1 .\" Copyright (c) 2000 David E. O'Brien
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25 .\" $FreeBSD: src/usr.bin/uac/uac.1,v 1.3.2.7 2002/06/21 15:29:49 charnier Exp $
26 .\" $DragonFly: src/usr.bin/uac/Attic/uac.1,v 1.2 2003/06/17 04:29:33 dillon Exp $
33 .Nd Unaligned Access Message Control
40 utility sets the per-process handling of
43 Unlike many other CPU's the DEC Alpha processor cannot access unaligned data.
44 To work around this, the Alpha has the ability to fix the UA fault
45 rather than send the faulting process a
48 However, doing so does slow down the
49 execution of the faulting process.
50 At bootup, the DEC Alpha CPU defaults to printing
53 .Ar nnn Pq Ar <progname> :
55 .Em va Ns = Ns Ar 0xADDR
56 .Em pc Ns = Ns Ar 0xADDR
57 .Em ra Ns = Ns Ar 0xADDR
61 when a UA happens along with fixing it,
62 so the faulting instruction can continue.
63 UA handling settings are inherited by child process.
64 Issued without any options,
66 displays the current UA handling for the parent process.
68 The options are as follows:
71 Unaligned access errors are not fixed for the parent and its future descendants.
73 Unaligned access errors are not printed for the parent and its future
76 Resets the unaligned access error settings back to their bootup defaults.
78 Unaligned access errors result in a
80 being delivered to the parent and its future descendants.
81 This aids in pinpointing the faulting access so it can be debugged.
84 Exit status is 0 on success, and 1 if the command
89 command syntax is incompatible with the DEC OSF/1 syntax.
95 utility first appeared in DEC OSF/1.
102 was originally written by
103 .An Andrew Gallatin Aq gallatin@cs.duke.edu
105 .An David E. O'Brien Aq obrien@FreeBSD.org .
107 manual page was written by
108 .An David E. O'Brien Aq obrien@FreeBSD.org .