Begin persistent storage implementation

Most of the logic in the `init-storage` script is the same as it was in Aimee OS v1 (Gentoo). The major difference is now we are initializing the data volume in the initramfs instead of in the real OS. This allows us to make all of `/etc` writable via OverlayFS, instead of having only certain sub-directories writable via bind-mounts. Buildroot doesn't really have any tools for building an initramfs, unfortunately. It does have a bit of infrastructure for running `dracut`, but I'd really rather avoid having that much complexity in the initramfs; all we need is to run the `init-storage` script and then switch root. Instead, the `mkinitramfs.sh` script, called in the post-build stage, creates the CPIO archive from files in the target directory. The only particularly interesting bit is how it resolves shared library dependencies, to make sure the appropriate resources are available for the requisite commands. I briefly considered building a statically-linked BusyBox just for the initramfs. Since it doesn't provide several important tools like `btrfs`/`mkfs.btrfs`, I had to implement the dynamic link resolution function anyway. It made sense, then, to copy Dash and the necessary Coreutils binaries themselves.
configs/qemu: Enable debug shell on ttyAMA0
2025-08-29 20:17:52 -05:00 · 2025-08-29 20:17:52 -05:00 · 2025-08-29 20:17:52 -05:00 · 2025-08-29 20:17:52 -05:00
12 changed files with 388 additions and 5 deletions
--- a/Config.in
+++ b/Config.in
@ -15,6 +15,7 @@ config AIMEEOS
 	select BR2_PACKAGE_HOST_MTOOLS
 	select BR2_TARGET_GRUB2
 	select BR2_PACKAGE_HOST_ZSTD
+	select BR2_PACKAGE_AIMEE_OS_UTILS
 	help
 	  Enable all Aimee OS features.

@ -30,3 +31,10 @@ config AIMEEOS_RPI
 	select BR2_TARGET_GRUB2_ARM_EFI
 	help
 	  Support running Aimee OS on Rasperry Pi devices
+
+config AIMEEOS_DEFAULT_ROOTFLAGS
+	string "Default kernel command line argumens"
+	help
+	  Additional command line arguments to pass to the kernel by default.
+
+source "$BR2_EXTERNAL_AIMEEOS_PATH/package/aimee-os-utils/Config.in"
--- a/board/qemu/post-image.sh
+++ b/board/qemu/post-image.sh
@ -3,16 +3,12 @@
 set -e

 BOARD_DIR=$(dirname "$0")
-GRUBENV="${BINARIES_DIR}"/efi-part/EFI/BOOT/grubenv

 genimage_tmp=$(mktemp -d)
 trap 'rm -rf "${genimage_tmp}"' EXIT

 mkdir -p  "${genimage_tmp}"/rootfs "${genimage_tmp}"/tmp

-grub-editenv "${GRUBENV}" set default=0
-grub-editenv "${GRUBENV}" set timeout=3
-
 cd "${BINARIES_DIR}"
 genimage \
 	--rootpath "${genimage_tmp}/rootfs" \
--- a/boot/grub2/gen-grub-cfg.sh
+++ b/boot/grub2/gen-grub-cfg.sh
@ -8,6 +8,7 @@ kernel_filename=$1
 cat > "${TARGET_DIR}"/boot/grub.cfg <<EOF
 menuentry "Aimee OS ${vers} (Buildroot ${br2_vers}) on \$dev" --class gnu-linux --id "id-\$partuuid" "\$dev" "\$partuuid" {
    set root="\$2"
-    linux "/boot/${kernel_filename}" root=PARTUUID=\$3 ro
+    linux "/boot/${kernel_filename}" root=PARTUUID=\$3 ro \$rootflags
+    initrd "/boot/initramfs.img.zst"
 }
 EOF
--- a/boot/initramfs/init-storage.sh
+++ b/boot/initramfs/init-storage.sh
@ -0,0 +1,165 @@
+#!/bin/sh
+# vim: set sw=4 ts=4 sts=4 et :
+
+SUBVOLUMES='
+    /var
+    /var/log
+    /var/tmp
+    /etc
+'
+
+cleanup() {
+    if [ -n "${tmpdir}" ] && [ "${tmpdir}" != / ]; then
+        if mountpoint -q "${tmpdir}"; then
+            umount "${tmpdir}"
+        fi
+        rm -rf "${tmpdir}"
+        unset tmpdir
+    fi
+}
+
+copy_vol() {
+    dev="$1"
+    vol=$2
+
+    printf 'Copying %s contents to data volume\n' "${vol}" >&2
+    mount -o subvol="${vol#/}" "${dev}" "${tmpdir}" || exit
+    cp -au${VERBOSE+v} /sysroot/${vol#/}/. "${tmpdir}" || exit
+    umount "${tmpdir}"
+}
+
+format_dev() {
+    dev="$1"
+    partno=$(partition_number "${dev}")
+    if [ -n "${partno}" ]; then
+        disk="$(get_disk "${dev}")"
+        if [ -n "${disk}" ]; then
+            printf 'Resizing partition %d on disk %s\n' \
+                "${partno}" \
+                "${disk}" \
+                >&2
+            resize_partition "${disk}" "${partno}"
+        else
+            printf 'Could not find disk for device %s\n' \
+                "${dev}" \
+                >&2
+        fi
+    fi
+
+    printf 'Creating BTRFS filesystem on %s\n' "${dev}" >&2
+    mkfs.btrfs --quiet "${dev}" || exit
+
+    mount "${dev}" "${tmpdir}" || exit
+    for vol in ${SUBVOLUMES}; do
+        mkdir -p "${tmpdir}${vol%/*}" || exit
+        btrfs subvolume create "${tmpdir}${vol}" || exit
+    done
+    relabel_all
+    umount "${dev}" || exit
+}
+
+get_disk() {
+    _syspath=/sys/class/block/${1##*/}
+    [ -d "${_syspath}" ] || return 1
+    if [ ! -f "${_syspath}"/partition ]; then
+        readlink -f "${1}"
+        return $?
+    fi
+    _disk=$(readlink -f "${_syspath}"/..)
+    if [ -n "${_disk}" ]; then
+        printf '/dev/%s\n' "${_disk##*/}"
+        return 0
+    fi
+    return 1
+}
+
+has_fs() {
+    dev="$1"
+    fstype=$(blkid -o value -s TYPE "${dev}")
+    [ -n "${fstype}" ]
+}
+
+last_partition() {
+    cat /sys/class/block/"${1##*/}"/*/partition \
+        | sort -n \
+        | tail -n1
+}
+
+partition_number() {
+    cat /sys/class/block/${1##*/}/partition
+}
+
+relabel_all() {
+    if [ ! -d /sys/fs/selinux ] || [ ! -f /etc/selinux/config ]; then
+        return
+    fi
+    selinuxtype=$(. /etc/selinux/config && echo ${SELINUXTYPE})
+    find "${tmpdir}" | \
+    setfiles \
+        -v \
+        -F \
+        -m \
+        -r "${tmpdir}" \
+        -s \
+        /etc/selinux/${selinuxtype}/contexts/files/file_contexts
+}
+
+resize_partition() {
+    _disk="${1}"
+    _part="${2}"
+    _lastpart=$(last_partition "${_disk}")
+    if [ "${_part}" -ne "${_lastpart}" ]; then
+        printf 'Cannot resize %s, it is not the last partition on the disk\n' \
+            "${_dev}" \
+            >&2
+        return 1
+    fi
+    _uuid=$(sfdisk --part-uuid "${_disk}" "${_part}") || return $?
+    _type=$(sfdisk --part-type "${_disk}" "${_part}") || return $?
+    _label=$(sfdisk --part-label "${_disk}" "${_part}") || return $?
+    sfdisk --delete "${_disk}" "${_part}" || return $?
+    printf 'type=%s, uuid=%s, name="%s"\n' \
+        "${_type}" \
+        "${_uuid}" \
+        "${_label}" \
+        | sfdisk -N "${_part}" "${_disk}" --quiet --force \
+        || return $?
+    partx -u "${_disk}"
+}
+
+setup_etc() {
+    dev="$1"
+
+    echo 'Initializing /etc overlay' >&2
+    mkdir -p /run/aimeeos/etc || return
+    mount -o subvol=etc "${dev}" /run/aimeeos/etc || return
+    mkdir -p /run/aimeeos/etc/rw /run/aimeeos/etc/work || return
+    mount -t overlay \
+        -o lowerdir=/sysroot/etc,upperdir=/run/aimeeos/etc/rw,workdir=/run/aimeeos/etc/work \
+        overlay \
+        /sysroot/etc
+}
+
+rootdev=$(findfs "$1")
+datapart=$(findfs "${2:-PARTLABEL=aimeeos-data}")
+if [ -b "${datapart}" ]; then
+    printf 'Found data partition: %s\n' "${datapart}" >&2
+else
+    echo 'Could not identify data partition' >&2
+    exit 1
+fi
+
+trap cleanup INT TERM QUIT EXIT
+tmpdir=/run/storinit
+mkdir -p "${tmpdir}"
+
+if ! has_fs "${datapart}"; then
+    format_dev "${datapart}"
+fi
+
+mkdir -p /sysroot
+mount -o ro "${rootdev}" /sysroot || exit
+
+setup_etc "${datapart}"
+copy_vol "${datapart}" /var
+exit 0
--- a/boot/initramfs/initramfs-init.sh
+++ b/boot/initramfs/initramfs-init.sh
@ -0,0 +1,27 @@
+#!/bin/sh
+
+mkdir -p \
+    /dev \
+    /proc \
+    /run \
+    /sys \
+    /sysroot \
+    && :
+
+mount -t devtmpfs devtmpfs /dev
+mount -t proc proc /proc
+mount -t sysfs sysfs /sys
+mount -t tmpfs tmpfs /run
+
+set -- $(cat /proc/cmdline)
+for arg; do
+    case "${arg}" in
+    root=*)
+        root=${arg#root=}
+        ;;
+    esac
+done
+
+init-storage "${root}"
+
+exec switch_root /sysroot /sbin/init
--- a/boot/mkinitramfs.sh
+++ b/boot/mkinitramfs.sh
@ -0,0 +1,113 @@
+#!/bin/sh
+
+if [ $(id -u) != 0 ]; then
+    exec "${HOST_DIR}"/bin/fakeroot "$0" "$@"
+fi
+
+export PATH="${HOST_DIR}:${PATH}"
+
+TARGET_DIR=$1
+WORKDIR=$(mktemp -d)
+OUTDIR="${WORKDIR}"/initramfs
+LIB_CACHE="${WORKDIR}"/libs.cache
+PKGDIR="${0%/*}"
+
+trap 'rm -rf "${WORKDIR}"' INT QUIT TERM EXIT
+
+cache_libs() {
+    find \
+        "${TARGET_DIR}"/usr/lib \
+        "${TARGET_DIR}"/usr/lib64 \
+        \( -type f -o -type l \) \
+        -name '*.so*' \
+        | sed "s@${TARGET_DIR}@@" \
+        > "${LIB_CACHE}"
+}
+
+bin_install() {
+    for arg; do
+        arg=${arg#/}
+        [ -e "${OUTDIR}/${arg}" ] && continue
+        mkdir -p "${OUTDIR}/${arg%/*}"
+        cp -a "${TARGET_DIR}/${arg}" "${OUTDIR}/${arg}"
+        if [ -h "${TARGET_DIR}/${arg}" ]; then
+            bin_install "$(realpath --relative-to "${TARGET_DIR}" "${TARGET_DIR}/${arg}")"
+        elif [ -f "${TARGET_DIR}/${arg}" ]; then
+            readelf --dynamic "${TARGET_DIR}/${arg}" \
+                | awk '$2=="(NEEDED)"{gsub(/\[|\]/,"",$5); print $5}' \
+                | while IFS= read -r lib; do
+                    path="$(grep "${lib}"'$' "${LIB_CACHE}")"
+                    if [ -z "${path}" ]; then
+                        printf 'ERROR could not resolve shared library %s\n' "${lib}" >&2
+                        return 1
+                    fi
+                    bin_install "${path}"
+            done
+        elif [ ! -e "${TARGET_DIR}/${arg}" ]; then
+            printf 'ERROR could not find /%s to copy\n' "${arg}" >&2
+            return 1
+        fi
+    done
+}
+
+mk_skel() {
+    mkdir -p "${OUTDIR}"/dev
+    mknod -m 0622 "${OUTDIR}"/dev/console c 5 1
+
+    mkdir -p \
+        "${OUTDIR}"/usr \
+        "${OUTDIR}"/usr/bin \
+        "${OUTDIR}"/usr/sbin \
+        "${OUTDIR}"/usr/lib
+    ln -s usr/bin "${OUTDIR}"/bin
+    ln -s usr/sbin "${OUTDIR}"/sbin
+    ln -s usr/lib "${OUTDIR}"/lib
+    if [ -h "${TARGET_DIR}"/usr/lib64 ]; then
+        cp -P "${TARGET_DIR}"/usr/lib64 "${OUTDIR}"/usr
+    fi
+    if [ -h "${TARGET_DIR}"/lib64 ]; then
+        cp -P "${TARGET_DIR}"/lib64 "${OUTDIR}"
+    fi
+}
+
+rm -rf "${OUTDIR}"
+
+mk_skel || exit
+cache_libs || exit
+
+bin_install \
+    /bin/cat \
+    /bin/cp \
+    /bin/ls \
+    /bin/mkdir \
+    /bin/mount \
+    /bin/rm \
+    /bin/sh \
+    /bin/sort \
+    /bin/tail \
+    /bin/umount \
+    /usr/bin/btrfs \
+    /usr/bin/mkfs.btrfs \
+    /usr/bin/mountpoint \
+    /usr/bin/readlink \
+    /usr/sbin/blkid \
+    /usr/sbin/findfs \
+    /usr/sbin/partx \
+    /usr/sbin/sfdisk \
+    /usr/sbin/switch_root \
+    || exit
+
+if [ -e "${TARGET_DIR}"/usr/bin/setfiles ]; then
+    bin_install /usr/bin/setfiles || exit
+fi
+
+install "${PKGDIR}"/initramfs/initramfs-init.sh "${OUTDIR}"/init || exit
+install "${PKGDIR}"/initramfs/init-storage.sh "${OUTDIR}"/usr/bin/init-storage || exit
+
+mkdir -p "${TARGET_DIR}"/boot
+
+(cd "${OUTDIR}" && find . -mindepth 1 \
+    | LC_ALL=C sort \
+    | cpio --reproducible --quiet -o -H newc \
+    | zstd \
+) > "${TARGET_DIR}"/boot/initramfs.img.zst
--- a/ci/Jenkinsfile
+++ b/ci/Jenkinsfile
@ -1,6 +1,7 @@
 pipeline {
    parameters {
        booleanParam 'CLEAN_BUILD'
+        string 'CUSTOM_TARGET'
    }

    options {
@ -45,6 +46,11 @@ pipeline {
        stage('Build') {
            steps {
                sh 'make -C buildroot O="${PWD}"/_build BR2_EXTERNAL="${PWD}" aimeeos_qemu_aarch64_defconfig'
+                script {
+                    if (params.CUSTOM_TARGET) {
+                        sh "make -C _build '${CUSTOM_TARGET}'"
+                    }
+                }
                sh 'make -C _build'
            }
            post {
--- a/configs/aimeeos_qemu_aarch64_defconfig
+++ b/configs/aimeeos_qemu_aarch64_defconfig
@ -12,4 +12,5 @@ BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
 # BR2_PACKAGE_BUSYBOX is not set
 # BR2_TARGET_ROOTFS_TAR is not set
 AIMEEOS=y
+AIMEEOS_DEFAULT_ROOTFLAGS="systemd.mask=serial-getty@ttyAMA0 systemd.debug_shell systemd.default_debug_tty=ttyAMA0"
 BR2_TARGET_GRUB2_BUILTIN_MODULES_EFI="boot configfile echo efi_gop fat gzio linux loadenv minicmd normal part_gpt probe regexp squash4 terminfo test zstd"
--- a/external.mk
+++ b/external.mk
@ -1,8 +1,29 @@
+ifeq ($(AIMEEOS),y)
+
+# Disable the default fstab
+SKELETON_INIT_SYSTEMD_ROOT_RO_OR_RW =
+# Disable the default var.mount
+SKELETON_INIT_SYSTEMD_ROOTFS_PRE_CMD_HOOKS =
+
+# Enable required kernel options for Aimee OS storage
+define AIMEEOS_LINUX_CONFIG_FIXUPS
+$(call KCONFIG_ENABLE_OPT,CONFIG_BTRFS_FS)
+$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD)
+endef
+LINUX_KCONFIG_FIXUP_CMDS += $(AIMEEOS_LINUX_CONFIG_FIXUPS)
+
+# Generate the initramfs image after building the target
+BR2_ROOTFS_POST_BUILD_SCRIPT += $(BR2_EXTERNAL_AIMEEOS_PATH)/boot/mkinitramfs.sh
+
 # Overwrite the grub.cfg provided by Buildroot with our own.
 define AIMEEOS_GRUB2_INSTALL_IMAGES_CMDS
 $(foreach tuple, $(GRUB2_TUPLES-y), \
 	$(INSTALL) -D -m 0644 $(BR2_EXTERNAL_AIMEEOS_PATH)/boot/grub2/grub.cfg $(GRUB2_CFG_$(tuple))
 )
+$(HOST_DIR)/bin/grub-editenv $(BINARIES_DIR)/efi-part/EFI/BOOT/grubenv set \
+	default=0 \
+	timeout=3 \
+	rootflags=$(AIMEEOS_DEFAULT_ROOTFLAGS)
 endef
 GRUB2_INSTALL_IMAGES_CMDS += $(AIMEEOS_GRUB2_INSTALL_IMAGES_CMDS)

@ -23,3 +44,7 @@ define AIMEEOS_GEN_GRUB_CFG
 $(BR2_EXTERNAL_AIMEEOS_PATH)/boot/grub2/gen-grub-cfg.sh $(AIMEEOS_KERNEL_FILENAME)
 endef
 LINUX_TARGET_FINALIZE_HOOKS += AIMEEOS_GEN_GRUB_CFG
+
+endif
+
+include $(sort $(wildcard $(BR2_EXTERNAL_AIMEEOS_PATH)/package/*/*.mk))
--- a/package/aimee-os-utils/Config.in
+++ b/package/aimee-os-utils/Config.in
@ -0,0 +1,8 @@
+config BR2_PACKAGE_AIMEE_OS_UTILS
+    bool
+    select BR2_PACKAGE_BTRFS_PROGS
+    select BR2_PACKAGE_UTIL_LINUX
+    select BR2_PACKAGE_UTIL_LINUX_BINARIES
+    select BR2_PACKAGE_UTIL_LINUX_MOUNTPOINT
+    select BR2_PACKAGE_UTIL_LINUX_PARTX
+    select BR2_PACKAGE_UTIL_LINUX_SWITCH_ROOT
--- a/package/aimee-os-utils/aimee-os-utils.mk
+++ b/package/aimee-os-utils/aimee-os-utils.mk
@ -0,0 +1,21 @@
+################################################################################
+#
+# Aimee OS Utils
+#
+################################################################################
+
+AIMEE_OS_UTILS_VERSION = 2.0
+AIMEE_OS_UTILS_LICENSE = GPL-3.0+
+AIMEE_OS_UTILS_DEPENDENCIES = \
+	host-fakeroot \
+	btrfs-progs \
+
+AIMEE_OS_UTILS_SOURCE =
+
+define AIMEE_OS_UTILS_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m u=rw,go=r \
+		$(AIMEE_OS_UTILS_PKGDIR)/var.mount \
+		$(TARGET_DIR)/usr/lib/systemd/system/var.mount
+endef
+
+$(eval $(generic-package))
--- a/package/aimee-os-utils/var.mount
+++ b/package/aimee-os-utils/var.mount
@ -0,0 +1,12 @@
+[Unit]
+Description=/var
+DefaultDependencies=no
+Conflicts=umount.target
+Before=local-fs.target umount.target
+After=swap.target
+
+[Mount]
+What=PARTLABEL=aimeeos-data
+Where=/var
+Type=btrfs
+Options=subvol=var,nosuid,nodev,noexec
Author	SHA1	Message	Date
Dustin	44b2ce8a99	Begin persistent storage implementation Aimee OS/aimee-os/pipeline/head This commit looks good Details Most of the logic in the `init-storage` script is the same as it was in Aimee OS v1 (Gentoo). The major difference is now we are initializing the data volume in the initramfs instead of in the real OS. This allows us to make all of `/etc` writable via OverlayFS, instead of having only certain sub-directories writable via bind-mounts. Buildroot doesn't really have any tools for building an initramfs, unfortunately. It does have a bit of infrastructure for running `dracut`, but I'd really rather avoid having that much complexity in the initramfs; all we need is to run the `init-storage` script and then switch root. Instead, the `mkinitramfs.sh` script, called in the post-build stage, creates the CPIO archive from files in the target directory. The only particularly interesting bit is how it resolves shared library dependencies, to make sure the appropriate resources are available for the requisite commands. I briefly considered building a statically-linked BusyBox just for the initramfs. Since it doesn't provide several important tools like `btrfs`/`mkfs.btrfs`, I had to implement the dynamic link resolution function anyway. It made sense, then, to copy Dash and the necessary Coreutils binaries themselves.	2025-08-29 20:17:52 -05:00
Dustin	05dd3810c9	configs/qemu: Enable debug shell on ttyAMA0 We set the default kernel command-line arguments to tell systemd to spawn a debug shell on the serial console, instead of the default getty. This will allow tests to run commands directly on the console, without any authentication, etc.	2025-08-29 20:17:52 -05:00
Dustin	8a2d305b04	grub2: Support setting rootflags in config The `AIMEEOS_DEFAULT_ROOTFLAGS` kconfig option can be used to set the default value for the `rootflags` GRUB2 environment variable. The value of this variable will be passed along as command-line arguments to whatever kernel is chosen at boot. Since post-image scripts do not have access to kconfig option values, we need to build the GRUB2 environment file in the `GRUB2_INSTALL_IMAGES_CMDS` script fragment instead.	2025-08-29 20:17:52 -05:00
Dustin	20c92961d6	ci: Add CUSTOM_TARGET parameter If a value is provided for the `CUSTOM_TARGET` parameter, the specified target will be built first, before building the filesystem images. This provides a way to e.g. rebuild a specific package.	2025-08-29 20:17:52 -05:00