diff --git a/VERSION b/VERSION
index f42a27c..7776610 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.96
+1.0.97
diff --git a/pdk.patch b/pdk.patch
deleted file mode 100644
index 166dda4..0000000
--- a/pdk.patch
+++ /dev/null
@@ -1,337 +0,0 @@
-commit c8e490f65d8624cc2e39147afd1c0269cac7f8b4
-Author: Donn <me@donn.website>
-Date:   Tue Dec 29 01:38:02 2020 +0200
-
-    Looking for PDKs in standard directories then downloading
-
-diff --git a/scripts/.gitignore b/scripts/.gitignore
-index b1083e1..1383243 100644
---- a/scripts/.gitignore
-+++ b/scripts/.gitignore
-@@ -4,4 +4,4 @@
- !configure.ac
- !tools.txt
- !print_tools_make.pl
--!dl
-\ No newline at end of file
-+!download.sh
-\ No newline at end of file
-diff --git a/scripts/configure b/scripts/configure
-index ba4f0c8..5e03076 100755
---- a/scripts/configure
-+++ b/scripts/configure
-@@ -628,6 +628,7 @@ infodir
- docdir
- oldincludedir
- includedir
-+runstatedir
- localstatedir
- sharedstatedir
- sysconfdir
-@@ -706,6 +707,7 @@ datadir='${datarootdir}'
- sysconfdir='${prefix}/etc'
- sharedstatedir='${prefix}/com'
- localstatedir='${prefix}/var'
-+runstatedir='${localstatedir}/run'
- includedir='${prefix}/include'
- oldincludedir='/usr/include'
- docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
-@@ -958,6 +960,15 @@ do
-   | -silent | --silent | --silen | --sile | --sil)
-     silent=yes ;;
- 
-+  -runstatedir | --runstatedir | --runstatedi | --runstated \
-+  | --runstate | --runstat | --runsta | --runst | --runs \
-+  | --run | --ru | --r)
-+    ac_prev=runstatedir ;;
-+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
-+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
-+  | --run=* | --ru=* | --r=*)
-+    runstatedir=$ac_optarg ;;
-+
-   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
-     ac_prev=sbindir ;;
-   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
-@@ -1095,7 +1106,7 @@ fi
- for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
- 		datadir sysconfdir sharedstatedir localstatedir includedir \
- 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
--		libdir localedir mandir
-+		libdir localedir mandir runstatedir
- do
-   eval ac_val=\$$ac_var
-   # Remove trailing slashes.
-@@ -1248,6 +1259,7 @@ Fine tuning of the installation directories:
-   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
-   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
-   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
-+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
-   --libdir=DIR            object code libraries [EPREFIX/lib]
-   --includedir=DIR        C header files [PREFIX/include]
-   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
-@@ -1279,7 +1291,7 @@ Optional Features:
-   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
-   --enable-sky130-pdk=[/path/to/sky130/] --disable-sky130-pdk
-                           "location of the source files for the sky130 (pdks
--                          with a pdk_url file can automatically download them
-+                          with a pdk_info file can automatically download them
-                           if the path is omitted)"
-   --enable-klayout
-                 Enable or disable klayout [default=enabled]
-@@ -1797,22 +1809,22 @@ $as_echo "$as_me: Found technology directories: sky130" >&6;}
-         SKY130_LINK_TARGETS="none"
- 
-         pdk_get() {
--            { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ../sky130/pdk_url" >&5
--$as_echo_n "checking for ../sky130/pdk_url... " >&6; }
--if ${ac_cv_file____sky130_pdk_url+:} false; then :
-+            { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ../sky130/pdk_info" >&5
-+$as_echo_n "checking for ../sky130/pdk_info... " >&6; }
-+if ${ac_cv_file____sky130_pdk_info+:} false; then :
-   $as_echo_n "(cached) " >&6
- else
-   test "$cross_compiling" = yes &&
-   as_fn_error $? "cannot check for file existence when cross compiling" "$LINENO" 5
--if test -r "../sky130/pdk_url"; then
--  ac_cv_file____sky130_pdk_url=yes
-+if test -r "../sky130/pdk_info"; then
-+  ac_cv_file____sky130_pdk_info=yes
- else
--  ac_cv_file____sky130_pdk_url=no
-+  ac_cv_file____sky130_pdk_info=no
- fi
- fi
--{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_file____sky130_pdk_url" >&5
--$as_echo "$ac_cv_file____sky130_pdk_url" >&6; }
--if test "x$ac_cv_file____sky130_pdk_url" = xyes; then :
-+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_file____sky130_pdk_info" >&5
-+$as_echo "$ac_cv_file____sky130_pdk_info" >&6; }
-+if test "x$ac_cv_file____sky130_pdk_info" = xyes; then :
- 
-                 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ../pdks/sky130" >&5
- $as_echo_n "checking for ../pdks/sky130... " >&6; }
-@@ -1835,9 +1847,11 @@ if test "x$ac_cv_file____pdks_sky130" = xyes; then :
- 
- else
- 
--                    mkdir -p ../pdks/sky130
--                    sh dl $(cat "../sky130/pdk_get") ../pdks/sky130.tar.gz;
--                    (echo "Extracting sky130" && cd ../pdks && tar -xf sky130.tar.gz --strip-components 1 -C ../pdks/sky130)
-+                    REPO=$(cat "../sky130/pdk_info" | sed -n "1p")
-+                    POST_CLONE_COMMANDS=$(cat "../sky130/pdk_info" | sed "1d")
-+                    mkdir -p ../pdks
-+                    git clone "$REPO" ../pdks/sky130;
-+                    (cd ../pdks/sky130 && sh -c "$POST_CLONE_COMMANDS")
- 
- fi
- 
-@@ -1851,11 +1865,26 @@ fi
- 
-         }
- 
-+        pdk_find() {
-+            FOUND=0
-+            for path in /opt/pdks/sky130 /usr/share/pdks/sky130 /usr/local/share/pdks/sky130; do
-+                if [ -d $path ] ; then
-+                    echo "Found sky130 in $path, using this installation..."
-+                    export SKY130_SOURCE_PATH=$path
-+                    FOUND=1
-+                fi
-+            done
-+            if [ "$FOUND" = "sky130" ]; then
-+                echo "Could not found sky130 in standard search paths, manually downloading to ../pdks/sky130 ..."
-+                pdk_find
-+            fi
-+        }
-+
-         # Check whether --enable-sky130-sky130 was given.
- if test "${enable_sky130_pdk+set}" = set; then :
-   enableval=$enable_sky130_pdk;
-                 if test "$enableval" == "yes" -o "$enableval" == "YES"; then
--                    pdk_get
-+                   pdk_find
-                 elif test "$enableval" == "no" -o "$enableval" == "NO"; then
-                     echo "Disabling sky130..."
-                 else
-@@ -1864,7 +1893,7 @@ if test "${enable_sky130_pdk+set}" = set; then :
- 
- else
- 
--                pdk_get
-+                pdk_find
- 
- 
- fi
-@@ -2455,7 +2484,7 @@ if ${am_cv_pathless_PYTHON+:} false; then :
-   $as_echo_n "(cached) " >&6
- else
- 
--	for am_cv_pathless_PYTHON in python python2 python3 python3.3 python3.2 python3.1 python3.0 python2.7  python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python2.0 none; do
-+	for am_cv_pathless_PYTHON in python python2 python3 python3.8 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python3.1 python3.0 python2.7  python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python2.0 none; do
- 	  test "$am_cv_pathless_PYTHON" = none && break
- 	  prog="import sys
- # split strings by '.' and convert to numeric.  Append some zeros
-@@ -2678,28 +2707,33 @@ $as_echo "$am_cv_python_pyexecdir" >&6; }
- 
-     if test -z $PYTHON;
-     then
--        PYTHON="python"
-+        if test -z "";
-+        then
-+            PYTHON="python3"
-+        else
-+            PYTHON=""
-+        fi
-     fi
-     PYTHON_NAME=`basename $PYTHON`
-     { $as_echo "$as_me:${as_lineno-$LINENO}: checking $PYTHON_NAME module: distutils" >&5
- $as_echo_n "checking $PYTHON_NAME module: distutils... " >&6; }
--	$PYTHON -c "import distutils" 2>/dev/null
--	if test $? -eq 0;
--	then
--		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-+    $PYTHON -c "import distutils" 2>/dev/null
-+    if test $? -eq 0;
-+    then
-+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
- $as_echo "yes" >&6; }
--		eval HAVE_PYMOD_DISTUTILS=yes
--	else
--		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-+        eval HAVE_PYMOD_DISTUTILS=yes
-+    else
-+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
- $as_echo "no" >&6; }
--		eval HAVE_PYMOD_DISTUTILS=no
--		#
--		if test -n ""
--		then
--			as_fn_error $? "failed to find required module distutils" "$LINENO" 5
--			exit 1
--		fi
--	fi
-+        eval HAVE_PYMOD_DISTUTILS=no
-+        #
-+        if test -n ""
-+        then
-+            as_fn_error $? "failed to find required module distutils" "$LINENO" 5
-+            exit 1
-+        fi
-+    fi
- 
- 
- # Check for "--with-ef-style"
-diff --git a/scripts/configure.ac b/scripts/configure.ac
-index 1c06fcf..03866fc 100755
---- a/scripts/configure.ac
-+++ b/scripts/configure.ac
-@@ -24,13 +24,15 @@ AC_DEFUN([M4_GEN_WITH_PDK_ARGS], [
-         pdkvar[]_LINK_TARGETS="none"
- 
-         pdk_get() {
--            AC_CHECK_FILE(../pdk/[pdk]_url, [
-+            AC_CHECK_FILE(../pdk/[pdk]_info, [
-                 AC_CHECK_FILE(../pdks/pdk,[
-                     echo "Using pre-existing pdk download..."
-                 ], [
--                    mkdir -p ../pdks/pdk
--                    sh dl $(cat "../pdk/pdk_get") ../pdks/pdk.tar.gz;
--                    (echo "Extracting pdk..." && cd ../pdks && tar -xf pdk.tar.gz --strip-components 1 -C ../pdks/pdk)
-+                    REPO=$(cat "../pdk/pdk_info" | sed -n "1p")
-+                    POST_CLONE_COMMANDS=$(cat "../pdk/pdk_info" | sed "1d")
-+                    mkdir -p ../pdks
-+                    git clone "$REPO" ../pdks/pdk;
-+                    (cd ../pdks/pdk && sh -c "$POST_CLONE_COMMANDS")
-                 ])
-                 export pdkvar[]_SOURCE_PATH=../pdks/pdk
-             ], [
-@@ -38,18 +40,33 @@ AC_DEFUN([M4_GEN_WITH_PDK_ARGS], [
-             ])
-         }
- 
-+        pdk_find() {
-+            FOUND=0
-+            for path in /opt/pdks/pdk /usr/share/pdks/pdk /usr/local/share/pdks/pdk; do
-+                if @<:@ -d $path @:>@ ; then
-+                    echo "Found pdk in $path, using this installation..."
-+                    export pdkvar[]_SOURCE_PATH=$path
-+                    FOUND=1
-+                fi
-+            done
-+            if @<:@ "$FOUND" = "$1" @:>@; then
-+                echo "Could not found pdk in standard search paths, manually downloading to ../pdks/pdk ..."
-+                pdk_find
-+            fi
-+        }
-+
-         AC_ARG_ENABLE(pdk-[pdk],
-             [AS_HELP_STRING([--enable-pdk-[pdk]=@<:@/path/to/pdk/@:>@ --disable-pdk-[pdk]], "location of the source files for the pdk (pdks with a [pdk]_url file can automatically download them if the path is omitted)")],
-             [
-                 if test "$enableval" == "yes" -o "$enableval" == "YES"; then
--                    pdk_get
-+                   pdk_find
-                 elif test "$enableval" == "no" -o "$enableval" == "NO"; then
-                     echo "Disabling pdk..."
-                 else
-                     export pdkvar[]_SOURCE_PATH=$enableval
-                 fi
-             ], [
--                pdk_get
-+                pdk_find
-             ]
-         )
- 	    # # Require this argument
-diff --git a/scripts/download.sh b/scripts/download.sh
-new file mode 100755
-index 0000000..7623f32
---- /dev/null
-+++ b/scripts/download.sh
-@@ -0,0 +1,22 @@
-+#!/bin/sh
-+#
-+# Neither curl or wget are guaranteed to be included in all *nix systems,
-+# (but most have *one* of them). This tools tries its best to find one.
-+#
-+
-+DL_CMD=
-+if type "wget" > /dev/null; then
-+    DL_CMD="wget -qO"
-+fi
-+
-+if type "curl" > /dev/null; then
-+    DL_CMD="curl -sLo"
-+fi
-+
-+if [ "$DL_CMD" = "" ]; then
-+    echo "Either curl or wget are required to automatically install tools."
-+    exit 1
-+fi
-+
-+echo "Downloading $1 to $2..."
-+$DL_CMD $2 $1
-\ No newline at end of file
-diff --git a/sky130/pdk_info b/sky130/pdk_info
-new file mode 100644
-index 0000000..ee872cd
---- /dev/null
-+++ b/sky130/pdk_info
-@@ -0,0 +1,10 @@
-+https://github.com/google/skywater-pdk
-+
-+# Post Clone Commands
-+for i in $(git submodule | grep /latest | awk '{print $2}'); do
-+    git submodule init $i
-+done
-+
-+git submodule update
-+
-+make timing
-\ No newline at end of file
-diff --git a/sky130/pdk_url b/sky130/pdk_url
-deleted file mode 100644
-index 11a17e1..0000000
---- a/sky130/pdk_url
-+++ /dev/null
-@@ -1 +0,0 @@
--https://github.com/google/skywater-pdk/archive/master.tar.gz
-\ No newline at end of file
diff --git a/sky130/custom/scripts/generate_fill.py b/sky130/custom/scripts/generate_fill.py
new file mode 100755
index 0000000..9a1e3dc
--- /dev/null
+++ b/sky130/custom/scripts/generate_fill.py
@@ -0,0 +1,239 @@
+#!/bin/env python3
+# SPDX-FileCopyrightText: 2020 Efabless Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
+
+#
+# generate_fill.py ---
+#
+#    Run the fill generation on a layout top level.
+#
+
+import sys
+import os
+import re
+import subprocess
+
+def usage():
+    print("Usage:")
+    print("generate_fill.py <layout_name> [-keep] [-test]")
+    print("")
+    print("where:")
+    print("    <layout_name> is the path to the .mag file to be filled.")
+    print("")
+    print("  If '-keep' is specified, then keep the generation script.")
+    print("  If '-test' is specified, then create but do not run the generation script.")
+    return 0
+
+if __name__ == '__main__':
+
+    optionlist = []
+    arguments = []
+
+    debugmode = False
+    keepmode = False
+    testmode = False
+
+    for option in sys.argv[1:]:
+        if option.find('-', 0) == 0:
+            optionlist.append(option)
+        else:
+            arguments.append(option)
+
+    if len(arguments) != 1:
+        print("Wrong number of arguments given to generate_fill.py.")
+        usage()
+        sys.exit(1)
+
+    user_project_path = arguments[0]
+
+    magpath = os.path.split(user_project_path)[0]
+    if magpath == '':
+        magpath = os.getcwd()
+
+    if os.path.splitext(user_project_path)[1] != '.mag':
+        if os.path.splitext(user_project_path)[1] == '':
+            user_project_path += '.mag'
+        else:
+            print('Error:  Project is not a magic database .mag file!')
+            sys.exit(1)
+
+    if not os.path.isfile(user_project_path):
+        print('Error:  Project "' + user_project_path + '" does not exist or is not readable.')
+        sys.exit(1)
+
+    if '-debug' in optionlist:
+        debugmode = True
+    if '-keep' in optionlist:
+        keepmode = True
+    if '-test' in optionlist:
+        testmode = True
+
+    rcfile = magpath + '/.magicrc'
+    if not os.path.isfile(rcfile):
+        rcfile = None
+
+    project = os.path.splitext(os.path.split(user_project_path)[1])[0]
+
+    topdir = os.path.split(magpath)[0]
+    gdsdir = topdir + '/gds'
+    hasgdsdir = True if os.path.isdir(gdsdir) else False
+
+    with open(magpath + '/generate_fill.tcl', 'w') as ofile:
+        print('#!/bin/env wish', file=ofile)
+        print('drc off', file=ofile)
+        print('tech unlock *', file=ofile)
+        print('snap internal', file=ofile)
+        print('box values 0 0 0 0', file=ofile)
+        print('box size 700um 700um', file=ofile)
+        print('set stepbox [box values]', file=ofile)
+        print('set stepwidth [lindex $stepbox 2]', file=ofile)
+        print('set stepheight [lindex $stepbox 3]', file=ofile)
+        print('', file=ofile)
+        print('set starttime [orig_clock format [orig_clock seconds] -format "%D %T"]', file=ofile)
+        print('puts stdout "Started: $starttime"', file=ofile)
+        print('', file=ofile)
+        print('load ' + project + ' -dereference', file=ofile)
+        print('select top cell', file=ofile)
+        print('expand', file=ofile)
+        print('cif ostyle wafflefill(tiled)', file=ofile)
+        print('', file=ofile)
+        print('set fullbox [box values]', file=ofile)
+        print('set xmax [lindex $fullbox 2]', file=ofile)
+        print('set xmin [lindex $fullbox 0]', file=ofile)
+        print('set fullwidth [expr {$xmax - $xmin}]', file=ofile)
+        print('set xtiles [expr {int(ceil($fullwidth / $stepwidth))}]', file=ofile)
+        print('set ymax [lindex $fullbox 3]', file=ofile)
+        print('set ymin [lindex $fullbox 1]', file=ofile)
+        print('set fullheight [expr {$ymax - $ymin}]', file=ofile)
+        print('set ytiles [expr {int(ceil($fullheight / $stepheight))}]', file=ofile)
+        print('box size $stepwidth $stepheight', file=ofile)
+        print('set xbase [lindex $fullbox 0]', file=ofile)
+        print('set ybase [lindex $fullbox 1]', file=ofile)
+        print('', file=ofile)
+
+        # Break layout into tiles and process each separately
+        print('for {set y 0} {$y < $ytiles} {incr y} {', file=ofile)
+        print('    for {set x 0} {$x < $xtiles} {incr x} {', file=ofile)
+        print('        set xlo [expr $xbase + $x * $stepwidth]', file=ofile)
+        print('        set ylo [expr $ybase + $y * $stepheight]', file=ofile)
+        print('        set xhi [expr $xlo + $stepwidth]', file=ofile)
+        print('        set yhi [expr $ylo + $stepheight]', file=ofile)
+        print('        box values $xlo $ylo $xhi $yhi', file=ofile)
+        # The flattened area must be larger than the fill tile by >1.5um
+        print('        box grow c 1.6um', file=ofile)
+
+        # Flatten into a cell with a new name
+        print('        puts stdout "Flattening layout of tile x=$x y=$y. . . "', file=ofile)
+        print('        flush stdout', file=ofile)
+        print('        update idletasks', file=ofile)
+        print('        flatten -dobox -nolabels ' + project + '_fill_pattern_${x}_$y', file=ofile)
+        print('        load ' + project + '_fill_pattern_${x}_$y', file=ofile)
+
+        # Remove any GDS_FILE reference
+        print('        property GDS_FILE ""', file=ofile)
+        # Set boundary using comment layer, to the size of the step box
+        print('        box values $xlo $ylo $xhi $yhi', file=ofile)
+        print('        paint comment', file=ofile)
+        print('        puts stdout "Writing GDS. . . "', file=ofile)
+        print('        flush stdout', file=ofile)
+        print('        update idletasks', file=ofile)
+        print('        gds write ' + project + '_fill_pattern_${x}_$y.gds', file=ofile)
+
+        # Reload project top
+        print('        load ' + project, file=ofile)
+
+        # Remove last generated cell to save memory
+        print('        cellname delete ' + project + '_fill_pattern_${x}_$y', file=ofile)
+
+        print('    }', file=ofile)
+        print('}', file=ofile)
+
+        # Now create simple "fake" views of all the tiles.
+        print('gds readonly true')
+        print('gds rescale false')
+        print('for {set y 0} {$y < $ytiles} {incr y} {', file=ofile)
+        print('    for {set x 0} {$x < $xtiles} {incr x} {', file=ofile)
+        print('        set xlo [expr $xbase + $x * $stepwidth]', file=ofile)
+        print('        set ylo [expr $ybase + $y * $stepheight]', file=ofile)
+        print('        set xhi [expr $xlo + $stepwidth]', file=ofile)
+        print('        set yhi [expr $ylo + $stepheight]', file=ofile)
+        print('        load ' + project + '_fill_pattern_${x}_$y', file=ofile)
+        print('        box values $xlo $ylo $xhi $yhi', file=ofile)
+        print('        paint comment', file=ofile)
+        print('        property FIXED_BBOX "$xlo $ylo $xhi $yhi"', file=ofile)
+        print('        property GDS_FILE ' + project + '_fill_pattern_${x}_${y}.gds', file=ofile)
+        print('        property GDS_START 0', file=ofile)
+        print('    }', file=ofile)
+        print('}', file=ofile)
+
+        # Now tile everything back together
+        print('load ' + project + '_fill_pattern', file=ofile)
+        print('for {set y 0} {$y < $ytiles} {incr y} {', file=ofile)
+        print('    for {set x 0} {$x < $xtiles} {incr x} {', file=ofile)
+        print('        box values 0 0 0 0', file=ofile)
+        print('        getcell ' + project + '_fill_pattern_${x}_$y child 0 0', file=ofile)
+        print('    }', file=ofile)
+        print('}', file=ofile)
+
+        # And write final GDS
+        print('puts stdout "Writing final GDS"', file=ofile)
+
+        print('cif *hier write disable', file=ofile)
+        print('cif *array write disable', file=ofile)
+        if hasgdsdir:
+            print('gds write ../gds/' + project + '_fill_pattern.gds', file=ofile)
+        else:
+            print('gds write ' + project + '_fill_pattern.gds', file=ofile)
+        print('set endtime [orig_clock format [orig_clock seconds] -format "%D %T"]', file=ofile)
+        print('puts stdout "Ended: $endtime"', file=ofile)
+        print('quit -noprompt', file=ofile)
+    myenv = os.environ.copy()
+    myenv['MAGTYPE'] = 'mag'
+
+    if not testmode:
+        # Diagnostic
+        # print('This script will generate file ' + project + '_fill_pattern.gds')
+        print('This script will generate files ' + project + '_fill_pattern_x_y.gds')
+        print('Now generating fill patterns.  This may take. . . quite. . . a while.', flush=True)
+        mproc = subprocess.run(['magic', '-dnull', '-noconsole',
+		'-rcfile', rcfile, magpath + '/generate_fill.tcl'],
+		stdin = subprocess.DEVNULL,
+		stdout = subprocess.PIPE,
+		stderr = subprocess.PIPE,
+		cwd = magpath,
+		env = myenv,
+		universal_newlines = True)
+        if mproc.stdout:
+            for line in mproc.stdout.splitlines():
+                print(line)
+        if mproc.stderr:
+            print('Error message output from magic:')
+            for line in mproc.stderr.splitlines():
+                print(line)
+            if mproc.returncode != 0:
+                print('ERROR:  Magic exited with status ' + str(mproc.returncode))
+
+    if not keepmode:
+        # Remove fill generation script
+        os.remove(magpath + '/generate_fill.tcl')
+        # Remove all individual fill tiles, leaving only the composite GDS.
+        filelist = os.listdir(magpath)
+        for file in filelist:
+            if os.path.splitext(magpath + '/' + file)[1] == '.gds':
+                if file.startswith(project + '_fill_pattern_')
+                    os.remove(magpath + '/' + file
+
+    print('Done!')
+    exit(0)
diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index 95fc2f4..67047b2 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -1707,7 +1707,7 @@
 #endif (EXPERIMENTAL)
 
 #----------------------------------------------------------------
-style wafflefill
+style wafflefill variants (),(tiled)
 #----------------------------------------------------------------
 # Style used by scripts for automatically generating fill layers
 # NOTE: Be sure to generate output on flattened layout.
@@ -1717,10 +1717,30 @@
  gridlimit 5
 
 #----------------------------------------------------------------
-# Generate and retain a layer representing the bounding box
+# Generate and retain a layer representing the bounding box.
+#
+# For variant ():
+# The bounding box is the full extent of geometry on the top level
+# cell.
+#
+# For variant (tiled):
+# Use with a script that breaks layout into flattened tiles and runs
+# fill individually on each.  The tiles should be larger than the
+# step size, and each should draw a layer "comment" the size of the
+# step box.
 #----------------------------------------------------------------
- templayer	topbox
-	bbox	top
+
+ variants ()
+     templayer	topbox
+	 bbox	top
+
+ variants (tiled)
+     templayer	topbox comment
+	 # Each tile imposes the full keepout distance rule of
+	 # 3um on all sides.
+	 shrink 1500
+
+ variants *
 
 #----------------------------------------------------------------
 # Generate guard-band around nwells to keep FOM from crossing
@@ -1732,25 +1752,27 @@
  templayer mvnwell
  	bloat-all alldiffmv nwell
 
- templayer lvnwell nwell
+ templayer lvnwell allnwell
 	and-not mvnwell
 
  templayer	well_shrink mvnwell
 	shrink 	250
 	or lvnwell
 	shrink	180
- templayer	well_guardband nwell
+ templayer	well_guardband allnwell
 	grow	340
 	and-not	well_shrink
 
 #---------------------------------------------------
 # Diffusion and poly keep-out areas
 #---------------------------------------------------
- templayer      obstruct_fom alldiff,allpoly,rpw
+ templayer      obstruct_fom alldiff,allpoly,fomfill,polyfill,obspoly,obsactive
+	or	rpw,pnp,npn
         grow    500
 	or	well_guardband
 
- templayer      obstruct_poly alldiff,allpoly,rpw
+ templayer      obstruct_poly alldiff,allpolyfomfill,polyfill,obspoly,obsactive
+	or	rpw,pnp,npn
 	grow	1000
 
 #---------------------------------------------------
@@ -2045,6 +2067,7 @@
  templayer	met4fill_medium topbox
         slots   0 1000 300 0 1000 300 700 1050
         and-not obstruct_m4_medium
+	and	topbox
         shrink  495
         grow    495