3.3. Construction

3.3.1. Create a ramdisk

bash# dd if=/dev/zero of=/dev/ram7 bs=1k count=4096 bash# mke2fs -m0 /dev/ram7 bash# mount /dev/ram7 /mnt

3.3.2. Rebuild the BASH shell

bash# cd /usr/src/bash-2.05a bash# make distclean bash# export CC="gcc -mcpu=i386" bash# ./configure --enable-minimal-config --host=i386-pc-linux-gnu bash# make bash# strip bash

3.3.3. Determine which libraries are required

bash# ldd bash

Note the output from the ldd command. It should look similar to the example below.

bash# ldd bash
  libdl.so.2 => /lib/libdl.so.2 (0x4001d000)
  libc.so.6 => /lib/libc.so.6 (0x40020000)
  /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)

3.3.4. Copy BASH and its libraries to the ramdisk

bash# mkdir /mnt/bin bash# cp bash /mnt/bin bash# ln -s bash /mnt/bin/sh bash# mkdir /mnt/lib bash# strip --strip-unneeded -o /mnt/lib/libdl.so.2 /lib/libdl.so.2 bash# strip --strip-unneeded -o /mnt/lib/libc.so.6 /lib/libc.so.6 bash# strip --strip-unneeded -o /mnt/lib/ld-linux.so.2 /lib/ld-linux.so.2 bash# chmod +x /mnt/lib/*

Using strip -o might seem an odd way to copy library files from the development system to the ramdisk. What it does is strip the symbols while the file is in transit from the source location to the destination. This has the effect of stripping symbols from the library on the ramdisk without altering the libraries on the development system. Unfortunately file permissions are lost when copying libraries this way which is why the chmod +x command is then used to set the execute flag on all of the libraries on the rootdisk.

3.3.5. Create a console device

bash# mkdir /mnt/dev bash# mknod /mnt/dev/console c 5 1

3.3.6. Compress the ramdisk image

bash# cd / bash# umount /dev/ram7 bash# dd if=/dev/ram7 of=~/phase2-image bs=1k bash# gzip -9 ~/phase2-image

3.3.7. Copy the compressed image to diskette

Insert the floppy labeled "root disk" into drive fd0.

bash# dd if=~/phase2-image.gz of=/dev/fd0 bs=1k