2.2.20 ramdisk(initrd) not found by kernel

2.2.20 ramdisk(initrd) not found by kernel

[Andrew]

I have a problem that I have been wrestling with now for a number of days
with no solution, and I'm hoping someone can help.

My problem is that when the 2.2.20 kernel loads, lilo doesn't seem to load
the rootfs.img into RAM or it gets dropped before the kernel finds it. That
is I don't get the
kernel message 'RAMDISK found at block 0' message and thus Linux panics with
something like "root file system not found on dev 1:0".

I have a stock 2.2.20 kernel with ramdisk and initrd support compiled in.
RAMdisk size is 64MB although I've also tried 32MB and 128MB.
I have tried kernel builds with module support and without (everything
compiled in)
I'm using the latest lilo I can find with the following config:

boot=/dev/hdc
disk=/dev/hdc
 bios=0x80
map=/map
install=/boot.b
backup=/boot.1600
prompt
linear
timeout=50
password=maintenance
restricted
image=/vmlinuz-2.2.20up
        label=test
        ramdisk=65536
        initrd=/rootfs.img
        root=/dev/ram

The server is a uni processor PIII server with 512MB of RAM

The sizes of my rootfs.img and kernel are:
 8713856 Aug  7 12:55 rootfs.img (this is an ext2 compressed image)
 787022 Aug  7 12:17 vmlinuz-2.2.20up (this is a monolithic bzImage kernel)

Lilo when building doesn't report any errors in fact it says it successfully
maps the RAMdisk ok

It almost seems like there is some finite size or block limit that my
rootfs.img+kernel is greater than, that stops the
RAMdisk being loaded or being found if it is infact being loaded at all.

Is there a finite limit on the size initrd can be? Enlarging the ramdisk
size or altering the block size of the image doesn't seem to make any
difference.

Any help much appreciated.

Andrew.
ps. Can you please reply to me directly, thanks.

Re: 2.2.20 ramdisk(initrd) not found by kernel

[Andrew Hall]

This infact seems to be correct. After investigation it turns out that it is
lilo that baulks at anything bigger than 16MB of initrd (after
decompression). I have confirmed this using 2.2.20, 2.2.21, 2.4.7 and a few
printks to see if these images are actually getting the start_initrd value
passed. Anything bigger than 16MB and lilo will either:

a. Seem to complete the load but not pass the ramdisk_start value to the
kernel
or
b. Cold hang during the copy of the compressed image into memory

I've had a bit of a look at the lilo source but the assembly stuff is
meaningless to me. Can anyone please tell me if this is the intended
function of lilo (to be limited to a 16MB initrd?) or point me in the right
direction as to where I might start looking for this bug in the lilo source.
>From what Mike says, below it would seem that this problem is not specific
to Lilo, but effects Loadlin aswell. I will try grub next.

Thanks,

Andrew.
----- Original Message -----
From: "Mike Galbraith" <EFAULT@gmx.de>
To: "Andrew" <temp01@bluereef.com.au>
Sent: Friday, August 09, 2002 10:45 PM
Subject: Re: 2.2.20 ramdisk(initrd) not found by kernel


> Andrew wrote:
>
> >I have a problem that I have been wrestling with now for a number of days
> >with no solution, and I'm hoping someone can help.
> >
> >My problem is that when the 2.2.20 kernel loads, lilo doesn't seem to
load
> >the rootfs.img into RAM or it gets dropped before the kernel finds it.
That
> >is I don't get the
> >kernel message 'RAMDISK found at block 0' message and thus Linux panics
with
> >something like "root file system not found on dev 1:0".
> >
> >I have a stock 2.2.20 kernel with ramdisk and initrd support compiled in.
> >RAMdisk size is 64MB although I've also tried 32MB and 128MB.
> >I have tried kernel builds with module support and without (everything
> >compiled in)
> >I'm using the latest lilo I can find with the following config:
> >
> >boot=/dev/hdc
> >disk=/dev/hdc
> > bios=0x80
> >map=/map
> >install=/boot.b
> >backup=/boot.1600
> >prompt
> >linear
> >timeout=50
> >password=maintenance
> >restricted
> >image=/vmlinuz-2.2.20up
> >        label=test
> >        ramdisk=65536
> >        initrd=/rootfs.img
> >        root=/dev/ram
> >
> >The server is a uni processor PIII server with 512MB of RAM
> >
> >The sizes of my rootfs.img and kernel are:
> > 8713856 Aug  7 12:55 rootfs.img (this is an ext2 compressed image)
> > 787022 Aug  7 12:17 vmlinuz-2.2.20up (this is a monolithic bzImage
kernel)
> >
> >Lilo when building doesn't report any errors in fact it says it
successfully
> >maps the RAMdisk ok
> >
> >It almost seems like there is some finite size or block limit that my
> >rootfs.img+kernel is greater than, that stops the
> >RAMdisk being loaded or being found if it is infact being loaded at all.
> >
> >Is there a finite limit on the size initrd can be? Enlarging the ramdisk
> >size or altering the block size of the image doesn't seem to make any
> >difference.
> >
>
> 16MB was the largest I could ever load.  (but that could have been a
> loadlin limitation)
>
>     -Mike
>
>
>
>