[pocket-linux] Chapter 3 Question/Problem

[James Maki]

First, thanks for the reply and ideas. More comments below.

> -----Original Message-----
>
>
> James Maki wrote:
> > I have been going through the Pocket Linux as a means to learn
> > more about Linux. I am a Linux newbie, but have been using
> > computers for 20 years.
>
> Just out of curiosity, what was your first computer?

An Atari 800 with 48k of memory and a single 88 K 5-1/4" floppy. Followed
with a Kaypro IV, Atari 520ST, Sharp 8086 based laptop, and my first desktop
clone, a Gateway 386/20.

> > I
> > was able to get the boot disk/root disk from chapter 2 to work as
> > advertised. I am using the GRUB loader rather than LILO. I am
> > creating the boot disks on a Fedora Core 1 system.
> >
> > After creating the root disk several times, I automated with a
> > BASH script.
> > Creating the Chapter 2 root disk with the following script
> > gives me a system that works as is should according to
> > Chapter 2:
> >
> > # SCRIPT ch2_bash.sh
> > dd if=/dev/zero of=/dev/fd0 bs=1k count=1440
> > mke2fs -m0 /dev/fd0
> > mount /dev/fd0 /mnt
> > cd /usr/src/bash-2.05a
> > export CC="gcc -mcpu=i386"
> > ./configure --enable-static-link --enable-minimal-config
> --host=i386-pc-linu
> > x-gnu
> > make
> > strip bash
> > mkdir /mnt/bin
> > cp bash /mnt/bin/bash
> > ln -s bash /mnt/bin/sh
> > mkdir /mnt/dev
> > mknod /mnt/dev/console c 5 1
> > cd /
> > umount /mnt
> > echo "Script is DONE"
> > # End of ch2_bash.sh
> >
> > When I go onto Chapter 3 to create the compressed root disk, I use the
> > following BASH script:
> >
> > # SCRIPT ch3_bash.sh
> > dd if=/dev/zero of=/dev/ram7 bs=1k count=4096
> > mke2fs -m0 /dev/ram7 4096
> > mount /dev/ram7 /mnt
> > cd /usr/src/bash-2.05a
> > make distclean
> > export CC="gcc -mcpu=i386"
> > ./configure --enable-minimal-config --host=i386-pc-linux-gnu
> > make
> > strip 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)
> > #
> > mkdir /mnt/bin
> > cp bash /mnt/bin
> > ln -s bash /mnt/bin/sh
> > mkdir /mnt/lib
> > strip --strip-unneeded -o /mnt/lib/libdl.so.2 /lib/libdl.so.2
> > strip --strip-unneeded -o /mnt/lib/libc.so.6 /lib/libc.so.6
> > strip --strip-unneeded -o /mnt/lib/ld-linux.so.2 /lib/ld-linux.so.2
> > chmod +x /mnt/lib/*
> > mkdir /mnt/dev
> > mknod /mnt/dev/console c 5 1
> > cd /
> > umount /dev/ram7
> > dd if=/dev/ram7 of=~/phase2-image bs=1k
> > gzip -9 ~/phase2-image
> > ls -l
> > dd if=~/phase2-image.gz of=/dev/fd0 bs=1k
> > echo " "
> > echo "Script is DONE"
> > echo " "
> > # End of script ch3_bash.sh
> >
>
> Good idea using scripts.  It saves time and typographical errors.
>
> > The only discrepancy I see is that the ldd bash output gives
> > the following:
> > libc.so.6 => /lib/tls/libc.so.6
> >   RATHER THAN
> > libc.so.6=> /lilb/libc.so.6
> >
>
> As far as I can tell this /lib/tls thing does not create a problem.  I
> have used Redhat 9.0 to build the pocket linux guide without any
> problems.  RH9 has the /lib/tls as well.
>
> My understanding is that 'libc.so.6' is what the bash binary is actually
> looking for, not the full path.  Bash tells ld-linux.so.2, "Hey, I need
> libc.so.6" and it's up to ld-linux to figure out what file it is and
> what the path is.  ld-linux looks in /lib and /usr/lib by default.
>
> So, in short, I don't think that is where the problem lies.
>
> > When I use this Chapter 3 created boot disk, I get the
> > following error after GRUB runs -
> > kernel panic : VFS : unable to mount root fs on 02:00
> >
> > If I try to mount the floppy with : mount /dev/fd0, I get the
> > error message:
> > mount: you must specify the filesystem type.
> >
>
> I'm not a GRUB expert, but his error makes me think that your kernel
> might not have support for ramdisk or that the kernel option to load fd0
> into ramdisk is not being specified correctly in the grub config file.
> Try downloading and using the LILO bootdisk just to see if the problem
> is with the root disk or the boot disk.

I downloaded the disk files from the website and copied the
ch2-bootdisk.image to a floppy. The boot disk with LILO and the chapter 3
root disk I created seemed to work fine. So it is either a problem with the
kernel I compiled or the GRUB loader. More work!

> > If I try to mount the floppy from chapter 2, it works.
> >
> > The phase2-image.gz file is 758.9k on the hard drive
> > Looking "inside" the gzipped file gives an image file of 8.0 MB.
> >
>
> Are you sure the 8.0 is in Meg or is it in blocks?  Some commands give
> sizes in 512b blocks rather than kilobytes.  Just a thought.

ls- l for the gzipped and uncompressed files gives the following:

total 8968
-rw-r--r--    1 root     root      8388608 Feb 25 15:52 phase2-image
-rw-r--r--    1 root     root       778002 Feb 25 15:12 phase2-image.gz

Looks like approximately 8.0 M.

> > I do not understand all of the inner workings of all of the
> > commands. Any hints or ideas as to the problem would be appreciated.
> > So far, this has been a great learning experience.
> >
> > TIA
> >
> > Jim Maki
> > jwmaki at att.net
> >
> >
>
> Glad to hear you are learning and enjoying.  Good luck tracking down the
> errors.
>
> Dave

Thanks. Back to work.

Jim