1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdint.h>
#include <assert.h>
#include <gpxe/nvs.h>
/** @file
*
* Non-volatile storage
*
*/
/**
* Read from non-volatile storage device
*
* @v nvs NVS device
* @v address Address from which to read
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
int nvs_read ( struct nvs_device *nvs, unsigned int address,
void *data, size_t len ) {
size_t frag_len;
int rc;
/* We don't even attempt to handle buffer lengths that aren't
* an integral number of words.
*/
assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
while ( len ) {
/* Calculate space remaining up to next block boundary */
frag_len = ( ( nvs->block_size -
( address & ( nvs->block_size - 1 ) ) )
<< nvs->word_len_log2 );
/* Limit to space remaining in buffer */
if ( frag_len > len )
frag_len = len;
/* Read this portion of the buffer from the device */
if ( ( rc = nvs->read ( nvs, address, data, frag_len ) ) != 0 )
return rc;
/* Update parameters */
data += frag_len;
address += ( frag_len >> nvs->word_len_log2 );
len -= frag_len;
}
return 0;
}
/**
* Write to non-volatile storage device
*
* @v nvs NVS device
* @v address Address to which to write
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
int nvs_write ( struct nvs_device *nvs, unsigned int address,
const void *data, size_t len ) {
size_t frag_len;
int rc;
/* We don't even attempt to handle buffer lengths that aren't
* an integral number of words.
*/
assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
while ( len ) {
/* Calculate space remaining up to next block boundary */
frag_len = ( ( nvs->block_size -
( address & ( nvs->block_size - 1 ) ) )
<< nvs->word_len_log2 );
/* Limit to space remaining in buffer */
if ( frag_len > len )
frag_len = len;
/* Read this portion of the buffer from the device */
if ( ( rc = nvs->write ( nvs, address, data, frag_len ) ) != 0)
return rc;
/* Update parameters */
data += frag_len;
address += ( frag_len >> nvs->word_len_log2 );
len -= frag_len;
}
return 0;
}
|
