overlay builder

.gitignore

@@ -1,6 +1,8 @@
 # specific to this repo
 build-trees/*.dt*
 build-trees/*/*.dt*
+build-overlays/*.dt*
+build-overlays/*/*.dt*
 source/*
 
 # Byte-compiled / optimized / DLL files

build-overlays/README.md

@@ -0,0 +1,5 @@
+# Overlay build system is a Work In Progress
+Status:
+* can build the example overlay
+* cannot deploy/activate the overlay, see issue #7
+* and not sure if using overlays is needed, they still have to be built for each new kernel and activated by a reboot. So not much less overhead vs compiling a full device tree.

build-overlays/make_overlays.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+# Takes a list of dts files for the specified architecture and emits appropriate compiled dtb files for use in customised deviceTree setups.
+#
+
+dtc=/usr/bin/dtc
+
+cdir=`pwd`
+versions=`dpkg --list | grep linux-image-[0-9].* | cut -d" " -s -f 3 | sed s/^linux-image-// | sort -V`
+
+echo -ne "\nBuilding for kernels: "
+echo `echo $versions | sed "s/ /, /g"`
+echo
+
+# Disabled auto building of all alt trees, better to do individually
+#alt=../alt-trees
+#echo "Linking alt dts sources to build root"
+#for dts in `ls -d $alt/*/*.dts`; do
+#    echo "$dts"
+#    ln -s "$dts" .
+#done
+
+# Ensure sure build roots exist and are clean
+for revision in $versions ; do
+    if [ -d "$cdir/$revision" ]; then
+        echo "Cleaning existing $revision build directory"
+        rm -f $revision/*.dts $revision/*.dtsi $revision/*.dtb
+    else
+        echo "Creating new build directory: $revision"
+        mkdir $revision
+    fi
+done
+
+failed=0
+# Compile for each revision
+for revision in $versions ; do
+    cd $cdir
+    echo -e "\nCompiling against headers for $revision"
+    if compgen -G "${PROJECT_DIR}/*.png" > /dev/null; then
+        echo "Precompiling all includes in build root into $revision build directory"
+        for file in `ls *.dtsi`; do
+            echo "  $file -> $revision/${file##*/}"
+            cpp -I/usr/src/linux-headers-$revision/include/ -nostdinc -undef -x assembler-with-cpp $file > $revision/${file##*/}
+            if [ ! -s "$revision/${file##*/}" ] ; then
+                rm "$revision/${file##*/}"
+                echo -e "**** ERROR ****\nPrecompile failed for include: $revision/${file##*/}\n"
+                failed=1
+            fi
+        done
+    else
+        echo "No includes to Precompile"
+    fi
+    for file in `ls *.dts`; do
+        echo "  $file -> $revision/${file##*/}"
+        cpp -I/usr/src/linux-headers-$revision/include/ -nostdinc -undef -x assembler-with-cpp $file > $revision/${file##*/}
+        if [ ! -s "$revision/${file##*/}" ] ; then
+            rm "$revision/${file##*/}"
+            echo -e "**** ERROR ****\nPrecompile failed for source: $revision/${file##*/}\n"
+            failed=1
+        fi
+    done
+
+    echo "Compiling all device tree sources in $revision build directory"
+    cd $revision
+    for file in `ls *.dts`; do
+        out=${file/.dts/.dtbo}
+        echo "  $revision/$file -> $revision/$out"
+        $dtc $file > $out
+        if [ ! -s "$out" ] ; then
+            rm "$out"
+            echo -e "**** ERROR ****\nCompile failed for: $out\n"
+            failed=1
+        fi
+    done
+done
+
+# Clean up any empty (failed) build folders.
+cd $cdir
+rmdir --ignore-fail-on-non-empty $versions
+
+# Notify that errors happened
+if [ $failed -eq 1 ]; then
+    echo -e "\n**** ERRORS detected, see above.\n"
+    exit 1
+fi
+
+echo -e "\nSuccess."
+#echo -e "\nSuccess. Consider running 'flash_overlays.sh' to make permanent (see docs)"

build-overlays/pwm2-pb11.dts

@@ -0,0 +1,31 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+    compatible = "widora,mangopi-mq-pro", "allwinner,sun20i-d1";
+
+    /* identification */
+    // part-number = "ADAFRUIT-SPI0";
+
+    /* version */
+    // version = "00A0";
+
+    fragment@0 {
+        target = <&pio>;
+        __overlay__ {
+            pwm2_pb11_pin: pwm2-pb11-pin {
+                pins = "PB11";
+                function = "pwm2";
+            };
+        };
+    };
+
+    fragment@1 {
+        target = <&pwm>;
+        __overlay__ {
+            pinctrl-0 = <&pwm0_pb12_pin>;
+            pinctrl-names = "default";
+            status = "okay";
+        };
+    };
+};