Linux under 8MB

Linux under 8MB

[Imanpreet Arora]

Hi all,

              For the last couple of days, I have been trying to set
up linux kernel under 8MB. So far I have set up a linux 2.4.31, which
just works under 8MB. However, I would be grateful if someone could
help with the following queries

a)          Is linux2.4 just the right option? What about linux 2.0.x?
Or for that matter even <2.0
b)          What are the specific issues that are to be considered
while compiling an old kernel on a newer setup? I ask this because I
compiled my current setup on a 2.6.11 machine and while doing "make
modules_install", I got errors from depmod[%], complaining about
depmod.old.  I had to kludge my way through by setting up a link from
depmod.old to depmod.



[%] Not to mention that on a FC4 machine, gcc 4,x meowed  while
compiling the kernel.


TIA,
-- 
Imanpreet Singh Arora
                  If I am given six hours to chop a tree, I will spend
the first four sharpening the knife.
                         -- A.L.

Re: Linux under 8MB

[Adrian Bunk]

On Fri, Aug 19, 2005 at 03:41:30AM +0530, Imanpreet Arora wrote:
> Hi all,
> 
>               For the last couple of days, I have been trying to set
> up linux kernel under 8MB. So far I have set up a linux 2.4.31, which
> just works under 8MB. However, I would be grateful if someone could
> help with the following queries
> 
> a)          Is linux2.4 just the right option? What about linux 2.0.x?
> Or for that matter even <2.0

The more interesting case would ne a recent 2.6 kernel with

  General setup
    Configure standard kernel features (for small systems)

enabled and appropriate options below this option selected.

> b)          What are the specific issues that are to be considered
> while compiling an old kernel on a newer setup? I ask this because I
> compiled my current setup on a 2.6.11 machine and while doing "make
> modules_install", I got errors from depmod[%], complaining about
> depmod.old.  I had to kludge my way through by setting up a link from
> depmod.old to depmod.

What userspace do you want to use on the 8MB machine?
You need a userspace that supports such an old kernel.

> [%] Not to mention that on a FC4 machine, gcc 4,x meowed  while
> compiling the kernel.

gcc 4.0 is not a working compiler for _any_ kernel below 2.6.12.

> TIA,

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: Linux under 8MB

[Pedro Venda (SYSADM)]

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On Thursday 18 August 2005 22:11, Imanpreet Arora wrote:
> Hi all,
>
>               For the last couple of days, I have been trying to set
> up linux kernel under 8MB. So far I have set up a linux 2.4.31, which
> just works under 8MB. However, I would be grateful if someone could
> help with the following queries

hi,

what do you mean 8MB? RAM or storage space? what do you intend to acomplish 
with such project?

I've been working on something simillar. I've been able to create a micro 
distro which runs from a floppy disk (kernel+initrd.gz+bootloader<=1.44MB) 
and boots well with as low as 5MB of RAM (tested with qemu). The kernel I've 
used was 2.6.9, but 2.6.12 should work as well.

> a)          Is linux2.4 just the right option? What about linux 2.0.x?
> Or for that matter even <2.0

2.6 has serious advantage over others when considering embedded environments 
(not sure if it applies to you)

> b)          What are the specific issues that are to be considered
> while compiling an old kernel on a newer setup? I ask this because I
> compiled my current setup on a 2.6.11 machine and while doing "make
> modules_install", I got errors from depmod[%], complaining about
> depmod.old.  I had to kludge my way through by setting up a link from
> depmod.old to depmod.

I did use uClibc and busybox (crosso compiled and linked to uClibc) to keep 
the distro as small as possible. (see buildroot from the maker of uClibc and 
busybox)

regards,
-- 

Pedro João Lopes Venda
email: pjvenda < at > rnl.ist.utl.pt
http://arrakis.dhis.org

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Re: Linux under 8MB

[Ondrej Zary]

I've made a printserver with i386DX/25, 8MB RAM and 170MB HDD. Kernel is 
2.6.12 (very light - 1.2MB uncompressed), userspace is based on 
Slackware 9.0 (init scripts modified), print server is CUPS. It boots in 
about a minute. It ran with 4MB too but the boot time was around 15 
minutes :-) (with original init scripts).

root@printserver:~# uname -a
Linux printserver 2.6.12-printserver #6 Fri Jul 1 23:40:17 CEST 2005 
i386 unknown
root@printserver:~# cat /proc/cpuinfo
processor       : 0
vendor_id       : unknown
cpu family      : 3
model           : 0
model name      : 386
stepping        : unknown
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : no
fpu_exception   : no
cpuid level     : -1
wp              : no
flags           :
bogomips        : 4.28

root@printserver:~# free
              total       used       free     shared    buffers     cached
Mem:          6752       6196        556          0        528       3980
-/+ buffers/cache:       1688       5064
Swap:        32000          0      32000

-- 
Ondrej Zary

Re: Linux under 8MB

[Eric Piel]

19.08.2005 00:11, Imanpreet Arora wrote/a écrit:
> Hi all,
> 
>               For the last couple of days, I have been trying to set
> up linux kernel under 8MB. So far I have set up a linux 2.4.31, which
> just works under 8MB. However, I would be grateful if someone could
> help with the following queries
> 
> a)          Is linux2.4 just the right option? What about linux 2.0.x?
> Or for that matter even <2.0
> b)          What are the specific issues that are to be considered
> while compiling an old kernel on a newer setup? I ask this because I
> compiled my current setup on a 2.6.11 machine and while doing "make
> modules_install", I got errors from depmod[%], complaining about
> depmod.old.  I had to kludge my way through by setting up a link from
> depmod.old to depmod.
> 

Last year, at the Realtime linux workshop, there was a paper about 
running Linux on a machine with 2Mb of RAM + 2Mb of Flash. They even 
manage to boot in 1 second! Nevertheless, they had to do several 
modifications to achieve this. Maybe with the new options in the 2.6 
kernel, it would be easier...

Check it here:
http://www.realtimelinuxfoundation.org/events/rtlws-2004/papers.html#PAPER_5795


Regards,
Eric

Re: Linux under 8MB

[Eric W. Biederman]

Imanpreet Arora <imanpreet@gmail.com> writes:

> Hi all,
>
>               For the last couple of days, I have been trying to set
> up linux kernel under 8MB. So far I have set up a linux 2.4.31, which
> just works under 8MB. However, I would be grateful if someone could
> help with the following queries
>
> a)          Is linux2.4 just the right option? What about linux 2.0.x?
> Or for that matter even <2.0

2.4 is the worst choice.  You want either 2.6 + patches from
the linux-tiny project or you want a noticably older kernel.
The 2.6 option as it is works with what is being developed should
be the more maintainable option.

Eric