[U-Boot-Users] Newbie needs help with RAMDISK

[U-Boot-Users] Newbie needs help with RAMDISK

[Luke Fimmerzane]

Hi,
I'm new to u-boot and would like to mount my rootfile system on a RAM disk. 
Its an arm 9 target.
I'm using a book from KARIM YAGHMOUR called Building Embedded Linux systems 
as a reference guide to help with creating the RAM disk and understand the 
features of u-boot. (There's a really good section on u-boot in this book).
I've managed to create the ramdisk, download it to my target but when I boot 
I get this message (only relevant sections included):

Kernel command line: root=/dev/ram
......
......
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
......
.....
cramfs: wrong magic
FAT: bogus logical sector size 65535
Kernel panic: VFS: Unable to mount root fs on 01:00

AAgh!!! Where could I have gone wrong!!
I know this is a voluntary site but if someone could give me some give me a 
few hints then thanks.


Luke F

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[U-Boot-Users] Newbie needs help with RAMDISK

[Wolfgang Denk]

Dear Luke,

in message <BAY10-F113QOTQWKySS0001f3e9@hotmail.com> you wrote:
>
> I've managed to create the ramdisk, download it to my target but when I boot 
> I get this message (only relevant sections included):
> 
> Kernel command line: root=/dev/ram

Actually this is a Linux problem.  Strictly  speaking,  this  is  off
topic on the U-Boot list.

> ......
> RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
> ......
> .....
> cramfs: wrong magic
> FAT: bogus logical sector size 65535
> Kernel panic: VFS: Unable to mount root fs on 01:00
> 
> AAgh!!! Where could I have gone wrong!!

One of your mistakes is not providing enough  information.  It  would
have  been  VERY useful to see the COMPLETE log of the boot messages.
So we can only speculate. Do you have ext2 support  enabled  in  your
kernel configuration?

> I know this is a voluntary site but if someone could give me some give me a 
> few hints then thanks.

This is what these lists are for.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
"They that can give up essential liberty to obtain a little temporary
saftey deserve neither liberty not saftey." - Benjamin Franklin, 1759

[U-Boot-Users] Newbie needs help with RAMDISK

[Luke Fimmerzane]

Sorry for the wrong posting. Because I was slavely following the set-up in 
the book I referred to in my earlier email for configuring u-boot and 
running the root file system from RAM disk, I thought someone else might 
also have followed the same path and might have indicated whether it worked 
for them or not.

The info in the book suggested that as long as you did a
bootm <kernel address> <RAM disk address> it should work. I've also read 
this in the README but I think its only in the context of PPC.  I do have 
ext2 configured in my kernel but maybe I need other options also enabled. 
(What kind of message should I get if its not enabled)
Also what kernel command line should I use? Is root =/dev/ram correct? Do I 
have to set-up a u-boot envionment variable for a RAM disk?

I don't have access to the hardware for the next few days so can't send the 
full error message list you mentioned. But I want to prepare as much as 
possible.

Thanks again,
Luke

I know I am present at the alter of the gods of booting and linux and I 
apologise if my requests fall short...... :(






>From: Wolfgang Denk <wd@denx.de>
>To: "Luke Fimmerzane" <lukefimmerzane@hotmail.com>
>CC: u-boot-users at lists.sourceforge.net
>Subject: Re: [U-Boot-Users] Newbie needs help with RAMDISK Date: Wed, 10 
>Mar 2004 19:02:42 +0100
>
>Dear Luke,
>
>in message <BAY10-F113QOTQWKySS0001f3e9@hotmail.com> you wrote:
> >
> > I've managed to create the ramdisk, download it to my target but when I 
>boot
> > I get this message (only relevant sections included):
> >
> > Kernel command line: root=/dev/ram
>
>Actually this is a Linux problem.  Strictly  speaking,  this  is  off
>topic on the U-Boot list.
>
> > ......
> > RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
> > ......
> > .....
> > cramfs: wrong magic
> > FAT: bogus logical sector size 65535
> > Kernel panic: VFS: Unable to mount root fs on 01:00
> >
> > AAgh!!! Where could I have gone wrong!!
>
>One of your mistakes is not providing enough  information.  It  would
>have  been  VERY useful to see the COMPLETE log of the boot messages.
>So we can only speculate. Do you have ext2 support  enabled  in  your
>kernel configuration?
>
> > I know this is a voluntary site but if someone could give me some give 
>me a
> > few hints then thanks.
>
>This is what these lists are for.
>
>Best regards,
>
>Wolfgang Denk
>
>--
>Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
>Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
>"They that can give up essential liberty to obtain a little temporary
>saftey deserve neither liberty not saftey." - Benjamin Franklin, 1759

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[U-Boot-Users] Newbie needs help with RAMDISK

[Wolfgang Denk]

In message <BAY10-F7NuQuN6tdqVv0001a88a@hotmail.com> you wrote:
>
> The info in the book suggested that as long as you did a
> bootm <kernel address> <RAM disk address> it should work. I've also read 
> this in the README but I think its only in the context of PPC.  I do have 

This syntax is correct for all working ports of U-Boot.

> ext2 configured in my kernel but maybe I need other options also enabled. 
> (What kind of message should I get if its not enabled)
> Also what kernel command line should I use? Is root =/dev/ram correct? Do I 

No, the space between "rot" and "=" is wrong ;-)

> have to set-up a u-boot envionment variable for a RAM disk?

Yes, at least you must define a valit "bootargs".

> I know I am present at the alter of the gods of booting and linux and I 
> apologise if my requests fall short...... :(

:-)

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
"Probably the best operating system in the world  is  the  [operating
system] made for the PDP-11 by Bell Laboratories."
                                           - Ted Nelson, October 1977