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 YAFFS nand emulation on a file.
16 // THis is only intended as test code to test persistence etc.
17
18 const char *yaffs_flashif_c_version = "$Id: yaffs_fileem.c,v 1.1 2004/11/03 08:29:28 charles Exp $";
19
20
21 #include "yportenv.h"
22
23 #include "yaffs_flashif.h"
24 #include "yaffs_guts.h"
25
26 #include "devextras.h"
27
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32
33
34
35 #define SIZE_IN_MB 16
36
37 #define BLOCK_SIZE (32 * 528)
38 #define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
39
40
41
42 typedef struct
43 {
44 __u8 data[528]; // Data + spare
45 } yflash_Page;
46
47 typedef struct
48 {
49 yflash_Page page[32]; // The pages in the block
50
51 } yflash_Block;
52
53
54
55 typedef struct
56 {
57 int handle;
58 int nBlocks;
59 } yflash_Device;
60
61 static yflash_Device filedisk;
62
CheckInit(yaffs_Device * dev)63 static int CheckInit(yaffs_Device *dev)
64 {
65 static int initialised = 0;
66
67 int i;
68
69
70 int fSize;
71 int written;
72
73 yflash_Page p;
74
75 if(initialised)
76 {
77 return YAFFS_OK;
78 }
79
80 initialised = 1;
81
82
83 filedisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
84
85 filedisk.handle = open("yaffsemfile", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
86
87 if(filedisk.handle < 0)
88 {
89 perror("Failed to open yaffs emulation file");
90 return YAFFS_FAIL;
91 }
92
93
94 fSize = lseek(filedisk.handle,0,SEEK_END);
95
96 if(fSize < SIZE_IN_MB * 1024 * 1024)
97 {
98 printf("Creating yaffs emulation file\n");
99
100 lseek(filedisk.handle,0,SEEK_SET);
101
102 memset(&p,0xff,sizeof(yflash_Page));
103
104 for(i = 0; i < SIZE_IN_MB * 1024 * 1024; i+= 512)
105 {
106 written = write(filedisk.handle,&p,sizeof(yflash_Page));
107
108 if(written != sizeof(yflash_Page))
109 {
110 printf("Write failed\n");
111 return YAFFS_FAIL;
112 }
113 }
114 }
115
116 return 1;
117 }
118
yflash_WriteChunkToNAND(yaffs_Device * dev,int chunkInNAND,const __u8 * data,const yaffs_Spare * spare)119 int yflash_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_Spare *spare)
120 {
121 int written;
122
123 CheckInit(dev);
124
125
126
127 if(data)
128 {
129 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
130 written = write(filedisk.handle,data,512);
131
132 if(written != 512) return YAFFS_FAIL;
133 }
134
135 if(spare)
136 {
137 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
138 written = write(filedisk.handle,spare,16);
139
140 if(written != 16) return YAFFS_FAIL;
141 }
142
143
144 return YAFFS_OK;
145
146 }
147
148
yflash_ReadChunkFromNAND(yaffs_Device * dev,int chunkInNAND,__u8 * data,yaffs_Spare * spare)149 int yflash_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
150 {
151 int nread;
152
153 CheckInit(dev);
154
155
156
157 if(data)
158 {
159 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
160 nread = read(filedisk.handle,data,512);
161
162 if(nread != 512) return YAFFS_FAIL;
163 }
164
165 if(spare)
166 {
167 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
168 nread= read(filedisk.handle,spare,16);
169
170 if(nread != 16) return YAFFS_FAIL;
171 }
172
173
174 return YAFFS_OK;
175
176 }
177
178
yflash_EraseBlockInNAND(yaffs_Device * dev,int blockNumber)179 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
180 {
181
182 int i;
183
184 CheckInit(dev);
185
186 if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
187 {
188 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
189 return YAFFS_FAIL;
190 }
191 else
192 {
193
194 yflash_Page pg;
195
196 memset(&pg,0xff,sizeof(yflash_Page));
197
198 lseek(filedisk.handle, blockNumber * 32 * 528, SEEK_SET);
199
200 for(i = 0; i < 32; i++)
201 {
202 write(filedisk.handle,&pg,528);
203 }
204 return YAFFS_OK;
205 }
206
207 }
208
yflash_InitialiseNAND(yaffs_Device * dev)209 int yflash_InitialiseNAND(yaffs_Device *dev)
210 {
211 dev->useNANDECC = 1; // force on useNANDECC which gets faked.
212 // This saves us doing ECC checks.
213
214 return YAFFS_OK;
215 }
216
217
218