source: ps2launchargs/source/uLaunchELF/vmcfs/src/vmc_fat.c@ 1108

Last change on this file since 1108 was 1101, checked in by iritscen, 7 years ago

Added following to ps2launchargs:\n-Source code.\n-DLL needed to run ps2client.\n-Instructions for building uLaunchELF.
  • Property svn:executable set to *
File size: 5.1 KB
Line 
1#include "vmc.h"
2
3
4// Fat table functions
5
6unsigned int getFatEntry ( int fd, unsigned int cluster, unsigned int* indir_fat_clusters, GetFat_Mode Mode )
7{
8
9 int unit = ( fd == g_Vmc_Image[ 0 ].fd ) ? 0 : 1;
10
11 // The fat index, aka which cluster we want to know about
12 unsigned int fat_index = cluster;
13
14 // The offset in the fat cluster where we can find information about the sector
15 unsigned int fat_offset = fat_index % ( g_Vmc_Image[ unit ].cluster_size / 4 );
16
17 // Which fat cluster that the information would be in
18 unsigned int indirect_index = fat_index / ( g_Vmc_Image[ unit ].cluster_size / 4 );
19
20 // The offset in the indirect fat cluster that points to the fat table we are interested in
21 unsigned int indirect_offset = indirect_index % ( g_Vmc_Image[ unit ].cluster_size / 4 );
22
23 // This gives the location of the fat_offset inside of the indirect fat cluster list. Each indirect fat cluster can point to
24 // 256 regular fat clusters, and each fat cluster holds information on 256 sectors.
25 unsigned int dbl_indirect_index = fat_index / ( ( g_Vmc_Image[ unit ].cluster_size / 4 ) * ( g_Vmc_Image[ unit ].cluster_size / 4 ) );
26
27 // Cache indirect file table? ( Generally we will be accessing the first part of it for most virtual memory cards )
28 // Get the data for the indirect fat cluster ( as indicated by dbl_indirect_index )
29 unsigned int indirect_cluster_num = indir_fat_clusters[ dbl_indirect_index ];
30
31 if ( g_Vmc_Image[ unit ].last_idc != indirect_cluster_num )
32 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].indirect_cluster, indirect_cluster_num );
33
34 g_Vmc_Image[ unit ].last_idc = indirect_cluster_num;
35
36 // Get the data from the fat cluster ( pointed to by the indirect fat cluster )
37 unsigned int fat_cluster_num = g_Vmc_Image[ unit ].indirect_cluster[ indirect_offset ];
38
39 if ( g_Vmc_Image[ unit ].last_cluster != fat_cluster_num )
40 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num );
41
42 g_Vmc_Image[ unit ].last_cluster = fat_cluster_num;
43
44 // Check if the entry in the fat table corresponds to a free cluster or a eof cluster
45 if ( g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] == FREE_CLUSTER || g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] == EOF_CLUSTER )
46 return g_Vmc_Image[ unit ].fat_cluster[ fat_offset ];
47
48 if ( Mode == FAT_MASK )
49 {
50
51 if ( g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] & MASK_CLUSTER )
52 {
53
54 return MASK_CLUSTER;
55
56 }
57 else
58 {
59
60 return 0;
61
62 }
63
64 }
65
66 // Return the fat entry, but remove the most significant bit.
67 return g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] & FREE_CLUSTER;
68
69}
70
71unsigned int setFatEntry ( int fd, unsigned int cluster, unsigned int value, unsigned int* indir_fat_clusters, SetFat_Mode Mode )
72{
73
74 int unit = ( fd == g_Vmc_Image[ 0 ].fd ) ? 0 : 1;
75
76 // The fat index, aka which cluster we want to know about
77 unsigned int fat_index = cluster;
78
79 // The offset in the fat cluster where we can find information about the sector
80 unsigned int fat_offset = fat_index % ( g_Vmc_Image[ unit ].cluster_size / 4 );
81
82 // Which fat cluster that the information would be in
83 unsigned int indirect_index = fat_index / ( g_Vmc_Image[ unit ].cluster_size / 4 );
84
85 // The offset in the indirect fat cluster that points to the fat table we are interested in
86 unsigned int indirect_offset = indirect_index % ( g_Vmc_Image[ unit ].cluster_size / 4 );
87
88 // This gives the location of the fat_offset inside of the indirect fat cluster list. Each indirect fat cluster can point to
89 // 256 regular fat clusters, and each fat cluster holds information on 256 sectors.
90 unsigned int dbl_indirect_index = fat_index / ( ( g_Vmc_Image[ unit ].cluster_size / 4 ) * ( g_Vmc_Image[ unit ].cluster_size / 4 ) );
91
92 // Cache indirect file table? ( Generally we will be accessing the first part of it for most virtual memory cards
93 // Get the data for the indirect fat cluster ( as indicated by dbl_indirect_index )
94 unsigned int indirect_cluster_num = indir_fat_clusters[ dbl_indirect_index ];
95
96 if ( g_Vmc_Image[ unit ].last_idc != indirect_cluster_num )
97 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].indirect_cluster, indirect_cluster_num );
98
99 g_Vmc_Image[ unit ].last_idc = indirect_cluster_num;
100
101 // Get the data from the fat cluster ( pointed to by the indirect fat cluster )
102 unsigned int fat_cluster_num = g_Vmc_Image[ unit ].indirect_cluster[ indirect_offset ];
103
104 if ( g_Vmc_Image[ unit ].last_cluster != fat_cluster_num )
105 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num );
106
107 g_Vmc_Image[ unit ].last_cluster = fat_cluster_num;
108
109 if ( value == FREE_CLUSTER || value == EOF_CLUSTER || Mode == FAT_RESET )
110 {
111
112 g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] = value;
113
114 }
115 else
116 {
117
118 g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] = value | MASK_CLUSTER;
119
120 }
121
122 writeCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num );
123
124 // Update last free cluster
125 if ( ( value == FREE_CLUSTER && Mode == FAT_SET ) || ( Mode == FAT_RESET ) )
126 {
127
128 if ( cluster < g_Vmc_Image[ unit ].last_free_cluster )
129 {
130
131 g_Vmc_Image[ unit ].last_free_cluster = cluster;
132
133 }
134
135 }
136
137 return 0;
138
139}
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