1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * init.c:  Initialize internal variables used by the PROM
4  *          library functions.
5  *
6  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7  * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 
14 #include <asm/openprom.h>
15 #include <asm/oplib.h>
16 
17 struct linux_romvec *romvec;
18 EXPORT_SYMBOL(romvec);
19 
20 enum prom_major_version prom_vers;
21 unsigned int prom_rev, prom_prev;
22 
23 /* The root node of the prom device tree. */
24 phandle prom_root_node;
25 EXPORT_SYMBOL(prom_root_node);
26 
27 /* Pointer to the device tree operations structure. */
28 struct linux_nodeops *prom_nodeops;
29 
30 /* You must call prom_init() before you attempt to use any of the
31  * routines in the prom library.
32  * It gets passed the pointer to the PROM vector.
33  */
34 
prom_init(struct linux_romvec * rp)35 void __init prom_init(struct linux_romvec *rp)
36 {
37 	romvec = rp;
38 
39 	switch(romvec->pv_romvers) {
40 	case 0:
41 		prom_vers = PROM_V0;
42 		break;
43 	case 2:
44 		prom_vers = PROM_V2;
45 		break;
46 	case 3:
47 		prom_vers = PROM_V3;
48 		break;
49 	default:
50 		prom_printf("PROMLIB: Bad PROM version %d\n",
51 			    romvec->pv_romvers);
52 		prom_halt();
53 		break;
54 	}
55 
56 	prom_rev = romvec->pv_plugin_revision;
57 	prom_prev = romvec->pv_printrev;
58 	prom_nodeops = romvec->pv_nodeops;
59 
60 	prom_root_node = prom_getsibling(0);
61 	if ((prom_root_node == 0) || ((s32)prom_root_node == -1))
62 		prom_halt();
63 
64 	if((((unsigned long) prom_nodeops) == 0) ||
65 	   (((unsigned long) prom_nodeops) == -1))
66 		prom_halt();
67 
68 	prom_meminit();
69 
70 	prom_ranges_init();
71 
72 	printk("PROMLIB: Sun Boot Prom Version %d Revision %d\n",
73 	       romvec->pv_romvers, prom_rev);
74 
75 	/* Initialization successful. */
76 }
77