1 /*
2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <stdint.h>
22 #include <string.h>
23 #include <errno.h>
24 #include <assert.h>
25 #include <gpxe/nvs.h>
26
27 /** @file
28 *
29 * Non-volatile storage
30 *
31 */
32
33 /**
34 * Read from non-volatile storage device
35 *
36 * @v nvs NVS device
37 * @v address Address from which to read
38 * @v data Data buffer
39 * @v len Length of data buffer
40 * @ret rc Return status code
41 */
nvs_read(struct nvs_device * nvs,unsigned int address,void * data,size_t len)42 int nvs_read ( struct nvs_device *nvs, unsigned int address,
43 void *data, size_t len ) {
44 size_t frag_len;
45 int rc;
46
47 /* We don't even attempt to handle buffer lengths that aren't
48 * an integral number of words.
49 */
50 assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
51
52 while ( len ) {
53
54 /* Calculate space remaining up to next block boundary */
55 frag_len = ( ( nvs->block_size -
56 ( address & ( nvs->block_size - 1 ) ) )
57 << nvs->word_len_log2 );
58
59 /* Limit to space remaining in buffer */
60 if ( frag_len > len )
61 frag_len = len;
62
63 /* Read this portion of the buffer from the device */
64 if ( ( rc = nvs->read ( nvs, address, data, frag_len ) ) != 0 )
65 return rc;
66
67 /* Update parameters */
68 data += frag_len;
69 address += ( frag_len >> nvs->word_len_log2 );
70 len -= frag_len;
71 }
72
73 return 0;
74 }
75
76 /**
77 * Verify content of non-volatile storage device
78 *
79 * @v nvs NVS device
80 * @v address Address from which to read
81 * @v data Data to compare against
82 * @v len Length of data buffer
83 * @ret rc Return status code
84 */
nvs_verify(struct nvs_device * nvs,unsigned int address,const void * data,size_t len)85 static int nvs_verify ( struct nvs_device *nvs, unsigned int address,
86 const void *data, size_t len ) {
87 uint8_t read_data[len];
88 int rc;
89
90 /* Read data into temporary buffer */
91 if ( ( rc = nvs_read ( nvs, address, read_data, len ) ) != 0 )
92 return rc;
93
94 /* Compare data */
95 if ( memcmp ( data, read_data, len ) != 0 ) {
96 DBG ( "NVS %p verification failed at %#04x+%zd\n",
97 nvs, address, len );
98 return -EIO;
99 }
100
101 return 0;
102 }
103
104 /**
105 * Write to non-volatile storage device
106 *
107 * @v nvs NVS device
108 * @v address Address to which to write
109 * @v data Data buffer
110 * @v len Length of data buffer
111 * @ret rc Return status code
112 */
nvs_write(struct nvs_device * nvs,unsigned int address,const void * data,size_t len)113 int nvs_write ( struct nvs_device *nvs, unsigned int address,
114 const void *data, size_t len ) {
115 size_t frag_len;
116 int rc;
117
118 /* We don't even attempt to handle buffer lengths that aren't
119 * an integral number of words.
120 */
121 assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
122
123 while ( len ) {
124
125 /* Calculate space remaining up to next block boundary */
126 frag_len = ( ( nvs->block_size -
127 ( address & ( nvs->block_size - 1 ) ) )
128 << nvs->word_len_log2 );
129
130 /* Limit to space remaining in buffer */
131 if ( frag_len > len )
132 frag_len = len;
133
134 /* Write this portion of the buffer to the device */
135 if ( ( rc = nvs->write ( nvs, address, data, frag_len ) ) != 0)
136 return rc;
137
138 /* Read back and verify data */
139 if ( ( rc = nvs_verify ( nvs, address, data, frag_len ) ) != 0)
140 return rc;
141
142 /* Update parameters */
143 data += frag_len;
144 address += ( frag_len >> nvs->word_len_log2 );
145 len -= frag_len;
146 }
147
148 return 0;
149 }
150