View of xos/fs/device_manager.c

/* Copyright (C) 2008  Emmanuel Varoquaux
 
   This file is part of XOS.
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
#include "device_struct.h"
 
#include <floppy.h>
#include <consts.h>
#include <config.h>
#include <stddef.h>
 
/* device */
 
static void init_device(struct device_struct *device, const char *name, int type, const struct block_driver_struct *block_driver)
{
  device->name = name;
  device->type = type;
  if (type == FT_BLK) {
    device->block_driver = block_driver;
    device->file_system = NULL;
    device->data = NULL;
    device->count = 0;
  }
}
 
/* device_manager */
 
static struct device_table_entry {
  struct device_struct device;
  unsigned present : 1;
} device_table[NR_DEVICES];
static const unsigned int device_table_size = sizeof device_table / sizeof *device_table;
 
void device_manager_init()
{
  struct device_table_entry *entry;
  int id;
 
  for (entry = &device_table[0], id = 0; entry < &device_table[device_table_size]; entry++, id++) {
    entry->device.id = id;
    entry->present = 0;
  }
 
  /* DEV_FD */
  entry = &device_table[DEV_FD];
  init_device(&entry->device, "fd", FT_BLK, &floppy_driver);
 
  /* DEV_CONSOLE */
  entry = &device_table[DEV_CONSOLE];
  init_device(&entry->device, "console", FT_CHR, NULL);
  entry->present = 1;
 
  /* DEV_NULL */
  entry = &device_table[DEV_NULL];
  init_device(&entry->device, "null", FT_CHR, NULL);
  entry->present = 1;
 
  /* DEV_ZERO */
  entry = &device_table[DEV_ZERO];
  init_device(&entry->device, "zero", FT_CHR, NULL);
  entry->present = 1;
 
  /* DEV_FULL */
  entry = &device_table[DEV_FULL];
  init_device(&entry->device, "full", FT_CHR, NULL);
  entry->present = 1;
}
 
void device_set_present(int id)
{
  device_table[id].present = 1;
}
 
struct device_struct *get_device(int id)
{
  return device_table[id].present ? &device_table[id].device : NULL;
}