sys/arch/mac68k/dev/if_sn.c

   1 /*      $NetBSD: if_sn.c,v 1.45.10.1 2007/06/26 18:12:52 garbled Exp $  */
   2
   3 /*
   4  * National Semiconductor  DP8393X SONIC Driver
   5  * Copyright (c) 1991   Algorithmics Ltd (http://www.algor.co.uk)
   6  * You may use, copy, and modify this program so long as you retain the
   7  * copyright line.
   8  *
   9  * This driver has been substantially modified since Algorithmics donated
  10  * it.
  11  *
  12  *   Denton Gentry <denny1@home.com>
  13  * and also
  14  *   Yanagisawa Takeshi <yanagisw@aa.ap.titech.ac.jp>
  15  * did the work to get this running on the Macintosh.
  16  */
  17
  18 #include <sys/cdefs.h>
  19 __KERNEL_RCSID(0, "$NetBSD: if_sn.c,v 1.45.10.1 2007/06/26 18:12:52 garbled Exp $");
  20
  21 #include <sys/param.h>
  22 #include <sys/systm.h>
  23
  24 #include <net/if.h>
  25 #include <net/if_ether.h>
  26
  27 #include <machine/bus.h>
  28
  29 #include <mac68k/dev/if_snvar.h>
  30
  31 static const uint8_t bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
  32 #define bbr(v)  ((bbr4[(v) & 0xf] << 4) | bbr4[((v) >> 4) & 0xf])
  33
  34 void
  35 sn_get_enaddr(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o,
  36     uint8_t *dst)
  37 {
  38         int i, do_bbr;
  39         uint8_t b;
  40
  41         /*
  42          * For reasons known only to Apple, MAC addresses in the ethernet
  43          * PROM are stored in Token Ring (IEEE 802.5) format, that is
  44          * with all of the bits in each byte reversed (canonical bit format).
  45          * When the address is read out it must be reversed to ethernet format
  46          * before use.
  47          *
  48          * Apple has been assigned OUI's 08:00:07 and 00:a0:40. All onboard
  49          * ethernet addresses on 68K machines should be in one of these
  50          * two ranges.
  51          *
  52          * Here is where it gets complicated.
  53          *
  54          * The PMac 7200, 7500, 8500, and 9500 accidentally had the PROM
  55          * written in standard ethernet format. The MacOS accounted for this
  56          * in these systems, and did not reverse the bytes. Some other
  57          * networking utilities were not so forgiving, and got confused.
  58          * "Some" of Apple's Nubus ethernet cards also had their bits
  59          * burned in ethernet format.
  60          *
  61          * Apple petitioned the IEEE and was granted the 00:05:02 (bit reversal
  62          * of 00:a0:40) as well. As of OpenTransport 1.1.1, Apple removed
  63          * their workaround and now reverses the bits regardless of
  64          * what kind of machine it is. So PMac systems and the affected
  65          * Nubus cards now use 00:05:02, instead of the 00:a0:40 for which they
  66          * were intended.
  67          *
  68          * See Apple Techinfo article TECHINFO-0020552, "OpenTransport 1.1.1
  69          * and MacOS System 7.5.3 FAQ (10/96)" for more details.
  70          */
  71         do_bbr = 0;
  72         b = bus_space_read_1(t, h, o);
  73         if (b == 0x10)
  74                 do_bbr = 1;
  75         dst[0] = (do_bbr) ? bbr(b) : b;
  76
  77         for (i = 1 ; i < ETHER_ADDR_LEN ; i++) {
  78                 b = bus_space_read_1(t, h, o + i);
  79                 dst[i] = (do_bbr) ? bbr(b) : b;
  80         }
  81 }