openwrt/scripts/mkits.sh
Daniel Golle 330bd380e8 image: allow building FIT and uImage with ramdisk
Instead of embedding the initrd cpio archive into the kernel, allow
for having an external ramdisk added to the FIT or uImage.
This is useful to overcome kernel size limitations present in many
stock bootloaders, as the ramdisk is then loaded seperately and doesn't
add to the kernel size. Hence we can have larger ramdisks to host ie.
installers with all binaries to flash included (or a web-based
firmware selector).
In terms of performance and total size the differences are neglectible.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2021-02-24 01:35:20 +00:00

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#!/bin/sh
#
# Licensed under the terms of the GNU GPL License version 2 or later.
#
# Author: Peter Tyser <ptyser@xes-inc.com>
#
# U-Boot firmware supports the booting of images in the Flattened Image
# Tree (FIT) format. The FIT format uses a device tree structure to
# describe a kernel image, device tree blob, ramdisk, etc. This script
# creates an Image Tree Source (.its file) which can be passed to the
# 'mkimage' utility to generate an Image Tree Blob (.itb file). The .itb
# file can then be booted by U-Boot (or other bootloaders which support
# FIT images). See doc/uImage.FIT/howto.txt in U-Boot source code for
# additional information on FIT images.
#
usage() {
printf "Usage: %s -A arch -C comp -a addr -e entry" "$(basename "$0")"
printf " -v version -k kernel [-D name -n address -d dtb] -o its_file"
printf "\n\t-A ==> set architecture to 'arch'"
printf "\n\t-C ==> set compression type 'comp'"
printf "\n\t-c ==> set config name 'config'"
printf "\n\t-a ==> set load address to 'addr' (hex)"
printf "\n\t-e ==> set entry point to 'entry' (hex)"
printf "\n\t-f ==> set device tree compatible string"
printf "\n\t-i ==> include initrd Blob 'initrd'"
printf "\n\t-v ==> set kernel version to 'version'"
printf "\n\t-k ==> include kernel image 'kernel'"
printf "\n\t-D ==> human friendly Device Tree Blob 'name'"
printf "\n\t-n ==> fdt unit-address 'address'"
printf "\n\t-d ==> include Device Tree Blob 'dtb'"
printf "\n\t-r ==> include RootFS blob 'rootfs'"
printf "\n\t-H ==> specify hash algo instead of SHA1"
printf "\n\t-o ==> create output file 'its_file'\n"
exit 1
}
FDTNUM=1
ROOTFSNUM=1
INITRDNUM=1
HASH=sha1
LOADABLES=
while getopts ":A:a:c:C:D:d:e:f:i:k:n:o:v:r:S" OPTION
do
case $OPTION in
A ) ARCH=$OPTARG;;
a ) LOAD_ADDR=$OPTARG;;
c ) CONFIG=$OPTARG;;
C ) COMPRESS=$OPTARG;;
D ) DEVICE=$OPTARG;;
d ) DTB=$OPTARG;;
e ) ENTRY_ADDR=$OPTARG;;
f ) COMPATIBLE=$OPTARG;;
i ) INITRD=$OPTARG;;
k ) KERNEL=$OPTARG;;
n ) FDTNUM=$OPTARG;;
o ) OUTPUT=$OPTARG;;
r ) ROOTFS=$OPTARG;;
S ) HASH=$OPTARG;;
v ) VERSION=$OPTARG;;
* ) echo "Invalid option passed to '$0' (options:$*)"
usage;;
esac
done
# Make sure user entered all required parameters
if [ -z "${ARCH}" ] || [ -z "${COMPRESS}" ] || [ -z "${LOAD_ADDR}" ] || \
[ -z "${ENTRY_ADDR}" ] || [ -z "${VERSION}" ] || [ -z "${KERNEL}" ] || \
[ -z "${OUTPUT}" ] || [ -z "${CONFIG}" ]; then
usage
fi
ARCH_UPPER=$(echo "$ARCH" | tr '[:lower:]' '[:upper:]')
if [ -n "${COMPATIBLE}" ]; then
COMPATIBLE_PROP="compatible = \"${COMPATIBLE}\";"
fi
# Conditionally create fdt information
if [ -n "${DTB}" ]; then
FDT_NODE="
fdt@$FDTNUM {
description = \"${ARCH_UPPER} OpenWrt ${DEVICE} device tree blob\";
${COMPATIBLE_PROP}
data = /incbin/(\"${DTB}\");
type = \"flat_dt\";
arch = \"${ARCH}\";
compression = \"none\";
hash@1 {
algo = \"crc32\";
};
hash@2 {
algo = \"${HASH}\";
};
};
"
FDT_PROP="fdt = \"fdt@$FDTNUM\";"
fi
if [ -n "${INITRD}" ]; then
INITRD_NODE="
initrd@$INITRDNUM {
description = \"${ARCH_UPPER} OpenWrt ${DEVICE} initrd\";
${COMPATIBLE_PROP}
data = /incbin/(\"${INITRD}\");
type = \"ramdisk\";
arch = \"${ARCH}\";
os = \"linux\";
hash@1 {
algo = \"crc32\";
};
hash@2 {
algo = \"${HASH}\";
};
};
"
INITRD_PROP="ramdisk=\"initrd@${INITRDNUM}\";"
fi
if [ -n "${ROOTFS}" ]; then
dd if="${ROOTFS}" of="${ROOTFS}.pagesync" bs=4096 conv=sync
ROOTFS_NODE="
rootfs@$ROOTFSNUM {
description = \"${ARCH_UPPER} OpenWrt ${DEVICE} rootfs\";
${COMPATIBLE_PROP}
data = /incbin/(\"${ROOTFS}.pagesync\");
type = \"filesystem\";
arch = \"${ARCH}\";
compression = \"none\";
hash@1 {
algo = \"crc32\";
};
hash@2 {
algo = \"${HASH}\";
};
};
"
LOADABLES="${LOADABLES:+$LOADABLES, }\"rootfs@${ROOTFSNUM}\""
fi
# Create a default, fully populated DTS file
DATA="/dts-v1/;
/ {
description = \"${ARCH_UPPER} OpenWrt FIT (Flattened Image Tree)\";
#address-cells = <1>;
images {
kernel@1 {
description = \"${ARCH_UPPER} OpenWrt Linux-${VERSION}\";
data = /incbin/(\"${KERNEL}\");
type = \"kernel\";
arch = \"${ARCH}\";
os = \"linux\";
compression = \"${COMPRESS}\";
load = <${LOAD_ADDR}>;
entry = <${ENTRY_ADDR}>;
hash@1 {
algo = \"crc32\";
};
hash@2 {
algo = \"$HASH\";
};
};
${INITRD_NODE}
${FDT_NODE}
${ROOTFS_NODE}
};
configurations {
default = \"${CONFIG}\";
${CONFIG} {
description = \"OpenWrt ${DEVICE}\";
kernel = \"kernel@1\";
${FDT_PROP}
${LOADABLES:+loadables = ${LOADABLES};}
${COMPATIBLE_PROP}
${INITRD_PROP}
};
};
};"
# Write .its file to disk
echo "$DATA" > "${OUTPUT}"