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
|
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include "fs.h"
#include "cache.h"
/* The currently mounted filesystem */
struct fs_info *this_fs = NULL;
struct fs_info fs;
/* Actual file structures (we don't have malloc yet...) */
struct file files[MAX_OPEN];
/*
* Get an empty file structure
*/
static struct file *alloc_file(void)
{
int i;
struct file *file = files;
for (i = 0; i < MAX_OPEN; i++) {
if (!file->open_file)
return file;
file++;
}
return NULL;
}
/*
* Close and free a file structure
*/
static inline void free_file(struct file *file)
{
memset(file, 0, sizeof *file);
}
void _close_file(struct file *file)
{
if (file->open_file)
file->fs->fs_ops->close_file(file);
free_file(file);
}
/*
* Convert between a 16-bit file handle and a file structure
*/
inline uint16_t file_to_handle(struct file *file)
{
return file ? (file - files)+1 : 0;
}
inline struct file *handle_to_file(uint16_t handle)
{
return handle ? &files[handle-1] : NULL;
}
void load_config(void)
{
int err;
err = this_fs->fs_ops->load_config();
#if 0
printf("Loading config file %s\n", err ? "failed" : "successed");
#endif
}
void mangle_name(com32sys_t *regs)
{
const char *src = MK_PTR(regs->ds, regs->esi.w[0]);
char *dst = MK_PTR(regs->es, regs->edi.w[0]);
this_fs->fs_ops->mangle_name(dst, src);
}
void unmangle_name(com32sys_t *regs)
{
const char *src = MK_PTR(regs->ds, regs->esi.w[0]);
char *dst = MK_PTR(regs->es, regs->edi.w[0]);
dst = this_fs->fs_ops->unmangle_name(dst, src);
/* Update the di register to point to the last null char */
regs->edi.w[0] = OFFS_WRT(dst, regs->es);
}
void getfssec(com32sys_t *regs)
{
int sectors;
bool have_more;
uint32_t bytes_read;
char *buf;
struct file *file;
uint16_t handle;
sectors = regs->ecx.w[0];
handle = regs->esi.w[0];
file = handle_to_file(handle);
buf = MK_PTR(regs->es, regs->ebx.w[0]);
bytes_read = file->fs->fs_ops->getfssec(file, buf, sectors, &have_more);
/*
* If we reach EOF, the filesystem driver will have already closed
* the underlying file... this really should be cleaner.
*/
if (!have_more) {
_close_file(file);
regs->esi.w[0] = 0;
}
regs->ecx.l = bytes_read;
}
void searchdir(com32sys_t *regs)
{
char *filename = (char *)MK_PTR(regs->ds, regs->edi.w[0]);;
struct file *file;
#if 0
printf("filename: %s\n", filename);
#endif
file = alloc_file();
if (file) {
file->fs = this_fs;
file->fs->fs_ops->searchdir(filename, file);
if (file->open_file) {
regs->esi.w[0] = file_to_handle(file);
regs->eax.l = file->file_len;
regs->eflags.l &= ~EFLAGS_ZF;
return;
}
}
/* failure... */
regs->esi.w[0] = 0;
regs->eax.l = 0;
regs->eflags.l |= EFLAGS_ZF;
}
void close_file(com32sys_t *regs)
{
uint16_t handle = regs->esi.w[0];
struct file *file;
if (handle) {
file = handle_to_file(handle);
_close_file(file);
}
}
/*
* it will do:
* set up the vfs fs structure;
* initialize the device structure;
* invoke the fs-specific init function;
* finally, initialize the cache
*
*/
void fs_init(com32sys_t *regs)
{
int blk_shift;
const struct fs_ops *ops = (const struct fs_ops *)regs->eax.l;
/* set up the fs stucture */
fs.fs_ops = ops;
/* this is a total hack... */
if (ops->fs_flags & FS_NODEV)
fs.fs_dev = NULL; /* Non-device filesystem */
else
fs.fs_dev = device_init(regs->edx.b[0], regs->edx.b[1], regs->ecx.l,
regs->esi.w[0], regs->edi.w[0]);
this_fs = &fs;
/* invoke the fs-specific init code */
blk_shift = fs.fs_ops->fs_init(&fs);
/* initialize the cache */
if (fs.fs_dev && fs.fs_dev->cache_data)
cache_init(fs.fs_dev, blk_shift);
}
|
