svn commit: r340610 - stable/12/libexec/rc

[Eugene Grosbein]

Author: eugen
Date: Mon Nov 19 06:33:38 2018
New Revision: 340610
URL: https://svnweb.freebsd.org/changeset/base/340610

Log:
  MFC r339465: rc.initdiskless: add support for auxiliary NVRAM.
  
    Currently, rc.inidiskless assumes that local system configuration
    changes are kept in some mountable file system. For example,
    nanobsd uses dedicated partition mounted as /cfg for this.
  
    However, small embedded devices like MIPS routers may have no enough flash
    space to keep full-blown file system but have only one or couple
    small flash blocks to keep persistent local configuration overrides.
  
    This change extends rc.initdiskless and introduces ability to run auxiliary
    command /conf/T/M/extract that is supposed to extract configuration overrides
    from such local storage.
  
    For example, the command /conf/default/etc/extract may contain something like:
  
    cd "$1" && bsdcpio --quiet -idu < /dev/map/cfg
  
    bsdcpio command extracts compressed archive from the storage to /etc
    assuming the storage is exposed by the kernel as /dev/map/cfg to userland.
  
  PR:		204215

Modified:
  stable/12/libexec/rc/rc.initdiskless
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/libexec/rc/rc.initdiskless
==============================================================================
--- stable/12/libexec/rc/rc.initdiskless	Mon Nov 19 06:07:17 2018	(r340609)
+++ stable/12/libexec/rc/rc.initdiskless	Mon Nov 19 06:33:38 2018	(r340610)
@@ -111,6 +111,15 @@
 #		created for /SUBDIR if necessary). The presence of this file
 #		prevents the copy from /conf/T/SUBDIR/
 #
+# /conf/T/M/extract
+#		This is alternative to SUBDIR.cpio.gz and remount.
+#		Similar to remount case, a memory filesystem is created
+#		for /M and initialized from a template but no mounting
+#		performed. Instead, this file is run passing /M as singe
+#		argument. It is expected to extract template override to /M
+#		using auxiliary storage found in some embedded systems
+#		having NVRAM too small to hold mountable file system.
+#
 # /conf/T/SUBDIR.remove
 #		The list of paths contained in the file are rm -rf'd
 #		relative to /SUBDIR.
@@ -343,8 +352,8 @@ done
 
 # - Create all required MFS filesystems and populate them from
 #   our templates.  Support both a direct template and a dir.cpio.gz
-#   archive.  Support dir.remove files containing a list of relative
-#   paths to remove.
+#   archive. Support for auxiliary NVRAM. Support dir.remove files containing
+#   a list of relative paths to remove.
 #
 # The dir.cpio.gz form is there to make the copy process more efficient,
 # so if the cpio archive is present, it prevents the files from dir/
@@ -365,6 +374,15 @@ for i in ${templates} ; do
 	    create_md $subdir
 	    echo "Loading /$subdir from cpio archive $j"
 	    (cd / ; /rescue/tar -xpf $j)
+	fi
+    done
+    for j in /conf/$i/*/extract ; do
+	if [ -x $j ]; then
+	    subdir=${j%*/extract}
+	    subdir=${subdir##*/}
+	    create_md $subdir
+	    echo "Loading /$subdir using auxiliary command $j"
+	    $j /$subdir
 	fi
     done
     for j in /conf/$i/*.remove ; do