Index: user/gjb/thermite/README.txt
===================================================================
--- user/gjb/thermite/README.txt	(revision 359724)
+++ user/gjb/thermite/README.txt	(revision 359725)
@@ -1,88 +1,88 @@
 #
 # $FreeBSD$
 #
 
 1) Configuration Files:
 
    - Each architecture and individual kernel have their own configuration file
      used by release.sh.  Each branch has its own defaults-X.conf file which
      contains entries common throughout each architecture, where overrides or
      special variables are set and/or overridden in the per-build files.
 
      The per-build configuration file naming scheme is in the form of:
 
      ${revision}-${TARGET_ARCH}-${KERNCONF}-${type}.conf
 
      where the uppercase variables are equivalent to what make(1) uses in the
      build system, and lowercase variables are set within the configuration
      files, mapping to the major version of the respective branch.
 
    - Each branch also has its own builds-X.conf file, which is used by
      thermite.sh.  The thermite.sh script iterates through each ${revision},
      ${TARGET_ARCH}, ${KERNCONF}, and ${type} value, creating a master list
      of what to build.  However, a given combination from the list will only
      be built if the respective configuration file exists, which is where the
      naming convention above is relevant.
 
    - There are two paths of file sourcing:
 
      - builds-X.conf -> main.conf:
        This controls thermite.sh behavior.
 
      - X-arch-KERNCONF-type.conf -> defaults-X.conf -> main.conf
        This controls release/release.sh behavior.
 
 2) Filesystem Layout:
 
    - The official release build machines have a specific filesystem layout,
      which using ZFS, thermite.sh takes heavy advantage of with clones,
      snapshots, etc., ensuring a pristine build environment.
 
    - The build scripts reside in /releng/scripts-snapshot/scripts or
      /releng/scripts-release/scripts respectfully, to avoid collisions between
      an RC build from a releng branch versus a STABLE snapshot from the
      respective stable branch.
 
    - A separate dataset exists for the final build images, /snap/ftp.  This
      directory contains both snapshots and releases directories.  They are
      only used if the EVERYTHINGISFINE variable is defined in main.conf.
 
    - As thermite.sh iterates through the master list of combinations and
      locates the per-build configuration file, a zfs dataset is created under
      the /releng directory, such as /releng/12-amd64-GENERIC-snap.  The src,
      ports, and doc trees are checked out to separate zfs datasets, such as
      /releng/12-src-snap, which are then cloned into the respective build
      datasets.  This is done to avoid checking out a given tree more than
      once.
 
 3) Helper Scripts:
 
    - To avoid repetition and possible human error, a few scripts were written
      to help keep things as automated as possible:
 
-     - zfs-setup.sh:
-       Destroys and creates pristine zfs datasets for each build.
-
      - setrev.sh:
        Retrieves the 'Last Changed Revision' from the target branch and writes
        the version to a 'svnrev_src' file, and outputs the date in YYYYMMDD
        format to a builddate file.
 
      - get-checksums.sh:
        When all builds have completed, this script will iterate through and
        generate a list of sha512 and sha256 checksums for all builds.
 
      - generate-email.pl:
        This script generates the snapshot announcement email text.
+
+     - zfs-cleanup.sh:
+       Destroys zfs datasets from previous builds.
 
 4) Example Usage:
 
    root@builder:~ # mkdir -p /releng/scripts-snapshot/scripts
    root@builder:~ # cd /releng/scripts-snapshot/scripts
    root@builder:~ # svn co svn://svn.freebsd.org/base/user/gjb/thermite .
    root@builder:~ # ./zfs-setup.sh -c ./builds-12.conf
    root@builder:~ # ./setrev.sh -b head
    root@builder:~ # ./thermite.sh -c ./builds-12.conf
    root@builder:~ # ./get-checksums.sh -c ./builds-12.conf | ./generate-email.pl \
                     > 12-snap-mail