FDS/OS 1.0

tools/in-rootfs

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Execute ARM userspace with no host binfmt registration or physical USB access.
+source "$(dirname -- "${BASH_SOURCE[0]}")/lib.sh"
+(( $# >= 2 )) || die 'Usage: tools/in-rootfs ROOT [--direct] COMMAND [ARGUMENT...]'
+root=$(realpath -e -- "$1")
+shift
+[[ -x $root/usr/bin/bash ]] || die 'Not an assembled FDS rootfs'
+check_void_pin
+"$FDS_ROOT/tools/verify-elf" "$FDS_VOID/masterdir-x86_64/usr/bin/qemu-aarch64" x86_64 static >/dev/null
+# The target is the actual kernel-visible root. Linux 6.7+ gives this new user
+# namespace its own binfmt registry; host registration is never changed.
+# The native loader and tools are read-only temporary mounts, absent from tar.
+host=/tmp/fds-build-host
+runner=("$host/usr/lib/ld-linux-x86-64.so.2" --library-path "$host/usr/lib"
+    "$host/usr/bin/bash" /tmp/fds-rootfs-namespace)
+capabilities=(--cap-add CAP_SYS_ADMIN --cap-add CAP_SETPCAP)
+# A single ELF needs no child-exec handler.
+if [[ ${1:-} == --direct ]]; then
+    shift
+    (( $# > 0 )) || die 'Missing command after --direct'
+    runner=("$host/usr/bin/qemu-aarch64")
+    capabilities=()
+fi
+exec bwrap --unshare-user --uid 0 --gid 0 --cap-add CAP_SETFCAP "${capabilities[@]}" --unshare-pid \
+    --bind "$root" / --dev /dev --proc /proc --tmpfs /tmp --tmpfs /run \
+    --ro-bind "$FDS_VOID/masterdir-x86_64" "$host" \
+    --ro-bind "$FDS_ROOT/tools/finalize-rootfs" /tmp/fds-finalize \
+    --ro-bind "$FDS_ROOT/tools/rootfs-namespace" /tmp/fds-rootfs-namespace \
+    --chdir / --clearenv --setenv PATH /usr/bin:/bin \
+    --setenv HOME /root \
+    --setenv XBPS_ARCH aarch64 --setenv LC_ALL C "${runner[@]}" "$@"