[src/trunk]: src/sys/sys comment which bits of uc_flags are used by MD code.

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/19b2613c4e16
branches:  trunk
changeset: 749120:19b2613c4e16
user:      yamt <yamt%NetBSD.org@localhost>
date:      Wed Nov 18 12:29:22 2009 +0000

description:
comment which bits of uc_flags are used by MD code.

+ * if your port needs more MD bits, please try to choose bits from _UC_MD
+ * first, rather than picking random unused bits.

diffstat:

 sys/sys/ucontext.h |  18 +++++++++++++++++-
 1 files changed, 17 insertions(+), 1 deletions(-)

diffs (32 lines):

diff -r f0e086e2d7d4 -r 19b2613c4e16 sys/sys/ucontext.h
--- a/sys/sys/ucontext.h        Wed Nov 18 12:27:58 2009 +0000
+++ b/sys/sys/ucontext.h        Wed Nov 18 12:29:22 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ucontext.h,v 1.11 2008/10/15 06:51:21 wrstuden Exp $   */
+/*     $NetBSD: ucontext.h,v 1.12 2009/11/18 12:29:22 yamt Exp $       */
 
 /*-
  * Copyright (c) 1999, 2003 The NetBSD Foundation, Inc.
@@ -57,6 +57,22 @@
 #define _UC_STACK      0x02            /* valid uc_stack */
 #define _UC_CPU                0x04            /* valid GPR context in uc_mcontext */
 #define _UC_FPU                0x08            /* valid FPU context in uc_mcontext */
+#define        _UC_MD          0x40070020      /* MD bits.  see below */
+
+/*
+ * _UC_MD includes:
+ *     _UC_SETSTACK    0x00010000 (many ports) and 0x00020000 (arm)
+ *     _UC_CLRSTACK    0x00020000 (many ports) and 0x00040000 (arm)
+ *     _UC_POWERPC_VEC 0x00010000 (powerpc)
+ *     _UC_M68K_UC_USER 0x40000000 (m68k)
+ *     _UC_UNIQUE      0x00000020 (alpha)
+ *     _UC_ARM_VFP     0x00010000 (arm)
+ *     _UC_VM          0x00040000 (i386)
+ *     _UC_FXSAVE      0x00000020 (i386)
+ *
+ * if your port needs more MD bits, please try to choose bits from _UC_MD
+ * first, rather than picking random unused bits.
+ */
 
 #ifdef _KERNEL
 struct lwp;