Unprotecting I/O above 10 bits
Walt Croom
waltc at cpqhou.uucp
Tue Dec 18 03:15:16 AEST 1990
> 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
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