add step 03, copy back sdcard and shrink image.

prototype, derivated from 01_create_sdcard.sh
Seems working.

build_arm_image/03_copy_sdcard_to_img.sh

@@ -0,0 +1,188 @@
+#!/bin/bash 
+#
+# Create the image file from the sdcard
+#
+# Usage:
+#  ./03_copy_sdcard_to_img.sh /dev/sdcard_device
+#
+# the resulting image will be stored in _build_arm_steps
+#
+# Status: prototype
+# Licence: GPLv3
+# Author: sylvain303@github
+
+die() {
+    echo "$*"
+    exit 1
+}
+
+# helper, test if a shell program exists in PATH
+test_tool() {
+    local cmd=$1
+    if type $cmd > /dev/null
+    then
+        # OK
+        return 0
+    else
+        die "tool missing: $cmd"
+    fi
+}
+
+# skip if the file exists.
+# usage: skip_if _build_arm_steps/somefile && return 2
+skip_if() {
+    if [[ -e "$1" ]]
+    then
+        echo "cached"
+        return 0
+    fi
+   # echo -n "continue for $1"
+    return 1
+}
+
+# helper, try to guess top device name
+# /dev/sdp2 => /dev/sdp
+# /dev/mmcblk0p1 => /dev/mmcblk0
+# just some regexp, no smart thing
+get_top_device() {
+    local device="$1"
+    local regexp1='^/dev/sd[a-z]'
+    local regexp2='^/dev/mmcblk[0-9]'
+
+    if [[ "$device" =~ $regexp1 ]]
+    then
+        #echo sd
+        device="${device/[0-9]/}"
+    elif [[ "$device" =~ $regexp2 ]]
+    then
+        #echo mmcblk
+        device="${device/p[0-9]/}"
+    fi
+
+    echo "$device"
+}
+
+# helper, umount the sdcard partition if any
+umount_sdcard_partition() {
+    [[ -z "$SDCARD" ]] && { echo '$SDCARD is empty refusing to run'; return; }
+    local p
+    # search and replace all occurence of / by .
+    local pattern=${SDCARD////.}
+    pattern=${pattern/p[0-9]/}
+    for p in $(df | awk "/^$pattern/ { print \$1 }")
+    do
+        sudo umount $p
+    done
+    echo "done device for sdcard=${pattern//.//}"
+}
+
+dd_from_sdcard() {
+    [[ -z "$SDCARD" ]] && { echo '$SDCARD is empty refusing to run'; return; }
+    [[ -z "$OUTPUT_IMG" ]] && { echo '$OUTPUT_IMG is empty refusing to run'; return; }
+    local count
+    if [[ ! -z "$1" ]]
+    then
+        count="count=$1"
+    fi
+    # ensure that sdcard partitions are unmounted with umount_sdcard_partition
+    sudo dd bs=16M if=$SDCARD of=_build_arm_steps/$OUTPUT_IMG $count
+}
+
+test_all_tools() {
+    for t in $*
+    do
+        test_tool $t
+    done
+}
+
+# mount the .img so we can write on it before copying on the sdcard
+mount_loopback_img() {
+    [[ -z "$OUTPUT_IMG" ]] && { echo '$OUTPUT_IMG is empty refusing to run'; return; }
+    [[ ! -d _build_arm_steps/mnt ]] && mkdir _build_arm_steps/mnt
+    local dev_loop0=$(sudo losetup -f --show _build_arm_steps/$OUTPUT_IMG)
+    local part_offset=$(sudo fdisk -l $dev_loop0 | awk '/Linux/ { print $2 }')
+    # mount the ext4 partition at computed offset
+    local dev_loop1=$(sudo losetup -f --show -o $((512 * $part_offset)) _build_arm_steps/$OUTPUT_IMG)
+    sudo mount $dev_loop1 _build_arm_steps/mnt/
+}
+
+umount_loopback_img() {
+    # find mounted loopback
+    local dev_loop1=$(mount | awk '/_build_arm_steps/ { print $1 }')
+    # compute loop n-1
+    local n=${dev_loop1#/dev/loop}
+    local dev_loop0="/dev/loop$(($n - 1))"
+    sudo umount _build_arm_steps/mnt
+    sudo losetup -d $dev_loop1
+    sudo losetup -d $dev_loop0
+}
+
+mount_sdcard_data_partition() {
+    local part_data=2
+    [[ ! -d _build_arm_steps/sdcard ]] && mkdir _build_arm_steps/sdcard
+    sudo mount ${SDCARD}p2 _build_arm_steps/sdcard
+}
+
+get_used_partition_size() {
+    local start_offset=$(sudo fdisk -l /dev/mmcblk0 | awk '/Linux/ { print $2 * 512 }')
+    local used=$(df -B1 _build_arm_steps/sdcard | awk '/dev.mmcblk0p2/ { print $3 }')
+
+    echo "start_offset=$start_offset"
+    echo "used        =$used"
+
+    local count=$(($start_offset + $used))
+    echo "count       =$count"
+    local div=$(($count / (16 * 1048576) ))
+    echo "16M         =$(($count /      (16 * 1048576) ))"
+    echo "verif       =$(( ($div + 1) * (16 * 1048576) ))"
+}
+
+shrink_img() {
+    echo "shrinking _build_arm_steps/$OUTPUT_IMG"
+    sudo ./autosizer.sh _build_arm_steps/$OUTPUT_IMG
+}
+
+# functions call in that order, edit remove a long running step if already done or if
+# you want to skip it, step states are saved in folder _build_arm_steps and skipped automatically.
+STEPS="
+umount_sdcard_partition
+dd_from_sdcard
+shrink_img"
+
+# main wrapper, so the script can be sourced for debuging purpose or unittesting
+main() {
+    # positional argument must be script argument.
+    # init
+    if [[ -z "$1" ]]
+    then
+        echo "argument 1 error: expecting sdcard_device"
+        exit 1
+    fi
+
+    test_all_tools dd sync sudo losetup
+    if [[ ! -d _build_arm_steps ]]
+    then
+        die "cannot find _build_arm_steps/ folder are you following build step?"
+    fi
+    # reading script argument
+    SDCARD=$(get_top_device "$1")
+    OUTPUT_IMG="$(date "+%Y-%m-%d")_yunohost_rasbian-jessie.img"
+
+    # actions loop
+    for s in $STEPS
+    do
+        echo -n "$s: "
+        eval $s
+    done
+}
+
+# sourcing code detection, if code is sourced for debug purpose, main is not executed.
+[[ $0 != "$BASH_SOURCE" ]] && sourced=1 || sourced=0
+if  [[ $sourced -eq 0 ]]
+then
+    # pass positional argument as is
+    main "$@"
+else
+    # just print STEPS so I can copy/paste to call them interactivly
+    echo $STEPS
+fi

build_arm_image/autosizer.sh

@@ -3,6 +3,8 @@
 # Written by SirLagz
 #
 # got from: http://sirlagz.net/2013/03/10/script-automatic-rpi-image-downsizer/
+#
+# Usage: sudo autosizer.sh sdcard.img
 
 strImgFile=$1