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From: waltc@cpqhou.uucp (Walt Croom)
Newsgroups: comp.unix.sysv386
Subject: re: Unprotecting I/O above 10 bits
Message-ID: <1990Dec17.161516.8756@cpqhou.uucp>
Date: 17 Dec 90 16:15:16 GMT
Organization: Compaq Computer Corporation
Lines: 20

> 	I wanna do "outb(0x3000,0xff)". How do I do this under SCO or
> any other 386 unix from a user program. 
> I have routines that go into the GDT, then TSS I/O bitmaps to clear out
> protection on 0x000 to 0x3ff but thats it (the I/O bitmap only covers
> that range).
> 				Thanx
> 					Rick

Do the following before your outb to write to any I/O address:

  #define SI86V86 71
  #define V86SC_IOPL 4

  sysi86(SI86V86, V86SC_IOPL, 0x3000);        /* must be root */

--
Walt Croom               ..!uunet!cpqhou!waltc
Compaq Computer Corp.    voice: 713-374-6027
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