xref: /openbmc/qemu/hw/net/i82596.c (revision 764a6ee9)
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 "exec/address-spaces.h"
19 #include "qemu/module.h"
20 #include "trace.h"
21 #include "i82596.h"
22 #include <zlib.h> /* for crc32 */
23 
24 #if defined(ENABLE_DEBUG)
25 #define DBG(x)          x
26 #else
27 #define DBG(x)          do { } while (0)
28 #endif
29 
30 #define USE_TIMER       0
31 
32 #define BITS(n, m) (((0xffffffffU << (31 - n)) >> (31 - n + m)) << m)
33 
34 #define PKT_BUF_SZ      1536
35 #define MAX_MC_CNT      64
36 
37 #define ISCP_BUSY       0x0001
38 
39 #define I596_NULL       ((uint32_t)0xffffffff)
40 
41 #define SCB_STATUS_CX   0x8000 /* CU finished command with I bit */
42 #define SCB_STATUS_FR   0x4000 /* RU finished receiving a frame */
43 #define SCB_STATUS_CNA  0x2000 /* CU left active state */
44 #define SCB_STATUS_RNR  0x1000 /* RU left active state */
45 
46 #define SCB_COMMAND_ACK_MASK \
47         (SCB_STATUS_CX | SCB_STATUS_FR | SCB_STATUS_CNA | SCB_STATUS_RNR)
48 
49 #define CU_IDLE         0
50 #define CU_SUSPENDED    1
51 #define CU_ACTIVE       2
52 
53 #define RX_IDLE         0
54 #define RX_SUSPENDED    1
55 #define RX_READY        4
56 
57 #define CMD_EOL         0x8000  /* The last command of the list, stop. */
58 #define CMD_SUSP        0x4000  /* Suspend after doing cmd. */
59 #define CMD_INTR        0x2000  /* Interrupt after doing cmd. */
60 
61 #define CMD_FLEX        0x0008  /* Enable flexible memory model */
62 
63 enum commands {
64         CmdNOp = 0, CmdSASetup = 1, CmdConfigure = 2, CmdMulticastList = 3,
65         CmdTx = 4, CmdTDR = 5, CmdDump = 6, CmdDiagnose = 7
66 };
67 
68 #define STAT_C          0x8000  /* Set to 0 after execution */
69 #define STAT_B          0x4000  /* Command being executed */
70 #define STAT_OK         0x2000  /* Command executed ok */
71 #define STAT_A          0x1000  /* Command aborted */
72 
73 #define I596_EOF        0x8000
74 #define SIZE_MASK       0x3fff
75 
76 /* various flags in the chip config registers */
77 #define I596_PREFETCH   (s->config[0] & 0x80)
78 #define I596_PROMISC    (s->config[8] & 0x01)
79 #define I596_BC_DISABLE (s->config[8] & 0x02) /* broadcast disable */
80 #define I596_NOCRC_INS  (s->config[8] & 0x08)
81 #define I596_CRCINM     (s->config[11] & 0x04) /* CRC appended */
82 #define I596_MC_ALL     (s->config[11] & 0x20)
83 #define I596_MULTIIA    (s->config[13] & 0x40)
84 
85 
86 static uint8_t get_byte(uint32_t addr)
87 {
88     return ldub_phys(&address_space_memory, addr);
89 }
90 
91 static void set_byte(uint32_t addr, uint8_t c)
92 {
93     return stb_phys(&address_space_memory, addr, c);
94 }
95 
96 static uint16_t get_uint16(uint32_t addr)
97 {
98     return lduw_be_phys(&address_space_memory, addr);
99 }
100 
101 static void set_uint16(uint32_t addr, uint16_t w)
102 {
103     return stw_be_phys(&address_space_memory, addr, w);
104 }
105 
106 static uint32_t get_uint32(uint32_t addr)
107 {
108     uint32_t lo = lduw_be_phys(&address_space_memory, addr);
109     uint32_t hi = lduw_be_phys(&address_space_memory, addr + 2);
110     return (hi << 16) | lo;
111 }
112 
113 static void set_uint32(uint32_t addr, uint32_t val)
114 {
115     set_uint16(addr, (uint16_t) val);
116     set_uint16(addr + 2, val >> 16);
117 }
118 
119 
120 struct qemu_ether_header {
121     uint8_t ether_dhost[6];
122     uint8_t ether_shost[6];
123     uint16_t ether_type;
124 };
125 
126 #define PRINT_PKTHDR(txt, BUF) do {                  \
127     struct qemu_ether_header *hdr = (void *)(BUF); \
128     printf(txt ": packet dhost=" MAC_FMT ", shost=" MAC_FMT ", type=0x%04x\n",\
129            MAC_ARG(hdr->ether_dhost), MAC_ARG(hdr->ether_shost),        \
130            be16_to_cpu(hdr->ether_type));       \
131 } while (0)
132 
133 static void i82596_transmit(I82596State *s, uint32_t addr)
134 {
135     uint32_t tdb_p; /* Transmit Buffer Descriptor */
136 
137     /* TODO: Check flexible mode */
138     tdb_p = get_uint32(addr + 8);
139     while (tdb_p != I596_NULL) {
140         uint16_t size, len;
141         uint32_t tba;
142 
143         size = get_uint16(tdb_p);
144         len = size & SIZE_MASK;
145         tba = get_uint32(tdb_p + 8);
146         trace_i82596_transmit(len, tba);
147 
148         if (s->nic && len) {
149             assert(len <= sizeof(s->tx_buffer));
150             address_space_read(&address_space_memory, tba,
151                                MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len);
152             DBG(PRINT_PKTHDR("Send", &s->tx_buffer));
153             DBG(printf("Sending %d bytes\n", len));
154             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, len);
155         }
156 
157         /* was this the last package? */
158         if (size & I596_EOF) {
159             break;
160         }
161 
162         /* get next buffer pointer */
163         tdb_p = get_uint32(tdb_p + 4);
164     }
165 }
166 
167 static void set_individual_address(I82596State *s, uint32_t addr)
168 {
169     NetClientState *nc;
170     uint8_t *m;
171 
172     nc = qemu_get_queue(s->nic);
173     m = s->conf.macaddr.a;
174     address_space_read(&address_space_memory, addr + 8,
175                        MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN);
176     qemu_format_nic_info_str(nc, m);
177     trace_i82596_new_mac(nc->info_str);
178 }
179 
180 static void set_multicast_list(I82596State *s, uint32_t addr)
181 {
182     uint16_t mc_count, i;
183 
184     memset(&s->mult[0], 0, sizeof(s->mult));
185     mc_count = get_uint16(addr + 8) / ETH_ALEN;
186     addr += 10;
187     if (mc_count > MAX_MC_CNT) {
188         mc_count = MAX_MC_CNT;
189     }
190     for (i = 0; i < mc_count; i++) {
191         uint8_t multicast_addr[ETH_ALEN];
192         address_space_read(&address_space_memory, addr + i * ETH_ALEN,
193                            MEMTXATTRS_UNSPECIFIED, multicast_addr, ETH_ALEN);
194         DBG(printf("Add multicast entry " MAC_FMT "\n",
195                     MAC_ARG(multicast_addr)));
196         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
197                               BITS(7, 2)) >> 2;
198         assert(mcast_idx < 8 * sizeof(s->mult));
199         s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));
200     }
201     trace_i82596_set_multicast(mc_count);
202 }
203 
204 void i82596_set_link_status(NetClientState *nc)
205 {
206     I82596State *d = qemu_get_nic_opaque(nc);
207 
208     d->lnkst = nc->link_down ? 0 : 0x8000;
209 }
210 
211 static void update_scb_status(I82596State *s)
212 {
213     s->scb_status = (s->scb_status & 0xf000)
214         | (s->cu_status << 8) | (s->rx_status << 4);
215     set_uint16(s->scb, s->scb_status);
216 }
217 
218 
219 static void i82596_s_reset(I82596State *s)
220 {
221     trace_i82596_s_reset(s);
222     s->scp = 0;
223     s->scb_status = 0;
224     s->cu_status = CU_IDLE;
225     s->rx_status = RX_SUSPENDED;
226     s->cmd_p = I596_NULL;
227     s->lnkst = 0x8000; /* initial link state: up */
228     s->ca = s->ca_active = 0;
229     s->send_irq = 0;
230 }
231 
232 
233 static void command_loop(I82596State *s)
234 {
235     uint16_t cmd;
236     uint16_t status;
237     uint8_t byte_cnt;
238 
239     DBG(printf("STARTING COMMAND LOOP cmd_p=%08x\n", s->cmd_p));
240 
241     while (s->cmd_p != I596_NULL) {
242         /* set status */
243         status = STAT_B;
244         set_uint16(s->cmd_p, status);
245         status = STAT_C | STAT_OK; /* update, but write later */
246 
247         cmd = get_uint16(s->cmd_p + 2);
248         DBG(printf("Running command %04x at %08x\n", cmd, s->cmd_p));
249 
250         switch (cmd & 0x07) {
251         case CmdNOp:
252             break;
253         case CmdSASetup:
254             set_individual_address(s, s->cmd_p);
255             break;
256         case CmdConfigure:
257             byte_cnt = get_byte(s->cmd_p + 8) & 0x0f;
258             byte_cnt = MAX(byte_cnt, 4);
259             byte_cnt = MIN(byte_cnt, sizeof(s->config));
260             /* copy byte_cnt max. */
261             address_space_read(&address_space_memory, s->cmd_p + 8,
262                                MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt);
263             /* config byte according to page 35ff */
264             s->config[2] &= 0x82; /* mask valid bits */
265             s->config[2] |= 0x40;
266             s->config[7]  &= 0xf7; /* clear zero bit */
267             assert(I596_NOCRC_INS == 0); /* do CRC insertion */
268             s->config[10] = MAX(s->config[10], 5); /* min frame length */
269             s->config[12] &= 0x40; /* only full duplex field valid */
270             s->config[13] |= 0x3f; /* set ones in byte 13 */
271             break;
272         case CmdTDR:
273             /* get signal LINK */
274             set_uint32(s->cmd_p + 8, s->lnkst);
275             break;
276         case CmdTx:
277             i82596_transmit(s, s->cmd_p);
278             break;
279         case CmdMulticastList:
280             set_multicast_list(s, s->cmd_p);
281             break;
282         case CmdDump:
283         case CmdDiagnose:
284             printf("FIXME Command %d !!\n", cmd & 7);
285             g_assert_not_reached();
286         }
287 
288         /* update status */
289         set_uint16(s->cmd_p, status);
290 
291         s->cmd_p = get_uint32(s->cmd_p + 4); /* get link address */
292         DBG(printf("NEXT addr would be %08x\n", s->cmd_p));
293         if (s->cmd_p == 0) {
294             s->cmd_p = I596_NULL;
295         }
296 
297         /* Stop when last command of the list. */
298         if (cmd & CMD_EOL) {
299             s->cmd_p = I596_NULL;
300         }
301         /* Suspend after doing cmd? */
302         if (cmd & CMD_SUSP) {
303             s->cu_status = CU_SUSPENDED;
304             printf("FIXME SUSPEND !!\n");
305         }
306         /* Interrupt after doing cmd? */
307         if (cmd & CMD_INTR) {
308             s->scb_status |= SCB_STATUS_CX;
309         } else {
310             s->scb_status &= ~SCB_STATUS_CX;
311         }
312         update_scb_status(s);
313 
314         /* Interrupt after doing cmd? */
315         if (cmd & CMD_INTR) {
316             s->send_irq = 1;
317         }
318 
319         if (s->cu_status != CU_ACTIVE) {
320             break;
321         }
322     }
323     DBG(printf("FINISHED COMMAND LOOP\n"));
324     qemu_flush_queued_packets(qemu_get_queue(s->nic));
325 }
326 
327 static void i82596_flush_queue_timer(void *opaque)
328 {
329     I82596State *s = opaque;
330     if (0) {
331         timer_del(s->flush_queue_timer);
332         qemu_flush_queued_packets(qemu_get_queue(s->nic));
333         timer_mod(s->flush_queue_timer,
334               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1000);
335     }
336 }
337 
338 static void examine_scb(I82596State *s)
339 {
340     uint16_t command, cuc, ruc;
341 
342     /* get the scb command word */
343     command = get_uint16(s->scb + 2);
344     cuc = (command >> 8) & 0x7;
345     ruc = (command >> 4) & 0x7;
346     DBG(printf("MAIN COMMAND %04x  cuc %02x ruc %02x\n", command, cuc, ruc));
347     /* and clear the scb command word */
348     set_uint16(s->scb + 2, 0);
349 
350     s->scb_status &= ~(command & SCB_COMMAND_ACK_MASK);
351 
352     switch (cuc) {
353     case 0:     /* no change */
354         break;
355     case 1:     /* CUC_START */
356         s->cu_status = CU_ACTIVE;
357         break;
358     case 4:     /* CUC_ABORT */
359         s->cu_status = CU_SUSPENDED;
360         s->scb_status |= SCB_STATUS_CNA; /* CU left active state */
361         break;
362     default:
363         printf("WARNING: Unknown CUC %d!\n", cuc);
364     }
365 
366     switch (ruc) {
367     case 0:     /* no change */
368         break;
369     case 1:     /* RX_START */
370     case 2:     /* RX_RESUME */
371         s->rx_status = RX_IDLE;
372         if (USE_TIMER) {
373             timer_mod(s->flush_queue_timer, qemu_clock_get_ms(
374                                 QEMU_CLOCK_VIRTUAL) + 1000);
375         }
376         break;
377     case 3:     /* RX_SUSPEND */
378     case 4:     /* RX_ABORT */
379         s->rx_status = RX_SUSPENDED;
380         s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
381         break;
382     default:
383         printf("WARNING: Unknown RUC %d!\n", ruc);
384     }
385 
386     if (command & 0x80) { /* reset bit set? */
387         i82596_s_reset(s);
388     }
389 
390     /* execute commands from SCBL */
391     if (s->cu_status != CU_SUSPENDED) {
392         if (s->cmd_p == I596_NULL) {
393             s->cmd_p = get_uint32(s->scb + 4);
394         }
395     }
396 
397     /* update scb status */
398     update_scb_status(s);
399 
400     command_loop(s);
401 }
402 
403 static void signal_ca(I82596State *s)
404 {
405     uint32_t iscp = 0;
406 
407     /* trace_i82596_channel_attention(s); */
408     if (s->scp) {
409         /* CA after reset -> do init with new scp. */
410         s->sysbus = get_byte(s->scp + 3); /* big endian */
411         DBG(printf("SYSBUS = %08x\n", s->sysbus));
412         if (((s->sysbus >> 1) & 0x03) != 2) {
413             printf("WARNING: NO LINEAR MODE !!\n");
414         }
415         if ((s->sysbus >> 7)) {
416             printf("WARNING: 32BIT LINMODE IN B-STEPPING NOT SUPPORTED !!\n");
417         }
418         iscp = get_uint32(s->scp + 8);
419         s->scb = get_uint32(iscp + 4);
420         set_byte(iscp + 1, 0); /* clear BUSY flag in iscp */
421         s->scp = 0;
422     }
423 
424     s->ca++;    /* count ca() */
425     if (!s->ca_active) {
426         s->ca_active = 1;
427         while (s->ca)   {
428             examine_scb(s);
429             s->ca--;
430         }
431         s->ca_active = 0;
432     }
433 
434     if (s->send_irq) {
435         s->send_irq = 0;
436         qemu_set_irq(s->irq, 1);
437     }
438 }
439 
440 void i82596_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
441 {
442     I82596State *s = opaque;
443     /* printf("i82596_ioport_writew addr=0x%08x val=0x%04x\n", addr, val); */
444     switch (addr) {
445     case PORT_RESET: /* Reset */
446         i82596_s_reset(s);
447         break;
448     case PORT_ALTSCP:
449         s->scp = val;
450         break;
451     case PORT_CA:
452         signal_ca(s);
453         break;
454     }
455 }
456 
457 uint32_t i82596_ioport_readw(void *opaque, uint32_t addr)
458 {
459     return -1;
460 }
461 
462 void i82596_h_reset(void *opaque)
463 {
464     I82596State *s = opaque;
465 
466     i82596_s_reset(s);
467 }
468 
469 bool i82596_can_receive(NetClientState *nc)
470 {
471     I82596State *s = qemu_get_nic_opaque(nc);
472 
473     if (s->rx_status == RX_SUSPENDED) {
474         return false;
475     }
476 
477     if (!s->lnkst) {
478         return false;
479     }
480 
481     if (USE_TIMER && !timer_pending(s->flush_queue_timer)) {
482         return true;
483     }
484 
485     return true;
486 }
487 
488 ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
489 {
490     I82596State *s = qemu_get_nic_opaque(nc);
491     uint32_t rfd_p;
492     uint32_t rbd;
493     uint16_t is_broadcast = 0;
494     size_t len = sz; /* length of data for guest (including CRC) */
495     size_t bufsz = sz; /* length of data in buf */
496     uint32_t crc;
497     uint8_t *crc_ptr;
498     static const uint8_t broadcast_macaddr[6] = {
499                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
500 
501     DBG(printf("i82596_receive() start\n"));
502 
503     if (USE_TIMER && timer_pending(s->flush_queue_timer)) {
504         return 0;
505     }
506 
507     /* first check if receiver is enabled */
508     if (s->rx_status == RX_SUSPENDED) {
509         trace_i82596_receive_analysis(">>> Receiving suspended");
510         return -1;
511     }
512 
513     if (!s->lnkst) {
514         trace_i82596_receive_analysis(">>> Link down");
515         return -1;
516     }
517 
518     /* Received frame smaller than configured "min frame len"? */
519     if (sz < s->config[10]) {
520         printf("Received frame too small, %zu vs. %u bytes\n",
521                sz, s->config[10]);
522         return -1;
523     }
524 
525     DBG(printf("Received %lu bytes\n", sz));
526 
527     if (I596_PROMISC) {
528 
529         /* promiscuous: receive all */
530         trace_i82596_receive_analysis(
531                 ">>> packet received in promiscuous mode");
532 
533     } else {
534 
535         if (!memcmp(buf,  broadcast_macaddr, 6)) {
536             /* broadcast address */
537             if (I596_BC_DISABLE) {
538                 trace_i82596_receive_analysis(">>> broadcast packet rejected");
539 
540                 return len;
541             }
542 
543             trace_i82596_receive_analysis(">>> broadcast packet received");
544             is_broadcast = 1;
545 
546         } else if (buf[0] & 0x01) {
547             /* multicast */
548             if (!I596_MC_ALL) {
549                 trace_i82596_receive_analysis(">>> multicast packet rejected");
550 
551                 return len;
552             }
553 
554             int mcast_idx = (net_crc32(buf, ETH_ALEN) & BITS(7, 2)) >> 2;
555             assert(mcast_idx < 8 * sizeof(s->mult));
556 
557             if (!(s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7)))) {
558                 trace_i82596_receive_analysis(">>> multicast address mismatch");
559 
560                 return len;
561             }
562 
563             trace_i82596_receive_analysis(">>> multicast packet received");
564             is_broadcast = 1;
565 
566         } else if (!memcmp(s->conf.macaddr.a, buf, 6)) {
567 
568             /* match */
569             trace_i82596_receive_analysis(
570                     ">>> physical address matching packet received");
571 
572         } else {
573 
574             trace_i82596_receive_analysis(">>> unknown packet");
575 
576             return len;
577         }
578     }
579 
580     /* Calculate the ethernet checksum (4 bytes) */
581     len += 4;
582     crc = cpu_to_be32(crc32(~0, buf, sz));
583     crc_ptr = (uint8_t *) &crc;
584 
585     rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
586     assert(rfd_p && rfd_p != I596_NULL);
587 
588     /* get first Receive Buffer Descriptor Address */
589     rbd = get_uint32(rfd_p + 8);
590     assert(rbd && rbd != I596_NULL);
591 
592     trace_i82596_receive_packet(len);
593     /* PRINT_PKTHDR("Receive", buf); */
594 
595     while (len) {
596         uint16_t command, status;
597         uint32_t next_rfd;
598 
599         command = get_uint16(rfd_p + 2);
600         assert(command & CMD_FLEX); /* assert Flex Mode */
601         /* get first Receive Buffer Descriptor Address */
602         rbd = get_uint32(rfd_p + 8);
603         assert(get_uint16(rfd_p + 14) == 0);
604 
605         /* printf("Receive: rfd is %08x\n", rfd_p); */
606 
607         while (len) {
608             uint16_t buffer_size, num;
609             uint32_t rba;
610             size_t bufcount, crccount;
611 
612             /* printf("Receive: rbd is %08x\n", rbd); */
613             buffer_size = get_uint16(rbd + 12);
614             /* printf("buffer_size is 0x%x\n", buffer_size); */
615             assert(buffer_size != 0);
616 
617             num = buffer_size & SIZE_MASK;
618             if (num > len) {
619                 num = len;
620             }
621             rba = get_uint32(rbd + 8);
622             /* printf("rba is 0x%x\n", rba); */
623             /*
624              * Calculate how many bytes we want from buf[] and how many
625              * from the CRC.
626              */
627             if ((len - num) >= 4) {
628                 /* The whole guest buffer, we haven't hit the CRC yet */
629                 bufcount = num;
630             } else {
631                 /* All that's left of buf[] */
632                 bufcount = len - 4;
633             }
634             crccount = num - bufcount;
635 
636             if (bufcount > 0) {
637                 /* Still some of the actual data buffer to transfer */
638                 assert(bufsz >= bufcount);
639                 bufsz -= bufcount;
640                 address_space_write(&address_space_memory, rba,
641                                     MEMTXATTRS_UNSPECIFIED, buf, bufcount);
642                 rba += bufcount;
643                 buf += bufcount;
644                 len -= bufcount;
645             }
646 
647             /* Write as much of the CRC as fits */
648             if (crccount > 0) {
649                 address_space_write(&address_space_memory, rba,
650                                     MEMTXATTRS_UNSPECIFIED, crc_ptr, crccount);
651                 rba += crccount;
652                 crc_ptr += crccount;
653                 len -= crccount;
654             }
655 
656             num |= 0x4000; /* set F BIT */
657             if (len == 0) {
658                 num |= I596_EOF; /* set EOF BIT */
659             }
660             set_uint16(rbd + 0, num); /* write actual count with flags */
661 
662             /* get next rbd */
663             rbd = get_uint32(rbd + 4);
664             /* printf("Next Receive: rbd is %08x\n", rbd); */
665 
666             if (buffer_size & I596_EOF) /* last entry */
667                 break;
668         }
669 
670         /* Housekeeping, see pg. 18 */
671         next_rfd = get_uint32(rfd_p + 4);
672         set_uint32(next_rfd + 8, rbd);
673 
674         status = STAT_C | STAT_OK | is_broadcast;
675         set_uint16(rfd_p, status);
676 
677         if (command & CMD_SUSP) {  /* suspend after command? */
678             s->rx_status = RX_SUSPENDED;
679             s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
680             break;
681         }
682         if (command & CMD_EOL) /* was it last Frame Descriptor? */
683             break;
684 
685         assert(len == 0);
686     }
687 
688     assert(len == 0);
689 
690     s->scb_status |= SCB_STATUS_FR; /* set "RU finished receiving frame" bit. */
691     update_scb_status(s);
692 
693     /* send IRQ that we received data */
694     qemu_set_irq(s->irq, 1);
695     /* s->send_irq = 1; */
696 
697     if (0) {
698         DBG(printf("Checking:\n"));
699         rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
700         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
701         rfd_p = get_uint32(rfd_p + 4); /* get Next Receive Frame Descriptor */
702         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
703         /* get first Receive Buffer Descriptor Address */
704         rbd = get_uint32(rfd_p + 8);
705         DBG(printf("Next Receive: rbd is %08x\n", rbd));
706     }
707 
708     return sz;
709 }
710 
711 
712 const VMStateDescription vmstate_i82596 = {
713     .name = "i82596",
714     .version_id = 1,
715     .minimum_version_id = 1,
716     .fields = (const VMStateField[]) {
717         VMSTATE_UINT16(lnkst, I82596State),
718         VMSTATE_TIMER_PTR(flush_queue_timer, I82596State),
719         VMSTATE_END_OF_LIST()
720     }
721 };
722 
723 void i82596_common_init(DeviceState *dev, I82596State *s, NetClientInfo *info)
724 {
725     if (s->conf.macaddr.a[0] == 0) {
726         qemu_macaddr_default_if_unset(&s->conf.macaddr);
727     }
728     s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)),
729                 dev->id, &dev->mem_reentrancy_guard, s);
730     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
731 
732     if (USE_TIMER) {
733         s->flush_queue_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
734                                     i82596_flush_queue_timer, s);
735     }
736     s->lnkst = 0x8000; /* initial link state: up */
737 }
738