Ioperm-set Port permissions in Windows

There are two system calls for setting Port permissions in Windows: ioperm and iopl functions.
1. ioperm Function
Function Description:
Set the I/O port access capability for the calling process. Ioperm requires Super User Permissions. Only the low-end [0-0x3ff] I/O port can be set. to specify more port capabilities, you can use the iopl function. This call can only be used on the i386 platform.

Usage:
[Cpp]
# Include <ioperm. h>/* for libc5 */
# Include <sys/io. h>/* for glibc */
Int ioperm (unsigned long from, unsigned long num, int turn_on );

# Include <ioperm. h>/* for libc5 */
# Include <sys/io. h>/* for glibc */
Int ioperm (unsigned long from, unsigned long num, int turn_on); parameter:
From: Start port address.
Num: the number of ports that need to be modified.
Turn_on: The New Power bit of the port. 1 is enabled, 0 is disabled.
Return description:
0 is returned when execution is successful. -1 is returned for failure, and errno is set to one of the following values
EINVAL: the parameter is invalid.
EIO: This call is not supported
EPERM: unable to call the process.

2. iopl Functions

Function Description: This call is used to modify the operation Port permissions of the current process. It can be used for permissions on all 65536 ports. Therefore, ioperm is equivalent to a subset of the call. Like ioperm, this call is only applicable to the i386 platform.

Usage:
[Cpp]
# Include <ioperm. h>
Int iopl (int level );

# Include <ioperm. h>
Int iopl (int level); parameter:
Level: the port permission level. The read/write port is 3. The default capability level is 0, and the user space cannot be read or written.
Return Description: 0 is returned when execution is successful. -1 is returned for failure, and errno is set to one of the following values
EINVAL: The level value is greater than 3.
ENOSYS: The call is not implemented.
EPERM: unable to call the process.

Currently, the main part has been changed to support GCC compilation. Supports GCC inline assembly.
The Code is as follows (the C compiler of Windows is used by default ):
[Cpp]
/*
* Function: read cmos data using rtc port (0x70 -- port, 0x71 -- data)
*/
# Include <stdio. h>
# Include <stdlib. h>
# Include <string. h>
# Include <windows. h>
 
Extern int install (int );
Extern int uninstall (int );
Extern ioperm (unsigned long from, unsigned long num, int turn_on );
 
# Ifdef _ GCC
Void outp (unsigned short addr, unsigned short data ){
_ Asm __(
"Mov % 1, % al ;"
"Mov % 0, % dx ;"
"Out % al, % dx ;"
:/* No output */
: "M" (addr), "m" (data)/* input addr and data */
: "Ax", "dx"
);
}
Unsigned char Indium (unsigned short addr)
{
Unsigned char cha;
_ Asm __(
"Mov % 1, % dx ;"
"In % dx, % al ;"
"Mov % al, % 0 ;"
: "= R" (cha)/* output to var (cha )*/
: "M" (addr)/* input addr */
: "Ax", "dx"
);
Return cha;
}
# Else/* using windows asm */
Void outp (unsigned short addr, unsigned short data ){
Asm {
Mov al, data
Mov dx, addr
Out dx, al
}
}
Unsigned char Indium (unsigned short addr)
{
Unsigned char cha;
Asm {
Mov dx, addr
In al, dx
Mov cha, al
}
Return cha;
}
 
# Endif
 
Int main (void)
{
Int I;
Unsigned char c;
Install (0 );
Sleep (500 );
If (ioperm (0x70, 2, 1 )){
Fprintf (stderr, "Error: ioperm () failed. Please install ioperm. sys driver. \ n ");
} Else {
For (I = 0; I <260; I ++)
{
// Sleep (1, 100 );
Outp (0x70, I );
C = Indium (0x71 );
Printf ("% 02x", c );
If (I + 1) % 20 = 0)
Printf ("\ n ");
}
}
Uninstall (0 );
Return 0;
}

/*
* Function: read cmos data using rtc port (0x70 -- port, 0x71 -- data)
*/
# Include <stdio. h>
# Include <stdlib. h>
# Include <string. h>
# Include <windows. h>

Extern int install (int );
Extern int uninstall (int );
Extern ioperm (unsigned long from, unsigned long num, int turn_on );

# Ifdef _ GCC
Void outp (unsigned short addr, unsigned short data ){
_ Asm __(
"Mov % 1, % al ;"
"Mov % 0, % dx ;"
"Out % al, % dx ;"
:/* No output */
: "M" (addr), "m" (data)/* input addr and data */
: "Ax", "dx"
);
}
Unsigned char Indium (unsigned short addr)
{
Unsigned char cha;
_ Asm __(
"Mov % 1, % dx ;"
"In % dx, % al ;"
"Mov % al, % 0 ;"
: "= R" (cha)/* output to var (cha )*/
: "M" (addr)/* input addr */
: "Ax", "dx"
);
Return cha;
}
# Else/* using windows asm */
Void outp (unsigned short addr, unsigned short data ){
Asm {
Mov al, data
Mov dx, addr
Out dx, al
}
}
Unsigned char Indium (unsigned short addr)
{
Unsigned char cha;
Asm {
Mov dx, addr
In al, dx
Mov cha, al
}
Return cha;
}

# Endif

Int main (void)
{
Int I;
Unsigned char c;
Install (0 );
Sleep (500 );
If (ioperm (0x70, 2, 1 )){
Fprintf (stderr, "Error: ioperm () failed. Please install ioperm. sys driver. \ n ");
} Else {
For (I = 0; I <260; I ++)
{
// Sleep (1, 100 );
Outp (0x70, I );
C = Indium (0x71 );
Printf ("% 02x", c );
If (I + 1) % 20 = 0)
Printf ("\ n ");
}
}
Uninstall (0 );
Return 0;
}