Re: ftrace breaks sparc64 build

David Miller
2009-01-06T18:39:54Z

From: Sam Ravnborg <sam@ravnborg.org>
Date: Tue, 6 Jan 2009 14:34:42 +0100

> But I never managed to really understand what the btfixup thing is all
> about and has then been sidetracked by funnier stuff.

It's recording relocations that get fixed up at boot time.

The way it works is that each btfixup emits a reference to a symbol
that will be unresolved.

The btfixup tool under arch/sparc/boot/ scans the unlinked kernel
image, generates dummy symbol definitions into a foo.s file so that
the kernel can be linked, and builds the btfixup tables so the kernel
can patch up these relocations at boot time.