scripts/mkits.sh: add support for adding DT overlay blobs to image

Allow adding multiple device tree overlay blobs to an image and
generate configurations for each of them.
This is useful on boards with modern U-Boot which allow e.g. user-
configurable peripherals ("shields") in that way.
Note that currently, each generated configuration adds exactly one
overlay on top of the base image, ie. adding multiple overlays at the
same time is not yet supported.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/scripts/mkits.sh b/scripts/mkits.sh
index e5369548d76034e33171cc001de91c9f9abdfccc..7533baf79999c1f84bc9e1fb61a999aa52cbe395 100755 (executable)
--- a/scripts/mkits.sh
+++ b/scripts/mkits.sh
@@ -32,7 +32,9 @@ usage() {
        printf "\n\t-d ==> include Device Tree Blob 'dtb'"
        printf "\n\t-r ==> include RootFS blob 'rootfs'"
        printf "\n\t-H ==> specify hash algo instead of SHA1"
-       printf "\n\t-o ==> create output file 'its_file'\n"
+       printf "\n\t-o ==> create output file 'its_file'"
+       printf "\n\t-O ==> create config with dt overlay 'name:dtb'"
+       printf "\n\t\t(can be specified more than once)\n"
        exit 1
 }
 
@@ -41,8 +43,10 @@ ROOTFSNUM=1
 INITRDNUM=1
 HASH=sha1
 LOADABLES=
+DTOVERLAY=
+DTADDR=
 
-while getopts ":A:a:c:C:D:d:e:f:i:k:n:o:v:r:S" OPTION
+while getopts ":A:a:c:C:D:d:e:f:i:k:n:o:O:v:r:S" OPTION
 do
        case $OPTION in
                A ) ARCH=$OPTARG;;
@@ -57,6 +61,7 @@ do
                k ) KERNEL=$OPTARG;;
                n ) FDTNUM=$OPTARG;;
                o ) OUTPUT=$OPTARG;;
+               O ) DTOVERLAY="$DTOVERLAY ${OPTARG}";;
                r ) ROOTFS=$OPTARG;;
                S ) HASH=$OPTARG;;
                v ) VERSION=$OPTARG;;
@@ -78,6 +83,11 @@ if [ -n "${COMPATIBLE}" ]; then
        COMPATIBLE_PROP="compatible = \"${COMPATIBLE}\";"
 fi
 
+[ "$DTOVERLAY" ] && {
+       dtbsize=$(wc -c "$DTB" | cut -d' ' -f1)
+       DTADDR=$(printf "0x%08x" $(($LOAD_ADDR - $dtbsize)) )
+}
+
 # Conditionally create fdt information
 if [ -n "${DTB}" ]; then
        FDT_NODE="
@@ -86,6 +96,7 @@ if [ -n "${DTB}" ]; then
                        ${COMPATIBLE_PROP}
                        data = /incbin/(\"${DTB}\");
                        type = \"flat_dt\";
+                       ${DTADDR:+load = <${DTADDR}>;}
                        arch = \"${ARCH}\";
                        compression = \"none\";
                        hash@1 {
@@ -141,6 +152,47 @@ if [ -n "${ROOTFS}" ]; then
        LOADABLES="${LOADABLES:+$LOADABLES, }\"rootfs-${ROOTFSNUM}\""
 fi
 
+# add DT overlay blobs
+FDTOVERLAY_NODE=""
+OVCONFIGS=""
+[ "$DTOVERLAY" ] && for overlay in $DTOVERLAY ; do
+       overlay_blob=${overlay##*:}
+       ovname=${overlay%%:*}
+       ovnode="fdt-$ovname"
+       ovsize=$(wc -c "$overlay_blob" | cut -d' ' -f1)
+       echo "$ovname ($overlay_blob) : $ovsize" >&2
+       DTADDR=$(printf "0x%08x" $(($DTADDR - $ovsize)))
+       FDTOVERLAY_NODE="$FDTOVERLAY_NODE
+
+               $ovnode {
+                       description = \"${ARCH_UPPER} OpenWrt ${DEVICE} device tree overlay $ovname\";
+                       ${COMPATIBLE_PROP}
+                       data = /incbin/(\"${overlay_blob}\");
+                       type = \"flat_dt\";
+                       arch = \"${ARCH}\";
+                       load = <${DTADDR}>;
+                       compression = \"none\";
+                       hash@1 {
+                               algo = \"crc32\";
+                       };
+                       hash@2 {
+                               algo = \"${HASH}\";
+                       };
+               };
+"
+       OVCONFIGS="$OVCONFIGS
+
+               config-$ovname {
+                       description = \"OpenWrt ${DEVICE} with $ovname\";
+                       kernel = \"kernel-1\";
+                       fdt = \"fdt-$FDTNUM\", \"$ovnode\";
+                       ${LOADABLES:+loadables = ${LOADABLES};}
+                       ${COMPATIBLE_PROP}
+                       ${INITRD_PROP}
+               };
+       "
+done
+
 # Create a default, fully populated DTS file
 DATA="/dts-v1/;
 
@@ -167,6 +219,7 @@ DATA="/dts-v1/;
                };
 ${INITRD_NODE}
 ${FDT_NODE}
+${FDTOVERLAY_NODE}
 ${ROOTFS_NODE}
        };
 
@@ -180,6 +233,7 @@ ${ROOTFS_NODE}
                        ${COMPATIBLE_PROP}
                        ${INITRD_PROP}
                };
+               ${OVCONFIGS}
        };
 };"