if_mc.c revision 1.37 1 /* $NetBSD: if_mc.c,v 1.37 2010/01/19 22:06:20 pooka Exp $ */
2
3 /*-
4 * Copyright (c) 1997 David Huang <khym (at) azeotrope.org>
5 * All rights reserved.
6 *
7 * Portions of this code are based on code by Denton Gentry <denny1 (at) home.com>,
8 * Charles M. Hannum, Yanagisawa Takeshi <yanagisw (at) aa.ap.titech.ac.jp>, and
9 * Jason R. Thorpe.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 */
31
32 /*
33 * Driver for the AMD Am79C940 (MACE) ethernet chip, used for onboard
34 * ethernet on the Centris/Quadra 660av and Quadra 840av.
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: if_mc.c,v 1.37 2010/01/19 22:06:20 pooka Exp $");
39
40 #include "opt_ddb.h"
41 #include "opt_inet.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/mbuf.h>
46 #include <sys/buf.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
49 #include <sys/syslog.h>
50 #include <sys/ioctl.h>
51 #include <sys/errno.h>
52 #include <sys/device.h>
53
54 #include <uvm/uvm_extern.h>
55
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_ether.h>
59
60 #ifdef INET
61 #include <netinet/in.h>
62 #include <netinet/if_inarp.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/in_var.h>
65 #include <netinet/ip.h>
66 #endif
67
68
69
70 #include <net/bpf.h>
71 #include <net/bpfdesc.h>
72
73 #include <machine/bus.h>
74 #include <mac68k/dev/if_mcreg.h>
75 #include <mac68k/dev/if_mcvar.h>
76
77 hide void mcwatchdog(struct ifnet *);
78 hide int mcinit(struct mc_softc *);
79 hide int mcstop(struct mc_softc *);
80 hide int mcioctl(struct ifnet *, u_long, void *);
81 hide void mcstart(struct ifnet *);
82 hide void mcreset(struct mc_softc *);
83
84 integrate u_int maceput(struct mc_softc *, struct mbuf *);
85 integrate void mc_tint(struct mc_softc *);
86 integrate void mace_read(struct mc_softc *, void *, int);
87 integrate struct mbuf *mace_get(struct mc_softc *, void *, int);
88 static void mace_calcladrf(struct ethercom *, u_int8_t *);
89 static inline u_int16_t ether_cmp(void *, void *);
90
91
92 /*
93 * Compare two Ether/802 addresses for equality, inlined and
94 * unrolled for speed. Use this like memcmp().
95 *
96 * XXX: Add <machine/inlines.h> for stuff like this?
97 * XXX: or maybe add it to libkern.h instead?
98 *
99 * "I'd love to have an inline assembler version of this."
100 * XXX: Who wanted that? mycroft? I wrote one, but this
101 * version in C is as good as hand-coded assembly. -gwr
102 *
103 * Please do NOT tweak this without looking at the actual
104 * assembly code generated before and after your tweaks!
105 */
106 static inline u_int16_t
107 ether_cmp(void *one, void *two)
108 {
109 u_int16_t *a = (u_short *) one;
110 u_int16_t *b = (u_short *) two;
111 u_int16_t diff;
112
113 #ifdef m68k
114 /*
115 * The post-increment-pointer form produces the best
116 * machine code for m68k. This was carefully tuned
117 * so it compiles to just 8 short (2-byte) op-codes!
118 */
119 diff = *a++ - *b++;
120 diff |= *a++ - *b++;
121 diff |= *a++ - *b++;
122 #else
123 /*
124 * Most modern CPUs do better with a single expresion.
125 * Note that short-cut evaluation is NOT helpful here,
126 * because it just makes the code longer, not faster!
127 */
128 diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
129 #endif
130
131 return (diff);
132 }
133
134 #define ETHER_CMP ether_cmp
135
136 /*
137 * Interface exists: make available by filling in network interface
138 * record. System will initialize the interface when it is ready
139 * to accept packets.
140 */
141 int
142 mcsetup(struct mc_softc *sc, u_int8_t *lladdr)
143 {
144 struct ifnet *ifp = &sc->sc_if;
145
146 /* reset the chip and disable all interrupts */
147 NIC_PUT(sc, MACE_BIUCC, SWRST);
148 DELAY(100);
149 NIC_PUT(sc, MACE_IMR, ~0);
150
151 memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
152 printf(": address %s\n", ether_sprintf(lladdr));
153
154 memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ);
155 ifp->if_softc = sc;
156 ifp->if_ioctl = mcioctl;
157 ifp->if_start = mcstart;
158 ifp->if_flags =
159 IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
160 ifp->if_watchdog = mcwatchdog;
161
162 if_attach(ifp);
163 ether_ifattach(ifp, lladdr);
164
165 return (0);
166 }
167
168 hide int
169 mcioctl(struct ifnet *ifp, u_long cmd, void *data)
170 {
171 struct mc_softc *sc = ifp->if_softc;
172 struct ifaddr *ifa;
173
174 int s = splnet(), err = 0;
175
176 switch (cmd) {
177
178 case SIOCINITIFADDR:
179 ifa = (struct ifaddr *)data;
180 ifp->if_flags |= IFF_UP;
181 mcinit(sc);
182 switch (ifa->ifa_addr->sa_family) {
183 #ifdef INET
184 case AF_INET:
185 arp_ifinit(ifp, ifa);
186 break;
187 #endif
188 default:
189 break;
190 }
191 break;
192
193 case SIOCSIFFLAGS:
194 if ((err = ifioctl_common(ifp, cmd, data)) != 0)
195 break;
196 /* XXX see the comment in ed_ioctl() about code re-use */
197 if ((ifp->if_flags & IFF_UP) == 0 &&
198 (ifp->if_flags & IFF_RUNNING) != 0) {
199 /*
200 * If interface is marked down and it is running,
201 * then stop it.
202 */
203 mcstop(sc);
204 ifp->if_flags &= ~IFF_RUNNING;
205 } else if ((ifp->if_flags & IFF_UP) != 0 &&
206 (ifp->if_flags & IFF_RUNNING) == 0) {
207 /*
208 * If interface is marked up and it is stopped,
209 * then start it.
210 */
211 (void)mcinit(sc);
212 } else {
213 /*
214 * reset the interface to pick up any other changes
215 * in flags
216 */
217 mcreset(sc);
218 mcstart(ifp);
219 }
220 break;
221
222 case SIOCADDMULTI:
223 case SIOCDELMULTI:
224 if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
225 /*
226 * Multicast list has changed; set the hardware
227 * filter accordingly. But remember UP flag!
228 */
229 if (ifp->if_flags & IFF_RUNNING)
230 mcreset(sc);
231 err = 0;
232 }
233 break;
234 default:
235 err = ether_ioctl(ifp, cmd, data);
236 }
237 splx(s);
238 return (err);
239 }
240
241 /*
242 * Encapsulate a packet of type family for the local net.
243 */
244 hide void
245 mcstart(struct ifnet *ifp)
246 {
247 struct mc_softc *sc = ifp->if_softc;
248 struct mbuf *m;
249
250 if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
251 return;
252
253 while (1) {
254 if (ifp->if_flags & IFF_OACTIVE)
255 return;
256
257 IF_DEQUEUE(&ifp->if_snd, m);
258 if (m == 0)
259 return;
260
261 /*
262 * If bpf is listening on this interface, let it
263 * see the packet before we commit it to the wire.
264 */
265 if (ifp->if_bpf)
266 bpf_ops->bpf_mtap(ifp->if_bpf, m);
267
268 /*
269 * Copy the mbuf chain into the transmit buffer.
270 */
271 ifp->if_flags |= IFF_OACTIVE;
272 maceput(sc, m);
273
274 ifp->if_opackets++; /* # of pkts */
275 }
276 }
277
278 /*
279 * reset and restart the MACE. Called in case of fatal
280 * hardware/software errors.
281 */
282 hide void
283 mcreset(struct mc_softc *sc)
284 {
285 mcstop(sc);
286 mcinit(sc);
287 }
288
289 hide int
290 mcinit(struct mc_softc *sc)
291 {
292 int s;
293 u_int8_t maccc, ladrf[8];
294
295 if (sc->sc_if.if_flags & IFF_RUNNING)
296 /* already running */
297 return (0);
298
299 s = splnet();
300
301 NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
302 NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
303 NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
304 NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
305
306 NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
307
308 /* set MAC address */
309 NIC_PUT(sc, MACE_IAC, ADDRCHG);
310 while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
311 ;
312 NIC_PUT(sc, MACE_IAC, PHYADDR);
313 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
314 sc->sc_enaddr, ETHER_ADDR_LEN);
315
316 /* set logical address filter */
317 mace_calcladrf(&sc->sc_ethercom, ladrf);
318
319 NIC_PUT(sc, MACE_IAC, ADDRCHG);
320 while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
321 ;
322 NIC_PUT(sc, MACE_IAC, LOGADDR);
323 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
324 ladrf, 8);
325
326 NIC_PUT(sc, MACE_XMTFC, APADXMT);
327 /*
328 * No need to autostrip padding on receive... Ethernet frames
329 * don't have a length field, unlike 802.3 frames, so the MACE
330 * can't figure out the length of the packet anyways.
331 */
332 NIC_PUT(sc, MACE_RCVFC, 0);
333
334 maccc = ENXMT | ENRCV;
335 if (sc->sc_if.if_flags & IFF_PROMISC)
336 maccc |= PROM;
337
338 NIC_PUT(sc, MACE_MACCC, maccc);
339
340 if (sc->sc_bus_init)
341 (*sc->sc_bus_init)(sc);
342
343 /*
344 * Enable all interrupts except receive, since we use the DMA
345 * completion interrupt for that.
346 */
347 NIC_PUT(sc, MACE_IMR, RCVINTM);
348
349 /* flag interface as "running" */
350 sc->sc_if.if_flags |= IFF_RUNNING;
351 sc->sc_if.if_flags &= ~IFF_OACTIVE;
352
353 splx(s);
354 return (0);
355 }
356
357 /*
358 * close down an interface and free its buffers
359 * Called on final close of device, or if mcinit() fails
360 * part way through.
361 */
362 hide int
363 mcstop(struct mc_softc *sc)
364 {
365 int s;
366
367 s = splnet();
368
369 NIC_PUT(sc, MACE_BIUCC, SWRST);
370 DELAY(100);
371
372 sc->sc_if.if_timer = 0;
373 sc->sc_if.if_flags &= ~IFF_RUNNING;
374
375 splx(s);
376 return (0);
377 }
378
379 /*
380 * Called if any Tx packets remain unsent after 5 seconds,
381 * In all cases we just reset the chip, and any retransmission
382 * will be handled by higher level protocol timeouts.
383 */
384 hide void
385 mcwatchdog(struct ifnet *ifp)
386 {
387 struct mc_softc *sc = ifp->if_softc;
388
389 printf("mcwatchdog: resetting chip\n");
390 mcreset(sc);
391 }
392
393 /*
394 * stuff packet into MACE (at splnet)
395 */
396 integrate u_int
397 maceput(struct mc_softc *sc, struct mbuf *m)
398 {
399 struct mbuf *n;
400 u_int len, totlen = 0;
401 u_char *buff;
402
403 buff = (u_char*)sc->sc_txbuf + (sc->sc_txset == 0 ? 0 : 0x800);
404
405 for (; m; m = n) {
406 u_char *data = mtod(m, u_char *);
407 len = m->m_len;
408 totlen += len;
409 memcpy(buff, data, len);
410 buff += len;
411 MFREE(m, n);
412 }
413
414 if (totlen > PAGE_SIZE)
415 panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
416
417 #if 0
418 if (totlen < ETHERMIN + sizeof(struct ether_header)) {
419 int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
420 memset(sc->sc_txbuf + totlen, 0, pad);
421 totlen = ETHERMIN + sizeof(struct ether_header);
422 }
423 #endif
424
425 (*sc->sc_putpacket)(sc, totlen);
426
427 sc->sc_if.if_timer = 5; /* 5 seconds to watch for failing to transmit */
428 return (totlen);
429 }
430
431 void
432 mcintr(void *arg)
433 {
434 struct mc_softc *sc = arg;
435 u_int8_t ir;
436
437 ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
438 if (ir & JAB) {
439 #ifdef MCDEBUG
440 printf("%s: jabber error\n", sc->sc_dev.dv_xname);
441 #endif
442 sc->sc_if.if_oerrors++;
443 }
444
445 if (ir & BABL) {
446 #ifdef MCDEBUG
447 printf("%s: babble\n", sc->sc_dev.dv_xname);
448 #endif
449 sc->sc_if.if_oerrors++;
450 }
451
452 if (ir & CERR) {
453 #ifdef MCDEBUG
454 printf("%s: collision error\n", sc->sc_dev.dv_xname);
455 #endif
456 sc->sc_if.if_collisions++;
457 }
458
459 /*
460 * Pretend we have carrier; if we don't this will be cleared
461 * shortly.
462 */
463 sc->sc_havecarrier = 1;
464
465 if (ir & XMTINT)
466 mc_tint(sc);
467
468 if (ir & RCVINT)
469 mc_rint(sc);
470 }
471
472 integrate void
473 mc_tint(struct mc_softc *sc)
474 {
475 u_int8_t xmtrc, xmtfs;
476
477 xmtrc = NIC_GET(sc, MACE_XMTRC);
478 xmtfs = NIC_GET(sc, MACE_XMTFS);
479
480 if ((xmtfs & XMTSV) == 0)
481 return;
482
483 if (xmtfs & UFLO) {
484 printf("%s: underflow\n", sc->sc_dev.dv_xname);
485 mcreset(sc);
486 return;
487 }
488
489 if (xmtfs & LCOL) {
490 printf("%s: late collision\n", sc->sc_dev.dv_xname);
491 sc->sc_if.if_oerrors++;
492 sc->sc_if.if_collisions++;
493 }
494
495 if (xmtfs & MORE)
496 /* Real number is unknown. */
497 sc->sc_if.if_collisions += 2;
498 else if (xmtfs & ONE)
499 sc->sc_if.if_collisions++;
500 else if (xmtfs & RTRY) {
501 printf("%s: excessive collisions\n", sc->sc_dev.dv_xname);
502 sc->sc_if.if_collisions += 16;
503 sc->sc_if.if_oerrors++;
504 }
505
506 if (xmtfs & LCAR) {
507 sc->sc_havecarrier = 0;
508 printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
509 sc->sc_if.if_oerrors++;
510 }
511
512 sc->sc_if.if_flags &= ~IFF_OACTIVE;
513 sc->sc_if.if_timer = 0;
514 mcstart(&sc->sc_if);
515 }
516
517 void
518 mc_rint(struct mc_softc *sc)
519 {
520 #define rxf sc->sc_rxframe
521 u_int len;
522
523 len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
524
525 #ifdef MCDEBUG
526 if (rxf.rx_rcvsts & 0xf0)
527 printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
528 sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
529 rxf.rx_rntpc, rxf.rx_rcvcc);
530 #endif
531
532 if (rxf.rx_rcvsts & OFLO) {
533 printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
534 sc->sc_if.if_ierrors++;
535 return;
536 }
537
538 if (rxf.rx_rcvsts & CLSN)
539 sc->sc_if.if_collisions++;
540
541 if (rxf.rx_rcvsts & FRAM) {
542 #ifdef MCDEBUG
543 printf("%s: framing error\n", sc->sc_dev.dv_xname);
544 #endif
545 sc->sc_if.if_ierrors++;
546 return;
547 }
548
549 if (rxf.rx_rcvsts & FCS) {
550 #ifdef MCDEBUG
551 printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
552 #endif
553 sc->sc_if.if_ierrors++;
554 return;
555 }
556
557 mace_read(sc, rxf.rx_frame, len);
558 #undef rxf
559 }
560
561 integrate void
562 mace_read(struct mc_softc *sc, void *pkt, int len)
563 {
564 struct ifnet *ifp = &sc->sc_if;
565 struct mbuf *m;
566
567 if (len <= sizeof(struct ether_header) ||
568 len > ETHERMTU + sizeof(struct ether_header)) {
569 #ifdef MCDEBUG
570 printf("%s: invalid packet size %d; dropping\n",
571 sc->sc_dev.dv_xname, len);
572 #endif
573 ifp->if_ierrors++;
574 return;
575 }
576
577 m = mace_get(sc, pkt, len);
578 if (m == NULL) {
579 ifp->if_ierrors++;
580 return;
581 }
582
583 ifp->if_ipackets++;
584
585 /* Pass the packet to any BPF listeners. */
586 if (ifp->if_bpf)
587 bpf_ops->bpf_mtap(ifp->if_bpf, m);
588
589 /* Pass the packet up. */
590 (*ifp->if_input)(ifp, m);
591 }
592
593 /*
594 * Pull data off an interface.
595 * Len is length of data, with local net header stripped.
596 * We copy the data into mbufs. When full cluster sized units are present
597 * we copy into clusters.
598 */
599 integrate struct mbuf *
600 mace_get(struct mc_softc *sc, void *pkt, int totlen)
601 {
602 struct mbuf *m;
603 struct mbuf *top, **mp;
604 int len;
605
606 MGETHDR(m, M_DONTWAIT, MT_DATA);
607 if (m == 0)
608 return (0);
609 m->m_pkthdr.rcvif = &sc->sc_if;
610 m->m_pkthdr.len = totlen;
611 len = MHLEN;
612 top = 0;
613 mp = ⊤
614
615 while (totlen > 0) {
616 if (top) {
617 MGET(m, M_DONTWAIT, MT_DATA);
618 if (m == 0) {
619 m_freem(top);
620 return 0;
621 }
622 len = MLEN;
623 }
624 if (totlen >= MINCLSIZE) {
625 MCLGET(m, M_DONTWAIT);
626 if ((m->m_flags & M_EXT) == 0) {
627 m_free(m);
628 m_freem(top);
629 return 0;
630 }
631 len = MCLBYTES;
632 }
633 m->m_len = len = min(totlen, len);
634 memcpy(mtod(m, void *), pkt, len);
635 pkt = (char*)pkt + len;
636 totlen -= len;
637 *mp = m;
638 mp = &m->m_next;
639 }
640
641 return (top);
642 }
643
644 /*
645 * Go through the list of multicast addresses and calculate the logical
646 * address filter.
647 */
648 void
649 mace_calcladrf(struct ethercom *ac, u_int8_t *af)
650 {
651 struct ifnet *ifp = &ac->ec_if;
652 struct ether_multi *enm;
653 u_char *cp;
654 u_int32_t crc;
655 static const u_int32_t crctab[] = {
656 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
657 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
658 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
659 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
660 };
661 int len;
662 struct ether_multistep step;
663
664 /*
665 * Set up multicast address filter by passing all multicast addresses
666 * through a crc generator, and then using the high order 6 bits as an
667 * index into the 64 bit logical address filter. The high order bit
668 * selects the word, while the rest of the bits select the bit within
669 * the word.
670 */
671
672 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
673 ETHER_FIRST_MULTI(step, ac, enm);
674 while (enm != NULL) {
675 if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
676 /*
677 * We must listen to a range of multicast addresses.
678 * For now, just accept all multicasts, rather than
679 * trying to set only those filter bits needed to match
680 * the range. (At this time, the only use of address
681 * ranges is for IP multicast routing, for which the
682 * range is big enough to require all bits set.)
683 */
684 goto allmulti;
685 }
686
687 cp = enm->enm_addrlo;
688 crc = 0xffffffff;
689 for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
690 crc ^= *cp++;
691 crc = (crc >> 4) ^ crctab[crc & 0xf];
692 crc = (crc >> 4) ^ crctab[crc & 0xf];
693 }
694 /* Just want the 6 most significant bits. */
695 crc >>= 26;
696
697 /* Set the corresponding bit in the filter. */
698 af[crc >> 3] |= 1 << (crc & 7);
699
700 ETHER_NEXT_MULTI(step, enm);
701 }
702 ifp->if_flags &= ~IFF_ALLMULTI;
703 return;
704
705 allmulti:
706 ifp->if_flags |= IFF_ALLMULTI;
707 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
708 }
709
710 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
711 #define bbr(v) ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
712
713 u_char
714 mc_get_enaddr(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o,
715 u_char *dst)
716 {
717 int i;
718 u_char b, csum;
719
720 /*
721 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
722 * valid
723 */
724 for (i = 0, csum = 0; i < 8; i++) {
725 b = bus_space_read_1(t, h, o+16*i);
726 if (i < ETHER_ADDR_LEN)
727 dst[i] = bbr(b);
728 csum ^= b;
729 }
730
731 return csum;
732 }
733