I downloaded the 2.6.11 kernel on IBM ThinkPadT42, make menuconfig,make,make install,make modules_install.then update-grub.
However,when I reboot with the new kernel,it cannot boot up and there is nothing appearing on the screen. (but,the previous version 2.6.8 can boot up perfectly) so,I need some suggestion.
Currently,I'm trying to find the files which have the information about the booting up. Does anyone know where're these files on debian sarge?

thanks

I am not sure what exactly you mean about nothing appearing on screen but I do know when I upgrade my kernel I have to reinstall the nvidia drivers as they are compiled against the kernel. Are you using nvidia rather than nv in you xfree86 config? If so, reinstall nvidia against your new kernel.

ohhh,it's ATI Rageon and built as modules.
cos after selecting the new kernel linux-2.6.11, there are some words passing so rapidly that cannot be caught,and then the screen is empty. weird.
I want to read the words before the screen go to empty,maybe there're some hints.
so,is there some booting information stored on machine?

the ones that immediately come to mind are in /var/log: dmesg and xfree86 logs

I had this problem too since the release of the 2.6.11 kernel series. It looks like something is broken regarding the ATI drivers especially if you want to combine AGP with framebuffer support.
And AFAIK, you won't find too useful stuff in the logs. Except maybe for the fact that the DirectRenderingManager failed to load and some other weird kernel reports on the graphic card, which you probably won't be interested into reading.
If you want to see both text during startup and also have DRM and AGP enabled, I'd suggest you to drop the framebuffer support (even if it sounds like something terrible, it isn't), and compile with DRM, RADEON_DRM, TMPFS, MTRR, AGP, AGP_chipset all as modules. I made it work somehow this way yet I'm still not really happy with it...I'll have to keep searching on the matter.
Or you may try to download, convert to .deb and attempt to install the proprietary drivers from ati.com but it's at your own risk and it's possible to break things even more (I once broke apt-get while trying to do it...luckily I fixed it eventually).

Anyway, you might have to try several kernel configurations before you hit the right one, it looks like it's pretty much machine dependant. So, happy recompiling!

I did it a bit different (after the kernel source is installed)
sux
passwd
cd /usr/src/linux
nano Makefile and changed EXTRAVERSION to something different
I did make_oldconfig (merged what I had too new kernel config)
make menuconfig and added/removed what I wanted
make source
then cd to /usr/src and look for the debs with the name you changed EXTRAVERSION in Makefile too.
The config,kernel,docs,and headers will be there
Then dpkg -i each new deb

If it fails you now have your existing old version to boot from and now also have debs that can be removed in the future.

I think i covered all the steps.

You can look at the docs for changes between the two....somewhere in the above steps it pops up the changes,I believe after you dpkg -i the kernel .deb.

May need too reinstall graphics drivers.