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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/syslib/prep_nvram.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc/syslib/prep_nvram.c')
-rw-r--r--arch/ppc/syslib/prep_nvram.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/ppc/syslib/prep_nvram.c b/arch/ppc/syslib/prep_nvram.c
new file mode 100644
index 000000000000..2bcf8a16d1c9
--- /dev/null
+++ b/arch/ppc/syslib/prep_nvram.c
@@ -0,0 +1,141 @@
1/*
2 * arch/ppc/kernel/prep_nvram.c
3 *
4 * Copyright (C) 1998 Corey Minyard
5 *
6 * This reads the NvRAM on PReP compliant machines (generally from IBM or
7 * Motorola). Motorola kept the format of NvRAM in their ROM, PPCBUG, the
8 * same, long after they had stopped producing PReP compliant machines. So
9 * this code is useful in those cases as well.
10 *
11 */
12#include <linux/init.h>
13#include <linux/delay.h>
14#include <linux/slab.h>
15#include <linux/ioport.h>
16
17#include <asm/sections.h>
18#include <asm/segment.h>
19#include <asm/io.h>
20#include <asm/machdep.h>
21#include <asm/prep_nvram.h>
22
23static char nvramData[MAX_PREP_NVRAM];
24static NVRAM_MAP *nvram=(NVRAM_MAP *)&nvramData[0];
25
26unsigned char __prep prep_nvram_read_val(int addr)
27{
28 outb(addr, PREP_NVRAM_AS0);
29 outb(addr>>8, PREP_NVRAM_AS1);
30 return inb(PREP_NVRAM_DATA);
31}
32
33void __prep prep_nvram_write_val(int addr,
34 unsigned char val)
35{
36 outb(addr, PREP_NVRAM_AS0);
37 outb(addr>>8, PREP_NVRAM_AS1);
38 outb(val, PREP_NVRAM_DATA);
39}
40
41void __init init_prep_nvram(void)
42{
43 unsigned char *nvp;
44 int i;
45 int nvramSize;
46
47 /*
48 * The following could fail if the NvRAM were corrupt but
49 * we expect the boot firmware to have checked its checksum
50 * before boot
51 */
52 nvp = (char *) &nvram->Header;
53 for (i=0; i<sizeof(HEADER); i++)
54 {
55 *nvp = ppc_md.nvram_read_val(i);
56 nvp++;
57 }
58
59 /*
60 * The PReP NvRAM may be any size so read in the header to
61 * determine how much we must read in order to get the complete
62 * GE area
63 */
64 nvramSize=(int)nvram->Header.GEAddress+nvram->Header.GELength;
65 if(nvramSize>MAX_PREP_NVRAM)
66 {
67 /*
68 * NvRAM is too large
69 */
70 nvram->Header.GELength=0;
71 return;
72 }
73
74 /*
75 * Read the remainder of the PReP NvRAM
76 */
77 nvp = (char *) &nvram->GEArea[0];
78 for (i=sizeof(HEADER); i<nvramSize; i++)
79 {
80 *nvp = ppc_md.nvram_read_val(i);
81 nvp++;
82 }
83}
84
85__prep
86char __prep *prep_nvram_get_var(const char *name)
87{
88 char *cp;
89 int namelen;
90
91 namelen = strlen(name);
92 cp = prep_nvram_first_var();
93 while (cp != NULL) {
94 if ((strncmp(name, cp, namelen) == 0)
95 && (cp[namelen] == '='))
96 {
97 return cp+namelen+1;
98 }
99 cp = prep_nvram_next_var(cp);
100 }
101
102 return NULL;
103}
104
105__prep
106char __prep *prep_nvram_first_var(void)
107{
108 if (nvram->Header.GELength == 0) {
109 return NULL;
110 } else {
111 return (((char *)nvram)
112 + ((unsigned int) nvram->Header.GEAddress));
113 }
114}
115
116__prep
117char __prep *prep_nvram_next_var(char *name)
118{
119 char *cp;
120
121
122 cp = name;
123 while (((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength)
124 && (*cp != '\0'))
125 {
126 cp++;
127 }
128
129 /* Skip over any null characters. */
130 while (((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength)
131 && (*cp == '\0'))
132 {
133 cp++;
134 }
135
136 if ((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength) {
137 return cp;
138 } else {
139 return NULL;
140 }
141}