src/add-ons/kernel/drivers/common/zero.c

   1 /*
   2 ** Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
   3 ** Distributed under the terms of the NewOS License.
   4 */
   5
   6
   7 #include <Drivers.h>
   8 #include <KernelExport.h>
   9
  10 #include <string.h>
  11
  12
  13 #define DEVICE_NAME "zero"
  14
  15 int32 api_version = B_CUR_DRIVER_API_VERSION;
  16
  17
  18 static status_t
  19 zero_open(const char *name, uint32 flags, void **cookie)
  20 {
  21         *cookie = NULL;
  22         return B_OK;
  23 }
  24
  25
  26 static status_t
  27 zero_close(void *cookie)
  28 {
  29         return B_OK;
  30 }
  31
  32
  33 static status_t
  34 zero_freecookie(void *cookie)
  35 {
  36         return B_OK;
  37 }
  38
  39
  40 static status_t
  41 zero_ioctl(void *cookie, uint32 op, void *buffer, size_t length)
  42 {
  43         return EPERM;
  44 }
  45
  46
  47 static status_t
  48 zero_read(void *cookie, off_t pos, void *buffer, size_t *_length)
  49 {
  50         if (user_memset(buffer, 0, *_length) < B_OK)
  51                 return B_BAD_ADDRESS;
  52
  53         return B_OK;
  54 }
  55
  56
  57 static status_t
  58 zero_write(void *cookie, off_t pos, const void *buffer, size_t *_length)
  59 {
  60         return B_OK;
  61 }
  62
  63
  64 //      #pragma mark -
  65
  66
  67 status_t
  68 init_hardware(void)
  69 {
  70         return B_OK;
  71 }
  72
  73
  74 const char **
  75 publish_devices(void)
  76 {
  77         static const char *devices[] = {
  78                 DEVICE_NAME,
  79                 NULL
  80         };
  81
  82         return devices;
  83 }
  84
  85
  86 device_hooks *
  87 find_device(const char *name)
  88 {
  89         static device_hooks hooks = {
  90                 &zero_open,
  91                 &zero_close,
  92                 &zero_freecookie,
  93                 &zero_ioctl,
  94                 &zero_read,
  95                 &zero_write,
  96                 /* Leave select/deselect/readv/writev undefined. The kernel will
  97                  * use its own default implementation. The basic hooks above this
  98                  * line MUST be defined, however. */
  99                 NULL,
 100                 NULL,
 101                 NULL,
 102                 NULL
 103         };
 104
 105         if (!strcmp(name, DEVICE_NAME))
 106                 return &hooks;
 107
 108         return NULL;
 109 }
 110
 111
 112 status_t
 113 init_driver(void)
 114 {
 115         return B_OK;
 116 }
 117
 118
 119 void
 120 uninit_driver(void)
 121 {
 122 }
 123