A.3. Construction
A.3.1. Create an enhanced boot disk
A.3.1.1. Build a new kernel
bash# cd /usr/src/linux bash# make menuconfig |
Be sure to configure support for the following:
386 processor
Floppy disk
RAM disk
Second extended (ext2) filesystem
Virtual console
Audio hardware
CD-ROM hardware
ISO-9660 and Joliet filesystems
bash# make dep bash# make clean bash# make bzImage |
A.3.2. Create an enhanced root disk
A.3.2.1. Create additional device files
A.3.2.1.1. IDE CD-ROM
bash# mknod -m640 ~/staging/dev/hdc b 22 0 bash# mknod -m640 ~/staging/dev/hdd b 22 64 |
Optionally create additional IDE devices.
A.3.2.1.2. Ramdisk
bash# mknod -m 640 ~/staging/dev/ram1 b 1 1 bash# mknod -m 640 ~/staging/dev/ram2 b 1 2 bash# mknod -m 640 ~/staging/dev/ram3 b 1 3 bash# mknod -m 640 ~/staging/dev/ram4 b 1 4 bash# mknod -m 640 ~/staging/dev/ram5 b 1 5 bash# mknod -m 640 ~/staging/dev/ram6 b 1 6 bash# mknod -m 640 ~/staging/dev/ram7 b 1 7 |
A.3.2.2. Install the gunzip binary
bash# cd /usr/src/gzip-1.2.4a bash# export CC="gcc -mcpu=i386" bash# ./configure --host=i386-pc-linux-gnu bash# make bash# strip gzip bash# cp gzip ~/staging/bin bash# ln -s gzip ~/staging/bin/gunzip |
Don't forget to verify library requirements, check the ownership and check permissions on the gzip binary.
A.3.2.3. Write a startup script to mount a compressed floppy
Use a text editor to create the following script and save it as ~/staging/etc/init.d/usr_image
#!/bin/sh
#
# usr_image - load compressed images from floppy into ramdisk and
# mount on /usr.
#
echo -n "Is there a compressed diskette to load for /usr [y/N]? "
read REPLY
if [ "$REPLY" = "y" ] || [ "$REPLY" = "Y" ]; then
echo -n "Please insert the /usr floppy into fd0 and press <ENTER>."
read REPLY
echo "Clearing /dev/ram1."
dd if=/dev/zero of=/dev/ram1 bs=1k count=4096
echo "Loading compressed image from /dev/fd0 into /dev/ram1..."
(dd if=/dev/fd0 bs=1k | gunzip -cq) >/dev/ram1 2>/dev/null
fsck -fp /dev/ram1
if [ $? -gt 1 ]; then
echo "Filesystem errors on /dev/ram1! Manual intervention required."
else
echo "Mounting /usr."
mount /dev/ram1 /usr
fi
fi
#
# end of usr_image |
Configure the script to run right after root is mounted.
bash# ln -s ../init.d/usr_image ~/staging/etc/rcS.d/S21usr_image |
A.3.2.4. Create a compressed root disk
bash# cd / bash# dd if=/dev/zero of=/dev/ram7 bs=1k count=4096 bash# mke2fs -m0 /dev/ram7 bash# mount /dev/ram7 /mnt bash# cp -dpR ~/staging/* /mnt bash# umount /dev/ram7 bash# dd if=/dev/ram7 of=~/phase8-image bs=1k bash# gzip -9 ~/phase8-image |
Insert the diskette labeled "root disk" into drive fd0.
bash# dd if=~/phase8-image.gz of=/dev/fd0 bs=1k |
A.3.3. Create a compressed /usr disk for mp3blaster
The compressed /usr diskette will be created in using the same process that is used to create the compressed root disk. We will copy files to a staging area, copy the staging area to ramdisk, compress the ramdisk and write it to diskette.
A.3.3.1. Create a staging area
bash# mkdir ~/usr-staging bash# cd ~/usr-staging bash# mkdir bin lib bash# mkdir -p share/terminfo/l |
A.3.3.2. Install the mp3blaster program
Download the latest version of mp3blaster source code from its home at http://www.stack.nl/~brama/mp3blaster/.
bash# cd ~/usr/src/mp3blaster-3.2.0 bash# ./configure bash# make bash# cp src/mp3blaster ~/usr-staging/bin |
A.3.3.3. Copy additional libraries and terminfo
Use ldd to find out which libraries are needed for mp3blaster.
 | The following is an example from the author's development system. It is possible that different systems may yield slightly different results in terms of library requirements. |
bash# cd ~/usr-staging/lib bash# ldd ~/usr-staging/bin/mp3blaster bash# cp /usr/lib/ncurses.so.5.0 . bash# cp /usr/lib/stdc++.so.3 . bash# cp /lib/libm.so.6 . bash# cp /usr/lib/libgcc_s.so.1 . bash# cd ~/usr-staging/share/terminfo/l bash# cp /usr/share/terminfo/l/linux . |
A.3.3.4. Make a compressed image and copy it to diskette
bash# cd / bash# dd if=/dev/zero of=/dev/ram7 bs=1k count=4096 bash# mke2fs -m0 /dev/ram7 bash# mount /dev/ram7 /mnt bash# cp -dpR ~/usr-staging/* /mnt bash# umount /dev/ram7 bash# dd if=/dev/ram7 of=~/mp3blaster-image bs=1k bash# gzip -9 ~/mp3blaster-image |
Insert the diskette labeled "mp3blaster" into drive fd0.
bash# dd if=~/mp3blaster-image.gz of=/dev/fd0 bs=1k |
A.3.4. Create a data diskette for testing
Go to the Internet site http://www.paul.sladen.org and download the mp3 file of Linus Torvalds pronouncing "Linux." The direct link is: http://www.paul.sladen.org/pronunciation/torvalds-says-linux.mp3. Create a Second Extended (ext2) filesystem on a floppy and copy the mp3 file onto the diskette.