1#
2# Copyright OpenEmbedded Contributors
3#
4# SPDX-License-Identifier: MIT
5#
6
7# This class installs additional files found on the build host
8# directly into the rootfs.
9#
10# One use case is to install a constant ssh host key in
11# an image that gets created for just one machine. This
12# solves two issues:
13# - host key generation on the device can stall when the
14#   kernel has not gathered enough entropy yet (seen in practice
15#   under qemu)
16# - ssh complains by default when the host key changes
17#
18# For dropbear, with the ssh host key store along side the local.conf:
19# 1. Extend local.conf:
20#    INHERIT += "rootfsdebugfiles"
21#    ROOTFS_DEBUG_FILES += "${TOPDIR}/conf/dropbear_rsa_host_key ${IMAGE_ROOTFS}/etc/dropbear/dropbear_rsa_host_key ;"
22# 2. Boot the image once, copy the dropbear_rsa_host_key from
23#    the device into your build conf directory.
24# 3. A optional parameter can be used to set file mode
25#    of the copied target, for instance:
26#    ROOTFS_DEBUG_FILES += "${TOPDIR}/conf/dropbear_rsa_host_key ${IMAGE_ROOTFS}/etc/dropbear/dropbear_rsa_host_key 0600;"
27#    in case they might be required to have a specific mode. (Shoundn't be too open, for example)
28#
29# Do not use for production images! It bypasses several
30# core build mechanisms (updating the image when one
31# of the files changes, license tracking in the image
32# manifest, ...).
33
34ROOTFS_DEBUG_FILES ?= ""
35ROOTFS_DEBUG_FILES[doc] = "Lists additional files or directories to be installed with 'cp -a' in the format 'source1 target1;source2 target2;...'"
36
37ROOTFS_POSTPROCESS_COMMAND += "rootfs_debug_files"
38rootfs_debug_files () {
39   #!/bin/sh -e
40   echo "${ROOTFS_DEBUG_FILES}" | sed -e 's/;/\n/g' | while read source target mode; do
41      if [ -e "$source" ]; then
42         mkdir -p $(dirname $target)
43         cp -a $source $target
44         [ -n "$mode" ] && chmod $mode $target
45      fi
46   done
47}
48