ioperm() with ports above 0x3ff

Daniel Noll
Fri Feb 22 09:56:00 GMT 2008

On Friday 22 February 2008 07:46:18 Samuel Thibault wrote:
> Yes: on Linux ioperm doesn't work above 0x400.  On Linux, so as to
> access ports above 0x400 you need to use iopl(), that's why ioperm in
> cygwin does this.  Now, allowing >= 0x400 would be possible in cygwin's
> ioperm, but then you'd get problems when using the code on Linux...  The
> truly proper way is really to use iopl().

On the other hand the iopl() man page specifically says that it shouldn't be 
used in processes intended to be portable. ;-D


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