Date: Fri, 13 Feb 2004 11:38:50 +1100
From: Glenn McGrath <glennm@hydrix.com>
Subject: microwindows, arm, -mstructure-size-boundary=8

Hi, im using nano-X on a pxa (arm) development board.

I ran into a problem, by default microwindows builds with a compiler
option -mstructure-size-boundary=8, i think the kernel im using is
aligned to 32 bit boundaries.

In my nano-X app i am using ioctl, which indirectly uses kernel macro
_IOR to calculate the ioctl command number, this number is based on the
sizeof(struct ).

Because sizeof struct is different when compiled with
-mstruct-size-boundard my app was using an incorrect ioctl command
number, which of course leads to runtime problems.


This is the first time ive had a problem like this, it seems to me that
setting -mstructure-size-boundary is a dangerous thing to do, the
changelog entry says it fixes some bugs... i dont know wht bugs it
fixes, but it sure introduces some.



Glenn