xref: /openbmc/linux/arch/sparc/kernel/idprom.c (revision cfbb9be8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * idprom.c: Routines to load the idprom into kernel addresses and
4  *           interpret the data contained within.
5  *
6  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/init.h>
12 #include <linux/export.h>
13 #include <linux/etherdevice.h>
14 
15 #include <asm/oplib.h>
16 #include <asm/idprom.h>
17 
18 struct idprom *idprom;
19 EXPORT_SYMBOL(idprom);
20 
21 static struct idprom idprom_buffer;
22 
23 #ifdef CONFIG_SPARC32
24 #include <asm/machines.h>  /* Fun with Sun released architectures. */
25 
26 /* Here is the master table of Sun machines which use some implementation
27  * of the Sparc CPU and have a meaningful IDPROM machtype value that we
28  * know about.  See asm-sparc/machines.h for empirical constants.
29  */
30 static struct Sun_Machine_Models Sun_Machines[] = {
31 /* First, Leon */
32 { .name = "Leon3 System-on-a-Chip",  .id_machtype = (M_LEON | M_LEON3_SOC) },
33 /* Finally, early Sun4m's */
34 { .name = "Sun4m SparcSystem600",    .id_machtype = (SM_SUN4M | SM_4M_SS60) },
35 { .name = "Sun4m SparcStation10/20", .id_machtype = (SM_SUN4M | SM_4M_SS50) },
36 { .name = "Sun4m SparcStation5",     .id_machtype = (SM_SUN4M | SM_4M_SS40) },
37 /* One entry for the OBP arch's which are sun4d, sun4e, and newer sun4m's */
38 { .name = "Sun4M OBP based system",  .id_machtype = (SM_SUN4M_OBP | 0x0) } };
39 
40 static void __init display_system_type(unsigned char machtype)
41 {
42 	char sysname[128];
43 	register int i;
44 
45 	for (i = 0; i < ARRAY_SIZE(Sun_Machines); i++) {
46 		if (Sun_Machines[i].id_machtype == machtype) {
47 			if (machtype != (SM_SUN4M_OBP | 0x00) ||
48 			    prom_getproperty(prom_root_node, "banner-name",
49 					     sysname, sizeof(sysname)) <= 0)
50 				printk(KERN_WARNING "TYPE: %s\n",
51 				       Sun_Machines[i].name);
52 			else
53 				printk(KERN_WARNING "TYPE: %s\n", sysname);
54 			return;
55 		}
56 	}
57 
58 	prom_printf("IDPROM: Warning, bogus id_machtype value, 0x%x\n", machtype);
59 }
60 #else
61 static void __init display_system_type(unsigned char machtype)
62 {
63 }
64 #endif
65 
66 unsigned char *arch_get_platform_mac_address(void)
67 {
68 	return idprom->id_ethaddr;
69 }
70 
71 /* Calculate the IDPROM checksum (xor of the data bytes). */
72 static unsigned char __init calc_idprom_cksum(struct idprom *idprom)
73 {
74 	unsigned char cksum, i, *ptr = (unsigned char *)idprom;
75 
76 	for (i = cksum = 0; i <= 0x0E; i++)
77 		cksum ^= *ptr++;
78 
79 	return cksum;
80 }
81 
82 /* Create a local IDPROM copy, verify integrity, and display information. */
83 void __init idprom_init(void)
84 {
85 	prom_get_idprom((char *) &idprom_buffer, sizeof(idprom_buffer));
86 
87 	idprom = &idprom_buffer;
88 
89 	if (idprom->id_format != 0x01)
90 		prom_printf("IDPROM: Warning, unknown format type!\n");
91 
92 	if (idprom->id_cksum != calc_idprom_cksum(idprom))
93 		prom_printf("IDPROM: Warning, checksum failure (nvram=%x, calc=%x)!\n",
94 			    idprom->id_cksum, calc_idprom_cksum(idprom));
95 
96 	display_system_type(idprom->id_machtype);
97 
98 	printk(KERN_WARNING "Ethernet address: %pM\n", idprom->id_ethaddr);
99 }
100