ioport.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

/*
 * linux/arch/mips/kernel/ioport.c
 */
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/ioport.h>

/*
 * This changes the io permissions bitmap in the current task.
 */
asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
{
	return -ENOSYS;
}

/*
 * sys_iopl has to be used when you want to access the IO ports
 * beyond the 0x3ff range: to get the full 65536 ports bitmapped
 * you'd need 8kB of bitmaps/process, which is a bit excessive.
 *
 * Here we just change the eflags value on the stack: we allow
 * only the super-user to do it. This depends on the stack-layout
 * on system-call entry - see also fork() and the signal handling
 * code.
 */
asmlinkage int sys_iopl(long ebx,long ecx,long edx,
	     long esi, long edi, long ebp, long eax, long ds,
	     long es, long fs, long gs, long orig_eax,
	     long eip,long cs,long eflags,long esp,long ss)
{
	return -ENOSYS;
}