Skip to content

Commit

Permalink
kbuild: rebuild initramfs if content of initramfs changes
Browse files Browse the repository at this point in the history 
initramfs.cpio.gz being build in usr/ and included in the
kernel was not rebuild when the included files changed.

To fix this the following was done:
- let gen_initramfs.sh generate a list of files and directories included
  in the initramfs
- gen_initramfs generate the gzipped cpio archive so we could simplify
  the kbuild file (Makefile)
- utilising the kbuild infrastructure so when uid/gid root mapping changes
  the initramfs will be rebuild

With this change we have a much more robust initramfs generation.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
  • Loading branch information
Sam Ravnborg committed Apr 11, 2006
1 parent d9df92e commit d39a206
Show file tree
Hide file tree
Showing 2 changed files with 189 additions and 127 deletions.
225 changes: 152 additions & 73 deletions scripts/gen_initramfs_list.sh
View file
Original file line number Diff line number Diff line change
@@ -1,22 +1,55 @@
#!/bin/bash
# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
# Released under the terms of the GNU GPL
#
# Generate a newline separated list of entries from the file/directory
# supplied as an argument.
#
# If a file/directory is not supplied then generate a small dummy file.
# Copyright (c) 2006 Sam Ravnborg <sam@ravnborg.org>
#
# The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive, and gzip to pack it.
# The script may also be used to generate the inputfile used for gen_init_cpio
# This script assumes that gen_init_cpio is located in usr/ directory

# error out on errors
set -e

usage() {
cat << EOF
Usage:
$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
-o <file> Create gzipped initramfs file named <file> using
gen_init_cpio and gzip
-u <uid> User ID to map to user ID 0 (root).
<uid> is only meaningful if <cpio_source>
is a directory.
-g <gid> Group ID to map to group ID 0 (root).
<gid> is only meaningful if <cpio_source>
is a directory.
<cpio_source> File list or directory for cpio archive.
If <cpio_source> is a .cpio file it will be used
as direct input to initramfs.
-d Output the default cpio list.
All options except -o and -l may be repeated and are interpreted
sequentially and immediately. -u and -g states are preserved across
<cpio_source> options so an explicit "-u 0 -g 0" is required
to reset the root/group mapping.
EOF
}

list_default_initramfs() {
# echo usr/kinit/kinit
:
}

default_initramfs() {
cat <<-EOF
cat <<-EOF >> ${output}
# This is a very simple, default initramfs
dir /dev 0755 0 0
nod /dev/console 0600 0 0 c 5 1
dir /root 0700 0 0
# file /kinit usr/kinit/kinit 0755 0 0
# slink /init kinit 0755 0 0
EOF
}

Expand All @@ -42,18 +75,28 @@ filetype() {
return 0
}

list_print_mtime() {
:
}

print_mtime() {
local argv1="$1"
local my_mtime="0"

if [ -e "${argv1}" ]; then
my_mtime=$(find "${argv1}" -printf "%T@\n" | sort -r | head -n 1)
if [ -e "$1" ]; then
my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
fi

echo "# Last modified: ${my_mtime}"
echo

echo "# Last modified: ${my_mtime}" >> ${output}
echo "" >> ${output}
}

list_parse() {
echo "$1 \\"
}

# for each file print a line in following format
# <filetype> <name> <path to file> <octal mode> <uid> <gid>
# for links, devices etc the format differs. See gen_init_cpio for details
parse() {
local location="$1"
local name="${location/${srcdir}//}"
Expand Down Expand Up @@ -99,80 +142,112 @@ parse() {
;;
esac

echo "${str}"
echo "${str}" >> ${output}

return 0
}

usage() {
printf "Usage:\n"
printf "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"
printf "\n"
printf -- "-u <root_uid> User ID to map to user ID 0 (root).\n"
printf " <root_uid> is only meaningful if <cpio_source>\n"
printf " is a directory.\n"
printf -- "-g <root_gid> Group ID to map to group ID 0 (root).\n"
printf " <root_gid> is only meaningful if <cpio_source>\n"
printf " is a directory.\n"
printf "<cpio_source> File list or directory for cpio archive.\n"
printf " If <cpio_source> is not provided then a\n"
printf " a default list will be output.\n"
printf -- "-d Output the default cpio list. If no <cpio_source>\n"
printf " is given then the default cpio list will be output.\n"
printf "\n"
printf "All options may be repeated and are interpreted sequentially\n"
printf "and immediately. -u and -g states are preserved across\n"
printf "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"
printf "to reset the root/group mapping.\n"
unknown_option() {
printf "ERROR: unknown option \"$arg\"\n" >&2
printf "If the filename validly begins with '-', " >&2
printf "then it must be prefixed\n" >&2
printf "by './' so that it won't be interpreted as an option." >&2
printf "\n" >&2
usage >&2
exit 1
}

list_header() {
echo "deps_initramfs := \\"
}

header() {
printf "\n#####################\n# $1\n" >> ${output}
}

# process one directory (incl sub-directories)
dir_filelist() {
${dep_list}header "$1"

srcdir=$(echo "$1" | sed -e 's://*:/:g')
dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)

# If $dirlist is only one line, then the directory is empty
if [ "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
${dep_list}print_mtime "$1"

echo "${dirlist}" | \
while read x; do
${dep_list}parse ${x}
done
fi
}

build_list() {
printf "\n#####################\n# $cpio_source\n"

if [ -f "$cpio_source" ]; then
print_mtime "$cpio_source"
cat "$cpio_source"
elif [ -d "$cpio_source" ]; then
srcdir=$(echo "$cpio_source" | sed -e 's://*:/:g')
dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)

# If $dirlist is only one line, then the directory is empty
if [ "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
print_mtime "$cpio_source"

echo "${dirlist}" | \
while read x; do
parse ${x}
done
# if only one file is specified and it is .cpio file then use it direct as fs
# if a directory is specified then add all files in given direcotry to fs
# if a regular file is specified assume it is in gen_initramfs format
input_file() {
source="$1"
if [ -f "$1" ]; then
${dep_list}header "$1"
is_cpio="$(echo "$1" | sed 's/^.*\.cpio/cpio/')"
if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then
cpio_file=$1
[ ! -z ${dep_list} ] && echo "$1"
return 0
fi
if [ -z ${dep_list} ]; then
print_mtime "$1" >> ${output}
cat "$1" >> ${output}
else
# Failsafe in case directory is empty
default_initramfs
grep ^file "$1" | cut -d ' ' -f 3
fi
elif [ -d "$1" ]; then
dir_filelist "$1"
else
echo " $0: Cannot open '$cpio_source'" >&2
echo " ${prog}: Cannot open '$1'" >&2
exit 1
fi
}


prog=$0
root_uid=0
root_gid=0
dep_list=
cpio_file=
cpio_list=
output="/dev/stdout"
output_file=""

arg="$1"
case "$arg" in
"-l") # files included in initramfs - used by kbuild
dep_list="list_"
shift
;;
"-o") # generate gzipped cpio image named $1
shift
output_file="$1"
cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
output=${cpio_list}
shift
;;
esac
while [ $# -gt 0 ]; do
arg="$1"
shift
case "$arg" in
"-u")
"-u") # map $1 to uid=0 (root)
root_uid="$1"
shift
;;
"-g")
"-g") # map $1 to gid=0 (root)
root_gid="$1"
shift
;;
"-d")
"-d") # display default initramfs list
default_list="$arg"
default_initramfs
${dep_list}default_initramfs
;;
"-h")
usage
Expand All @@ -181,23 +256,27 @@ while [ $# -gt 0 ]; do
*)
case "$arg" in
"-"*)
printf "ERROR: unknown option \"$arg\"\n" >&2
printf "If the filename validly begins with '-', then it must be prefixed\n" >&2
printf "by './' so that it won't be interpreted as an option." >&2
printf "\n" >&2
usage >&2
exit 1
unknown_option
;;
*)
cpio_source="$arg"
build_list
*) # input file/dir - process it
input_file "$arg" "$#"
;;
esac
;;
esac
done

# spit out the default cpio list if a source hasn't been specified
[ -z "$cpio_source" -a -z "$default_list" ] && default_initramfs

# If output_file is set we will generate cpio archive and gzip it
# we are carefull to delete tmp files
if [ ! -z ${output_file} ]; then
if [ -z ${cpio_file} ]; then
cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}
else
cpio_tfile=${cpio_file}
fi
rm ${cpio_list}
cat ${cpio_tfile} | gzip -f -9 - > ${output_file}
[ -z ${cpio_file} ] && rm ${cpio_tfile}
fi
exit 0
Loading

0 comments on commit d39a206

Please sign in to comment.