Very Computer

I haven't been able to find any documentation that makes sense
on what exactly zImage, vmlinux & vmlinuz are. I know when I
compile a new kernel, zImage is created in
        /usr/src/linux/arch/ie86/boot
I've been moving this file to /vmlinuz, and marking it as an
executable.  I then run /etc/lilo/install to mark it bootable.
This works, but I wonder if it is right, and what exactly the
three files are. The vmlinux exists in /usr/src/linux.

In one piece of documentation I read, it states that the
zImage is dropped into /usr/src/linux as well, though as
stated above, this is not the case in my system.

If someone could explain this, or point me to a current doc
that explains this well, I'd be very grateful.

--

    Ed Learned                              |  Information

    http://www.winternet.com/~learned       |  Worker

I think the Kernel-HOWTO covers this, more or less.  When you see a z,
that is supposed to be code to make you think "compressed."  So zImage
is where your freshly compiled and compressed kernel may end up being
put (depending on the makefile I guess).

vmlinuz is a popular choice of name for your compressed kernel, but
you can use any name, as long as you set up lilo.conf appropriately,
and it can be in any directory with the same proviso.

So when I recompile the kernel, (after backing up my old one) I move
zImage to vmlinuz in the directory "/".

vmlinux is (I believe) the uncompressed kernel.  (Hence the popular
name for the compressed kernel, which involves changing the last
letter of vmlinux to a z.)  It is not normally used, and you _should_
be able to delete it to save on disk space if you feel like it.
Instead lilo expects a compressed kernel, which it uncompresses.

No doubt someone will correct me if I've made a mistake or been
imprecise.

        Hal

Hello Ed!

Thursday June 29 1995 20:56, Ed Learned wrote to All:

 EL> I haven't been able to find any documentation that makes sense
 EL> on what exactly zImage, vmlinux & vmlinuz are.

As I understand it, it's just a naming convention - they're all the same file.
I suspect that vmlinux is an unpacked vmlinuz and isn't used anymore, as the
unpacked version hasn't fit in memory for some time (just a guess).

 EL> I know when I
 EL> compile a new kernel, zImage is created in
 EL>     /usr/src/linux/arch/ie86/boot
 EL> I've been moving this file to /vmlinuz, and marking it as an
 EL> executable.  I then run /etc/lilo/install to mark it bootable.
 EL> This works, but I wonder if it is right, and what exactly the
 EL> three files are. The vmlinux exists in /usr/src/linux.

I just run 'lilo' from the command line after installing the kernel and it
works fine. Also, there is apparantly no need to flag it executable. On my
system i have /vmlinuz set with the protection bits -r--------. As for where
the kernel is reproduced has changed over time, I suspect, as the kernel
developement procedures have matured.

 EL> In one piece of documentation I read, it states that the
 EL> zImage is dropped into /usr/src/linux as well, though as
 EL> stated above, this is not the case in my system.

 EL> If someone could explain this, or point me to a current doc
 EL> that explains this well, I'd be very grateful.

In the README file in the kernel source directory, it is explained what happens
and what is produced and where. Other than that, I might suggest the LDP doc
about kernel hacking. I can't say anything about the contents, as I haven't
read it myself (lack of interest for the moment...).

             -------------------------------------------------
            | Physical:     Michael Olofsson                  |


             -------------------------------------------------

: So when I recompile the kernel, (after backing up my old one) I move
: zImage to vmlinuz in the directory "/".

I heard make zlilo do te same job. Copy zImage to / and run lilo. But....

Last week I installed Linux 1.2.1 for my friend. Afer recompiled the kernel
sucessfully, I make zlilo and I saw it went through every directory and did
something I didn't understand. The new compressed kernel is slightly large
than zImage and it doesn't boot.

My question is the new zlilo does more than
1. cp zImage to /
2. run lilo ?

Quote:>My question is the new zlilo does more than
>1. cp zImage to /
>2. run lilo ?

Hmm... I never bother with zlilo, personally.  I just do:
 1) make zImage
 2) cp arch/i386/boot/zImage /vmlinuz
 3) lilo

The third just uses the old lilo configuration, and tells lilo where to look
for the new kernel.  Good luck.
-- Glenn

Quote:>Hmm... I never bother with zlilo, personally.  I just do:
> 1) make zImage

1.5) mv /vmlinuz /vmlinuz.old

Quote:> 2) cp arch/i386/boot/zImage /vmlinuz
> 3) lilo

You left out 1.5. ;-) An extra entry in lilo.conf for vmlinuz.old is
required, of course.

--
      Artificial Intelligence stands no chance against Natural Stupidity.
                GAT d- -p+(--) c++++ l++ u++ t- m--- W--- !v
                     b+++ e* s-/+ n-(?) h++ f+g+ w+++ y*

Hello Ta!

Sunday July 02 1995 15:32, Ta Cheng Lin wrote to All:

 TCL> : So when I recompile the kernel, (after backing up my old one) I move
 TCL> : zImage to vmlinuz in the directory "/".

 TCL> I heard make zlilo do te same job. Copy zImage to / and run lilo. But....

 TCL> Last week I installed Linux 1.2.1 for my friend. Afer recompiled the
 TCL> kernel sucessfully, I make zlilo and I saw it went through every
 TCL> directory and did something I didn't understand. The new compressed
 TCL> kernel is slightly large than zImage and it doesn't boot.

 TCL> My question is the new zlilo does more than
 TCL> 1. cp zImage to /
 TCL> 2. run lilo ?

Check your /etc/lilo.config (or whatever it's called - unsure) and check that
the file name is correct. The default name that Slackware uses is /vmlinuz.

Greets, Mike.

             -------------------------------------------------
            | Physical:     Michael Olofsson                  |


             -------------------------------------------------

: I haven't been able to find any documentation that makes sense
: on what exactly zImage, vmlinux & vmlinuz are. I know when I
: compile a new kernel, zImage is created in
:       /usr/src/linux/arch/ie86/boot
: I've been moving this file to /vmlinuz, and marking it as an
: executable.  I then run /etc/lilo/install to mark it bootable.
: This works, but I wonder if it is right, and what exactly the
: three files are. The vmlinux exists in /usr/src/linux.

: In one piece of documentation I read, it states that the
: zImage is dropped into /usr/src/linux as well, though as
: stated above, this is not the case in my system.

: If someone could explain this, or point me to a current doc
: that explains this well, I'd be very grateful.

Well, here is a fast explanation:
vmlinuz is usually the actual kernel image that boots your system.
This has been specified by LILO (you can have a look at your
/etc/lilo.conf ) and you can change it. However I don't think
many people change it....
vmlinux is the new kernel built when you compile a new kernel. It is
common to copy this file on vmlinuz (cp vmlinux vmlinuz) and run
lilo so the new kernel is running after you reboot.
zImage is a compressed form of vmlinux. You can copy this file
on vmlinuz if you need a compressed kernel to boot with. This is
required when the "vmlinux" kernel is bigger than 512 kbytes,
because LILO cannot handle it if it is. In such cases you *must*
use zImage. For example my vmlinux is much bigger than 512 kbytes,
because I have a complicated (at least I think it is complicated :-)  )
system with a lot of networking, routing etc.on it. So I had to copy
the "zImage" to "vmlinuz".

For more info you could have a look at the HOWTO files.
Hope this helps..
Ciao, Panos