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, Uint Flags);
  16 size_t  CoreDevs_Read_Zero(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  17 size_t  CoreDevs_Read_One (tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  18 size_t  CoreDevs_Read_Null(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  19 size_t  CoreDevs_Read_FRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  20 size_t  CoreDevs_Read_GRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  21
  22 // === GLOBALS ===
  23 MODULE_DEFINE(0, 0x0100, CoreDevs, CoreDevs_Install, NULL, NULL);
  24 tVFS_NodeType   gCoreDevs_NT_Null = {
  25         .TypeName = "CoreDevs-null",
  26         .Flags = VFS_NODETYPEFLAG_STREAM,
  27         .Read  = CoreDevs_Read_Null,
  28         .Write = CoreDevs_Write
  29 };
  30 tVFS_NodeType   gCoreDevs_NT_Zero = {
  31         .TypeName = "CoreDevs-zero",
  32         .Flags = VFS_NODETYPEFLAG_STREAM,
  33         .Read  = CoreDevs_Read_Zero,
  34         .Write = CoreDevs_Write
  35 };
  36 tVFS_NodeType   gCoreDevs_NT_One = {
  37         .TypeName = "CoreDevs-one",
  38         .Flags = VFS_NODETYPEFLAG_STREAM,
  39         .Read  = CoreDevs_Read_One,
  40         .Write = CoreDevs_Write
  41 };
  42 tVFS_NodeType   gCoreDevs_NT_FRandom = {
  43         .TypeName = "CoreDevs-frandom",
  44         .Flags = VFS_NODETYPEFLAG_STREAM,
  45         .Read  = CoreDevs_Read_FRandom,
  46         .Write = CoreDevs_Write
  47 };
  48 tVFS_NodeType   gCoreDevs_NT_GRandom = {
  49         .TypeName = "CoreDevs-grandom",
  50         .Flags = VFS_NODETYPEFLAG_STREAM,
  51         .Read  = CoreDevs_Read_GRandom,
  52         .Write = CoreDevs_Write
  53 };
  54 tDevFS_Driver   gCoreDevs_Null = {
  55         NULL, "null",
  56         {
  57         .Size = -1, .NumACLs = 1,
  58         .ACLs = &gVFS_ACL_EveryoneRW,
  59         .Type = &gCoreDevs_NT_Null
  60         }
  61 };
  62 tDevFS_Driver   gCoreDevs_Zero = {
  63         NULL, "zero",
  64         {
  65         .Size = -1, .NumACLs = 1,
  66         .ACLs = &gVFS_ACL_EveryoneRW,
  67         .Type = &gCoreDevs_NT_Zero
  68         }
  69 };
  70 tDevFS_Driver   gCoreDevs_One = {
  71         NULL, "one",
  72         {
  73         .Size = -1, .NumACLs = 1,
  74         .ACLs = &gVFS_ACL_EveryoneRW,
  75         .Type = &gCoreDevs_NT_One
  76         }
  77 };
  78 tDevFS_Driver   gCoreDevs_FRandom = {
  79         NULL, "frandom",
  80         {
  81         .Size = -1, .NumACLs = 1,
  82         .ACLs = &gVFS_ACL_EveryoneRW,
  83         .Type = &gCoreDevs_NT_FRandom,
  84         .DataAvaliable = 1
  85         }
  86 };
  87 tDevFS_Driver   gCoreDevs_GRandom = {
  88         NULL, "grandom",
  89         {
  90         .Size = -1, .NumACLs = 1,
  91         .ACLs = &gVFS_ACL_EveryoneRW,
  92         .Type = &gCoreDevs_NT_GRandom,
  93         .DataAvaliable = 1
  94         }
  95 };
  96
  97 // === CODE ===
  98 /**
  99  * \brief Installs the CoreDevs driver
 100  */
 101 int CoreDevs_Install(char **Options)
 102 {
 103         DevFS_AddDevice( &gCoreDevs_Null );
 104         DevFS_AddDevice( &gCoreDevs_Zero );
 105         DevFS_AddDevice( &gCoreDevs_One  );
 106         DevFS_AddDevice( &gCoreDevs_FRandom  );
 107         //DevFS_AddDevice( &gCoreDevs_GRandom  );
 108         return MODULE_ERR_OK;
 109 }
 110
 111 size_t CoreDevs_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
 112 {
 113         return Length;  // Ignore
 114 }
 115
 116 size_t CoreDevs_Read_Zero(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 117 {
 118         memset(Buffer, 0, Length);
 119         return Length;
 120 }
 121
 122 size_t CoreDevs_Read_One (tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 123 {
 124         Uint8   *ptr = Buffer;
 125         size_t  rem;
 126         for( rem = Length; rem --; ptr ++ )
 127                 *ptr = 0xFF;
 128         return Length;
 129 }
 130
 131 size_t CoreDevs_Read_Null(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 132 {
 133         return 0;
 134 }
 135
 136 //! Fast random number generator
 137 size_t CoreDevs_Read_FRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 138 {
 139         Uint8   *cbuf = Buffer;
 140         for( int i = 0; i < Length; i ++ )
 141                 *cbuf++ = rand();
 142         return Length;
 143 }
 144
 145 size_t CoreDevs_Read_GRandom(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 146 {
 147         // TODO: VFS_IOFLAG_NOBLOCK
 148         Log_Error("CoreDevs", "GRandom is unimplimented");
 149         return -1;
 150 }
 151