update.sh: cleanup eMMC layout comments

The eMMC layout comments are confusing and in some regards outdated.
Clean it up.

While at it move the calculation of the rootfs file system size to
the rootfs creation to not confuse the rootfs file system size with
the size of the rootfs partition.

1 files changed, 17 insertions, 20 deletions

diff --git a/recipes/images/files/library/imx6/update.sh b/recipes/images/files/library/imx6/update.sh
index 773e812..96c1ddb 100755
--- a/recipes/images/files/library/imx6/update.sh
+++ b/recipes/images/files/library/imx6/update.sh
@@ -99,7 +99,7 @@ if [ "$CNT" -ge 1 ] ; then
 	U_BOOT_BINARY_IT=u-boot.imx
 	KERNEL_DEVICETREE="imx6dl-colibri-eval-v3.dtb imx6dl-colibri-cam-eval-v3.dtb"
 	LOCPATH="imx_flash"
-	# eMMC size [in sectors of 512]
+	# assumed minimal eMMC size [in sectors of 512]
 	EMMC_SIZE=$(expr 1024 \* 3500 \* 2)
 else
 	CNT=`grep -ic "imx6" rootfs/etc/issue || true`
@@ -111,7 +111,7 @@ else
 		U_BOOT_BINARY_IT=u-boot-it.imx
 		KERNEL_DEVICETREE="imx6q-apalis-eval.dtb imx6q-apalis-eval_v1_0.dtb"
 		LOCPATH="imx_flash"
-		# eMMC size [in sectors of 512]
+		# assumed minimal eMMC size [in sectors of 512]
 		EMMC_SIZE=$(expr 1024 \* 3500 \* 2)
 	else
 		echo "can not detect module type from ./rootfs/etc/issue"
@@ -182,17 +182,14 @@ grep -i imx6 rootfs/etc/issue >> ${BINARIES}/versions.txt
 #    IMAGE_ROOTFS_ALIGNMENT -> BOOT_SPACE                     - kernel and other data
 #    BOOT_SPACE             -> SDIMG_SIZE                     - rootfs
 #
-#                                                     Default Free space = 1.3x
-#                                                     Use IMAGE_OVERHEAD_FACTOR to add more space
-#                                                     <--------->
-#            4MiB               16MiB           SDIMG_ROOTFS                    4MiB
-# <-----------------------> <----------> <----------------------> <------------------------------>
-#  ------------------------ ------------ ------------------------ -------------------------------
-# | IMAGE_ROOTFS_ALIGNMENT | BOOT_SPACE | ROOTFS_SIZE            |     IMAGE_ROOTFS_ALIGNMENT    |
-#  ------------------------ ------------ ------------------------ -------------------------------
-# ^                        ^            ^                        ^                               ^
-# |                        |            |                        |                               |
-# 0                      4096     4MiB +  16MiB       4MiB +  16Mib + SDIMG_ROOTFS   4MiB +  16MiB + SDIMG_ROOTFS + 4MiB
+#            4MiB               16MiB           SDIMG_ROOTFS
+# <-----------------------> <----------> <---------------------->
+#  ------------------------ ------------ ------------------------
+# | IMAGE_ROOTFS_ALIGNMENT | BOOT_SPACE | ROOTFS_SIZE            |
+#  ------------------------ ------------ ------------------------
+# ^                        ^            ^
+# |                        |            |
+# 0                      4MiB      4MiB + 16MiB              EMMC_SIZE
 #
 # with U-Boot at 1024, the U-Boot environment at 512 * 1024, the config block is at 640 * 1024
 
@@ -204,13 +201,6 @@ ROOTFS_START=$(expr 20480 \* 2)
 # Boot partition volume id
 BOOTDD_VOLUME_ID="boot"
 
-#make the partition size size(rootfs used + MIN_PARTITION_FREE_SIZE)
-#add about 4% to the rootfs to account for fs overhead. (/1024/985 instead of /1024/1024).                                                                                    
-#add 512 bytes per file to account for small files
-NUMBER_OF_FILES=`sudo find ${ROOTFSPATH} | wc -l`
-EXT_SIZE=`sudo du -DsB1 ${ROOTFSPATH} | awk -v min=$MIN_PARTITION_FREE_SIZE -v f=${NUMBER_OF_FILES} \
-		'{rootfs_size=$1+f*512;rootfs_size=int(rootfs_size/1024/985); print (rootfs_size+min) }'`
-
 echo ""
 echo "Creating MBR file and do the partitioning"
 # Initialize a sparse file
@@ -257,6 +247,13 @@ fi
 
 echo ""
 echo "Creating rootfs partion image"
+#make the filesystem size size(rootfs used + MIN_PARTITION_FREE_SIZE)
+#add about 4% to the rootfs to account for fs overhead. (/1024/985 instead of /1024/1024).
+#add 512 bytes per file to account for small files
+#(resize it later on target to fill the size of the partition it lives in)
+NUMBER_OF_FILES=`sudo find ${ROOTFSPATH} | wc -l`
+EXT_SIZE=`sudo du -DsB1 ${ROOTFSPATH} | awk -v min=$MIN_PARTITION_FREE_SIZE -v f=${NUMBER_OF_FILES} \
+		'{rootfs_size=$1+f*512;rootfs_size=int(rootfs_size/1024/985); print (rootfs_size+min) }'`
 rm -f ${BINARIES}/${IMAGEFILE}
 sudo $LOCPATH/genext3fs.sh -d rootfs -b ${EXT_SIZE} ${BINARIES}/${IMAGEFILE} || exit 1