"man i386_iopl"

Note that this will only work from NetBSD/i386.

--Michael

Brian Stark <bstark@uswest.net> writes:

> Hello,
> 
> I'm having some trouble porting some code from a MS-DOS system to NetBSD
> and I hope someone can tell me what I might be doing wrong.
> 
> I wrote some code using Borland C++ 3.10 on a to NetBSD and my code made 
> use of the following Borland functions for reading and writing ports:
> 
>   unsigned      inport  (unsigned portid);
>   unsigned char inportb (unsigned portid);
>   void          outport (unsigned portid, unsigned      value);
>   void          outportb(unsigned portid, unsigned char value);
> 
> I found the header file /usr/include/machine/pio.h, and it looks like
> it contains some definitions that will work for me (inw, inb, outw, outb),
> so I modified my code to be like this:
> 
> #include <machine/types.h>
> #include <machine/pio.h>
> 
> /* This function will read a 16-bit word */
> u_int16_t inport (int portid)
> {
>   return (inw(portid));
> }
> 
> /* This function will read a 8-bit byte */
> u_int8_t inportb (int portid)
> {
>   return (inb(portid));
> }
> 
> /* This function will write a 16-bit word */
> void outport(int portid, u_int16_t value)
> {
>   outw(portid,value);
> }
> 
> /* This function will write a 8-bit word */
> void outportb(int portid, u_int8_t value)
> {
>   outb(portid,value);
> }
> 
> int DetectESP(int EIO)
> /* Look for a Hayes ESP signature at port EIO */
> {
>   if (0xF3 == inportb(EIO))
>     return 1; 
>   else      
>     return 0; 
> }
> 
> 
> But, when I attempt to run my program it crashes inside the inb()
> function:
> 
> callisto:bstark$ ./esic check 0x300
> Hayes Enhanced Serial Interface (ESI) Utility
> Copyright 1996-1999 by Brian P. Stark. All rights reserved.
> 
> Bus error (core dumped) 
> callisto:bstark$ gdb esic esic.core
> GNU gdb 4.17
> Copyright 1998 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are
> welcome to change it and/or distribute copies of it under certain
> conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for
> details.
> This GDB was configured as "i386--netbsd"...
> Core was generated by `esic'.
> Program terminated with signal 10, Bus error.
> Reading symbols from /usr/libexec/ld.so...done.
> Reading symbols from /usr/lib/libc.so.12.40...done.
> #0  0x37a2 in inportb (portid=768) at /usr/include/i386/pio.h:79
> 79              return data;
> (gdb) where
> #0  0x37a2 in inportb (portid=768) at /usr/include/i386/pio.h:79
> #1  0x30a7 in DetectESP (EIO=768) at ../s/esi.c:639
> #2  0x1e04 in DoCheck (EIO=768) at ../s/esic.c:134
> #3  0x23fd in main (argc=3, argv=0xefbfd3e8) at ../s/esic.c:275
> (gdb) list
> 74      static __inline u_int8_t
> 75      __inb(int port)
> 76      {
> 77              u_int8_t data;
> 78              __asm __volatile("inb %w1,%0" : "=a" (data) : "d" (port));
> 79              return data;
> 80      }
> 81      
> 82      static __inline void
> 83      insb(int port, void *addr, int cnt)
> (gdb) 
> 
> 
> Since this is the first program I've worked on for NetBSD that needs to
> read and write a port, I'm not sure if what I am doing is correct. 
> Should I be able to read and write the ports from inside my program
> by calling these functions? Is there any special setup/initialization
> code I am missing here?
> 
> Thanks,
> 
> 
> Brian
> bstark@uswest.net