Where to get the source code of the linux kernel that comes with beagle board?

I got a beagleboard-xm rev C. There is a linux kernel that comes pre-
loaded into the SDcard when we received the beagleboard. Does someone
knows where we can download the source code of this kernel? This
kernel works with angstrom. Does anyone know if it is possible to
simply use a Ubuntu linux kernel onto Angstrom? I am using Robert
Nelson's kernel for Ubuntu. Thank you.

Another thing ... does the bootloader matter for Ubuntu or Angstrom?
Can I use the same bootloader for both Angstrom and Ubuntu if the
hardware is the same? Thank you.

Another thing … does the bootloader matter for Ubuntu or Angstrom?
Can I use the same bootloader for both Angstrom and Ubuntu if the
hardware is the same? Thank you.

Yeap you can, the bootloader inatalled by my demo images actually comes from a build of angstrom…

You can pull the patches from Angstrom and apply to your git tree manually. If there is enough interest, I am thinking next week I will start a tree on http://github.com/beagleboard that will track the Angstrom kernels.

Another thing … does the bootloader matter for Ubuntu or Angstrom?
Can I use the same bootloader for both Angstrom and Ubuntu if the
hardware is the same? Thank you.

Yeap you can, the bootloader inatalled by my demo images actually comes from a build of angstrom…

I think the patches from upstream are fairly minimal now and only impact some corner cases.

I got a beagleboard-xm rev C. There is a linux kernel that comes pre-
loaded into the SDcard when we received the beagleboard. Does someone
knows where we can download the source code of this kernel? This
kernel works with angstrom. Does anyone know if it is possible to
simply use a Ubuntu linux kernel onto Angstrom? I am using Robert
Nelson’s kernel for Ubuntu. Thank you.

You could just use http://www.angstrom-distribution.org/building-angstrom and ‘bitbake virtual/kernel’ to build the kernel.

Thanks for all the replies. I am trying out the suggestions now.

While Ubuntu is much more convenient than Angstrom because of the
packages available, Angstrom is much faster. So, I am looking into
using Angstrom now. The one complaint about Angstrom is that the
packages are not as reliable as Ubuntu's.

See this : http://gitorious.org/beagleboard-validation/linux/trees/beagleboardXM