make_initrd_img

Linux嵌入式设计配套光盘,学习嵌入式设计可参考

#!/bin/sh

export PRJROOT=/lad

# This script will create a compressed root filesystem image from
# the $PRJROOT/initrd directory. The filesystem type, "ext2" or
# "minix" is specified on the command line.

# Inputs:  $PRJROOT/initrd root filesystem
# Outputs: $PRJROOT/images/initrd.img.gz

# if [ `whoami` != "root" ]
# then
#   echo "Must 'su root' before invoking this script."
#   exit 1
# fi

if [ "$2" = "" ]
then
  echo "usage: $0 {ext2 | minix} 1K_block_count"
  exit 1
fi


if [ "$1" = "ext2" ]
then
  FS_TYPE="ext2"
  # "-m 0" prevents saving space for root.
  MKFS_CMD="/sbin/mkfs.ext2 -m 0"
elif [ "$1" = "minix" ]
then
  FS_TYPE="minix"
  MKFS_CMD="/sbin/mkfs.minix"
else
  echo "usage: $0 {ext2 | minix} 1K_block_count"
  exit 1
fi

echo "Creating root filesystem image..."

# Change to the ''images'' directory and create a root filesystem image from
# a file using a loopback device.

pushd $PRJROOT/images
dd if=/dev/zero of=initrd.img bs=1k count=$2
$MKFS_CMD initrd.img

echo "Copying root filesystem to root filesystem image..."

if [ -d mnt ]
then
  mnt_already_exists=1
else
  mnt_already_exists=0
  mkdir mnt
fi

echo "Removing ~* backup files..."
rm -f $PRJROOT/initrd/*~ $PRJROOT/initrd/*/*~ $PRJROOT/initrd/*/*/*~

echo "Root privilege required for mkfs.xxx, copying dev/nodes, and umount..."
sudo mount -t $FS_TYPE initrd.img mnt -o loop
sudo cp -r ../initrd/* mnt/
sudo umount mnt

if [ $mnt_already_exists = 0 ]
then
  rmdir mnt
fi

echo "Compressing root filesystem image..."
gzip -c initrd.img > initrd.gz

popd