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The eMMC layout comments are confusing and in some regards outdated.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

2 files changed, 40 insertions, 44 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
 
diff --git a/recipes/images/files/library/tegra/update.sh b/recipes/images/files/library/tegra/update.sh
index 552f728..8b7ed94 100755
--- a/recipes/images/files/library/tegra/update.sh
+++ b/recipes/images/files/library/tegra/update.sh
@@ -132,7 +132,7 @@ if [ "$CNT" -ge 1 ] ; then
 		U_BOOT_BINARY=u-boot-dtb-tegra.bin
 		KERNEL_DEVICETREE="tegra30-apalis-eval.dtb"
 		LOCPATH="tegra-uboot-flasher"
-		# eMMC size [in sectors of 512]
+		# assumed minimal eMMC size [in sectors of 512]
 		EMMC_SIZE=$(expr 1024 \* 7450 \* 2)
 		BCT=apalis_t30_12MHz_MT41K512M8RH-125_533MHz.bct
 		CBOOT_IMAGE=apalis_t30.img
@@ -280,29 +280,27 @@ grep -i t[2-3]0 rootfs/etc/issue >> ${BINARIES}/versions.txt
 
 # The emmc layout used is:
 #
-# boot area partition 1 aka eMMC boot sector:
-#
+# boot area partition 1 aka primary eMMC boot sector:
 # with cbootimage containing BCT and U-Boot boot loader
+# and the configblock at the end of that boot area partition
+#
+# boot area partition 2 aka secondary eMMC boot sector:
+# with the U-Boot environment at the end of that boot area partition
 #
 # user area aka general purpose eMMC region:
 #
-#    0                      -> IMAGE_ROOTFS_ALIGNMENT         - reserved to bootloader (not partitioned)
+#    0                      -> IMAGE_ROOTFS_ALIGNMENT         - reserved ((not partitioned)
 #    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
-#
-# with the U-Boot environment at 512 * 1024, the config block is at 640 * 1024
+#            4MiB               16MiB           SDIMG_ROOTFS
+# <-----------------------> <----------> <---------------------->
+#  ------------------------ ------------ ------------------------
+# | IMAGE_ROOTFS_ALIGNMENT | BOOT_SPACE | ROOTFS_SIZE            |
+#  ------------------------ ------------ ------------------------
+# ^                        ^            ^                        ^
+# |                        |            |                        |
+# 0                      4MiB      4MiB + 16MiB              EMMC_SIZE
 
 # generate cbootimage(s) containing BCT(s) and U-Boot boot loader
 cd ${BINARIES}
@@ -329,13 +327,6 @@ else
 		# 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
@@ -381,6 +372,14 @@ else
 
 		echo ""
 		echo "Creating rootfs partion image"
+		#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
+		#(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
 	fi