1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
#!/bin/sh
# Copyright (c) 2016 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Note: In order to limit the damage this script can do, it is recommended
# to NOT run as root.
#
# 1. Download buildroot
# 2. Build buildroot kernel and root file system as per
# config files included in this package
# 3. Create empty disk image and extract buildroot root
# file system onto it, make it bootable
# 4. Apply any patches/additions included in this package
#
BUILD_DIR="$(dirname $0)/build"
BUILDROOT_NAME='buildroot-2016.02'
BUILDROOT_DIR="${BUILD_DIR}/${BUILDROOT_NAME}"
BUILDROOT_TARBALL="${BUILDROOT_NAME}.tar.gz"
BUILDROOT_URL="https://buildroot.org/downloads/${BUILDROOT_TARBALL}"
BUILDROOT_OUTPUT="${BUILDROOT_DIR}/output/images/rootfs.tar"
DISK_FREE_SIZE=8388608 # Min. free space on disk (8 MB)
DISK_ROUND_TO_NEAREST=16777216 # Round disk size up to nearest (16 MB)
VERSION=$(cat $(dirname $0)/CHANGELOG | grep '^## ' | head -1 | sed -e 's/.*\[\(.*\)\].*/\1/')
if [ "${VERSION}" = "" ]
then
echo "Unable to determine build version from CHANGELOG file. Make sure"
echo "that there is an entry for the most recent version in CHANGELOG,"
echo "and that the entry is formated like"
echo
echo "## [1.0] - 2016-05-16"
exit 1
fi
echo Building version: ${VERSION}
echo $VERSION > ${BUILD_DIR}/VERSION
echo "NESTED_VERSION=${VERSION}" > ${BUILD_DIR}/VERSION_HIDDEN
img_name="${BUILD_DIR}/csit-nested-${VERSION}.img"
# Normally no need to touch the variables below
DISK_SECT_SIZE=512
DISK_HEADS=16
DISK_SECT_PER_TRACK=63
DISK_RESERVED_SECTORS=2048
MOUNT_TMPDIR="${BUILD_DIR}/tmp-mount"
set -e
# Download buildroot if not already there
wget -P ${BUILD_DIR} -N $BUILDROOT_URL
tar -C ${BUILD_DIR} -xzf ${BUILD_DIR}/$BUILDROOT_TARBALL
cp -p buildroot-config $BUILDROOT_DIR/.config
cp -p kernel-defconfig $BUILDROOT_DIR/kernel-defconfig
make -C $BUILDROOT_DIR
if [ ! -f ${BUILDROOT_OUTPUT} ]
then
echo "Buildroot compiled OK, but root file system ${BUILDROOT_OUTPUT}"
echo "does not exist. Somethig is wrong. Exiting."
exit 1
fi
# If we got here, it means we downloaded (if applicable) and built (if
# applicable) buildroot OK.
#
# Now let's calculate the required disk size, and build an empty disk.
buildroot_size=$(stat -c%s ${BUILDROOT_OUTPUT})
desired_size=$(( ${buildroot_size} + ${DISK_FREE_SIZE} ))
rounded_size=$(( ((${desired_size}/${DISK_ROUND_TO_NEAREST})+1) * \
${DISK_ROUND_TO_NEAREST} ))
echo "Actual root FS size: ${buildroot_size}"
echo "Root FS size + desired free space (${DISK_FREE_SIZE}): ${desired_size}"
echo "Root FS size rounded to nearest ${DISK_ROUND_TO_NEAREST}:" \
"${rounded_size} ($(( ${rounded_size} / 1024 / 1024 )) MB)"
# In a normal world, we'd be creating a full-size empty image with "dd", an
# then use fdisk to partition it, and a tool like "kpartx" to map this into
# individual partitions. We'd then map the partition we're interested in.
# However, in order to avoid messing with /dev/mapper, we can also create
# our actual partition first, and then merge it with the MBR+partition table
# "prefix" to obtain our full disk.
sectors=$(( ${rounded_size} / ${DISK_SECT_SIZE} ))
disk_prefix=${img_name}.prefix
disk_main=${img_name}.main
dd if=/dev/zero of=${disk_prefix} bs=${DISK_SECT_SIZE} \
count=${DISK_RESERVED_SECTORS}
dd if=/dev/zero of=${disk_main} bs=${DISK_SECT_SIZE} \
count=$(( $sectors - ${DISK_RESERVED_SECTORS} ))
# Format and mount the root file system
mkfs.ext2 -F -L root ${disk_main}
mkdir -p ${MOUNT_TMPDIR}
sudo mount -o loop ${disk_main} ${MOUNT_TMPDIR}
trap "sudo umount ${MOUNT_TMPDIR}" EXIT
# Extract the root filesystem
echo "Extracting root filesystem..."
sudo tar -C ${MOUNT_TMPDIR} -xf ${BUILDROOT_OUTPUT}
# Apply any patches
echo "Applying patches/modifications"
mydir=$(pwd)
cd ${MOUNT_TMPDIR}
sudo run-parts -v ${mydir}/patches
cd ${mydir}
# Copy version and changelog
sudo cp ${BUILD_DIR}/VERSION ${MOUNT_TMPDIR}/
sudo cp ${mydir}/CHANGELOG ${MOUNT_TMPDIR}/
# Also embed this into a hidden file that we can easily retrieve with
# "cat <disk image> | strings | grep NESTED_VERSION"
sudo cp ${BUILD_DIR}/VERSION_HIDDEN ${MOUNT_TMPDIR}/.VERSION.HIDDEN
# Unmount root filesystem
sudo umount ${MOUNT_TMPDIR}
trap EXIT
rmdir ${MOUNT_TMPDIR}
# Now create our larger disk
cat ${disk_prefix} ${disk_main} > ${img_name}
rm -f ${disk_prefix} ${disk_main}
# Create partition table on the disk
sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << _EOF | fdisk -H ${DISK_HEADS} -S ${DISK_SECT_PER_TRACK} ${img_name}
o # clear the in memory partition table
n # new partition
p # primary partition
1 # partition number 1
${DISK_RESERVED_SECTORS} # Start a few KB into the disk, leave room for GRUB
# Default - all the way through the end of the disk
a # make a partition bootable
1 # bootable partition is partition 1
p # print the in-memory partition table
w # write the partition table
q # and we're done
_EOF
disk_cylinders=$(fdisk -l -H ${DISK_HEADS} -S ${DISK_SECT_PER_TRACK} ${img_name} | \
grep cylinders | \
sed -e 's/.* \([0-9][0-9]*\) cylinders.*/\1/')
echo "Disk has ${disk_cylinders} cylinders"
# Install GRUB bootloader on the disk image
${BUILDROOT_DIR}/output/host/sbin/grub --device-map=/dev/null <<_EOF
device (hd0) ${img_name}
geometry (hd0) ${disk_cylinders} ${DISK_HEADS} ${DISK_SECT_PER_TRACK}
root (hd0,0)
setup (hd0)
quit
_EOF
echo
echo
echo
echo "Your image should be ready in:"
ls -l ${img_name}
|
