[src/trunk]: src/sys/arch/luna68k/luna68k Update and clarify the comment desc...

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

details:   https://anonhg.NetBSD.org/src/rev/a373489c5485
branches:  trunk
changeset: 499637:a373489c5485
user:      nisimura <nisimura%NetBSD.org@localhost>
date:      Sat Nov 25 07:58:07 2000 +0000

description:
Update and clarify the comment description of how disklabel is managed.

diffstat:

 sys/arch/luna68k/luna68k/disksubr.c |  17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diffs (32 lines):

diff -r bb6dbac65d62 -r a373489c5485 sys/arch/luna68k/luna68k/disksubr.c
--- a/sys/arch/luna68k/luna68k/disksubr.c       Sat Nov 25 06:27:59 2000 +0000
+++ b/sys/arch/luna68k/luna68k/disksubr.c       Sat Nov 25 07:58:07 2000 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: disksubr.c,v 1.10 2000/11/20 08:24:15 chs Exp $ */
+/* $NetBSD: disksubr.c,v 1.11 2000/11/25 07:58:07 nisimura Exp $ */
 
 /*
  * Copyright (c) 1994, 1995 Gordon W. Ross
@@ -80,13 +80,16 @@
  * It is found that LUNA Mach2.5 has BSD label embedded at offset 64
  * retaining UniOS/ISI label at the end of label block.  LUNA Mach
  * manipulates BSD disklabel in the same manner as 4.4BSD.  It's
- * uncertain LUNA Mach can create a disklabel on fresh disks;
- * writedisklabel fails when no BSD label is found.
+ * uncertain LUNA Mach can create a disklabel on fresh disks since
+ * Mach writedisklabel logic seems to fail when no BSD label is found.
  *
- * NetBSD/luna68k (1) creates UniOS/ISI label with BSD label
- * embedded at offset 64, (2) reads BSD label if found, (3) falls
- * back to reading UniOS/ISI label when no BSD label is found.  Plus,
- * (4) reads SunOS label if found in place of UniOS/ISI label.
+ * Kernel handles disklabel in this way;
+ *     - searchs BSD label at offset 64
+ *     - if not found, searchs UniOS/ISI label at the end of block
+ *     - kernel can distinguish whether it was SunOS label or UniOS/ISI
+ *       label and understand both
+ *     - kernel writes UniOS/ISI label combined with BSD label to update
+ *       the label block
  */
 
 #if LABELSECTOR != 0