Module Name: src
Committed By: mlelstv
Date: Wed Nov 26 20:42:29 UTC 2014
Modified Files:
src/share/man/man9: cpu_rootconf.9
Log Message:
Mention the new bootspec variable.
Give more details about the root device configuration.
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/share/man/man9/cpu_rootconf.9
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/cpu_rootconf.9
diff -u src/share/man/man9/cpu_rootconf.9:1.8 src/share/man/man9/cpu_rootconf.9:1.9
--- src/share/man/man9/cpu_rootconf.9:1.8 Sun Jul 29 18:51:48 2012
+++ src/share/man/man9/cpu_rootconf.9 Wed Nov 26 20:42:29 2014
@@ -1,4 +1,4 @@
-.\" $NetBSD: cpu_rootconf.9,v 1.8 2012/07/29 18:51:48 wiz Exp $
+.\" $NetBSD: cpu_rootconf.9,v 1.9 2014/11/26 20:42:29 mlelstv Exp $
.\"
.\" Copyright (c) 2002 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -55,28 +55,81 @@ provides the global variables
.Fa booted_device ,
.Fa booted_partition ,
.Fa booted_startblk ,
+.Fa booted_nblks ,
and
-.Fa booted_nblks
-and invokes the machine-independent function
-.Fa rootconf
-which
+.Fa bootspec .
+.Fa cpu_rootconf
+invokes the machine-independent function
.Fa rootconf
-then calls the function
+which calls the function
.Fa setroot
-to record the boot/root device and the boot partition information
+to record the root device and the root partition information
for use in machine-independent code.
.Pp
-For disk boot, if
-.Fa booted_nblks
-is not 0, then
+.Fa rootconf
+may adjust the global variables and determines the parameters
+for setroot. This is for example used to translate a device
+and partition number provided by the bootloader into a disk
+wedge device covering the same partition.
+.Pp
+If the bootloader already identified a disk wedge, it passes
+a non-zero value for
+.Fa booted_nblks ,
+then
.Fa booted_startblk
and
.Fa booted_nblks
-are supposed to specify a disk wedge that is used as the root device.
-Otherwise the
-.Fa booted_partition
+specify a disk wedge as the boot device.
+.Pp
+.Fa setroot
+evaluates several sources to identify the root device in the
+following order until a valid device is selected:
+.Bl -enum
+.It
+The kernel configuration variable
+.Fa rootspec
+which is set by
+.Xr config 1 .
+The value is the name and unit of the root device, e.g. "sd0" (disk)
+or "dk0" (wedge) or "le0" (network) or the prefix "wedge:" followed
+by the name of the disk wedge. For disk devices the partition
+passed as argument to
+.Fa setroot
is used.
+.It
+The variable
+.Fa bootspec
+following the same syntax.
+.It
+The result of an interactive query of the root device if
+.Fa boothowto
+has set the flag RB_ASKNAME. The input uses the same syntax
+as the previous sources. Here also the kernel dump device
+is queried.
+.It
+The boot device and partition passed as arguments.
+.El
+.Pp
+If a root device cannot be selected,
+.Fa setroot
+sets the RB_ASKNAME flag and loops.
+.Pp
+Otherwise the kernel dump device is identified in a similar
+manner from
+.Bl -enum
+.It
+The result of a previous interactive query. See above.
+.It
+The kernel configuration variable
+.Fa dumpspec ,
+if set.
+.It
+The second partition of the root device, if it is a regular disk.
+.It
+The first disk wedge device of type DKW_PTYPE_SWAP.
+.El
.Sh SEE ALSO
.Xr dk 4 ,
.Xr boot 8 ,
+.Xr config 1 ,
.Xr boothowto 9
