1 /*
2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
3 * yaffs_ramdisk.c: yaffs ram disk component
4 *
5 * Copyright (C) 2002 Aleph One Ltd.
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 */
14
15 // This provides a rma disk under yaffs.
16 // NB this is not intended for NAND emulation.
17 // Use this with dev->useNANDECC enabled, then ECC overheads are not required.
18
19 const char *yaffs_ramdisk_c_version = "$Id: yaffs_ramdisk.c,v 1.2 2004/11/22 03:22:25 charles Exp $";
20
21
22 #include "yportenv.h"
23
24 #include "yaffs_ramdisk.h"
25 #include "yaffs_guts.h"
26 #include "devextras.h"
27 #include "yaffs_packedtags1.h"
28
29
30
31 #define SIZE_IN_MB 2
32
33 #define BLOCK_SIZE (32 * 528)
34 #define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
35
36
37
38
39
40 typedef struct
41 {
42 __u8 data[528]; // Data + spare
43 } yramdisk_Page;
44
45 typedef struct
46 {
47 yramdisk_Page page[32]; // The pages in the block
48
49 } yramdisk_Block;
50
51
52
53 typedef struct
54 {
55 yramdisk_Block **block;
56 int nBlocks;
57 } yramdisk_Device;
58
59 static yramdisk_Device ramdisk;
60
CheckInit(yaffs_Device * dev)61 static int CheckInit(yaffs_Device *dev)
62 {
63 static int initialised = 0;
64
65 int i;
66 int fail = 0;
67 //int nBlocks;
68 int nAllocated = 0;
69
70 if(initialised)
71 {
72 return YAFFS_OK;
73 }
74
75 initialised = 1;
76
77
78 ramdisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
79
80 ramdisk.block = YMALLOC(sizeof(yramdisk_Block *) * ramdisk.nBlocks);
81
82 if(!ramdisk.block) return 0;
83
84 for(i=0; i <ramdisk.nBlocks; i++)
85 {
86 ramdisk.block[i] = NULL;
87 }
88
89 for(i=0; i <ramdisk.nBlocks && !fail; i++)
90 {
91 if((ramdisk.block[i] = YMALLOC(sizeof(yramdisk_Block))) == 0)
92 {
93 fail = 1;
94 }
95 else
96 {
97 yramdisk_EraseBlockInNAND(dev,i);
98 nAllocated++;
99 }
100 }
101
102 if(fail)
103 {
104 for(i = 0; i < nAllocated; i++)
105 {
106 YFREE(ramdisk.block[i]);
107 }
108 YFREE(ramdisk.block);
109
110 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
111 nAllocated/64,ramdisk.nBlocks * 528));
112 return 0;
113 }
114
115
116 return 1;
117 }
118
yramdisk_WriteChunkWithTagsToNAND(yaffs_Device * dev,int chunkInNAND,const __u8 * data,yaffs_ExtendedTags * tags)119 int yramdisk_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
120 {
121 int blk;
122 int pg;
123
124
125 CheckInit(dev);
126
127 blk = chunkInNAND/32;
128 pg = chunkInNAND%32;
129
130
131 if(data)
132 {
133 memcpy(ramdisk.block[blk]->page[pg].data,data,512);
134 }
135
136
137 if(tags)
138 {
139 yaffs_PackedTags1 pt;
140
141 yaffs_PackTags1(&pt,tags);
142 memcpy(&ramdisk.block[blk]->page[pg].data[512],&pt,sizeof(pt));
143 }
144
145 return YAFFS_OK;
146
147 }
148
149
yramdisk_ReadChunkWithTagsFromNAND(yaffs_Device * dev,int chunkInNAND,__u8 * data,yaffs_ExtendedTags * tags)150 int yramdisk_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
151 {
152 int blk;
153 int pg;
154
155
156 CheckInit(dev);
157
158 blk = chunkInNAND/32;
159 pg = chunkInNAND%32;
160
161
162 if(data)
163 {
164 memcpy(data,ramdisk.block[blk]->page[pg].data,512);
165 }
166
167
168 if(tags)
169 {
170 yaffs_PackedTags1 pt;
171
172 memcpy(&pt,&ramdisk.block[blk]->page[pg].data[512],sizeof(pt));
173 yaffs_UnpackTags1(tags,&pt);
174
175 }
176
177 return YAFFS_OK;
178 }
179
180
yramdisk_CheckChunkErased(yaffs_Device * dev,int chunkInNAND)181 int yramdisk_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
182 {
183 int blk;
184 int pg;
185 int i;
186
187
188 CheckInit(dev);
189
190 blk = chunkInNAND/32;
191 pg = chunkInNAND%32;
192
193
194 for(i = 0; i < 528; i++)
195 {
196 if(ramdisk.block[blk]->page[pg].data[i] != 0xFF)
197 {
198 return YAFFS_FAIL;
199 }
200 }
201
202 return YAFFS_OK;
203
204 }
205
yramdisk_EraseBlockInNAND(yaffs_Device * dev,int blockNumber)206 int yramdisk_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
207 {
208
209 CheckInit(dev);
210
211 if(blockNumber < 0 || blockNumber >= ramdisk.nBlocks)
212 {
213 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
214 return YAFFS_FAIL;
215 }
216 else
217 {
218 memset(ramdisk.block[blockNumber],0xFF,sizeof(yramdisk_Block));
219 return YAFFS_OK;
220 }
221
222 }
223
yramdisk_InitialiseNAND(yaffs_Device * dev)224 int yramdisk_InitialiseNAND(yaffs_Device *dev)
225 {
226 //dev->useNANDECC = 1; // force on useNANDECC which gets faked.
227 // This saves us doing ECC checks.
228
229 return YAFFS_OK;
230 }
231
232
233