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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
/********************* (C) COPYRIGHT 2015 e-Design Co.,Ltd. ********************
File Name : 2FAT12.c
Version : S100 APP Ver 2.11
Description:
Author : bure & Celery
Data: 2015/08/03
History:
2015/08/03 ͳһ������
*******************************************************************************/
#include <string.h>
#include "FAT12.h"
#include "Bios.h"
#define FAT_LEN 0x1800
#define FAT1_BASE 0x00001000 // FAT1
#define FAT2_BASE 0x00002800 // FAT2
#define ROOT_BASE 0x00004000 //
#define FILE_BASE 0x00008000 //
#define SEC_LEN 0x200 //
#define FAT1_SEC 0x0C // FAT1
#define FAT2_SEC 0x0C // FAT2
#define OK 0 //
#define SEC_ERR 1 //
#define FAT_ERR 2 //
#define OVER 3 //
#define NEW 4 //
#define END 0xFFF //
#define OW 0 //
#define RW 1 //
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 NextCluster(u16* pCluster) {
u16 FatNum;
u32 Addr = FAT1_BASE + (*pCluster + *pCluster / 2);
*(pCluster + 1) = *pCluster; // ����ǰһ���غ�
// *(pCluster+1)= 0;
if ((*pCluster >= END) || (*pCluster < 2))
return OK;
if (ReadDiskData((u8*) &FatNum, Addr, 2) != OK)
return SEC_ERR;
*pCluster = (*pCluster & 1) ? (FatNum >> 4) : (FatNum & 0x0FFF); // ָ����һ���غ�
return OK;
}
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 ReadFileSec(u8* pBuffer, u16* pCluster) {
u32 ReadAddr = FILE_BASE + SEC_LEN * (*pCluster - 2);
if (ReadDiskData(pBuffer, ReadAddr, 256) != OK)
return SEC_ERR; // ��ǰ������
pBuffer += 256;
ReadAddr += 256;
if (ReadDiskData(pBuffer, ReadAddr, 256) != OK)
return SEC_ERR; // Failed to read the sector
if (NextCluster(pCluster) != 0)
return FAT_ERR; // ȡ��һ���غ�
return OK;
}
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 ProgFileSec(u8* pBuffer, u16* pCluster) {
u16 Tmp;
u32 ProgAddr = FILE_BASE + SEC_LEN * (*pCluster - 2);
if (ProgDiskPage(pBuffer, ProgAddr) != OK)
return SEC_ERR; // дǰ������
pBuffer += 256;
ProgAddr += 256;
if (ProgDiskPage(pBuffer, ProgAddr) != OK)
return SEC_ERR; // ������
Tmp = *pCluster;
switch (Tmp) {
case 0: // ���дغ�
case 1: // ���дغ�
if (SeekBlank(pBuffer, pCluster) != OK)
return OVER;
if (SetCluster(pBuffer, pCluster) != OK)
return SEC_ERR;
*(pCluster + 1) = Tmp;
return OK;
case END: // ���ӽ���
default:
if (NextCluster(pCluster) != OK)
return FAT_ERR; // ȡ��һ���غ�
return OK;
}
}
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 SeekBlank(u8* pBuffer, u16* pCluster) {
u16 Offset, Tmp, i, n = 0;
u32 SecAddr;
for (i = 0; i < 4096; i++) {
Offset = i + i / 2;
if ((Offset % 256) == 0) {
SecAddr = FAT1_BASE + (Offset & (~0xFF));
if (ReadDiskData(pBuffer, SecAddr, 258) != 0)
return SEC_ERR;
}
Offset %= 256;
Tmp = pBuffer[Offset] + (pBuffer[Offset + 1] << 8);
Tmp = (i & 1) ? (Tmp >> 4) : (Tmp & 0xFFF);
if (Tmp == 0) {
*pCluster++ = i;
n++;
if (n > 1)
return OK;
}
}
*(pCluster + 1) = 0xFFF;
return OK;
}
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 SetCluster(u8* pBuffer, u16* pCluster) {
u16 Offset, Tmp, i, k;
u32 SecAddr;
i = *pCluster; // ��ȡԭ��ǰ�غ�
k = *(pCluster + 1); // ��ȡ��һ�غ�
*pCluster = k;
Offset = i + i / 2;
SecAddr = FAT1_BASE + (Offset & (~0xFF));
Tmp = Offset & 0xFF;
if (ReadDiskData(pBuffer, SecAddr, 256) != 0)
return SEC_ERR;
if (i & 1)
pBuffer[Tmp] = ((k << 4) & 0xF0) + (pBuffer[Tmp] & 0x0F);
else
pBuffer[Tmp] = k;
if (Tmp++ < 256) {
if (i & 1)
pBuffer[Tmp] = k >> 4;
else
pBuffer[Tmp] = ((k >> 8) & 0x0F) + (pBuffer[Tmp] & 0xF0);
if (ProgDiskPage(pBuffer, SecAddr) != 0)
return SEC_ERR;
} else {
if (ProgDiskPage(pBuffer, SecAddr) != 0)
return SEC_ERR;
SecAddr += 256;
if (ReadDiskData(pBuffer, SecAddr, 256) != 0)
return SEC_ERR;
if (i & 1)
pBuffer[0] = k >> 4;
else
pBuffer[0] = ((k >> 8) & 0x0F) + (pBuffer[0] & 0xF0);
if (ProgDiskPage(pBuffer, SecAddr) != 0)
return SEC_ERR;
}
return OK;
}
/*******************************************************************************
Function:
Description:
Input:
*******************************************************************************/
u8 FAT_SearchFile(u8* pBuffer, u8* pFileName, u16* pCluster, u32* pDirAddr,
u32* flag) {
u16 i, n;
*pCluster = 0;
for (*pDirAddr = ROOT_BASE; *pDirAddr < FILE_BASE;) {
if (ReadDiskData(pBuffer, *pDirAddr, 256) != OK)
return SEC_ERR;
for (n = 0; n < 256; n += 32) {
for (i = 0; i < 4; i++) {
if (pBuffer[n + i] != 0) {
if (pBuffer[n + i] != pFileName[i])
break;
if (i == 3) { // �ҵ��ļ���
*pCluster = *(u16*) (pBuffer + n + 0x1A); // �ļ���һ���غ�
return OK;
}
} else
return NEW; // ������һ���հ�Ŀ¼���
}
*pDirAddr += 32;
}
}
return OVER;
}
/*******************************************************************************
Function:OpenFileRd
Description: Opens a file for reading from
Input:
*******************************************************************************/
u8 OpenFileRd(u8* pBuffer, u8* pFileName, u16* pCluster, u32* pDirAddr) {
u16 i, n;
*pCluster = 0;
for (*pDirAddr = ROOT_BASE; *pDirAddr < FILE_BASE;) {
if (ReadDiskData(pBuffer, *pDirAddr, 256) != OK)
return SEC_ERR;
for (n = 0; n < 256; n += 32) {
for (i = 0; i < 11; i++) {
if (pBuffer[n + i] != 0) {
if (pBuffer[n + i] != pFileName[i])
break;
if (i == 10) { // �ҵ��ļ���
*pCluster = *(u16*) (pBuffer + n + 0x1A); // �ļ���һ���غ�
return OK;
}
} else
return NEW; // ������һ���հ�Ŀ¼���
}
*pDirAddr += 32;
}
}
return OVER;
}
/*******************************************************************************
Function: OpenFileWr
Description: Opens a file for writing to
Input:
*******************************************************************************/
u8 OpenFileWr(u8* pBuffer, u8* pFileName, u16* pCluster, u32* pDirAddr) {
u16 i, n;
i = OpenFileRd(pBuffer, pFileName, pCluster, pDirAddr);
if (i != NEW)
return i;
else { // ��ǰ��Ϊ�հ�Ŀ¼��
if (SeekBlank(pBuffer, pCluster) != OK)
return OVER; // ��FAT��������
n = *pDirAddr & 0xFF; // nΪ��ǰҳĿ¼��
if (ReadDiskData(pBuffer, (*pDirAddr) - n, 256) != OK)
return SEC_ERR;
for (i = 0; i < 11; i++)
pBuffer[n + i] = pFileName[i]; // ������Ŀ¼��
*(u16*) (pBuffer + n + 0x1A) = *pCluster;
if (ProgDiskPage(pBuffer, (*pDirAddr) - n) != OK)
return SEC_ERR;
return OK;
}
}
/*******************************************************************************
Function: CloseFile
Description: Closes a file that was previously opened
Input:
*******************************************************************************/
u8 CloseFile(u8* pBuffer, u32 Lenght, u16* pCluster, u32* pDirAddr) {
u16 n;
// *pCluster = *(pCluster+1); // ��ȡǰһ���غ�
*(pCluster + 1) = 0xFFF;
SetCluster(pBuffer, pCluster);
if (ReadDiskData(pBuffer, (*pDirAddr & (~0xFF)), 256) != OK)
return SEC_ERR;
*(u8*) (pBuffer + (*pDirAddr & 0xFF) + 0x0B) = 0x20;
*(u32*) (pBuffer + (*pDirAddr & 0xFF) + 0x1C) = Lenght;
if (ProgDiskPage(pBuffer, (*pDirAddr & (~0xFF))) != OK)
return SEC_ERR;
for (n = 0; n < FAT1_SEC; n++) {
if (ReadDiskData(pBuffer, FAT1_BASE + n * 256, 256) != OK)
return SEC_ERR;
if (ProgDiskPage(pBuffer, FAT2_BASE + n * 256) != OK)
return SEC_ERR;
}
return OK;
}
/******************************** END OF FILE *********************************/
|
