I'm not a good high-level programmer at all but have some experience in
assembly programming. What I want to do is to add a private routine to
an existing ARM kernel which should be executed before the kernel
initialises. So far, I have used hexedit to squeeze in some operations
right at the beginning of the kernel binary. This really worked because
there were eight NOPs (mov r0, r0) at the beginning of the kernel which
I simply overwrote with my code. Now I would like to do it the clean
way. From what I have gathered in the net, this code should go to
"FIXUP" which in the kernel source that I have is quite a big
C-function that I don't understand at all. Now, my understanding of the
environment at this point is quite limited (you may wonder why I am
doing this, then. Well, I want to learn and I want to add a screen
blanking routine to get rid of some junk that gets displayed during
boot). So I wonder whether I can do a function call from the code in
FIXUP to my own asm function which would allow me to write a nice asm
routine outside the kernel src and link it in the right place. Calling
a function would require a working stack, though, which I fear isn't
available at this point in time. Or is it?