[1/3,v2] package/mke2img: new package

diff --git a/package/mke2img/mke2img b/package/mke2img/mke2img
new file mode 100755
index 0000000..98ac7e6
--- /dev/null
+++ b/package/mke2img/mke2img
@@ -0,0 +1,148 @@ 
+#!/bin/bash
+
+# Buildroot wrapper to the collection of ext2/3/4 filesystem tools:
+# - genext2fs, to generate ext2 filesystem images
+# - tune2fs, to modify an ext2/3/4 filesystem (possibly in an image file)
+# - e2fsck, to check and fix an ext2/3/4 filesystem (possibly in an image file)
+
+set -e
+
+main() {
+    local OPT OPTARG
+    local nb_blocks nb_inodes nb_res_blocks root_dir image gen rev label uuid
+    local -a genext2fs_opts
+    local -a tune2fs_opts
+    local tune2fs_O_opts
+
+    while getopts :b:i:r:d:o:G:R:l:u: OPT; do
+        case "${OPT}" in
+        b)  nb_blocks=${OPTARG};;
+        i)  nb_inodes=${OPTARG};;
+        r)  nb_res_blocks=${OPTARG};;
+        d)  root_dir="${OPTARG}";;
+        o)  image="${OPTARG}";;
+        G)  gen=${OPTARG};;
+        R)  rev=${OPTARG};;
+        l)  label="${OPTARG}";;
+        u)  uuid="${OPTARG}";;
+        :)  error "option '%s' expects a mandatory argument\n" "${OPTARG}";;
+        \?) error "unknown option '%s'\n" "${OPTARG}";;
+        esac
+    done
+
+    # Sanity checks
+    if [ -z "${root_dir}" ]; then
+        error "you must specify a root directory with '-d'\n"
+    fi
+    if [ -z "${image}" ]; then
+        error "you must specify an output image file with '-o'\n"
+    fi
+    case "${gen}:${rev}" in
+    2:0|2:1|3:1|4:1)    ;;
+    *)  error "unknown ext generation '%s' and/or revision '%s'\n" \
+               "${gen}" "${rev}"
+        ;;
+    esac
+
+    # calculate needed inodes
+    if [ -z "${nb_inodes}" ]; then
+        nb_inodes=$(find "${root_dir}" | wc -l)
+        nb_inodes=$((nb_inodes+400))
+    fi
+
+    # calculate needed blocks
+    if [ -z "${nb_blocks}" ]; then
+        # size ~= superblock, block+inode bitmaps, inodes (8 per block),
+        # blocks; we scale inodes / blocks with 10% to compensate for
+        # bitmaps size + slack
+        nb_blocks=$(du -s -k "${root_dir}" |sed -r -e 's/[[:space:]]+.*$//')
+        nb_blocks=$((500+(nb_blocks+nb_inodes/8)*11/10))
+    fi
+
+    # Upgrade to rev1 if needed
+    if [ ${rev} -ge 1 ]; then
+        tune2fs_O_opts+=",filetype"
+    fi
+
+    # Add a journal for ext3 and above
+    if [ ${gen} -ge 3 ]; then
+        tune2fs_opts+=( -j -J size=1 )
+        # we add 1300 blocks (a bit more than 1 MiB, assuming 1KiB blocks)
+        # for the journal
+        # Note: I came to 1300 blocks after trial-and-error checks. YMMV.
+        nb_blocks=$((nb_blocks+1300))
+    fi
+
+    # Add ext4 specific features
+    if [ ${gen} -ge 4 ]; then
+        tune2fs_O_opts+=",extents,uninit_bg,dir_index"
+    fi
+
+    # Add our -O options (there will be at most one leading comma, remove it)
+    if [ -n "${tune2fs_O_opts}" ]; then
+        tune2fs_opts+=( -O "${tune2fs_O_opts#,}" )
+    fi
+
+    # Add the label if specified
+    if [ -n "${label}" ]; then
+        tune2fs_opts+=( -L "${label}" )
+    fi
+
+    # Generate the filesystem
+    genext2fs_opts=( -b ${nb_blocks} -N ${nb_inodes} -d "${root_dir}" )
+    if [ -n "${nb_res_blocks}" ]; then
+        genext2fs_opts+=( -m ${nb_res_blocks} )
+    fi
+    genext2fs "${genext2fs_opts[@]}" "${image}"
+
+    # genext2fs does not generate a UUID, but fsck will whine if one is
+    # is missing, so we need to add a UUID.
+    # Of course, this has to happend _before_ we run fsck.
+    # Also, some ext4 metadata are based on the UUID, so we must
+    # set it before we can convert the filesystem to ext4.
+    # If the user did not specify a UUID, we generate a random one.
+    # Although a random UUID may seem bad for reproducibility, there
+    # already are so many things that are not reproducible in a
+    # filesystem: file dates, file ordering, content of the files...
+    tune2fs -U "${uuid:-random}" "${image}"
+
+    # Upgrade the filesystem
+    if [ ${#tune2fs_opts[@]} -ne 0 ]; then
+        tune2fs "${tune2fs_opts[@]}" "${image}"
+    fi
+
+    # After changing filesystem options, running fsck is required
+    # (see: man tune2fs). Running e2fsck in other cases will ensure
+    # coherency of the filesystem, although it is not required.
+    # 'e2fsck -pDf' means:
+    #  - automatically repair
+    #  - optimise and check for duplicate entries
+    #  - force checking
+    # Sending output to oblivion, as e2fsck can be *very* verbose,
+    # especially with filesystems generated by genext2fs.
+    # Exit codes 1 & 2 are OK, it means fs errors were successfully
+    # corrected, hence our little trick with $ret.
+    ret=0
+    e2fsck -pDf "${image}" >/dev/null || ret=$?
+    case ${ret} in
+       0|1|2) ;;
+       *)   errorN ${ret} "failed to run e2fsck on '%s' (ext%d)\n" \
+                   "${image}" ${gen}
+    esac
+    printf "\n"
+    trace "e2fsck was successfully run on '%s' (ext%d)\n" "${image}" ${gen}
+    printf "\n"
+
+    # Remove count- and time-based checks, they are not welcome
+    # on embedded devices, where they can cause serious boot-time
+    # issues by tremendously slowing down the boot.
+    tune2fs -c 0 -i 0 "${image}"
+}
+
+trace()  { local msg="${1}"; shift; printf "%s: ${msg}" "${my_name}" "${@}"; }
+warn()   { trace "${@}" >&2; }
+errorN() { local ret="${1}"; shift; warn "${@}"; exit ${ret}; }
+error()  { errorN 1 "${@}"; }
+
+my_name="${0##*/}"
+main "$@"
diff --git a/package/mke2img/mke2img.mk b/package/mke2img/mke2img.mk
new file mode 100644
index 0000000..04aaa8f
--- /dev/null
+++ b/package/mke2img/mke2img.mk
@@ -0,0 +1,14 @@ 
+################################################################################
+#
+# mke2img
+#
+################################################################################
+
+HOST_MKE2IMG_SOURCE =
+HOST_MKE2IMG_DEPENDENCIES = host-genext2fs host-e2fsprogs
+
+define HOST_MKE2IMG_INSTALL_CMDS
+	$(INSTALL) -D -m 0755 package/mke2img/mke2img $(HOST_DIR)/usr/bin/mke2img
+endef
+
+$(eval $(host-generic-package))