had grub2 . I replaced it with grub 0.97 . ubuntu 10.04 does not boot
 

Hi ,
ubuntu 10.04 installed grub2 by default. I installed tiny core OS later. I installed grub-0.97 which overwrote grub2 . I can easily boot iny core using
entry in /boot/grub/menu.lst as follows


title tinycore
root (hd0,0)
kernel /boot/vmlinuz waitusb=10 loop.max_loop=256
initrd /boot/core.gz

Similiarly I tried for ubuntu

title ubuntu
root (hd0,0)
kernel /boot/vmlinuz-2.6.32-21-generic ro quiet splash
initrd /boot/initrd.img-2.6.32-21-generic
I get dropped to initramfs prompt.
The files exist at location pointed to. I did not change their ownership or permissions.
I had simply noted down the entries of grub2 before changing to grub-legacy.
I like ubuntu 10.04 because I have its 47GB repository saved on my offline-computer.

What can I do to boot ubuntu-10.04?

The entries you posted both point to (hd0,0) or sda1. Did you install Tiny Core over Ubuntu, to the same partition? If Ubuntu is on a different partition, you will need the correct entry. There are two different types of entries I use to boot systems with Grub2 from Grub Legacy shown below:

You need to determine which partition has Ubuntu and change the root line above to the appropriate drive/partition number.
Have you tried mounting whichever partition Ubuntu is on to see if the files are there.

To yancek ,
I will give more details & try your suggestion.

'chainloader =1' says invalid executable elf file format .
I noticed that grub2 used linux <path to kernel> while legacy grub has no command called 'linux' . So i used kernel <path to kernel> followed by initrd <path to initramfs>
The message that follows indicate a little success but finally drop me to <initramfs> prompt.

That's not the actual entry you used, is it? You forgot to post the actual changes you made which you will need to do to get help. The entry you posted for Ubuntu in your initial post will not work when you are booting with Grub Legacy. Either of the options I showed you in my last post should work for a system with Grub2. I have used both on numerous occasions successfully.

Do you still have Tiny Core installed with its Grub Legacy bootloader in the master boot record?
Are you still able to successfully boot it?
Yes, Grub2 uses 'linux' in place of 'kernel' for the its entries.

Also, it would be helpful if you posted the output of the fdisk -l command run as root with an indication of which partition has TinyCore and which has Ubuntu.

i meant + . '=' was a typo while posting.
I overwrote grub2 with legacy-grub
I can boot tiny core in legacy-grub. I did not change any grub2 files.

What entry do you have in the TinyCore menu.lst for Ubuntu? Grub Legacy counts drives and partitions from zero unlike Grub2.
Which partition is Ubuntu on?
Do you get any message when you try to boot Ubuntu? The initrafs error?

further
 

please see attached screenshot.
Also see attached text file which is /boot/grub/menu.lst

Your TinyCore and Ubuntu root lines both point to the same partition so if TinyCore boots with that entry, you will need to change the Ubuntu root line to the correct partition. You have TinyCore on sda2 and windows 7 on sda4.

Change that line to indicate the correct partition for Ubuntu. Also, you need to use either the chainloader or core.img entries I posted above.

Actually I have installed tiny core & ubuntu on same partition which is ext3 while windows 7 is on an ntfs partition .
Actually the initrd & kernel files of tiny core have different name from that of ubuntu so there was no question of confusion between tiny core & ubuntu.

'chainloader +1' did not work for ubuntu.
I will try /boot/grub/core.img & revert back.

login problem & hardware problem
 

kernel /boot/grub/core.img

did the trick.
Thanks yancek.

I had changed ownership of all files of my ext2 partition to tc:staff (my tinycore equivalent) which caused ubuntu to crash . I remember my login name in ubuntu (lxuser) but do not know what was the default group . I tried at recovery root prompt
chown -R lxuser:lxuser /
That did not help.

Also my computer has VGA & HDMI port on graphic card which are separately attached to CRT & my TV . I see that TV goes off after startup splash screen ends though CRT shows login error messages. Please suggest ?