1 /* $NetBSD: if_sn.c,v 1.47 2007/10/17 19:55:13 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 1.47 2007/10/17 19:55:13 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 } 82