image_types_fsl: Align SD partition and optimize final SD image

SD image file was 4G in size but actually the rootfs partition was only
60MB (in some images).
The image file size is not fixed anymore but calculated inside this
class. In this way we will setup the partition for rootfs to fit the
ext file used as SDIMG_ROOTFS. By default the free space is calculated
with IMAGE_OVERHEAD_FACTOR which is by default 1.3. If more free space
is needed this can be overwritten.
IMAGE_ROOTFS_ALIGNMENT set at 4096. This should be the best value for a
SD card.

Signed-off-by: Andrei Gherzan <andrei@gherzan.ro>

diff --git a/meta-fsl-arm/classes/image_types_fsl.bbclass b/meta-fsl-arm/classes/image_types_fsl.bbclass
index 1b58df849bcfd546068ab6e554415eb059b4de22..1144bff409abe3588de204f4d74fdfb6056cd08d 100644 (file)
--- a/meta-fsl-arm/classes/image_types_fsl.bbclass
+++ b/meta-fsl-arm/classes/image_types_fsl.bbclass
@@ -43,14 +43,14 @@ IMAGE_DEPENDS_uboot.mxsboot-sdcard = "u-boot-mxsboot-native u-boot"
 IMAGE_CMD_uboot.mxsboot-sdcard = "mxsboot sd ${DEPLOY_DIR_IMAGE}/u-boot-${MACHINE}.${UBOOT_SUFFIX} \
                                              ${DEPLOY_DIR_IMAGE}/u-boot-${MACHINE}.${UBOOT_SUFFIX_SDCARD}"
 
-# Default to 3.4GiB images
-SDCARD_SIZE ?= "3400"
-
 # Boot partition volume id
 BOOTDD_VOLUME_ID ?= "Boot ${MACHINE}"
 
-# Addional space for boot partition
-BOOT_SPACE ?= "5MiB"
+# Boot partition size [in KiB]
+BOOT_SPACE ?= "8192"
+
+# Set alignment to 4MB [in KiB]
+IMAGE_ROOTFS_ALIGNMENT = "4096"
 
 IMAGE_DEPENDS_sdcard = "parted-native dosfstools-native mtools-native \
                         virtual/kernel ${IMAGE_BOOTLOADER}"
@@ -71,17 +71,29 @@ SDCARD_GENERATION_COMMAND_mx6 = "generate_imx_sdcard"
 #
 # The disk layout used is:
 #
-#    0  - 1M                  - reserved to bootloader (not partitioned)
-#    1M - BOOT_SPACE          - kernel
-#    BOOT_SPACE - SDCARD_SIZE - rootfs
+#    0                      -> IMAGE_ROOTFS_ALIGNMENT         - reserved to bootloader (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               8MiB           SDIMG_ROOTFS                    4MiB
+# <-----------------------> <----------> <----------------------> <------------------------------>
+#  ------------------------ ------------ ------------------------ -------------------------------
+# | IMAGE_ROOTFS_ALIGNMENT | BOOT_SPACE | ROOTFS_SIZE            |     IMAGE_ROOTFS_ALIGNMENT    |
+#  ------------------------ ------------ ------------------------ -------------------------------
+# ^                        ^            ^                        ^                               ^
+# |                        |            |                        |                               |
+# 0                      4096     4MiB +  8MiB       4MiB +  8Mib + SDIMG_ROOTFS   4MiB +  8MiB + SDIMG_ROOTFS + 4MiB
 generate_imx_sdcard () {
        # Create partition table
        parted -s ${SDCARD} mklabel msdos
-       parted -s ${SDCARD} mkpart primary 1MiB ${BOOT_SPACE}
-       parted -s ${SDCARD} mkpart primary ${BOOT_SPACE} 100%
+       parted -s ${SDCARD} unit KiB mkpart primary ${IMAGE_ROOTFS_ALIGNMENT} $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED})
+       parted -s ${SDCARD} unit KiB mkpart primary $(expr  ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED}) $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED} \+ $ROOTFS_SIZE)
        parted ${SDCARD} print
 
+       # Burn bootloader
        case "${IMAGE_BOOTLOADER}" in
                imx-bootlets)
                bberror "The imx-bootlets is not supported for i.MX based machines"
@@ -100,6 +112,7 @@ generate_imx_sdcard () {
                ;;
        esac
 
+       # Create boot partition image
        BOOT_BLOCKS=$(LC_ALL=C parted -s ${SDCARD} unit b print \
                          | awk '/ 1 / { print substr($4, 1, length($4 -1)) / 1024 }')
        mkfs.vfat -n "${BOOTDD_VOLUME_ID}" -S 512 -C ${WORKDIR}/boot.img $BOOT_BLOCKS
@@ -112,8 +125,9 @@ generate_imx_sdcard () {
                fi
        fi
 
-       dd if=${WORKDIR}/boot.img of=${SDCARD} conv=notrunc seek=1 bs=1M
-       dd if=${SDCARD_ROOTFS} of=${SDCARD} conv=notrunc seek=1 bs=${BOOT_SPACE}
+       # Burn Partition
+       dd if=${WORKDIR}/boot.img of=${SDCARD} conv=notrunc seek=1 bs=$(expr ${IMAGE_ROOTFS_ALIGNMENT} \* 1024) && sync && sync
+       dd if=${SDCARD_ROOTFS} of=${SDCARD} conv=notrunc seek=1 bs=$(expr ${BOOT_SPACE_ALIGNED} \* 1024 + ${IMAGE_ROOTFS_ALIGNMENT} \* 1024) && sync && sync
 }
 
 #
@@ -132,11 +146,23 @@ generate_mxs_sdcard () {
                imx-bootlets)
                # The disk layout used is:
                #
-               #    1M - BOOT_SPACE          - kernel
-               #    BOOT_SPACE - SDCARD_SIZE - rootfs
+               #    0                      -> IMAGE_ROOTFS_ALIGNMENT         - reserved for bootstream (not partitioned)
+               #    IMAGE_ROOTFS_ALIGNMENT -> BOOT_SPACE                     - kernel and other data
+               #    BOOT_SPACE             -> SDIMG_SIZE                     - rootfs
                #
-               parted -s ${SDCARD} mkpart primary 1MiB ${BOOT_SPACE}
-               parted -s ${SDCARD} mkpart primary ${BOOT_SPACE} 100%
+               #                                                     Default Free space = 1.3x
+               #                                                     Use IMAGE_OVERHEAD_FACTOR to add more space
+               #                                                     <--------->
+               #            4MiB               8MiB           SDIMG_ROOTFS                    4KiB
+               # <-----------------------> <----------> <----------------------> <------------------------------>
+               #  ------------------------ ------------ ------------------------ -------------------------------
+               # | IMAGE_ROOTFS_ALIGNMENT | BOOT_SPACE | ROOTFS_SIZE            |     IMAGE_ROOTFS_ALIGNMENT    |
+               #  ------------------------ ------------ ------------------------ -------------------------------
+               # ^                        ^            ^                        ^                               ^
+               # |                        |            |                        |                               |
+               # 0                      4096     4MiB +  8MiB       4MiB +  8Mib + SDIMG_ROOTFS   4MiB +  8MiB + SDIMG_ROOTFS + 4MiB
+               parted -s ${SDCARD} unit KiB mkpart primary ${IMAGE_ROOTFS_ALIGNMENT} $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED})
+               parted -s ${SDCARD} unit KiB mkpart primary $(expr  ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED}) $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED} \+ $ROOTFS_SIZE)
 
                # Empty 4 bytes from boot partition
                dd if=/dev/zero of=${SDCARD} conv=notrunc seek=2048 count=4
@@ -151,11 +177,29 @@ generate_mxs_sdcard () {
                #    2M - BOOT_SPACE          - kernel
                #    BOOT_SPACE - SDCARD_SIZE - rootfs
                #
-               parted -s ${SDCARD} mkpart primary 1MiB 2MiB
-               parted -s ${SDCARD} mkpart primary 2MiB ${BOOT_SPACE}
-               parted -s ${SDCARD} mkpart primary ${BOOT_SPACE} 100%
+               # The disk layout used is:
+               #
+               #    1M                     -> 2M                             - reserved to bootloader and other data
+               #    2M                     -> 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                8MiB             SDIMG_ROOTFS                    4MiB
+               # <-----------------------> <-------------> <----------------------> <------------------------------>
+               #  ---------------------------------------- ------------------------ -------------------------------
+               # |      |      |                          |ROOTFS_SIZE             |     IMAGE_ROOTFS_ALIGNMENT    |
+               #  ---------------------------------------- ------------------------ -------------------------------
+               # ^      ^      ^          ^               ^                        ^                               ^
+               # |      |      |          |               |                        |                               |
+               # 0     1M     2M         4M        4MiB + BOOTSPACE   4MiB + BOOTSPACE + SDIMG_ROOTFS   4MiB + BOOTSPACE + SDIMG_ROOTFS + 4MiB
+               #
+               parted -s ${SDCARD} unit KiB mkpart primary 1024 2048
+               parted -s ${SDCARD} unit KiB mkpart primary 2048 $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED})
+               parted -s ${SDCARD} unit KiB mkpart primary $(expr  ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED}) $(expr ${IMAGE_ROOTFS_ALIGNMENT} \+ ${BOOT_SPACE_ALIGNED} \+ $ROOTFS_SIZE)
 
-               dd if=${DEPLOY_DIR_IMAGE}/u-boot-${MACHINE}.${UBOOT_SUFFIX_SDCARD} of=${SDCARD} conv=notrunc seek=1 skip=${UBOOT_PADDING} bs=1MiB
+               dd if=${DEPLOY_DIR_IMAGE}/u-boot-${MACHINE}.${UBOOT_SUFFIX_SDCARD} of=${SDCARD} conv=notrunc seek=1 skip=${UBOOT_PADDING} bs=$(expr 1024 \* 1024)
                BOOT_BLOCKS=$(LC_ALL=C parted -s ${SDCARD} unit b print \
                | awk '/ 2 / { print substr($4, 1, length($4 -1)) / 1024 }')
 
@@ -169,7 +213,7 @@ generate_mxs_sdcard () {
                        fi
                fi
 
-               dd if=${WORKDIR}/boot.img of=${SDCARD} conv=notrunc seek=2 bs=1MiB
+               dd if=${WORKDIR}/boot.img of=${SDCARD} conv=notrunc seek=2 bs=$(expr 1024 \* 1024)
                ;;
                *)
                bberror "Unkown IMAGE_BOOTLOADER value"
@@ -183,7 +227,7 @@ generate_mxs_sdcard () {
 
        parted ${SDCARD} print
 
-       dd if=${SDCARD_ROOTFS} of=${SDCARD} conv=notrunc seek=1 bs=${BOOT_SPACE}
+       dd if=${SDCARD_ROOTFS} of=${SDCARD} conv=notrunc seek=1 bs=$(expr ${BOOT_SPACE_ALIGNED} \* 1024 + ${IMAGE_ROOTFS_ALIGNMENT} \* 1024) && sync && sync
 }
 
 IMAGE_CMD_sdcard () {
@@ -192,8 +236,13 @@ IMAGE_CMD_sdcard () {
                exit 1
        fi
 
+       # Align boot partition and calculate total SD card image size
+       BOOT_SPACE_ALIGNED=$(expr ${BOOT_SPACE} + ${IMAGE_ROOTFS_ALIGNMENT} - 1)
+       BOOT_SPACE_ALIGNED=$(expr ${BOOT_SPACE_ALIGNED} - ${BOOT_SPACE_ALIGNED} % ${IMAGE_ROOTFS_ALIGNMENT})
+       SDCARD_SIZE=$(expr ${IMAGE_ROOTFS_ALIGNMENT} + ${BOOT_SPACE_ALIGNED} + $ROOTFS_SIZE + ${IMAGE_ROOTFS_ALIGNMENT})
+
        # Initialize a sparse file
-       dd if=/dev/zero of=${SDCARD} bs=1 count=0 seek=$(expr 1000 \* 1000 \* ${SDCARD_SIZE})
+       dd if=/dev/zero of=${SDCARD} bs=1 count=0 seek=$(expr 1024 \* ${SDCARD_SIZE})
 
        ${SDCARD_GENERATION_COMMAND}
 }