KernelLand/Kernel/drv/zero-one.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * drv/zero-one.c
   6  * - /Devices/{null,zero,one}
   7  */
   8 #define DEBUG   0
   9 #include <acess.h>
  10 #include <modules.h>
  11 #include <fs_devfs.h>
  12
  13 // === PROTOTYPES ===
  14  int    CoreDevs_Install(char **Arguments);
  15 size_t  CoreDevs_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer);
  16 size_t  CoreDevs_Read_Zero(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  17 size_t  CoreDevs_Read_One (tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  18 size_t  CoreDevs_Read_Null(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  19 size_t  CoreDevs_Read_FRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  20 size_t  CoreDevs_Read_GRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  21
  22 // === GLOBALS ===
  23 MODULE_DEFINE(0, 0x0100, CoreDevs, CoreDevs_Install, NULL, NULL);
  24 tVFS_NodeType   gCoreDevs_NT_Null = {
  25         .TypeName = "CoreDevs-null",
  26         .Read  = CoreDevs_Read_Null,
  27         .Write = CoreDevs_Write
  28 };
  29 tVFS_NodeType   gCoreDevs_NT_Zero = {
  30         .TypeName = "CoreDevs-zero",
  31         .Read  = CoreDevs_Read_Zero,
  32         .Write = CoreDevs_Write
  33 };
  34 tVFS_NodeType   gCoreDevs_NT_One = {
  35         .TypeName = "CoreDevs-one",
  36         .Read  = CoreDevs_Read_One,
  37         .Write = CoreDevs_Write
  38 };
  39 tVFS_NodeType   gCoreDevs_NT_FRandom = {
  40         .TypeName = "CoreDevs-frandom",
  41         .Read  = CoreDevs_Read_FRandom,
  42         .Write = CoreDevs_Write
  43 };
  44 tVFS_NodeType   gCoreDevs_NT_GRandom = {
  45         .TypeName = "CoreDevs-grandom",
  46         .Read  = CoreDevs_Read_GRandom,
  47         .Write = CoreDevs_Write
  48 };
  49 tDevFS_Driver   gCoreDevs_Null = {
  50         NULL, "null",
  51         {
  52         .Size = 0, .NumACLs = 1,
  53         .ACLs = &gVFS_ACL_EveryoneRW,
  54         .Type = &gCoreDevs_NT_Null
  55         }
  56 };
  57 tDevFS_Driver   gCoreDevs_Zero = {
  58         NULL, "zero",
  59         {
  60         .Size = 0, .NumACLs = 1,
  61         .ACLs = &gVFS_ACL_EveryoneRW,
  62         .Type = &gCoreDevs_NT_Zero
  63         }
  64 };
  65 tDevFS_Driver   gCoreDevs_One = {
  66         NULL, "one",
  67         {
  68         .Size = 0, .NumACLs = 1,
  69         .ACLs = &gVFS_ACL_EveryoneRW,
  70         .Type = &gCoreDevs_NT_One
  71         }
  72 };
  73 tDevFS_Driver   gCoreDevs_FRandom = {
  74         NULL, "frandom",
  75         {
  76         .Size = 0, .NumACLs = 1,
  77         .ACLs = &gVFS_ACL_EveryoneRW,
  78         .Type = &gCoreDevs_NT_FRandom
  79         }
  80 };
  81 tDevFS_Driver   gCoreDevs_GRandom = {
  82         NULL, "grandom",
  83         {
  84         .Size = 0, .NumACLs = 1,
  85         .ACLs = &gVFS_ACL_EveryoneRW,
  86         .Type = &gCoreDevs_NT_GRandom
  87         }
  88 };
  89
  90 // === CODE ===
  91 /**
  92  * \brief Installs the CoreDevs driver
  93  */
  94 int CoreDevs_Install(char **Options)
  95 {
  96         DevFS_AddDevice( &gCoreDevs_Null );
  97         DevFS_AddDevice( &gCoreDevs_Zero );
  98         DevFS_AddDevice( &gCoreDevs_One  );
  99         DevFS_AddDevice( &gCoreDevs_FRandom  );
 100         //DevFS_AddDevice( &gCoreDevs_GRandom  );
 101         return MODULE_ERR_OK;
 102 }
 103
 104 size_t CoreDevs_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
 105 {
 106         return Length;  // Ignore
 107 }
 108
 109 size_t CoreDevs_Read_Zero(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 110 {
 111         memset(Buffer, 0, Length);
 112         return Length;
 113 }
 114
 115 size_t CoreDevs_Read_One (tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 116 {
 117         Uint8   *ptr = Buffer;
 118         size_t  rem;
 119         for( rem = Length; rem --; ptr ++ )
 120                 *ptr = 0xFF;
 121         return Length;
 122 }
 123
 124 size_t CoreDevs_Read_Null(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 125 {
 126         return 0;
 127 }
 128
 129 //! Fast random number generator
 130 size_t CoreDevs_Read_FRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 131 {
 132         Uint8   *cbuf = Buffer;
 133         for( int i = 0; i < Length; i ++ )
 134                 *cbuf++ = rand();
 135         return Length;
 136 }
 137
 138 size_t CoreDevs_Read_GRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 139 {
 140         Log_Error("CoreDevs", "GRandom is unimplimented");
 141         return -1;
 142 }
 143