usr/gen_initramfs.sh

Source file repositories/reference/linux-study-clean/usr/gen_initramfs.sh

File Facts

System
Linux kernel
Corpus path
usr/gen_initramfs.sh
Extension
.sh
Size
5922 bytes
Lines
251
Domain
Support Tooling And Documentation
Bucket
usr
Inferred role
Support Tooling And Documentation: usr
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#!/bin/sh
# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
# Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>
#
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive.
# 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>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
	-o <file>      Create initramfs file named <file> by using gen_init_cpio
	-l <dep_list>  Create dependency list named <dep_list>
	-u <uid>       User ID to map to user ID 0 (root).
		       <uid> is only meaningful if <cpio_source> is a
		       directory.  "squash" forces all files to uid 0.
	-g <gid>       Group ID to map to group ID 0 (root).
		       <gid> is only meaningful if <cpio_source> is a
		       directory.  "squash" forces all files to gid 0.
	-d <date>      Use date for all file mtime values
	<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.

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
}

# awk style field access
# $1 - field number; rest is argument string
field() {
	shift $1 ; echo $1
}

filetype() {
	local argv1="$1"

	# symlink test must come before file test
	if [ -L "${argv1}" ]; then
		echo "slink"
	elif [ -f "${argv1}" ]; then
		echo "file"
	elif [ -d "${argv1}" ]; then
		echo "dir"
	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
		echo "nod"
	elif [ -p "${argv1}" ]; then
		echo "pipe"
	elif [ -S "${argv1}" ]; then
		echo "sock"
	else
		echo "invalid"
	fi
	return 0
}

print_mtime() {
	local my_mtime="0"

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

Annotation

Implementation Notes