sdcard_image: Helper class to create SD Card images

Tested with 3 different beagleboard image release builds so far

For ideas, referenced Narcissus image builder written by Koen Kooi <k-kooi@ti.com>

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

1 files changed, 78 insertions, 0 deletions

diff --git a/classes/sdcard_image.bbclass b/classes/sdcard_image.bbclass
new file mode 100644
index 00000000..b3885df6
--- /dev/null
+++ b/classes/sdcard_image.bbclass
@@ -0,0 +1,78 @@
+inherit image
+
+IMAGE_CMD_sdimg () {
+        SDIMG=${WORKDIR}/sd.img
+
+        # cleanup loops
+        for loop in $(losetup -j ${SDIMG}); do
+                loop_dev=$(echo $loop|cut -d ":" -f 1)
+                umount $loop_dev || true
+                losetup -d $loop_dev || true
+        done
+
+        dd if=/dev/zero of=${SDIMG} bs=4k seek=$(echo '256 * 1024' | bc) count=1
+        losetup -f ${SDIMG}
+        LOOPDEV=$(losetup -j ${SDIMG} -o 0 | cut -d ":" -f 1)
+
+        # Create partition table
+        dd if=/dev/zero of=${LOOPDEV} bs=1024 count=1024
+        SIZE=`fdisk -l ${LOOPDEV} | grep Disk | grep bytes | awk '{print $5}'`
+        CYLINDERS=`echo $SIZE/255/63/512 | bc`
+        {
+        echo ,9,0x0C,*
+        echo ,,,-
+        } | sfdisk -D -H 255 -S 63 -C ${CYLINDERS} ${LOOPDEV}
+
+        # Prepare loop devices for boot and filesystem partitions
+        BOOT_OFFSET=32256
+        FS_OFFSET_SECT=$(/sbin/fdisk -l -u $LOOPDEV 2>&1 | grep Linux | perl -p -i -e "s/\s+/ /"|cut -d " " -f 2)
+        FS_OFFSET=$(echo "$FS_OFFSET_SECT * 512" | bc)
+        FS_SIZE_BLOCKS=$(/sbin/fdisk -l -u $LOOPDEV 2>&1 | grep Linux | perl -p -i -e "s/\s+/ /g" \ 
+        |cut -d " " -f 4 | cut -d "+" -f 1)
+ 
+        LOOPDEV_BLOCKS=$(/sbin/fdisk -l -u $LOOPDEV 2>&1 | grep FAT | perl -p -i -e "s/\s+/ /g"|cut -d " " -f 5)
+        LOOPDEV_BYTES=$(echo "$LOOPDEV_BLOCKS * 1024" | bc)
+
+        losetup -f ${SDIMG} -o ${BOOT_OFFSET} --sizelimit=$LOOPDEV_BYTES
+
+        LOOPDEV_BOOT=$(losetup -j ${SDIMG} -o ${BOOT_OFFSET} | cut -d ":" -f 1)
+        mkfs.msdos ${LOOPDEV_BOOT} -n boot
+
+        losetup -f ${SDIMG} -o ${FS_OFFSET}     
+        LOOPDEV_FS=$(losetup -j ${SDIMG} -o ${FS_OFFSET} | cut -d ":" -f 1)
+
+        # Prepare filesystem partition
+        # Copy ubi used by flashing scripts
+        if [ -e  ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ubi ] ; then
+                echo "Copying UBIFS image to file system"
+                cp ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ubi ${IMAGE_ROOTFS}/boot/fs.ubi
+        fi
+        ROOTFS_SIZE="$(du -ks ${IMAGE_ROOTFS} | awk '{print 65536 + $1}')"
+        genext2fs -b ${FS_SIZE_BLOCKS} -d ${IMAGE_ROOTFS} ${LOOPDEV_FS}
+        tune2fs -j ${LOOPDEV_FS}
+
+        # Prepare boot partion. First mount the boot partition, and copy the boot loader and supporting files
+        # from the root filesystem
+
+        # sanity check fstab entry for boot partition mounting
+        if [ "x$(cat /etc/fstab | grep $LOOPDEV_BOOT | grep ${WORKDIR}/tmp-mnt-boot | grep user || true)" = "x" ]; then
+                echo "/etc/fstab entries need to be created with the user flag for $LOOPDEV_BOOT like:"
+                echo "$LOOPDEV_BOOT ${WORKDIR}/tmp-mnt-boot msdos user 0 0"
+                false
+        fi
+
+        mkdir -p ${WORKDIR}/tmp-mnt-boot
+        mount $LOOPDEV_BOOT
+
+        echo "Copying bootloaders into the boot partition"
+        cp -v ${IMAGE_ROOTFS}/boot/MLO ${WORKDIR}/tmp-mnt-boot 
+        cp -v ${IMAGE_ROOTFS}/boot/{u-boot.bin,user.txt,uEnv.txt} ${WORKDIR}/tmp-mnt-boot || true
+
+        # cleanup
+        umount ${LOOPDEV_BOOT}
+        /sbin/losetup -d ${LOOPDEV}
+        /sbin/losetup -d ${LOOPDEV_BOOT}
+        /sbin/losetup -d ${LOOPDEV_FS}
+
+        gzip -c ${WORKDIR}/sd.img > ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}-${PR}.img.gz
+}