POLYNOMIAL
+}
+
+#define CRC(crc, ch)    (crc = (crc >> 8) ^ crctab[(crc ^ (ch)) & 0xff])
+
+/* generated using the AUTODIN II polynomial
+ *     x^32 + x^26 + x^23 + x^22 + x^16 +
+ *     x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + 1
+ */
+static const uint32_t crctab[256] = {
+       0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+       0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+       0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+       0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+       0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+       0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+       0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+       0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+       0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+       0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+       0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+       0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+       0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+       0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+       0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+       0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+       0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+       0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+       0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+       0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+       0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+       0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+       0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+       0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+       0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+       0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+       0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+       0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+       0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+       0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+       0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+       0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+       0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+       0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+       0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+       0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+       0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+       0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+       0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+       0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+       0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+       0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+       0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+       0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+       0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+       0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+       0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+       0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+       0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+       0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+       0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+       0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+       0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+       0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+       0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+       0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+       0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+       0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+       0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+       0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+       0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+       0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+       0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+       0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
+};
+
+static inline int padr_match(PCNetState *s, const uint8_t *buf, int size)
+{
+    struct qemu_ether_header *hdr = (void *)buf;
+    uint8_t padr[6] = {
+        s->csr[12] & 0xff, s->csr[12] >> 8,
+        s->csr[13] & 0xff, s->csr[13] >> 8,
+        s->csr[14] & 0xff, s->csr[14] >> 8
+    };
+    int result = (!CSR_DRCVPA(s)) && !memcmp(hdr->ether_dhost, padr, 6);
+#ifdef PCNET_DEBUG_MATCH
+    printf("packet dhost=%02x:%02x:%02x:%02x:%02x:%02x, "
+           "padr=%02x:%02x:%02x:%02x:%02x:%02x\n",
+           hdr->ether_dhost[0],hdr->ether_dhost[1],hdr->ether_dhost[2],
+           hdr->ether_dhost[3],hdr->ether_dhost[4],hdr->ether_dhost[5],
+           padr[0],padr[1],padr[2],padr[3],padr[4],padr[5]);
+    printf("padr_match result=%d\n", result);
+#endif
+    return result;
+}
+
+static inline int padr_bcast(PCNetState *s, const uint8_t *buf, int size)
+{
+    static const uint8_t BCAST[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+    struct qemu_ether_header *hdr = (void *)buf;
+    int result = !CSR_DRCVBC(s) && !memcmp(hdr->ether_dhost, BCAST, 6);
+#ifdef PCNET_DEBUG_MATCH
+    printf("padr_bcast result=%d\n", result);
+#endif
+    return result;
+}
+
+static inline int ladr_match(PCNetState *s, const uint8_t *buf, int size)
+{
+    struct qemu_ether_header *hdr = (void *)buf;
+    if ((*(hdr->ether_dhost)&0x01) &&
+        ((uint64_t *)&s->csr[8])[0] != 0LL) {
+        uint8_t ladr[8] = {
+            s->csr[8] & 0xff, s->csr[8] >> 8,
+            s->csr[9] & 0xff, s->csr[9] >> 8,
+            s->csr[10] & 0xff, s->csr[10] >> 8,
+            s->csr[11] & 0xff, s->csr[11] >> 8
+        };
+        int index = lnc_mchash(hdr->ether_dhost) >> 26;
+        return !!(ladr[index >> 3] & (1 << (index & 7)));
+    }
+    return 0;
+}
+
+static inline hwaddr pcnet_rdra_addr(PCNetState *s, int idx)
+{
+    while (idx < 1) idx += CSR_RCVRL(s);
+    return s->rdra + ((CSR_RCVRL(s) - idx) * (BCR_SWSTYLE(s) ? 16 : 8));
+}
+
+static inline int64_t pcnet_get_next_poll_time(PCNetState *s, int64_t current_time)
+{
+    int64_t next_time = current_time +
+        muldiv64(65536 - (CSR_SPND(s) ? 0 : CSR_POLL(s)),
+                 get_ticks_per_sec(), 33000000L);
+    if (next_time <= current_time)
+        next_time = current_time + 1;
+    return next_time;
+}
+
+static void pcnet_poll(PCNetState *s);
+static void pcnet_poll_timer(void *opaque);
+
+static uint32_t pcnet_csr_readw(PCNetState *s, uint32_t rap);
+static void pcnet_csr_writew(PCNetState *s, uint32_t rap, uint32_t new_value);
+static void pcnet_bcr_writew(PCNetState *s, uint32_t rap, uint32_t val);
+
+static void pcnet_s_reset(PCNetState *s)
+{
+    trace_pcnet_s_reset(s);
+
+    s->rdra = 0;
+    s->tdra = 0;
+    s->rap = 0;
+
+    s->bcr[BCR_BSBC] &= ~0x0080;
+
+    s->csr[0]   = 0x0004;
+    s->csr[3]   = 0x0000;
+    s->csr[4]   = 0x0115;
+    s->csr[5]   = 0x0000;
+    s->csr[6]   = 0x0000;
+    s->csr[8]   = 0;
+    s->csr[9]   = 0;
+    s->csr[10]  = 0;
+    s->csr[11]  = 0;
+    s->csr[12]  = le16_to_cpu(((uint16_t *)&s->prom[0])[0]);
+    s->csr[13]  = le16_to_cpu(((uint16_t *)&s->prom[0])[1]);
+    s->csr[14]  = le16_to_cpu(((uint16_t *)&s->prom[0])[2]);
+    s->csr[15] &= 0x21c4;
+    s->csr[72]  = 1;
+    s->csr[74]  = 1;
+    s->csr[76]  = 1;
+    s->csr[78]  = 1;
+    s->csr[80]  = 0x1410;
+    s->csr[88]  = 0x1003;
+    s->csr[89]  = 0x0262;
+    s->csr[94]  = 0x0000;
+    s->csr[100] = 0x0200;
+    s->csr[103] = 0x0105;
+    s->csr[112] = 0x0000;
+    s->csr[114] = 0x0000;
+    s->csr[122] = 0x0000;
+    s->csr[124] = 0x0000;
+
+    s->tx_busy = 0;
+}
+
+static void pcnet_update_irq(PCNetState *s)
+{
+    int isr = 0;
+    s->csr[0] &= ~0x0080;
+
+#if 1
+    if (((s->csr[0] & ~s->csr[3]) & 0x5f00) ||
+        (((s->csr[4]>>1) & ~s->csr[4]) & 0x0115) ||
+        (((s->csr[5]>>1) & s->csr[5]) & 0x0048))
+#else
+    if ((!(s->csr[3] & 0x4000) && !!(s->csr[0] & 0x4000)) /* BABL */ ||
+        (!(s->csr[3] & 0x1000) && !!(s->csr[0] & 0x1000)) /* MISS */ ||
+        (!(s->csr[3] & 0x0100) && !!(s->csr[0] & 0x0100)) /* IDON */ ||
+        (!(s->csr[3] & 0x0200) && !!(s->csr[0] & 0x0200)) /* TINT */ ||
+        (!(s->csr[3] & 0x0400) && !!(s->csr[0] & 0x0400)) /* RINT */ ||
+        (!(s->csr[3] & 0x0800) && !!(s->csr[0] & 0x0800)) /* MERR */ ||
+        (!(s->csr[4] & 0x0001) && !!(s->csr[4] & 0x0002)) /* JAB */ ||
+        (!(s->csr[4] & 0x0004) && !!(s->csr[4] & 0x0008)) /* TXSTRT */ ||
+        (!(s->csr[4] & 0x0010) && !!(s->csr[4] & 0x0020)) /* RCVO */ ||
+        (!(s->csr[4] & 0x0100) && !!(s->csr[4] & 0x0200)) /* MFCO */ ||
+        (!!(s->csr[5] & 0x0040) && !!(s->csr[5] & 0x0080)) /* EXDINT */ ||
+        (!!(s->csr[5] & 0x0008) && !!(s->csr[5] & 0x0010)) /* MPINT */)
+#endif
+    {
+
+        isr = CSR_INEA(s);
+        s->csr[0] |= 0x0080;
+    }
+
+    if (!!(s->csr[4] & 0x0080) && CSR_INEA(s)) { /* UINT */
+        s->csr[4] &= ~0x0080;
+        s->csr[4] |= 0x0040;
+        s->csr[0] |= 0x0080;
+        isr = 1;
+        trace_pcnet_user_int(s);
+    }
+
+#if 1
+    if (((s->csr[5]>>1) & s->csr[5]) & 0x0500)
+#else
+    if ((!!(s->csr[5] & 0x0400) && !!(s->csr[5] & 0x0800)) /* SINT */ ||
+        (!!(s->csr[5] & 0x0100) && !!(s->csr[5] & 0x0200)) /* SLPINT */ )
+#endif
+    {
+        isr = 1;
+        s->csr[0] |= 0x0080;
+    }
+
+    if (isr != s->isr) {
+        trace_pcnet_isr_change(s, isr, s->isr);
+    }
+    qemu_set_irq(s->irq, isr);
+    s->isr = isr;
+}
+
+static void pcnet_init(PCNetState *s)
+{
+    int rlen, tlen;
+    uint16_t padr[3], ladrf[4], mode;
+    uint32_t rdra, tdra;
+
+    trace_pcnet_init(s, PHYSADDR(s, CSR_IADR(s)));
+
+    if (BCR_SSIZE32(s)) {
+        struct pcnet_initblk32 initblk;
+        s->phys_mem_read(s->dma_opaque, PHYSADDR(s,CSR_IADR(s)),
+                (uint8_t *)&initblk, sizeof(initblk), 0);
+        mode = le16_to_cpu(initblk.mode);
+        rlen = initblk.rlen >> 4;
+        tlen = initblk.tlen >> 4;
+       ladrf[0] = le16_to_cpu(initblk.ladrf[0]);
+       ladrf[1] = le16_to_cpu(initblk.ladrf[1]);
+       ladrf[2] = le16_to_cpu(initblk.ladrf[2]);
+       ladrf[3] = le16_to_cpu(initblk.ladrf[3]);
+       padr[0] = le16_to_cpu(initblk.padr[0]);
+       padr[1] = le16_to_cpu(initblk.padr[1]);
+       padr[2] = le16_to_cpu(initblk.padr[2]);
+        rdra = le32_to_cpu(initblk.rdra);
+        tdra = le32_to_cpu(initblk.tdra);
+    } else {
+        struct pcnet_initblk16 initblk;
+        s->phys_mem_read(s->dma_opaque, PHYSADDR(s,CSR_IADR(s)),
+                (uint8_t *)&initblk, sizeof(initblk), 0);
+        mode = le16_to_cpu(initblk.mode);
+       ladrf[0] = le16_to_cpu(initblk.ladrf[0]);
+       ladrf[1] = le16_to_cpu(initblk.ladrf[1]);
+       ladrf[2] = le16_to_cpu(initblk.ladrf[2]);
+       ladrf[3] = le16_to_cpu(initblk.ladrf[3]);
+       padr[0] = le16_to_cpu(initblk.padr[0]);
+       padr[1] = le16_to_cpu(initblk.padr[1]);
+       padr[2] = le16_to_cpu(initblk.padr[2]);
+        rdra = le32_to_cpu(initblk.rdra);
+        tdra = le32_to_cpu(initblk.tdra);
+        rlen = rdra >> 29;
+        tlen = tdra >> 29;
+        rdra &= 0x00ffffff;
+        tdra &= 0x00ffffff;
+    }
+
+    trace_pcnet_rlen_tlen(s, rlen, tlen);
+
+    CSR_RCVRL(s) = (rlen < 9) ? (1 << rlen) : 512;
+    CSR_XMTRL(s) = (tlen < 9) ? (1 << tlen) : 512;
+    s->csr[ 6] = (tlen << 12) | (rlen << 8);
+    s->csr[15] = mode;
+    s->csr[ 8] = ladrf[0];
+    s->csr[ 9] = ladrf[1];
+    s->csr[10] = ladrf[2];
+    s->csr[11] = ladrf[3];
+    s->csr[12] = padr[0];
+    s->csr[13] = padr[1];
+    s->csr[14] = padr[2];
+    s->rdra = PHYSADDR(s, rdra);
+    s->tdra = PHYSADDR(s, tdra);
+
+    CSR_RCVRC(s) = CSR_RCVRL(s);
+    CSR_XMTRC(s) = CSR_XMTRL(s);
+
+    trace_pcnet_ss32_rdra_tdra(s, BCR_SSIZE32(s),
+                               s->rdra, CSR_RCVRL(s), s->tdra, CSR_XMTRL(s));
+
+    s->csr[0] |= 0x0101;
+    s->csr[0] &= ~0x0004;       /* clear STOP bit */
+
+    qemu_flush_queued_packets(qemu_get_queue(s->nic));
+}
+
+static void pcnet_start(PCNetState *s)
+{
+#ifdef PCNET_DEBUG
+    printf("pcnet_start\n");
+#endif
+
+    if (!CSR_DTX(s))
+        s->csr[0] |= 0x0010;    /* set TXON */
+
+    if (!CSR_DRX(s))
+        s->csr[0] |= 0x0020;    /* set RXON */
+
+    s->csr[0] &= ~0x0004;       /* clear STOP bit */
+    s->csr[0] |= 0x0002;
+    pcnet_poll_timer(s);
+
+    qemu_flush_queued_packets(qemu_get_queue(s->nic));
+}
+
+static void pcnet_stop(PCNetState *s)
+{
+#ifdef PCNET_DEBUG
+    printf("pcnet_stop\n");
+#endif
+    s->csr[0] &= ~0xffeb;
+    s->csr[0] |= 0x0014;
+    s->csr[4] &= ~0x02c2;
+    s->csr[5] &= ~0x0011;
+    pcnet_poll_timer(s);
+}
+
+static void pcnet_rdte_poll(PCNetState *s)
+{
+    s->csr[28] = s->csr[29] = 0;
+    if (s->rdra) {
+        int bad = 0;
+#if 1
+        hwaddr crda = pcnet_rdra_addr(s, CSR_RCVRC(s));
+        hwaddr nrda = pcnet_rdra_addr(s, -1 + CSR_RCVRC(s));
+        hwaddr nnrd = pcnet_rdra_addr(s, -2 + CSR_RCVRC(s));
+#else
+        hwaddr crda = s->rdra +
+            (CSR_RCVRL(s) - CSR_RCVRC(s)) *
+            (BCR_SWSTYLE(s) ? 16 : 8 );
+        int nrdc = CSR_RCVRC(s)<=1 ? CSR_RCVRL(s) : CSR_RCVRC(s)-1;
+        hwaddr nrda = s->rdra +
+            (CSR_RCVRL(s) - nrdc) *
+            (BCR_SWSTYLE(s) ? 16 : 8 );
+        int nnrc = nrdc<=1 ? CSR_RCVRL(s) : nrdc-1;
+        hwaddr nnrd = s->rdra +
+            (CSR_RCVRL(s) - nnrc) *
+            (BCR_SWSTYLE(s) ? 16 : 8 );
+#endif
+
+        CHECK_RMD(crda, bad);
+        if (!bad) {
+            CHECK_RMD(nrda, bad);
+            if (bad || (nrda == crda)) nrda = 0;
+            CHECK_RMD(nnrd, bad);
+            if (bad || (nnrd == crda)) nnrd = 0;
+
+            s->csr[28] = crda & 0xffff;
+            s->csr[29] = crda >> 16;
+            s->csr[26] = nrda & 0xffff;
+            s->csr[27] = nrda >> 16;
+            s->csr[36] = nnrd & 0xffff;
+            s->csr[37] = nnrd >> 16;
+#ifdef PCNET_DEBUG
+            if (bad) {
+                printf("pcnet: BAD RMD RECORDS AFTER 0x" TARGET_FMT_plx "\n",
+                       crda);
+            }
+        } else {
+            printf("pcnet: BAD RMD RDA=0x" TARGET_FMT_plx "\n",
+                   crda);
+#endif
+        }
+    }
+
+    if (CSR_CRDA(s)) {
+        struct pcnet_RMD rmd;
+        RMDLOAD(&rmd, PHYSADDR(s,CSR_CRDA(s)));
+        CSR_CRBC(s) = GET_FIELD(rmd.buf_length, RMDL, BCNT);
+        CSR_CRST(s) = rmd.status;
+#ifdef PCNET_DEBUG_RMD_X
+        printf("CRDA=0x%08x CRST=0x%04x RCVRC=%d RMDL=0x%04x RMDS=0x%04x RMDM=0x%08x\n",
+                PHYSADDR(s,CSR_CRDA(s)), CSR_CRST(s), CSR_RCVRC(s),
+                rmd.buf_length, rmd.status, rmd.msg_length);
+        PRINT_RMD(&rmd);
+#endif
+    } else {
+        CSR_CRBC(s) = CSR_CRST(s) = 0;
+    }
+
+    if (CSR_NRDA(s)) {
+        struct pcnet_RMD rmd;
+        RMDLOAD(&rmd, PHYSADDR(s,CSR_NRDA(s)));
+        CSR_NRBC(s) = GET_FIELD(rmd.buf_length, RMDL, BCNT);
+        CSR_NRST(s) = rmd.status;
+    } else {
+        CSR_NRBC(s) = CSR_NRST(s) = 0;
+    }
+
+}
+
+static int pcnet_tdte_poll(PCNetState *s)
+{
+    s->csr[34] = s->csr[35] = 0;
+    if (s->tdra) {
+        hwaddr cxda = s->tdra +
+            (CSR_XMTRL(s) - CSR_XMTRC(s)) *
+            (BCR_SWSTYLE(s) ? 16 : 8);
+        int bad = 0;
+        CHECK_TMD(cxda, bad);
+        if (!bad) {
+            if (CSR_CXDA(s) != cxda) {
+                s->csr[60] = s->csr[34];
+                s->csr[61] = s->csr[35];
+                s->csr[62] = CSR_CXBC(s);
+                s->csr[63] = CSR_CXST(s);
+            }
+            s->csr[34] = cxda & 0xffff;
+            s->csr[35] = cxda >> 16;
+#ifdef PCNET_DEBUG_X
+            printf("pcnet: BAD TMD XDA=0x%08x\n", cxda);
+#endif
+        }
+    }
+
+    if (CSR_CXDA(s)) {
+        struct pcnet_TMD tmd;
+
+        TMDLOAD(&tmd, PHYSADDR(s,CSR_CXDA(s)));
+
+        CSR_CXBC(s) = GET_FIELD(tmd.length, TMDL, BCNT);
+        CSR_CXST(s) = tmd.status;
+    } else {
+        CSR_CXBC(s) = CSR_CXST(s) = 0;
+    }
+
+    return !!(CSR_CXST(s) & 0x8000);
+}
+
+#define MIN_BUF_SIZE 60
+
+ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
+{
+    PCNetState *s = qemu_get_nic_opaque(nc);
+    int is_padr = 0, is_bcast = 0, is_ladr = 0;
+    uint8_t buf1[60];
+    int remaining;
+    int crc_err = 0;
+    int size = size_;
+
+    if (CSR_DRX(s) || CSR_STOP(s) || CSR_SPND(s) || !size ||
+        (CSR_LOOP(s) && !s->looptest)) {
+        return -1;
+    }
+#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;
+            hwaddr 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, nrda);
+                if (GET_FIELD(rmd.status, RMDS, 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;
+            hwaddr crda = CSR_CRDA(s);
+            struct pcnet_RMD rmd;
+            int pktcount = 0;
+
+            if (!s->looptest) {
+                memcpy(src, buf, size);
+                /* no need to compute the CRC */
+                src[size] = 0;
+                src[size + 1] = 0;
+                src[size + 2] = 0;
+                src[size + 3] = 0;
+                size += 4;
+            } else if (s->looptest == PCNET_LOOPTEST_CRC ||
+                       !CSR_DXMTFCS(s) || size < MIN_BUF_SIZE+4) {
+                uint32_t fcs = ~0;
+                uint8_t *p = src;
+
+                while (p != &src[size])
+                    CRC(fcs, *p++);
+                *(uint32_t *)p = htonl(fcs);
+                size += 4;
+            } else {
+                uint32_t fcs = ~0;
+                uint8_t *p = src;
+
+                while (p != &src[size-4])
+                    CRC(fcs, *p++);
+                crc_err = (*(uint32_t *)p != htonl(fcs));
+            }
+
+#ifdef PCNET_DEBUG_MATCH
+            PRINT_PKTHDR(buf);
+#endif
+
+            RMDLOAD(&rmd, PHYSADDR(s,crda));
+            /*if (!CSR_LAPPEN(s))*/
+                SET_FIELD(&rmd.status, RMDS, STP, 1);
+
+#define PCNET_RECV_STORE() do {                                 \
+    int count = MIN(4096 - GET_FIELD(rmd.buf_length, RMDL, BCNT),remaining); \
+    hwaddr rbadr = PHYSADDR(s, rmd.rbadr);          \
+    s->phys_mem_write(s->dma_opaque, rbadr, src, count, CSR_BSWP(s)); \
+    src += count; remaining -= count;                           \
+    SET_FIELD(&rmd.status, RMDS, OWN, 0);                       \
+    RMDSTORE(&rmd, PHYSADDR(s,crda));                           \
+    pktcount++;                                                 \
+} while (0)
+
+            remaining = size;
+            PCNET_RECV_STORE();
+            if ((remaining > 0) && CSR_NRDA(s)) {
+                hwaddr nrda = CSR_NRDA(s);
+#ifdef PCNET_DEBUG_RMD
+                PRINT_RMD(&rmd);
+#endif
+                RMDLOAD(&rmd, PHYSADDR(s,nrda));
+                if (GET_FIELD(rmd.status, RMDS, OWN)) {
+                    crda = nrda;
+                    PCNET_RECV_STORE();
+#ifdef PCNET_DEBUG_RMD
+                    PRINT_RMD(&rmd);
+#endif
+                    if ((remaining > 0) && (nrda=CSR_NNRD(s))) {
+                        RMDLOAD(&rmd, PHYSADDR(s,nrda));
+                        if (GET_FIELD(rmd.status, RMDS, OWN)) {
+                            crda = nrda;
+                            PCNET_RECV_STORE();
+                        }
+                    }
+                }
+            }
+
+#undef PCNET_RECV_STORE
+
+            RMDLOAD(&rmd, PHYSADDR(s,crda));
+            if (remaining == 0) {
+                SET_FIELD(&rmd.msg_length, RMDM, MCNT, size);
+                SET_FIELD(&rmd.status, RMDS, ENP, 1);
+                SET_FIELD(&rmd.status, RMDS, PAM, !CSR_PROM(s) && is_padr);
+                SET_FIELD(&rmd.status, RMDS, LFAM, !CSR_PROM(s) && is_ladr);
+                SET_FIELD(&rmd.status, RMDS, BAM, !CSR_PROM(s) && is_bcast);
+                if (crc_err) {
+                    SET_FIELD(&rmd.status, RMDS, CRC, 1);
+                    SET_FIELD(&rmd.status, RMDS, ERR, 1);
+                }
+            } else {
+                SET_FIELD(&rmd.status, RMDS, OFLO, 1);
+                SET_FIELD(&rmd.status, RMDS, BUFF, 1);
+                SET_FIELD(&rmd.status, RMDS, 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);
+
+    return size_;
+}
+
+void pcnet_set_link_status(NetClientState *nc)
+{
+    PCNetState *d = qemu_get_nic_opaque(nc);
+
+    d->lnkst = nc->link_down ? 0 : 0x40;
+}
+
+static void pcnet_transmit(PCNetState *s)
+{
+    hwaddr xmit_cxda = 0;
+    int count = CSR_XMTRL(s)-1;
+    int add_crc = 0;
+    int bcnt;
+    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 (GET_FIELD(tmd.status, TMDS, STP)) {
+            s->xmit_pos = 0;
+            xmit_cxda = PHYSADDR(s,CSR_CXDA(s));
+            if (BCR_SWSTYLE(s) != 1)
+                add_crc = GET_FIELD(tmd.status, TMDS, ADDFCS);
+        }
+        if (s->lnkst == 0 &&
+            (!CSR_LOOP(s) || (!CSR_INTL(s) && !BCR_TMAULOOP(s)))) {
+            SET_FIELD(&tmd.misc, TMDM, LCAR, 1);
+            SET_FIELD(&tmd.status, TMDS, ERR, 1);
+            SET_FIELD(&tmd.status, TMDS, OWN, 0);
+            s->csr[0] |= 0xa000; /* ERR | CERR */
+            s->xmit_pos = -1;
+            goto txdone;
+        }
+
+        if (s->xmit_pos < 0) {
+            goto txdone;
+        }
+
+        bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
+
+        /* if multi-tmd packet outsizes s->buffer then skip it silently.
+           Note: this is not what real hw does */
+        if (s->xmit_pos + bcnt > sizeof(s->buffer)) {
+            s->xmit_pos = -1;
+            goto txdone;
+        }
+
+        s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
+                         s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
+        s->xmit_pos += bcnt;
+        
+        if (!GET_FIELD(tmd.status, TMDS, ENP)) {
+            goto txdone;
+        }
+
+#ifdef PCNET_DEBUG
+        printf("pcnet_transmit size=%d\n", s->xmit_pos);
+#endif
+        if (CSR_LOOP(s)) {
+            if (BCR_SWSTYLE(s) == 1)
+                add_crc = !GET_FIELD(tmd.status, TMDS, NOFCS);
+            s->looptest = add_crc ? PCNET_LOOPTEST_CRC : PCNET_LOOPTEST_NOCRC;
+            pcnet_receive(qemu_get_queue(s->nic), s->buffer, s->xmit_pos);
+            s->looptest = 0;
+        } else {
+            if (s->nic) {
+                qemu_send_packet(qemu_get_queue(s->nic), s->buffer,
+                                 s->xmit_pos);
+            }
+        }
+
+        s->csr[0] &= ~0x0008;   /* clear TDMD */
+        s->csr[4] |= 0x0004;    /* set TXSTRT */
+        s->xmit_pos = -1;
+
+    txdone:
+        SET_FIELD(&tmd.status, TMDS, OWN, 0);
+        TMDSTORE(&tmd, PHYSADDR(s,CSR_CXDA(s)));
+        if (!CSR_TOKINTD(s) || (CSR_LTINTEN(s) && GET_FIELD(tmd.status, TMDS, 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, xmit_cxda);
+        SET_FIELD(&tmd.misc, TMDM, BUFF, 1);
+        SET_FIELD(&tmd.misc, TMDM, UFLO, 1);
+        SET_FIELD(&tmd.status, TMDS, ERR, 1);
+        SET_FIELD(&tmd.status, TMDS, OWN, 0);
+        TMDSTORE(&tmd, 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;
+
+    timer_del(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_clock_get_ns(QEMU_CLOCK_VIRTUAL) * 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;
+        }
+        timer_mod(s->poll_timer,
+            pcnet_get_next_poll_time(s,qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)));
+    }
+}
+
+
+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
+        /* fall through */
+    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;
+    }
+}
+
+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;
+
+    s->bcr[BCR_MSRDA] = 0x0005;
+    s->bcr[BCR_MSWRA] = 0x0005;
+    s->bcr[BCR_MC   ] = 0x0002;
+    s->bcr[BCR_LNKST] = 0x00c0;
+    s->bcr[BCR_LED1 ] = 0x0084;
+    s->bcr[BCR_LED2 ] = 0x0088;
+    s->bcr[BCR_LED3 ] = 0x0090;
+    s->bcr[BCR_FDC  ] = 0x0000;
+    s->bcr[BCR_BSBC ] = 0x9001;
+    s->bcr[BCR_EECAS] = 0x0002;
+    s->bcr[BCR_SWS  ] = 0x0200;
+    s->bcr[BCR_PLAT ] = 0xff06;
+
+    pcnet_s_reset(s);
+    pcnet_update_irq(s);
+    pcnet_poll_timer(s);
+}
+
+void pcnet_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
+{
+    PCNetState *s = opaque;
+    pcnet_poll_timer(s);
+#ifdef PCNET_DEBUG_IO
+    printf("pcnet_ioport_writew addr=0x%08x val=0x%04x\n", addr, val);
+#endif
+    if (!BCR_DWIO(s)) {
+        switch (addr & 0x0f) {
+        case 0x00: /* RDP */
+            pcnet_csr_writew(s, s->rap, val);
+            break;
+        case 0x02:
+            s->rap = val & 0x7f;
+            break;
+        case 0x06:
+            pcnet_bcr_writew(s, s->rap, val);
+            break;
+        }
+    }
+    pcnet_update_irq(s);
+}
+
+uint32_t pcnet_ioport_readw(void *opaque, uint32_t addr)
+{
+    PCNetState *s = opaque;
+    uint32_t val = -1;
+    pcnet_poll_timer(s);
+    if (!BCR_DWIO(s)) {
+        switch (addr & 0x0f) {
+        case 0x00: /* RDP */
+            val = pcnet_csr_readw(s, s->rap);
+            break;
+        case 0x02:
+            val = s->rap;
+            break;
+        case 0x04:
+            pcnet_s_reset(s);
+            val = 0;
+            break;
+        case 0x06:
+            val = pcnet_bcr_readw(s, s->rap);
+            break;
+        }
+    }
+    pcnet_update_irq(s);
+#ifdef PCNET_DEBUG_IO
+    printf("pcnet_ioport_readw addr=0x%08x val=0x%04x\n", addr, val & 0xffff);
+#endif
+    return val;
+}
+
+void pcnet_ioport_writel(void *opaque, uint32_t addr, uint32_t val)
+{
+    PCNetState *s = opaque;
+    pcnet_poll_timer(s);
+#ifdef PCNET_DEBUG_IO
+    printf("pcnet_ioport_writel addr=0x%08x val=0x%08x\n", addr, val);
+#endif
+    if (BCR_DWIO(s)) {
+        switch (addr & 0x0f) {
+        case 0x00: /* RDP */
+            pcnet_csr_writew(s, s->rap, val & 0xffff);
+            break;
+        case 0x04:
+            s->rap = val & 0x7f;
+            break;
+        case 0x0c:
+            pcnet_bcr_writew(s, s->rap, val & 0xffff);
+            break;
+        }
+    } else
+    if ((addr & 0x0f) == 0) {
+        /* switch device to dword i/o mode */
+        pcnet_bcr_writew(s, BCR_BSBC, pcnet_bcr_readw(s, BCR_BSBC) | 0x0080);
+#ifdef PCNET_DEBUG_IO
+        printf("device switched into dword i/o mode\n");
+#endif
+    }
+    pcnet_update_irq(s);
+}
+
+uint32_t pcnet_ioport_readl(void *opaque, uint32_t addr)
+{
+    PCNetState *s = opaque;
+    uint32_t val = -1;
+    pcnet_poll_timer(s);
+    if (BCR_DWIO(s)) {
+        switch (addr & 0x0f) {
+        case 0x00: /* RDP */
+            val = pcnet_csr_readw(s, s->rap);
+            break;
+        case 0x04:
+            val = s->rap;
+            break;
+        case 0x08:
+            pcnet_s_reset(s);
+            val = 0;
+            break;
+        case 0x0c:
+            val = pcnet_bcr_readw(s, s->rap);
+            break;
+        }
+    }
+    pcnet_update_irq(s);
+#ifdef PCNET_DEBUG_IO
+    printf("pcnet_ioport_readl addr=0x%08x val=0x%08x\n", addr, val);
+#endif
+    return val;
+}
+
+static bool is_version_2(void *opaque, int version_id)
+{
+    return version_id == 2;
+}
+
+const VMStateDescription vmstate_pcnet = {
+    .name = "pcnet",
+    .version_id = 3,
+    .minimum_version_id = 2,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(rap, PCNetState),
+        VMSTATE_INT32(isr, PCNetState),
+        VMSTATE_INT32(lnkst, PCNetState),
+        VMSTATE_UINT32(rdra, PCNetState),
+        VMSTATE_UINT32(tdra, PCNetState),
+        VMSTATE_BUFFER(prom, PCNetState),
+        VMSTATE_UINT16_ARRAY(csr, PCNetState, 128),
+        VMSTATE_UINT16_ARRAY(bcr, PCNetState, 32),
+        VMSTATE_UINT64(timer, PCNetState),
+        VMSTATE_INT32(xmit_pos, PCNetState),
+        VMSTATE_BUFFER(buffer, PCNetState),
+        VMSTATE_UNUSED_TEST(is_version_2, 4),
+        VMSTATE_INT32(tx_busy, PCNetState),
+        VMSTATE_TIMER_PTR(poll_timer, PCNetState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+void pcnet_common_init(DeviceState *dev, PCNetState *s, NetClientInfo *info)
+{
+    int i;
+    uint16_t checksum;
+
+    s->poll_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, pcnet_poll_timer, s);
+
+    qemu_macaddr_default_if_unset(&s->conf.macaddr);
+    s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)), dev->id, s);
+    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
+
+    /* Initialize the PROM */
+
+    /*
+      Datasheet: http://pdfdata.datasheetsite.com/web/24528/AM79C970A.pdf
+      page 95
+    */
+    memcpy(s->prom, s->conf.macaddr.a, 6);
+    /* Reserved Location: must be 00h */
+    s->prom[6] = s->prom[7] = 0x00;
+    /* Reserved Location: must be 00h */
+    s->prom[8] = 0x00;
+    /* Hardware ID: must be 11h if compatibility to AMD drivers is desired */
+    s->prom[9] = 0x11;
+    /* User programmable space, init with 0 */
+    s->prom[10] = s->prom[11] = 0x00;
+    /* LSByte of two-byte checksum, which is the sum of bytes 00h-0Bh
+       and bytes 0Eh and 0Fh, must therefore be initialized with 0! */
+    s->prom[12] = s->prom[13] = 0x00;
+    /* Must be ASCII W (57h) if compatibility to AMD
+       driver software is desired */
+    s->prom[14] = s->prom[15] = 0x57;
+
+    for (i = 0, checksum = 0; i < 16; i++) {
+        checksum += s->prom[i];
+    }
+    *(uint16_t *)&s->prom[12] = cpu_to_le16(checksum);
+
+    s->lnkst = 0x40; /* initial link state: up */
+}