xref: /openbmc/qemu/hw/net/i82596.c (revision b91a0fa7)
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 #define ETHER_TYPE_LEN 2
76 #define VLAN_TCI_LEN 2
77 #define VLAN_HLEN (ETHER_TYPE_LEN + VLAN_TCI_LEN)
78 
79 /* various flags in the chip config registers */
80 #define I596_PREFETCH   (s->config[0] & 0x80)
81 #define I596_PROMISC    (s->config[8] & 0x01)
82 #define I596_BC_DISABLE (s->config[8] & 0x02) /* broadcast disable */
83 #define I596_NOCRC_INS  (s->config[8] & 0x08)
84 #define I596_CRCINM     (s->config[11] & 0x04) /* CRC appended */
85 #define I596_MC_ALL     (s->config[11] & 0x20)
86 #define I596_MULTIIA    (s->config[13] & 0x40)
87 
88 
89 static uint8_t get_byte(uint32_t addr)
90 {
91     return ldub_phys(&address_space_memory, addr);
92 }
93 
94 static void set_byte(uint32_t addr, uint8_t c)
95 {
96     return stb_phys(&address_space_memory, addr, c);
97 }
98 
99 static uint16_t get_uint16(uint32_t addr)
100 {
101     return lduw_be_phys(&address_space_memory, addr);
102 }
103 
104 static void set_uint16(uint32_t addr, uint16_t w)
105 {
106     return stw_be_phys(&address_space_memory, addr, w);
107 }
108 
109 static uint32_t get_uint32(uint32_t addr)
110 {
111     uint32_t lo = lduw_be_phys(&address_space_memory, addr);
112     uint32_t hi = lduw_be_phys(&address_space_memory, addr + 2);
113     return (hi << 16) | lo;
114 }
115 
116 static void set_uint32(uint32_t addr, uint32_t val)
117 {
118     set_uint16(addr, (uint16_t) val);
119     set_uint16(addr + 2, val >> 16);
120 }
121 
122 
123 struct qemu_ether_header {
124     uint8_t ether_dhost[6];
125     uint8_t ether_shost[6];
126     uint16_t ether_type;
127 };
128 
129 #define PRINT_PKTHDR(txt, BUF) do {                  \
130     struct qemu_ether_header *hdr = (void *)(BUF); \
131     printf(txt ": packet dhost=" MAC_FMT ", shost=" MAC_FMT ", type=0x%04x\n",\
132            MAC_ARG(hdr->ether_dhost), MAC_ARG(hdr->ether_shost),        \
133            be16_to_cpu(hdr->ether_type));       \
134 } while (0)
135 
136 static void i82596_transmit(I82596State *s, uint32_t addr)
137 {
138     uint32_t tdb_p; /* Transmit Buffer Descriptor */
139 
140     /* TODO: Check flexible mode */
141     tdb_p = get_uint32(addr + 8);
142     while (tdb_p != I596_NULL) {
143         uint16_t size, len;
144         uint32_t tba;
145 
146         size = get_uint16(tdb_p);
147         len = size & SIZE_MASK;
148         tba = get_uint32(tdb_p + 8);
149         trace_i82596_transmit(len, tba);
150 
151         if (s->nic && len) {
152             assert(len <= sizeof(s->tx_buffer));
153             address_space_read(&address_space_memory, tba,
154                                MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len);
155             DBG(PRINT_PKTHDR("Send", &s->tx_buffer));
156             DBG(printf("Sending %d bytes\n", len));
157             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, len);
158         }
159 
160         /* was this the last package? */
161         if (size & I596_EOF) {
162             break;
163         }
164 
165         /* get next buffer pointer */
166         tdb_p = get_uint32(tdb_p + 4);
167     }
168 }
169 
170 static void set_individual_address(I82596State *s, uint32_t addr)
171 {
172     NetClientState *nc;
173     uint8_t *m;
174 
175     nc = qemu_get_queue(s->nic);
176     m = s->conf.macaddr.a;
177     address_space_read(&address_space_memory, addr + 8,
178                        MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN);
179     qemu_format_nic_info_str(nc, m);
180     trace_i82596_new_mac(nc->info_str);
181 }
182 
183 static void set_multicast_list(I82596State *s, uint32_t addr)
184 {
185     uint16_t mc_count, i;
186 
187     memset(&s->mult[0], 0, sizeof(s->mult));
188     mc_count = get_uint16(addr + 8) / ETH_ALEN;
189     addr += 10;
190     if (mc_count > MAX_MC_CNT) {
191         mc_count = MAX_MC_CNT;
192     }
193     for (i = 0; i < mc_count; i++) {
194         uint8_t multicast_addr[ETH_ALEN];
195         address_space_read(&address_space_memory, addr + i * ETH_ALEN,
196                            MEMTXATTRS_UNSPECIFIED, multicast_addr, ETH_ALEN);
197         DBG(printf("Add multicast entry " MAC_FMT "\n",
198                     MAC_ARG(multicast_addr)));
199         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
200                               BITS(7, 2)) >> 2;
201         assert(mcast_idx < 8 * sizeof(s->mult));
202         s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));
203     }
204     trace_i82596_set_multicast(mc_count);
205 }
206 
207 void i82596_set_link_status(NetClientState *nc)
208 {
209     I82596State *d = qemu_get_nic_opaque(nc);
210 
211     d->lnkst = nc->link_down ? 0 : 0x8000;
212 }
213 
214 static void update_scb_status(I82596State *s)
215 {
216     s->scb_status = (s->scb_status & 0xf000)
217         | (s->cu_status << 8) | (s->rx_status << 4);
218     set_uint16(s->scb, s->scb_status);
219 }
220 
221 
222 static void i82596_s_reset(I82596State *s)
223 {
224     trace_i82596_s_reset(s);
225     s->scp = 0;
226     s->scb_status = 0;
227     s->cu_status = CU_IDLE;
228     s->rx_status = RX_SUSPENDED;
229     s->cmd_p = I596_NULL;
230     s->lnkst = 0x8000; /* initial link state: up */
231     s->ca = s->ca_active = 0;
232     s->send_irq = 0;
233 }
234 
235 
236 static void command_loop(I82596State *s)
237 {
238     uint16_t cmd;
239     uint16_t status;
240     uint8_t byte_cnt;
241 
242     DBG(printf("STARTING COMMAND LOOP cmd_p=%08x\n", s->cmd_p));
243 
244     while (s->cmd_p != I596_NULL) {
245         /* set status */
246         status = STAT_B;
247         set_uint16(s->cmd_p, status);
248         status = STAT_C | STAT_OK; /* update, but write later */
249 
250         cmd = get_uint16(s->cmd_p + 2);
251         DBG(printf("Running command %04x at %08x\n", cmd, s->cmd_p));
252 
253         switch (cmd & 0x07) {
254         case CmdNOp:
255             break;
256         case CmdSASetup:
257             set_individual_address(s, s->cmd_p);
258             break;
259         case CmdConfigure:
260             byte_cnt = get_byte(s->cmd_p + 8) & 0x0f;
261             byte_cnt = MAX(byte_cnt, 4);
262             byte_cnt = MIN(byte_cnt, sizeof(s->config));
263             /* copy byte_cnt max. */
264             address_space_read(&address_space_memory, s->cmd_p + 8,
265                                MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt);
266             /* config byte according to page 35ff */
267             s->config[2] &= 0x82; /* mask valid bits */
268             s->config[2] |= 0x40;
269             s->config[7]  &= 0xf7; /* clear zero bit */
270             assert(I596_NOCRC_INS == 0); /* do CRC insertion */
271             s->config[10] = MAX(s->config[10], 5); /* min frame length */
272             s->config[12] &= 0x40; /* only full duplex field valid */
273             s->config[13] |= 0x3f; /* set ones in byte 13 */
274             break;
275         case CmdTDR:
276             /* get signal LINK */
277             set_uint32(s->cmd_p + 8, s->lnkst);
278             break;
279         case CmdTx:
280             i82596_transmit(s, s->cmd_p);
281             break;
282         case CmdMulticastList:
283             set_multicast_list(s, s->cmd_p);
284             break;
285         case CmdDump:
286         case CmdDiagnose:
287             printf("FIXME Command %d !!\n", cmd & 7);
288             assert(0);
289         }
290 
291         /* update status */
292         set_uint16(s->cmd_p, status);
293 
294         s->cmd_p = get_uint32(s->cmd_p + 4); /* get link address */
295         DBG(printf("NEXT addr would be %08x\n", s->cmd_p));
296         if (s->cmd_p == 0) {
297             s->cmd_p = I596_NULL;
298         }
299 
300         /* Stop when last command of the list. */
301         if (cmd & CMD_EOL) {
302             s->cmd_p = I596_NULL;
303         }
304         /* Suspend after doing cmd? */
305         if (cmd & CMD_SUSP) {
306             s->cu_status = CU_SUSPENDED;
307             printf("FIXME SUSPEND !!\n");
308         }
309         /* Interrupt after doing cmd? */
310         if (cmd & CMD_INTR) {
311             s->scb_status |= SCB_STATUS_CX;
312         } else {
313             s->scb_status &= ~SCB_STATUS_CX;
314         }
315         update_scb_status(s);
316 
317         /* Interrupt after doing cmd? */
318         if (cmd & CMD_INTR) {
319             s->send_irq = 1;
320         }
321 
322         if (s->cu_status != CU_ACTIVE) {
323             break;
324         }
325     }
326     DBG(printf("FINISHED COMMAND LOOP\n"));
327     qemu_flush_queued_packets(qemu_get_queue(s->nic));
328 }
329 
330 static void i82596_flush_queue_timer(void *opaque)
331 {
332     I82596State *s = opaque;
333     if (0) {
334         timer_del(s->flush_queue_timer);
335         qemu_flush_queued_packets(qemu_get_queue(s->nic));
336         timer_mod(s->flush_queue_timer,
337               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1000);
338     }
339 }
340 
341 static void examine_scb(I82596State *s)
342 {
343     uint16_t command, cuc, ruc;
344 
345     /* get the scb command word */
346     command = get_uint16(s->scb + 2);
347     cuc = (command >> 8) & 0x7;
348     ruc = (command >> 4) & 0x7;
349     DBG(printf("MAIN COMMAND %04x  cuc %02x ruc %02x\n", command, cuc, ruc));
350     /* and clear the scb command word */
351     set_uint16(s->scb + 2, 0);
352 
353     s->scb_status &= ~(command & SCB_COMMAND_ACK_MASK);
354 
355     switch (cuc) {
356     case 0:     /* no change */
357         break;
358     case 1:     /* CUC_START */
359         s->cu_status = CU_ACTIVE;
360         break;
361     case 4:     /* CUC_ABORT */
362         s->cu_status = CU_SUSPENDED;
363         s->scb_status |= SCB_STATUS_CNA; /* CU left active state */
364         break;
365     default:
366         printf("WARNING: Unknown CUC %d!\n", cuc);
367     }
368 
369     switch (ruc) {
370     case 0:     /* no change */
371         break;
372     case 1:     /* RX_START */
373     case 2:     /* RX_RESUME */
374         s->rx_status = RX_IDLE;
375         if (USE_TIMER) {
376             timer_mod(s->flush_queue_timer, qemu_clock_get_ms(
377                                 QEMU_CLOCK_VIRTUAL) + 1000);
378         }
379         break;
380     case 3:     /* RX_SUSPEND */
381     case 4:     /* RX_ABORT */
382         s->rx_status = RX_SUSPENDED;
383         s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
384         break;
385     default:
386         printf("WARNING: Unknown RUC %d!\n", ruc);
387     }
388 
389     if (command & 0x80) { /* reset bit set? */
390         i82596_s_reset(s);
391     }
392 
393     /* execute commands from SCBL */
394     if (s->cu_status != CU_SUSPENDED) {
395         if (s->cmd_p == I596_NULL) {
396             s->cmd_p = get_uint32(s->scb + 4);
397         }
398     }
399 
400     /* update scb status */
401     update_scb_status(s);
402 
403     command_loop(s);
404 }
405 
406 static void signal_ca(I82596State *s)
407 {
408     uint32_t iscp = 0;
409 
410     /* trace_i82596_channel_attention(s); */
411     if (s->scp) {
412         /* CA after reset -> do init with new scp. */
413         s->sysbus = get_byte(s->scp + 3); /* big endian */
414         DBG(printf("SYSBUS = %08x\n", s->sysbus));
415         if (((s->sysbus >> 1) & 0x03) != 2) {
416             printf("WARNING: NO LINEAR MODE !!\n");
417         }
418         if ((s->sysbus >> 7)) {
419             printf("WARNING: 32BIT LINMODE IN B-STEPPING NOT SUPPORTED !!\n");
420         }
421         iscp = get_uint32(s->scp + 8);
422         s->scb = get_uint32(iscp + 4);
423         set_byte(iscp + 1, 0); /* clear BUSY flag in iscp */
424         s->scp = 0;
425     }
426 
427     s->ca++;    /* count ca() */
428     if (!s->ca_active) {
429         s->ca_active = 1;
430         while (s->ca)   {
431             examine_scb(s);
432             s->ca--;
433         }
434         s->ca_active = 0;
435     }
436 
437     if (s->send_irq) {
438         s->send_irq = 0;
439         qemu_set_irq(s->irq, 1);
440     }
441 }
442 
443 void i82596_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
444 {
445     I82596State *s = opaque;
446     /* printf("i82596_ioport_writew addr=0x%08x val=0x%04x\n", addr, val); */
447     switch (addr) {
448     case PORT_RESET: /* Reset */
449         i82596_s_reset(s);
450         break;
451     case PORT_ALTSCP:
452         s->scp = val;
453         break;
454     case PORT_CA:
455         signal_ca(s);
456         break;
457     }
458 }
459 
460 uint32_t i82596_ioport_readw(void *opaque, uint32_t addr)
461 {
462     return -1;
463 }
464 
465 void i82596_h_reset(void *opaque)
466 {
467     I82596State *s = opaque;
468 
469     i82596_s_reset(s);
470 }
471 
472 bool i82596_can_receive(NetClientState *nc)
473 {
474     I82596State *s = qemu_get_nic_opaque(nc);
475 
476     if (s->rx_status == RX_SUSPENDED) {
477         return false;
478     }
479 
480     if (!s->lnkst) {
481         return false;
482     }
483 
484     if (USE_TIMER && !timer_pending(s->flush_queue_timer)) {
485         return true;
486     }
487 
488     return true;
489 }
490 
491 #define MIN_BUF_SIZE 60
492 
493 ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
494 {
495     I82596State *s = qemu_get_nic_opaque(nc);
496     uint32_t rfd_p;
497     uint32_t rbd;
498     uint16_t is_broadcast = 0;
499     size_t len = sz; /* length of data for guest (including CRC) */
500     size_t bufsz = sz; /* length of data in buf */
501     uint32_t crc;
502     uint8_t *crc_ptr;
503     uint8_t buf1[MIN_BUF_SIZE + VLAN_HLEN];
504     static const uint8_t broadcast_macaddr[6] = {
505                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
506 
507     DBG(printf("i82596_receive() start\n"));
508 
509     if (USE_TIMER && timer_pending(s->flush_queue_timer)) {
510         return 0;
511     }
512 
513     /* first check if receiver is enabled */
514     if (s->rx_status == RX_SUSPENDED) {
515         trace_i82596_receive_analysis(">>> Receiving suspended");
516         return -1;
517     }
518 
519     if (!s->lnkst) {
520         trace_i82596_receive_analysis(">>> Link down");
521         return -1;
522     }
523 
524     /* Received frame smaller than configured "min frame len"? */
525     if (sz < s->config[10]) {
526         printf("Received frame too small, %zu vs. %u bytes\n",
527                sz, s->config[10]);
528         return -1;
529     }
530 
531     DBG(printf("Received %lu bytes\n", sz));
532 
533     if (I596_PROMISC) {
534 
535         /* promiscuous: receive all */
536         trace_i82596_receive_analysis(
537                 ">>> packet received in promiscuous mode");
538 
539     } else {
540 
541         if (!memcmp(buf,  broadcast_macaddr, 6)) {
542             /* broadcast address */
543             if (I596_BC_DISABLE) {
544                 trace_i82596_receive_analysis(">>> broadcast packet rejected");
545 
546                 return len;
547             }
548 
549             trace_i82596_receive_analysis(">>> broadcast packet received");
550             is_broadcast = 1;
551 
552         } else if (buf[0] & 0x01) {
553             /* multicast */
554             if (!I596_MC_ALL) {
555                 trace_i82596_receive_analysis(">>> multicast packet rejected");
556 
557                 return len;
558             }
559 
560             int mcast_idx = (net_crc32(buf, ETH_ALEN) & BITS(7, 2)) >> 2;
561             assert(mcast_idx < 8 * sizeof(s->mult));
562 
563             if (!(s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7)))) {
564                 trace_i82596_receive_analysis(">>> multicast address mismatch");
565 
566                 return len;
567             }
568 
569             trace_i82596_receive_analysis(">>> multicast packet received");
570             is_broadcast = 1;
571 
572         } else if (!memcmp(s->conf.macaddr.a, buf, 6)) {
573 
574             /* match */
575             trace_i82596_receive_analysis(
576                     ">>> physical address matching packet received");
577 
578         } else {
579 
580             trace_i82596_receive_analysis(">>> unknown packet");
581 
582             return len;
583         }
584     }
585 
586     /* if too small buffer, then expand it */
587     if (len < MIN_BUF_SIZE + VLAN_HLEN) {
588         memcpy(buf1, buf, len);
589         memset(buf1 + len, 0, MIN_BUF_SIZE + VLAN_HLEN - len);
590         buf = buf1;
591         if (len < MIN_BUF_SIZE) {
592             len = MIN_BUF_SIZE;
593         }
594         bufsz = len;
595     }
596 
597     /* Calculate the ethernet checksum (4 bytes) */
598     len += 4;
599     crc = cpu_to_be32(crc32(~0, buf, sz));
600     crc_ptr = (uint8_t *) &crc;
601 
602     rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
603     assert(rfd_p && rfd_p != I596_NULL);
604 
605     /* get first Receive Buffer Descriptor Address */
606     rbd = get_uint32(rfd_p + 8);
607     assert(rbd && rbd != I596_NULL);
608 
609     trace_i82596_receive_packet(len);
610     /* PRINT_PKTHDR("Receive", buf); */
611 
612     while (len) {
613         uint16_t command, status;
614         uint32_t next_rfd;
615 
616         command = get_uint16(rfd_p + 2);
617         assert(command & CMD_FLEX); /* assert Flex Mode */
618         /* get first Receive Buffer Descriptor Address */
619         rbd = get_uint32(rfd_p + 8);
620         assert(get_uint16(rfd_p + 14) == 0);
621 
622         /* printf("Receive: rfd is %08x\n", rfd_p); */
623 
624         while (len) {
625             uint16_t buffer_size, num;
626             uint32_t rba;
627             size_t bufcount, crccount;
628 
629             /* printf("Receive: rbd is %08x\n", rbd); */
630             buffer_size = get_uint16(rbd + 12);
631             /* printf("buffer_size is 0x%x\n", buffer_size); */
632             assert(buffer_size != 0);
633 
634             num = buffer_size & SIZE_MASK;
635             if (num > len) {
636                 num = len;
637             }
638             rba = get_uint32(rbd + 8);
639             /* printf("rba is 0x%x\n", rba); */
640             /*
641              * Calculate how many bytes we want from buf[] and how many
642              * from the CRC.
643              */
644             if ((len - num) >= 4) {
645                 /* The whole guest buffer, we haven't hit the CRC yet */
646                 bufcount = num;
647             } else {
648                 /* All that's left of buf[] */
649                 bufcount = len - 4;
650             }
651             crccount = num - bufcount;
652 
653             if (bufcount > 0) {
654                 /* Still some of the actual data buffer to transfer */
655                 assert(bufsz >= bufcount);
656                 bufsz -= bufcount;
657                 address_space_write(&address_space_memory, rba,
658                                     MEMTXATTRS_UNSPECIFIED, buf, bufcount);
659                 rba += bufcount;
660                 buf += bufcount;
661                 len -= bufcount;
662             }
663 
664             /* Write as much of the CRC as fits */
665             if (crccount > 0) {
666                 address_space_write(&address_space_memory, rba,
667                                     MEMTXATTRS_UNSPECIFIED, crc_ptr, crccount);
668                 rba += crccount;
669                 crc_ptr += crccount;
670                 len -= crccount;
671             }
672 
673             num |= 0x4000; /* set F BIT */
674             if (len == 0) {
675                 num |= I596_EOF; /* set EOF BIT */
676             }
677             set_uint16(rbd + 0, num); /* write actual count with flags */
678 
679             /* get next rbd */
680             rbd = get_uint32(rbd + 4);
681             /* printf("Next Receive: rbd is %08x\n", rbd); */
682 
683             if (buffer_size & I596_EOF) /* last entry */
684                 break;
685         }
686 
687         /* Housekeeping, see pg. 18 */
688         next_rfd = get_uint32(rfd_p + 4);
689         set_uint32(next_rfd + 8, rbd);
690 
691         status = STAT_C | STAT_OK | is_broadcast;
692         set_uint16(rfd_p, status);
693 
694         if (command & CMD_SUSP) {  /* suspend after command? */
695             s->rx_status = RX_SUSPENDED;
696             s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
697             break;
698         }
699         if (command & CMD_EOL) /* was it last Frame Descriptor? */
700             break;
701 
702         assert(len == 0);
703     }
704 
705     assert(len == 0);
706 
707     s->scb_status |= SCB_STATUS_FR; /* set "RU finished receiving frame" bit. */
708     update_scb_status(s);
709 
710     /* send IRQ that we received data */
711     qemu_set_irq(s->irq, 1);
712     /* s->send_irq = 1; */
713 
714     if (0) {
715         DBG(printf("Checking:\n"));
716         rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
717         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
718         rfd_p = get_uint32(rfd_p + 4); /* get Next Receive Frame Descriptor */
719         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
720         /* get first Receive Buffer Descriptor Address */
721         rbd = get_uint32(rfd_p + 8);
722         DBG(printf("Next Receive: rbd is %08x\n", rbd));
723     }
724 
725     return sz;
726 }
727 
728 
729 const VMStateDescription vmstate_i82596 = {
730     .name = "i82596",
731     .version_id = 1,
732     .minimum_version_id = 1,
733     .fields = (VMStateField[]) {
734         VMSTATE_UINT16(lnkst, I82596State),
735         VMSTATE_TIMER_PTR(flush_queue_timer, I82596State),
736         VMSTATE_END_OF_LIST()
737     }
738 };
739 
740 void i82596_common_init(DeviceState *dev, I82596State *s, NetClientInfo *info)
741 {
742     if (s->conf.macaddr.a[0] == 0) {
743         qemu_macaddr_default_if_unset(&s->conf.macaddr);
744     }
745     s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)),
746                 dev->id, s);
747     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
748 
749     if (USE_TIMER) {
750         s->flush_queue_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
751                                     i82596_flush_queue_timer, s);
752     }
753     s->lnkst = 0x8000; /* initial link state: up */
754 }
755