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
|
#include "vfs.h"
#include <kernel/task.h>
#include <fs/stdio.h>
// +1 vol for stdio, +3 fd's for stdout, in, err
#define VFS_MAX_VOLS (1 + 8)
#define VFS_MAX_FILES (3 + 10)
static vfs_volume vfs_volumes[VFS_MAX_VOLS];
static vfs_file vfs_files[VFS_MAX_FILES];
void vfs_svc(uint32_t *args)
{
switch (args[0]) {
case 0:
*((int *)args[3]) = vfs_mount((vfs_volume_funcs *)args[1],
args[2]);
break;
case 1:
*((int *)args[3]) = vfs_open((const char *)args[1], args[2]);
break;
case 2:
*((int *)args[2]) = vfs_close(args[1]);
break;
case 3:
*((int *)args[4]) = vfs_read(args[1], args[2], (uint8_t *)args[3]);
break;
default:
break;
}
}
void vfs_init(void)
{
for (int i = 0; i < VFS_MAX_VOLS; i++)
vfs_volumes[i].flags = 0;
for (int i = 0; i < VFS_MAX_FILES; i++)
vfs_files[i].flags = 0;
vfs_mount(&stdio_funcs, 0);
// order is crucial
vfs_open("in", VFS_FILE_READ);
vfs_open("out", VFS_FILE_WRITE);
vfs_open("err", VFS_FILE_WRITE);
}
int vfs_mount(vfs_volume_funcs *funcs, uint32_t flags)
{
for (int i = 0; i < VFS_MAX_VOLS; i++) {
if (!(vfs_volumes[i].flags && VFS_MOUNTED)) {
vfs_volumes[i].flags = VFS_MOUNTED | flags;
vfs_volumes[i].funcs = funcs;
return i;
}
}
return -1;
}
int vfs_get_drive(const char *path)
{
// Validate parameters
if (path[0] == '\0' || path[1] == '\0' || path[1] != ':' ||
path[2] == '\0' || path[2] != '/')
return -1;
// Find chosen drive
int drive = -1;
for (int i = 0; i < VFS_MAX_VOLS; i++) {
if (path[0] == ('a' + i) || path[0] == ('A' + i)) {
drive = i;
break;
}
}
if (drive == -1 || !(vfs_volumes[drive].flags && VFS_MOUNTED))
return -1;
return drive;
}
int vfs_open(const char *path, uint32_t flags)
{
int drive = vfs_get_drive(path);
if (drive == -1)
return -1;
if (vfs_volumes[drive].funcs->open == 0)
return -1;
// Find available file handle
int file = -1;
for (int i = 0; i < VFS_MAX_FILES; i++) {
if (!(vfs_files[i].flags & VFS_FILE_OPEN)) {
file = i;
break;
}
}
if (file == -1)
return -1;
vfs_files[file].flags = VFS_FILE_OPEN | flags;
vfs_files[file].vol = drive;
vfs_files[file].pid = task_getpid();
vfs_files[file].fsinfo =
vfs_volumes[drive].funcs->open(path + 3);
return file;
}
int vfs_close(int fd)
{
if (fd < 0 || fd > VFS_MAX_FILES)
return -1;
if (vfs_volumes[vfs_files[fd].vol].funcs->close == 0)
return -1;
if (vfs_files[fd].pid != task_getpid())
return -1;
if (!(vfs_files[fd].flags & VFS_FILE_OPEN))
return 0;
// TODO care
/*int ret =*/ vfs_volumes[vfs_files[fd].vol].funcs->close(
vfs_files[fd].fsinfo);
vfs_files[fd].flags = 0;
vfs_files[fd].pid = 0;
return 0;
}
uint32_t vfs_read(int fd, uint32_t count, uint8_t *buffer)
{
if (fd < 0 || fd > VFS_MAX_FILES || count == 0 || buffer == 0)
return 0;
if (vfs_volumes[vfs_files[fd].vol].funcs->read == 0)
return -1;
if (vfs_files[fd].pid != task_getpid())
return 0;
if ((!(vfs_files[fd].flags & VFS_FILE_READ)) || (vfs_files[fd].flags &
VFS_EOF))
return 0;
uint32_t ret = vfs_volumes[vfs_files[fd].vol].funcs->read(vfs_files[fd].fsinfo,
count, buffer);
if (ret < count)
vfs_files[fd].flags |= VFS_EOF;
return ret;
}
|
