On Sat, May 08, 2010 at 10:34:23AM +0200, Patrick Georgi wrote: > Am Samstag, den 08.05.2010, 10:25 +0200 schrieb Stefan Reinauer: > > On 5/8/10 12:13 AM, Patrick Georgi wrote: > > > -#initobj-y += serial.o > > > +initobj-$(CONFIG_USE_DCACHE_RAM) += serial.o > > > subdirs-y += vga > > Awesome... the less .c file includes we have in romstage.c the better.. > > > > This way works in the case of converting code that was previously always > > compiled in. > > > > But how should we handle things in case of other conditions? > We could stuff all of the initobjs into an initobj.a, and use that for > linking. ld will only pick up the object files that are actually needed > then. This means we probably compile a serial port thingy too many, but > they're rather small.
I think coreboot should try to avoid using .a files. The latest version of gcc (v4.5) contains the -flto feature. This can provide significant benefits to coreboot code generation because it allows the entire romstage (and ramstage) to be analyzed as a whole. The resulting binaries are significantly smaller because unused code can be eliminated and more functions can be inlined. Unfortunately, the standard linker can't handle -flto with .a files. -Kevin -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
