Linux as a bootloader?
Is it possible to have linux boot another kernel? Like explained in this:
I have a device with a kernel on, limited flash and no console access. I want to make extensive mods but not to the kernel in flash as if i break it then its game over.
It would be ideal if i could run uboot as a native app.
I'm not sure I follow what you are planning here but just to be clear, uboot is a boot loader, it has nothing to do with Linux (as in it can load just about any OS if configured properly) and no, Linux is not a boot loader.
You can also use redboot as a boot loader and a search around the web will give you some other alternatives. Boot loaders are not really tied to the OS they are loading. The merely put the CPU and various devices into a "known" state and then load an image into memory, point the Instruction pointer at some known address within that image and then it dies. If that image is Linux so be it, it could also be vxWorks, OSE, that OS that shall not be named...