mke2img: add buildroot wrapper

2 files changed, 242 insertions, 0 deletions

diff --git a/package/mke2img/Makefile b/package/mke2img/Makefile
new file mode 100644
index 000000000..83390b94d
--- /dev/null
+++ b/package/mke2img/Makefile
@@ -0,0 +1,28 @@
+# This file is part of the OpenADK project. OpenADK is copyrighted
+# material, please see the LICENCE file in the top-level directory.
+
+include $(ADK_TOPDIR)/rules.mk
+
+PKG_NAME:=		mke2img
+PKG_VERSION:=		1
+PKG_RELEASE:=		1
+PKG_DESCR:=		wrapper for ext2/3/4 filesystem utility
+PKG_SECTION:=		sys/fs
+
+NO_DISTFILES:=		1
+
+PKG_CFLINE_MKE2IMG:=	depends on ADK_HOST_ONLY
+
+include $(ADK_TOPDIR)/mk/host.mk
+include $(ADK_TOPDIR)/mk/package.mk
+
+$(eval $(call HOST_template,MKE2IMG,mke2img,$(PKG_VERSION)-${PKG_RELEASE}))
+
+HOST_STYLE:=		manual
+
+mke2img-hostinstall:
+	$(INSTALL_DIR) $(STAGING_HOST_DIR)/usr/bin
+	$(INSTALL_BIN) ./files/mke2img $(STAGING_HOST_DIR)/usr/bin
+
+include ${ADK_TOPDIR}/mk/host-bottom.mk
+include ${ADK_TOPDIR}/mk/pkg-bottom.mk
diff --git a/package/mke2img/files/mke2img b/package/mke2img/files/mke2img
new file mode 100755
index 000000000..c2e0d02b7
--- /dev/null
+++ b/package/mke2img/files/mke2img
@@ -0,0 +1,214 @@
+#!/usr/bin/env bash
+
+# Buildroot wrapper to the collection of ext2/3/4 filesystem tools:
+# - genext2fs, to generate ext2 filesystem images
+# - tune2fs, to modify an ext2/3/4 filesystem (possibly in an image file)
+# - e2fsck, to check and fix an ext2/3/4 filesystem (possibly in an image file)
+
+set -e
+
+main() {
+    local OPT OPTARG
+    local nb_blocks nb_inodes nb_res_blocks root_dir image gen rev label uuid
+    local -a genext2fs_opts
+    local -a tune2fs_opts
+    local tune2fs_O_opts
+
+    # Default values
+    gen=2
+    rev=1
+    nb_extra_blocks=0
+    nb_extra_inodes=0
+
+    while getopts :hb:B:i:I:r:d:o:G:R:l:u: OPT; do
+        case "${OPT}" in
+        h)  help; exit 0;;
+        b)  nb_blocks=${OPTARG};;
+        B)  nb_extra_blocks=${OPTARG};;
+        i)  nb_inodes=${OPTARG};;
+        I)  nb_extra_inodes=${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}:${rev}" in
+    2:0|2:1|3:1|4:1)
+        ;;
+    3:0|4:0)
+        error "revision 0 is invalid for ext3 and ext4\n"
+        ;;
+    *)  error "unknown ext generation '%s' and/or revision '%s'\n" \
+               "${gen}" "${rev}"
+        ;;
+    esac
+
+    # calculate needed inodes
+    if [ -z "${nb_inodes}" ]; then
+        nb_inodes=$(find "${root_dir}" | wc -l)
+        nb_inodes=$((nb_inodes+400))
+    fi
+    nb_inodes=$((nb_inodes+nb_extra_inodes))
+
+    # 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))
+        if [ ${gen} -ge 3 ]; then
+            # we add 1300 blocks (a bit more than 1 MiB, assuming 1KiB blocks)
+            # for the journal
+            # Note: I came to 1300 blocks after trial-and-error checks. YMMV.
+            nb_blocks=$((nb_blocks+1300))
+        fi
+    fi
+    nb_blocks=$((nb_blocks+nb_extra_blocks))
+
+    # Upgrade to rev1 if needed
+    if [ ${rev} -ge 1 ]; then
+        tune2fs_O_opts+=",filetype,sparse_super"
+    fi
+
+    # Add a journal for ext3 and above
+    if [ ${gen} -ge 3 ]; then
+        tune2fs_opts+=( -j -J size=1 )
+    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=( -z -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[@]}" "${image}"
+
+    # genext2fs does not generate a UUID, but fsck will whine if one
+    # is missing, so we need to add a UUID.
+    # Of course, this has to happen _before_ we run fsck.
+    # Also, some ext4 metadata are based on the UUID, so we must
+    # set it before we can convert the filesystem to ext4.
+    # If the user did not specify a UUID, we generate a random one.
+    # Although a random UUID may seem bad for reproducibility, there
+    # already are so many things that are not reproducible in a
+    # filesystem: file dates, file ordering, content of the files...
+    tune2fs -U "${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}"
+}
+
+help() {
+    cat <<_EOF_
+NAME
+    ${my_name} - Create an ext2/3/4 filesystem image
+
+SYNOPSIS
+    ${my_name} [OPTION]...
+
+DESCRIPTION
+    Create ext2/3/4 filesystem image from the content of a directory.
+
+    -b BLOCKS
+        Create a filesystem of BLOCKS 1024-byte blocs. The default is to
+        compute the required number of blocks.
+
+    -i INODES
+        Create a filesystem with INODES inodes. The default is to compute
+        the required number of inodes.
+
+    -r RES_BLOCKS
+        Create a filesystem with RES_BLOCKS reserved blocks. The default
+        is to reserve 0 block.
+
+    -d ROOT_DIR
+        Create a filesystem, using the content of ROOT_DIR as the content
+        of the root of the filesystem. Mandatory.
+
+    -o FILE
+        Create the filesystem in FILE. Madatory.
+
+    -G GEN -R REV
+        Create a filesystem of generation GEN (2, 3 or 4), and revision
+        REV (0 or 1). The default is to generate an ext2 revision 1
+        filesystem; revision 0 is invalid for ext3 and ext4.
+
+    -l LABEL
+        Create a filesystem with label LABEL. The default is to not set
+        a label.
+
+    -u UUID
+        Create filesystem with uuid UUID. The default is to set a random
+        UUID.
+
+  Exit status:
+    0   if OK
+    !0  in case of error
+_EOF_
+}
+
+trace()  { local msg="${1}"; shift; printf "%s: ${msg}" "${my_name}" "${@}"; }
+warn()   { trace "${@}" >&2; }
+errorN() { local ret="${1}"; shift; warn "${@}"; exit ${ret}; }
+error()  { errorN 1 "${@}"; }
+
+my_name="${0##*/}"
+main "$@"