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         .DataAvaliable = 1
  80         }
  81 };
  82 tDevFS_Driver   gCoreDevs_GRandom = {
  83         NULL, "grandom",
  84         {
  85         .Size = 0, .NumACLs = 1,
  86         .ACLs = &gVFS_ACL_EveryoneRW,
  87         .Type = &gCoreDevs_NT_GRandom,
  88         .DataAvaliable = 1
  89         }
  90 };
  91
  92 // === CODE ===
  93 /**
  94  * \brief Installs the CoreDevs driver
  95  */
  96 int CoreDevs_Install(char **Options)
  97 {
  98         DevFS_AddDevice( &gCoreDevs_Null );
  99         DevFS_AddDevice( &gCoreDevs_Zero );
 100         DevFS_AddDevice( &gCoreDevs_One  );
 101         DevFS_AddDevice( &gCoreDevs_FRandom  );
 102         //DevFS_AddDevice( &gCoreDevs_GRandom  );
 103         return MODULE_ERR_OK;
 104 }
 105
 106 size_t CoreDevs_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
 107 {
 108         return Length;  // Ignore
 109 }
 110
 111 size_t CoreDevs_Read_Zero(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 112 {
 113         memset(Buffer, 0, Length);
 114         return Length;
 115 }
 116
 117 size_t CoreDevs_Read_One (tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 118 {
 119         Uint8   *ptr = Buffer;
 120         size_t  rem;
 121         for( rem = Length; rem --; ptr ++ )
 122                 *ptr = 0xFF;
 123         return Length;
 124 }
 125
 126 size_t CoreDevs_Read_Null(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 127 {
 128         return 0;
 129 }
 130
 131 //! Fast random number generator
 132 size_t CoreDevs_Read_FRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 133 {
 134         Uint8   *cbuf = Buffer;
 135         for( int i = 0; i < Length; i ++ )
 136                 *cbuf++ = rand();
 137         return Length;
 138 }
 139
 140 size_t CoreDevs_Read_GRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 141 {
 142         Log_Error("CoreDevs", "GRandom is unimplimented");
 143         return -1;
 144 }
 145