I installed Gentoo on my USB drive. Except that I replaced hda with sda, I did the installation as written in the Handbook. Grub starts and I can select the kernel to boot. During boot it hangs with the following lines:
VFS: Cannot open root device "sda3" or unknown_block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: unable to mont fs on unknown_block(0,0)
<6>usb 1-3: new high speed USB drive using ehci_hcd and address2
It looks to me as boot gets in troubles when the kernel re-initializes the USB hardware while it is booting from it at the same time. Am I correct and is there a way out of that?
I'm looking into initrd, but this seems for me to be a too big challenge.
[Solved] Boot from USB
Message
[Solved] Boot from USB
Last edited by lindegur on Mon May 09, 2005 7:05 pm, edited 5 times in total.
I managed to go one step further. I built a custom initrd and a new 2.6 kernel with initrd support and loopback device. As guide I took usr/src/linux/documentation/initrd.txt
It seems to run so far, but my init option gets lost:
Kernel panic - not syncing: No init found. Try passing init=option to kernel
I can plug in and out my usbhd and the system is alive and reports it. Without passing an init option that the kernel accepts, I can not write and debug the linuxrc script that sould finally bring back the usbhd as root device.
What are the necessary files to pack in the initrd?
It seems to run so far, but my init option gets lost:
Kernel panic - not syncing: No init found. Try passing init=option to kernel
I can plug in and out my usbhd and the system is alive and reports it. Without passing an init option that the kernel accepts, I can not write and debug the linuxrc script that sould finally bring back the usbhd as root device.
What are the necessary files to pack in the initrd?
Last edited by lindegur on Sat May 07, 2005 5:19 pm, edited 1 time in total.
Here's something related: http://forums.gentoo.org/viewtopic-t-32 ... t+usb.html
Maybe it will give you some pointers to solving your problem.
Maybe it will give you some pointers to solving your problem.
Please add [solved] to the initial post's subject line if you feel your problem is resolved. Help answer the unanswered
talk is cheap. supply exceeds demand
talk is cheap. supply exceeds demand
an other step forward, no kernel panics anymore. My major problem was, that I did not copy all libraries to the initrd. A chroot initrd would have shown this without boot. ldd shows what would have been required. Exept linux-gate.so that seems to be a so ghost on my computer.
I did two versions of Grub options, one that brings me into a shell where I can interactively work, the other version starts linuxrc that contains currently just some kind of hello world program.
The remaining work is now to pass the root back from the ramdisk to the usbhd using pivot_root and regularly start /sbin/init.
If everything works, I will clean up my personal notes and write a simple howto in n00b language. I also have to maintain my custom initrd and linuxrc.
Cool it works! I'm able to boot from the USB Harddisk. Ready to install KDE and all the fun stuff!initrd got all the files necessary including the devices in /dev (as sda1,sda2,sda3).
In the linuxrc script, I added some sleep commands to give the kernel some time to find the usbhd and to mount it, before the linuxrc script goes too many some steps ahead (not very clean synchronizing, but simple).
Now I have a USB-Gentoo-HardDisc that I can stick to lots of IBM-PC able to boot from USB (including my company laptop with its strange behaving operating system).
- Kokkor_Hekkus
- n00b
- Posts: 14
- Joined: Tue Feb 03, 2004 7:41 am
- Location: Lucerne (CH)
Major update to this post Jun 5. 2005.
In meantime I'm satisfyed with my installation: I installed Xorg, KDE, dri, Openoffice, NTFS watch out about not writing to it! Everything works well and I have no reason to modify it.
I do currently some experiments with a memory stick. My main motivation is to learn.
Ok. here what I have so far:
The following things are necessary:
1.) in the Grub.conf I have:
title=Gentoo Linux 2.6.11-r9-21may05 linuxrc rw
root (hd0,0)
kernel /kernel-2.6.11-gentoo-r9-21may05 root=/dev/ram0 init=/linuxrc rw
initrd /boot/initrd.gz
2.) I created /root/USBHD with the following contents:
bash-2.05b# ls -R
.:
bin dev etc lib linuxrc new-root proc sbin
./bin:
bash chroot echo mount sh sleep
./dev:
./etc:
fstab
./lib:
ld-2.3.4.so libblkid.so.1 libc-2.3.4.so libdl-2.3.4.so libm-2.3.4.so libpthread-2.3.4.so librt-2.3.4.so libuuid.so.1
ld-linux.so.2 libblkid.so.1.0 libc.so.6 libdl.so.2 libm.so.6 libpthread.so.0 librt.so.1 libuuid.so.1.2
./new-root:
./proc:
./sbin:
pivot_root
3.) in root I have the following script that converts the directory above into a initrd.gz
#!/bin/sh
echo "Creation of initrd to boot from USB HD"
#Urs Lindegger 3.6.5"
#dd creates a initrd file in current directory of bs size filled with zeros
dd if=/dev/zero of=initrd bs=3000k count=1
#format it as file system
mke2fs -F -m0 initrd
#mount file as device
mount -t ext2 -o loop initrd /mnt/initrd
echo "sleep for 5 seconds to give mount time to mount"
sleep 5
mkdir /mnt/initrd/dev
# cd /dev
# ls -t shows major and minor numbers c or b
mknod /mnt/initrd/dev/console c 5 1
mknod /mnt/initrd/dev/sda1 b 8 1
mknod /mnt/initrd/dev/sda2 b 8 2
mknod /mnt/initrd/dev/sda3 b 8 3
cp -R /root/USBHD/* /mnt/initrd
#test if everything is there to run later linuxrc
#if not copy all missing so file ldd /mnt/initrd/linuxrc shows them
#echo "Test if linuxrc starts dont be afraid about error messages, since ramdisk does not exist during test press CR"
#read
#chroot /mnt/initrd /linuxrc
#echo "control contents of /mnt/initrd leave it and press key CR and wait until zip has finished"
#read
#sleep 5
umount /mnt/initrd
sleep 5
gzip -9 initrd
echo "initrd.gz can now be found."
4.) the linuxrc script in /root/USBHD is:
#!/bin/bash
echo "Linuxrc script"
#Give the kernel some time to find the USBHD
sleep 5
echo "Linuxrc: Mount USB drive"
mount -t ext3 -o ro /dev/sda3 /new-root
#Give the kernel some time to mount the USBHD
sleep 5
echo "Linuxrc: Go to new root"
cd /new-root
#actual root will be moved into the old-root directory, whereas new-root takes over the real root.
# /initrd directory in the new root file system must exist
echo "Linuxrc: Exchange old root with new root (pivot root)"
#pivot moves the actual root into /initrd and shifts up new-root into real root.
/sbin/pivot_root . initrd
echo "Linuxrc: Change to new root and start /sbin/init"
#possibility to call bin/sh or /sbin/init
# dev or /dev (absolute or relative path) this is the question
exec chroot . /sbin/init <dev/console >dev/console 2>&1
#exec chroot . /bin/sh <dev/console >dev/console 2>&1
#The following lines would unmount the initial RAM disk and free memory.
#Those lines can not be run from this file, since this file resides in the initial RAM disk
#Eiter run a script from the USB HD to clean it up or keep the initial RAM disk alive and do nothing.
#Due to the reasons above the following lines are just a hint how to unmount the inital RAM disk.
#sleep 5
#
#echo"Linuxrc: Unmount RAM disk"
#umount /initrd
#echo "Linuxrc: Free RAM reserved by RAM disk"
#/sbin/blockdev --flushbufs /dev/ram0
#echo "Linuxrc: End of linuxrc script"
5.) and finally a dummy /etc/fstab with the following contents:
# /etc/fstab: static file system information.
# it is just a dummy file to not cause a kernel warning
Create on your Usb Harddisk a directory /initrd, when every thing went well you will see inside the initial ramdisk.
In meantime I'm satisfyed with my installation: I installed Xorg, KDE, dri, Openoffice, NTFS watch out about not writing to it! Everything works well and I have no reason to modify it.
I do currently some experiments with a memory stick. My main motivation is to learn.
Ok. here what I have so far:
The following things are necessary:
1.) in the Grub.conf I have:
title=Gentoo Linux 2.6.11-r9-21may05 linuxrc rw
root (hd0,0)
kernel /kernel-2.6.11-gentoo-r9-21may05 root=/dev/ram0 init=/linuxrc rw
initrd /boot/initrd.gz
2.) I created /root/USBHD with the following contents:
bash-2.05b# ls -R
.:
bin dev etc lib linuxrc new-root proc sbin
./bin:
bash chroot echo mount sh sleep
./dev:
./etc:
fstab
./lib:
ld-2.3.4.so libblkid.so.1 libc-2.3.4.so libdl-2.3.4.so libm-2.3.4.so libpthread-2.3.4.so librt-2.3.4.so libuuid.so.1
ld-linux.so.2 libblkid.so.1.0 libc.so.6 libdl.so.2 libm.so.6 libpthread.so.0 librt.so.1 libuuid.so.1.2
./new-root:
./proc:
./sbin:
pivot_root
3.) in root I have the following script that converts the directory above into a initrd.gz
#!/bin/sh
echo "Creation of initrd to boot from USB HD"
#Urs Lindegger 3.6.5"
#dd creates a initrd file in current directory of bs size filled with zeros
dd if=/dev/zero of=initrd bs=3000k count=1
#format it as file system
mke2fs -F -m0 initrd
#mount file as device
mount -t ext2 -o loop initrd /mnt/initrd
echo "sleep for 5 seconds to give mount time to mount"
sleep 5
mkdir /mnt/initrd/dev
# cd /dev
# ls -t shows major and minor numbers c or b
mknod /mnt/initrd/dev/console c 5 1
mknod /mnt/initrd/dev/sda1 b 8 1
mknod /mnt/initrd/dev/sda2 b 8 2
mknod /mnt/initrd/dev/sda3 b 8 3
cp -R /root/USBHD/* /mnt/initrd
#test if everything is there to run later linuxrc
#if not copy all missing so file ldd /mnt/initrd/linuxrc shows them
#echo "Test if linuxrc starts dont be afraid about error messages, since ramdisk does not exist during test press CR"
#read
#chroot /mnt/initrd /linuxrc
#echo "control contents of /mnt/initrd leave it and press key CR and wait until zip has finished"
#read
#sleep 5
umount /mnt/initrd
sleep 5
gzip -9 initrd
echo "initrd.gz can now be found."
4.) the linuxrc script in /root/USBHD is:
#!/bin/bash
echo "Linuxrc script"
#Give the kernel some time to find the USBHD
sleep 5
echo "Linuxrc: Mount USB drive"
mount -t ext3 -o ro /dev/sda3 /new-root
#Give the kernel some time to mount the USBHD
sleep 5
echo "Linuxrc: Go to new root"
cd /new-root
#actual root will be moved into the old-root directory, whereas new-root takes over the real root.
# /initrd directory in the new root file system must exist
echo "Linuxrc: Exchange old root with new root (pivot root)"
#pivot moves the actual root into /initrd and shifts up new-root into real root.
/sbin/pivot_root . initrd
echo "Linuxrc: Change to new root and start /sbin/init"
#possibility to call bin/sh or /sbin/init
# dev or /dev (absolute or relative path) this is the question
exec chroot . /sbin/init <dev/console >dev/console 2>&1
#exec chroot . /bin/sh <dev/console >dev/console 2>&1
#The following lines would unmount the initial RAM disk and free memory.
#Those lines can not be run from this file, since this file resides in the initial RAM disk
#Eiter run a script from the USB HD to clean it up or keep the initial RAM disk alive and do nothing.
#Due to the reasons above the following lines are just a hint how to unmount the inital RAM disk.
#sleep 5
#
#echo"Linuxrc: Unmount RAM disk"
#umount /initrd
#echo "Linuxrc: Free RAM reserved by RAM disk"
#/sbin/blockdev --flushbufs /dev/ram0
#echo "Linuxrc: End of linuxrc script"
5.) and finally a dummy /etc/fstab with the following contents:
# /etc/fstab: static file system information.
# it is just a dummy file to not cause a kernel warning
Create on your Usb Harddisk a directory /initrd, when every thing went well you will see inside the initial ramdisk.
Last edited by lindegur on Sat Aug 05, 2006 6:27 pm, edited 3 times in total.
I found my web page and have put my guide on it. The sample code you find above need still some improvements, but there is not big priority on my side since it runs perfectly. I also applied the same methode to a USB memory stick and will probably make my own Linux USB memory stick, my motivation behind it is learning the internals of Linux.
http://mypage.bluewin.ch/Urs_Lindegger/ ... romUsb.pdf
http://mypage.bluewin.ch/Urs_Lindegger/ ... romUsb.pdf
)..- lord_hypno
- n00b
- Posts: 35
- Joined: Fri May 07, 2004 4:43 pm
I found very usefull your guide, thaks for the good hints.
Just a coupple of things:
in your guide you write to use two sample files:
initrd.gz and mkinitrd.
I found the first at http://mypage.bluewin.ch/Urs_Lindegger/Linux/initrd.gz, but I can not find the second.
Just a coupple of things:
in your guide you write to use two sample files:
initrd.gz and mkinitrd.
I found the first at http://mypage.bluewin.ch/Urs_Lindegger/Linux/initrd.gz, but I can not find the second.
Hypno
Hi Hypno,
On my linux page you find the following text:
Sample Code: initrd mkinitrd
Click to initrd you get the initrd sample code
Click to mkinitrd you get the mkinitrd sample code (in zipped format)
Or the following link shoud bring you right to it:
http://mypage.bluewin.ch/Urs_Lindegger/ ... trd.tar.gz
On my linux page you find the following text:
Sample Code: initrd mkinitrd
Click to initrd you get the initrd sample code
Click to mkinitrd you get the mkinitrd sample code (in zipped format)
Or the following link shoud bring you right to it:
http://mypage.bluewin.ch/Urs_Lindegger/ ... trd.tar.gz
- lord_hypno
- n00b
- Posts: 35
- Joined: Fri May 07, 2004 4:43 pm
- kevintshaver
- n00b
- Posts: 49
- Joined: Tue Feb 14, 2006 3:06 am
I've used this method and I'm able to get the linuxrc script to start executing but it fails at the following line:
The error: /dev/sda3 is not a vaild block device
Any ideas on what causes this? Thanks.
Code: Select all
mount -t ext3 -o ro /dev/sda3 /new-rootAny ideas on what causes this? Thanks.
- kevintshaver
- n00b
- Posts: 49
- Joined: Tue Feb 14, 2006 3:06 am
Since more than a year I'm using my gentoo usb hd and I did all updates as usual (kernel 2.6.17, Xorg 7, Webcam, and so on).
Me and my gentoo usb installation collected many frequent flyer miles that year.
I forgot a lot, since it runs without problems. Therefore I wrote my guide also for myself to remember what I did.
So what did you do, when you got stuck with /dev/console, what do you see on the screen
Me and my gentoo usb installation collected many frequent flyer miles that year.
I forgot a lot, since it runs without problems. Therefore I wrote my guide also for myself to remember what I did.
So what did you do, when you got stuck with /dev/console, what do you see on the screen
Last edited by lindegur on Thu Jun 07, 2007 10:12 am, edited 1 time in total.
There is an easier way to do the same see:
http://forums.gentoo.org/viewtopic-t-55 ... ight-.html
If you have a problem Linux offers more than one solution
http://forums.gentoo.org/viewtopic-t-55 ... ight-.html
If you have a problem Linux offers more than one solution