finddevice.c

来自「FAT16 Filesystem on Philips LPC2000 seri」· C语言 代码 · 共 28 行

#include <reent.h>
#include <errno.h>
#include <devices.h>
#include <sysdefs.h>
#include <iface.h>

/***********************************************************
 * find_device
 *   search device table and return idx to device.
 *   or return -1 on not found.
***********************************************************/

int find_device (struct _reent *r, uchar device_type)
{
int	i;
		// consider all devices.
	for (i=0; i<MaxDeviceDescriptors && device_table_list[i].item; i++) {
		if (device_table_list[i].item->device_type == device_type) break;
	}
		// look to see which device to call.
	if (i >= MaxDeviceDescriptors || !device_table_list[i].item) {
		r->_errno = ENODEV;
		return -1;
	}
	return i;
}