xref: /openbmc/qemu/hw/net/i82596.c (revision e052944a)
1 /*
2  * QEMU Intel i82596 (Apricot) emulation
3  *
4  * Copyright (c) 2019 Helge Deller <deller@gmx.de>
5  * This work is licensed under the GNU GPL license version 2 or later.
6  *
7  * This software was written to be compatible with the specification:
8  * https://www.intel.com/assets/pdf/general/82596ca.pdf
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qemu/timer.h"
13 #include "net/net.h"
14 #include "net/eth.h"
15 #include "hw/irq.h"
16 #include "hw/qdev-properties.h"
17 #include "migration/vmstate.h"
18 #include "qemu/module.h"
19 #include "trace.h"
20 #include "i82596.h"
21 #include <zlib.h>       /* For crc32 */
22 
23 #if defined(ENABLE_DEBUG)
24 #define DBG(x)          x
25 #else
26 #define DBG(x)          do { } while (0)
27 #endif
28 
29 #define USE_TIMER       0
30 
31 #define BITS(n, m) (((0xffffffffU << (31 - n)) >> (31 - n + m)) << m)
32 
33 #define PKT_BUF_SZ      1536
34 #define MAX_MC_CNT      64
35 
36 #define ISCP_BUSY       0x0001
37 
38 #define I596_NULL       ((uint32_t)0xffffffff)
39 
40 #define SCB_STATUS_CX   0x8000 /* CU finished command with I bit */
41 #define SCB_STATUS_FR   0x4000 /* RU finished receiving a frame */
42 #define SCB_STATUS_CNA  0x2000 /* CU left active state */
43 #define SCB_STATUS_RNR  0x1000 /* RU left active state */
44 
45 #define SCB_COMMAND_ACK_MASK \
46         (SCB_STATUS_CX | SCB_STATUS_FR | SCB_STATUS_CNA | SCB_STATUS_RNR)
47 
48 #define CU_IDLE         0
49 #define CU_SUSPENDED    1
50 #define CU_ACTIVE       2
51 
52 #define RX_IDLE         0
53 #define RX_SUSPENDED    1
54 #define RX_READY        4
55 
56 #define CMD_EOL         0x8000  /* The last command of the list, stop. */
57 #define CMD_SUSP        0x4000  /* Suspend after doing cmd. */
58 #define CMD_INTR        0x2000  /* Interrupt after doing cmd. */
59 
60 #define CMD_FLEX        0x0008  /* Enable flexible memory model */
61 
62 enum commands {
63         CmdNOp = 0, CmdSASetup = 1, CmdConfigure = 2, CmdMulticastList = 3,
64         CmdTx = 4, CmdTDR = 5, CmdDump = 6, CmdDiagnose = 7
65 };
66 
67 #define STAT_C          0x8000  /* Set to 0 after execution */
68 #define STAT_B          0x4000  /* Command being executed */
69 #define STAT_OK         0x2000  /* Command executed ok */
70 #define STAT_A          0x1000  /* Command aborted */
71 
72 #define I596_EOF        0x8000
73 #define SIZE_MASK       0x3fff
74 
75 /* various flags in the chip config registers */
76 #define I596_PREFETCH   (s->config[0] & 0x80)
77 #define I596_PROMISC    (s->config[8] & 0x01)
78 #define I596_BC_DISABLE (s->config[8] & 0x02) /* broadcast disable */
79 #define I596_NOCRC_INS  (s->config[8] & 0x08)
80 #define I596_CRCINM     (s->config[11] & 0x04) /* CRC appended */
81 #define I596_MC_ALL     (s->config[11] & 0x20)
82 #define I596_MULTIIA    (s->config[13] & 0x40)
83 
84 
85 static uint8_t get_byte(uint32_t addr)
86 {
87     return ldub_phys(&address_space_memory, addr);
88 }
89 
90 static void set_byte(uint32_t addr, uint8_t c)
91 {
92     return stb_phys(&address_space_memory, addr, c);
93 }
94 
95 static uint16_t get_uint16(uint32_t addr)
96 {
97     return lduw_be_phys(&address_space_memory, addr);
98 }
99 
100 static void set_uint16(uint32_t addr, uint16_t w)
101 {
102     return stw_be_phys(&address_space_memory, addr, w);
103 }
104 
105 static uint32_t get_uint32(uint32_t addr)
106 {
107     uint32_t lo = lduw_be_phys(&address_space_memory, addr);
108     uint32_t hi = lduw_be_phys(&address_space_memory, addr + 2);
109     return (hi << 16) | lo;
110 }
111 
112 static void set_uint32(uint32_t addr, uint32_t val)
113 {
114     set_uint16(addr, (uint16_t) val);
115     set_uint16(addr + 2, val >> 16);
116 }
117 
118 
119 struct qemu_ether_header {
120     uint8_t ether_dhost[6];
121     uint8_t ether_shost[6];
122     uint16_t ether_type;
123 };
124 
125 #define PRINT_PKTHDR(txt, BUF) do {                  \
126     struct qemu_ether_header *hdr = (void *)(BUF); \
127     printf(txt ": packet dhost=" MAC_FMT ", shost=" MAC_FMT ", type=0x%04x\n",\
128            MAC_ARG(hdr->ether_dhost), MAC_ARG(hdr->ether_shost),        \
129            be16_to_cpu(hdr->ether_type));       \
130 } while (0)
131 
132 static void i82596_transmit(I82596State *s, uint32_t addr)
133 {
134     uint32_t tdb_p; /* Transmit Buffer Descriptor */
135 
136     /* TODO: Check flexible mode */
137     tdb_p = get_uint32(addr + 8);
138     while (tdb_p != I596_NULL) {
139         uint16_t size, len;
140         uint32_t tba;
141 
142         size = get_uint16(tdb_p);
143         len = size & SIZE_MASK;
144         tba = get_uint32(tdb_p + 8);
145         trace_i82596_transmit(len, tba);
146 
147         if (s->nic && len) {
148             assert(len <= sizeof(s->tx_buffer));
149             address_space_read(&address_space_memory, tba,
150                                MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len);
151             DBG(PRINT_PKTHDR("Send", &s->tx_buffer));
152             DBG(printf("Sending %d bytes\n", len));
153             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, len);
154         }
155 
156         /* was this the last package? */
157         if (size & I596_EOF) {
158             break;
159         }
160 
161         /* get next buffer pointer */
162         tdb_p = get_uint32(tdb_p + 4);
163     }
164 }
165 
166 static void set_individual_address(I82596State *s, uint32_t addr)
167 {
168     NetClientState *nc;
169     uint8_t *m;
170 
171     nc = qemu_get_queue(s->nic);
172     m = s->conf.macaddr.a;
173     address_space_read(&address_space_memory, addr + 8,
174                        MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN);
175     qemu_format_nic_info_str(nc, m);
176     trace_i82596_new_mac(nc->info_str);
177 }
178 
179 static void set_multicast_list(I82596State *s, uint32_t addr)
180 {
181     uint16_t mc_count, i;
182 
183     memset(&s->mult[0], 0, sizeof(s->mult));
184     mc_count = get_uint16(addr + 8) / ETH_ALEN;
185     addr += 10;
186     if (mc_count > MAX_MC_CNT) {
187         mc_count = MAX_MC_CNT;
188     }
189     for (i = 0; i < mc_count; i++) {
190         uint8_t multicast_addr[ETH_ALEN];
191         address_space_read(&address_space_memory, addr + i * ETH_ALEN,
192                            MEMTXATTRS_UNSPECIFIED, multicast_addr, ETH_ALEN);
193         DBG(printf("Add multicast entry " MAC_FMT "\n",
194                     MAC_ARG(multicast_addr)));
195         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
196                               BITS(7, 2)) >> 2;
197         assert(mcast_idx < 8 * sizeof(s->mult));
198         s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));
199     }
200     trace_i82596_set_multicast(mc_count);
201 }
202 
203 void i82596_set_link_status(NetClientState *nc)
204 {
205     I82596State *d = qemu_get_nic_opaque(nc);
206 
207     d->lnkst = nc->link_down ? 0 : 0x8000;
208 }
209 
210 static void update_scb_status(I82596State *s)
211 {
212     s->scb_status = (s->scb_status & 0xf000)
213         | (s->cu_status << 8) | (s->rx_status << 4);
214     set_uint16(s->scb, s->scb_status);
215 }
216 
217 
218 static void i82596_s_reset(I82596State *s)
219 {
220     trace_i82596_s_reset(s);
221     s->scp = 0;
222     s->scb_status = 0;
223     s->cu_status = CU_IDLE;
224     s->rx_status = RX_SUSPENDED;
225     s->cmd_p = I596_NULL;
226     s->lnkst = 0x8000; /* initial link state: up */
227     s->ca = s->ca_active = 0;
228     s->send_irq = 0;
229 }
230 
231 
232 static void command_loop(I82596State *s)
233 {
234     uint16_t cmd;
235     uint16_t status;
236     uint8_t byte_cnt;
237 
238     DBG(printf("STARTING COMMAND LOOP cmd_p=%08x\n", s->cmd_p));
239 
240     while (s->cmd_p != I596_NULL) {
241         /* set status */
242         status = STAT_B;
243         set_uint16(s->cmd_p, status);
244         status = STAT_C | STAT_OK; /* update, but write later */
245 
246         cmd = get_uint16(s->cmd_p + 2);
247         DBG(printf("Running command %04x at %08x\n", cmd, s->cmd_p));
248 
249         switch (cmd & 0x07) {
250         case CmdNOp:
251             break;
252         case CmdSASetup:
253             set_individual_address(s, s->cmd_p);
254             break;
255         case CmdConfigure:
256             byte_cnt = get_byte(s->cmd_p + 8) & 0x0f;
257             byte_cnt = MAX(byte_cnt, 4);
258             byte_cnt = MIN(byte_cnt, sizeof(s->config));
259             /* copy byte_cnt max. */
260             address_space_read(&address_space_memory, s->cmd_p + 8,
261                                MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt);
262             /* config byte according to page 35ff */
263             s->config[2] &= 0x82; /* mask valid bits */
264             s->config[2] |= 0x40;
265             s->config[7]  &= 0xf7; /* clear zero bit */
266             assert(I596_NOCRC_INS == 0); /* do CRC insertion */
267             s->config[10] = MAX(s->config[10], 5); /* min frame length */
268             s->config[12] &= 0x40; /* only full duplex field valid */
269             s->config[13] |= 0x3f; /* set ones in byte 13 */
270             break;
271         case CmdTDR:
272             /* get signal LINK */
273             set_uint32(s->cmd_p + 8, s->lnkst);
274             break;
275         case CmdTx:
276             i82596_transmit(s, s->cmd_p);
277             break;
278         case CmdMulticastList:
279             set_multicast_list(s, s->cmd_p);
280             break;
281         case CmdDump:
282         case CmdDiagnose:
283             printf("FIXME Command %d !!\n", cmd & 7);
284             assert(0);
285         }
286 
287         /* update status */
288         set_uint16(s->cmd_p, status);
289 
290         s->cmd_p = get_uint32(s->cmd_p + 4); /* get link address */
291         DBG(printf("NEXT addr would be %08x\n", s->cmd_p));
292         if (s->cmd_p == 0) {
293             s->cmd_p = I596_NULL;
294         }
295 
296         /* Stop when last command of the list. */
297         if (cmd & CMD_EOL) {
298             s->cmd_p = I596_NULL;
299         }
300         /* Suspend after doing cmd? */
301         if (cmd & CMD_SUSP) {
302             s->cu_status = CU_SUSPENDED;
303             printf("FIXME SUSPEND !!\n");
304         }
305         /* Interrupt after doing cmd? */
306         if (cmd & CMD_INTR) {
307             s->scb_status |= SCB_STATUS_CX;
308         } else {
309             s->scb_status &= ~SCB_STATUS_CX;
310         }
311         update_scb_status(s);
312 
313         /* Interrupt after doing cmd? */
314         if (cmd & CMD_INTR) {
315             s->send_irq = 1;
316         }
317 
318         if (s->cu_status != CU_ACTIVE) {
319             break;
320         }
321     }
322     DBG(printf("FINISHED COMMAND LOOP\n"));
323     qemu_flush_queued_packets(qemu_get_queue(s->nic));
324 }
325 
326 static void i82596_flush_queue_timer(void *opaque)
327 {
328     I82596State *s = opaque;
329     if (0) {
330         timer_del(s->flush_queue_timer);
331         qemu_flush_queued_packets(qemu_get_queue(s->nic));
332         timer_mod(s->flush_queue_timer,
333               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1000);
334     }
335 }
336 
337 static void examine_scb(I82596State *s)
338 {
339     uint16_t command, cuc, ruc;
340 
341     /* get the scb command word */
342     command = get_uint16(s->scb + 2);
343     cuc = (command >> 8) & 0x7;
344     ruc = (command >> 4) & 0x7;
345     DBG(printf("MAIN COMMAND %04x  cuc %02x ruc %02x\n", command, cuc, ruc));
346     /* and clear the scb command word */
347     set_uint16(s->scb + 2, 0);
348 
349     s->scb_status &= ~(command & SCB_COMMAND_ACK_MASK);
350 
351     switch (cuc) {
352     case 0:     /* no change */
353         break;
354     case 1:     /* CUC_START */
355         s->cu_status = CU_ACTIVE;
356         break;
357     case 4:     /* CUC_ABORT */
358         s->cu_status = CU_SUSPENDED;
359         s->scb_status |= SCB_STATUS_CNA; /* CU left active state */
360         break;
361     default:
362         printf("WARNING: Unknown CUC %d!\n", cuc);
363     }
364 
365     switch (ruc) {
366     case 0:     /* no change */
367         break;
368     case 1:     /* RX_START */
369     case 2:     /* RX_RESUME */
370         s->rx_status = RX_IDLE;
371         if (USE_TIMER) {
372             timer_mod(s->flush_queue_timer, qemu_clock_get_ms(
373                                 QEMU_CLOCK_VIRTUAL) + 1000);
374         }
375         break;
376     case 3:     /* RX_SUSPEND */
377     case 4:     /* RX_ABORT */
378         s->rx_status = RX_SUSPENDED;
379         s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
380         break;
381     default:
382         printf("WARNING: Unknown RUC %d!\n", ruc);
383     }
384 
385     if (command & 0x80) { /* reset bit set? */
386         i82596_s_reset(s);
387     }
388 
389     /* execute commands from SCBL */
390     if (s->cu_status != CU_SUSPENDED) {
391         if (s->cmd_p == I596_NULL) {
392             s->cmd_p = get_uint32(s->scb + 4);
393         }
394     }
395 
396     /* update scb status */
397     update_scb_status(s);
398 
399     command_loop(s);
400 }
401 
402 static void signal_ca(I82596State *s)
403 {
404     uint32_t iscp = 0;
405 
406     /* trace_i82596_channel_attention(s); */
407     if (s->scp) {
408         /* CA after reset -> do init with new scp. */
409         s->sysbus = get_byte(s->scp + 3); /* big endian */
410         DBG(printf("SYSBUS = %08x\n", s->sysbus));
411         if (((s->sysbus >> 1) & 0x03) != 2) {
412             printf("WARNING: NO LINEAR MODE !!\n");
413         }
414         if ((s->sysbus >> 7)) {
415             printf("WARNING: 32BIT LINMODE IN B-STEPPING NOT SUPPORTED !!\n");
416         }
417         iscp = get_uint32(s->scp + 8);
418         s->scb = get_uint32(iscp + 4);
419         set_byte(iscp + 1, 0); /* clear BUSY flag in iscp */
420         s->scp = 0;
421     }
422 
423     s->ca++;    /* count ca() */
424     if (!s->ca_active) {
425         s->ca_active = 1;
426         while (s->ca)   {
427             examine_scb(s);
428             s->ca--;
429         }
430         s->ca_active = 0;
431     }
432 
433     if (s->send_irq) {
434         s->send_irq = 0;
435         qemu_set_irq(s->irq, 1);
436     }
437 }
438 
439 void i82596_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
440 {
441     I82596State *s = opaque;
442     /* printf("i82596_ioport_writew addr=0x%08x val=0x%04x\n", addr, val); */
443     switch (addr) {
444     case PORT_RESET: /* Reset */
445         i82596_s_reset(s);
446         break;
447     case PORT_ALTSCP:
448         s->scp = val;
449         break;
450     case PORT_CA:
451         signal_ca(s);
452         break;
453     }
454 }
455 
456 uint32_t i82596_ioport_readw(void *opaque, uint32_t addr)
457 {
458     return -1;
459 }
460 
461 void i82596_h_reset(void *opaque)
462 {
463     I82596State *s = opaque;
464 
465     i82596_s_reset(s);
466 }
467 
468 bool i82596_can_receive(NetClientState *nc)
469 {
470     I82596State *s = qemu_get_nic_opaque(nc);
471 
472     if (s->rx_status == RX_SUSPENDED) {
473         return false;
474     }
475 
476     if (!s->lnkst) {
477         return false;
478     }
479 
480     if (USE_TIMER && !timer_pending(s->flush_queue_timer)) {
481         return true;
482     }
483 
484     return true;
485 }
486 
487 ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
488 {
489     I82596State *s = qemu_get_nic_opaque(nc);
490     uint32_t rfd_p;
491     uint32_t rbd;
492     uint16_t is_broadcast = 0;
493     size_t len = sz; /* length of data for guest (including CRC) */
494     size_t bufsz = sz; /* length of data in buf */
495     uint32_t crc;
496     uint8_t *crc_ptr;
497     static const uint8_t broadcast_macaddr[6] = {
498                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
499 
500     DBG(printf("i82596_receive() start\n"));
501 
502     if (USE_TIMER && timer_pending(s->flush_queue_timer)) {
503         return 0;
504     }
505 
506     /* first check if receiver is enabled */
507     if (s->rx_status == RX_SUSPENDED) {
508         trace_i82596_receive_analysis(">>> Receiving suspended");
509         return -1;
510     }
511 
512     if (!s->lnkst) {
513         trace_i82596_receive_analysis(">>> Link down");
514         return -1;
515     }
516 
517     /* Received frame smaller than configured "min frame len"? */
518     if (sz < s->config[10]) {
519         printf("Received frame too small, %zu vs. %u bytes\n",
520                sz, s->config[10]);
521         return -1;
522     }
523 
524     DBG(printf("Received %lu bytes\n", sz));
525 
526     if (I596_PROMISC) {
527 
528         /* promiscuous: receive all */
529         trace_i82596_receive_analysis(
530                 ">>> packet received in promiscuous mode");
531 
532     } else {
533 
534         if (!memcmp(buf,  broadcast_macaddr, 6)) {
535             /* broadcast address */
536             if (I596_BC_DISABLE) {
537                 trace_i82596_receive_analysis(">>> broadcast packet rejected");
538 
539                 return len;
540             }
541 
542             trace_i82596_receive_analysis(">>> broadcast packet received");
543             is_broadcast = 1;
544 
545         } else if (buf[0] & 0x01) {
546             /* multicast */
547             if (!I596_MC_ALL) {
548                 trace_i82596_receive_analysis(">>> multicast packet rejected");
549 
550                 return len;
551             }
552 
553             int mcast_idx = (net_crc32(buf, ETH_ALEN) & BITS(7, 2)) >> 2;
554             assert(mcast_idx < 8 * sizeof(s->mult));
555 
556             if (!(s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7)))) {
557                 trace_i82596_receive_analysis(">>> multicast address mismatch");
558 
559                 return len;
560             }
561 
562             trace_i82596_receive_analysis(">>> multicast packet received");
563             is_broadcast = 1;
564 
565         } else if (!memcmp(s->conf.macaddr.a, buf, 6)) {
566 
567             /* match */
568             trace_i82596_receive_analysis(
569                     ">>> physical address matching packet received");
570 
571         } else {
572 
573             trace_i82596_receive_analysis(">>> unknown packet");
574 
575             return len;
576         }
577     }
578 
579     /* Calculate the ethernet checksum (4 bytes) */
580     len += 4;
581     crc = cpu_to_be32(crc32(~0, buf, sz));
582     crc_ptr = (uint8_t *) &crc;
583 
584     rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
585     assert(rfd_p && rfd_p != I596_NULL);
586 
587     /* get first Receive Buffer Descriptor Address */
588     rbd = get_uint32(rfd_p + 8);
589     assert(rbd && rbd != I596_NULL);
590 
591     trace_i82596_receive_packet(len);
592     /* PRINT_PKTHDR("Receive", buf); */
593 
594     while (len) {
595         uint16_t command, status;
596         uint32_t next_rfd;
597 
598         command = get_uint16(rfd_p + 2);
599         assert(command & CMD_FLEX); /* assert Flex Mode */
600         /* get first Receive Buffer Descriptor Address */
601         rbd = get_uint32(rfd_p + 8);
602         assert(get_uint16(rfd_p + 14) == 0);
603 
604         /* printf("Receive: rfd is %08x\n", rfd_p); */
605 
606         while (len) {
607             uint16_t buffer_size, num;
608             uint32_t rba;
609             size_t bufcount, crccount;
610 
611             /* printf("Receive: rbd is %08x\n", rbd); */
612             buffer_size = get_uint16(rbd + 12);
613             /* printf("buffer_size is 0x%x\n", buffer_size); */
614             assert(buffer_size != 0);
615 
616             num = buffer_size & SIZE_MASK;
617             if (num > len) {
618                 num = len;
619             }
620             rba = get_uint32(rbd + 8);
621             /* printf("rba is 0x%x\n", rba); */
622             /*
623              * Calculate how many bytes we want from buf[] and how many
624              * from the CRC.
625              */
626             if ((len - num) >= 4) {
627                 /* The whole guest buffer, we haven't hit the CRC yet */
628                 bufcount = num;
629             } else {
630                 /* All that's left of buf[] */
631                 bufcount = len - 4;
632             }
633             crccount = num - bufcount;
634 
635             if (bufcount > 0) {
636                 /* Still some of the actual data buffer to transfer */
637                 assert(bufsz >= bufcount);
638                 bufsz -= bufcount;
639                 address_space_write(&address_space_memory, rba,
640                                     MEMTXATTRS_UNSPECIFIED, buf, bufcount);
641                 rba += bufcount;
642                 buf += bufcount;
643                 len -= bufcount;
644             }
645 
646             /* Write as much of the CRC as fits */
647             if (crccount > 0) {
648                 address_space_write(&address_space_memory, rba,
649                                     MEMTXATTRS_UNSPECIFIED, crc_ptr, crccount);
650                 rba += crccount;
651                 crc_ptr += crccount;
652                 len -= crccount;
653             }
654 
655             num |= 0x4000; /* set F BIT */
656             if (len == 0) {
657                 num |= I596_EOF; /* set EOF BIT */
658             }
659             set_uint16(rbd + 0, num); /* write actual count with flags */
660 
661             /* get next rbd */
662             rbd = get_uint32(rbd + 4);
663             /* printf("Next Receive: rbd is %08x\n", rbd); */
664 
665             if (buffer_size & I596_EOF) /* last entry */
666                 break;
667         }
668 
669         /* Housekeeping, see pg. 18 */
670         next_rfd = get_uint32(rfd_p + 4);
671         set_uint32(next_rfd + 8, rbd);
672 
673         status = STAT_C | STAT_OK | is_broadcast;
674         set_uint16(rfd_p, status);
675 
676         if (command & CMD_SUSP) {  /* suspend after command? */
677             s->rx_status = RX_SUSPENDED;
678             s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
679             break;
680         }
681         if (command & CMD_EOL) /* was it last Frame Descriptor? */
682             break;
683 
684         assert(len == 0);
685     }
686 
687     assert(len == 0);
688 
689     s->scb_status |= SCB_STATUS_FR; /* set "RU finished receiving frame" bit. */
690     update_scb_status(s);
691 
692     /* send IRQ that we received data */
693     qemu_set_irq(s->irq, 1);
694     /* s->send_irq = 1; */
695 
696     if (0) {
697         DBG(printf("Checking:\n"));
698         rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
699         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
700         rfd_p = get_uint32(rfd_p + 4); /* get Next Receive Frame Descriptor */
701         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
702         /* get first Receive Buffer Descriptor Address */
703         rbd = get_uint32(rfd_p + 8);
704         DBG(printf("Next Receive: rbd is %08x\n", rbd));
705     }
706 
707     return sz;
708 }
709 
710 
711 const VMStateDescription vmstate_i82596 = {
712     .name = "i82596",
713     .version_id = 1,
714     .minimum_version_id = 1,
715     .fields = (VMStateField[]) {
716         VMSTATE_UINT16(lnkst, I82596State),
717         VMSTATE_TIMER_PTR(flush_queue_timer, I82596State),
718         VMSTATE_END_OF_LIST()
719     }
720 };
721 
722 void i82596_common_init(DeviceState *dev, I82596State *s, NetClientInfo *info)
723 {
724     if (s->conf.macaddr.a[0] == 0) {
725         qemu_macaddr_default_if_unset(&s->conf.macaddr);
726     }
727     s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)),
728                 dev->id, s);
729     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
730 
731     if (USE_TIMER) {
732         s->flush_queue_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
733                                     i82596_flush_queue_timer, s);
734     }
735     s->lnkst = 0x8000; /* initial link state: up */
736 }
737