On Fri, Nov 23, 2018 at 05:49:30PM +0900, Masahiro Yamada wrote: > On Fri, Nov 16, 2018 at 11:31 PM Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > > > The socfpga xload images are limited to 64KiB. This doesn't fit if > > multiple boards are selected. The reason is that we include huge > > C files and arrays in the early init code which get compiled once > > for each board. -ffunction-sections is without effect here since all > > functions have the same name and hence we get the same function > > multiple times in the same section. > > > > To overcome this we surround all function names with a SECT() macro which > > is used to add a board specific prefix to the section names. This way > > -ffunction-sections can now do its work and discard unused functions. > > > > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > > > I just accidentally stopped by this commit. > > It is a good thing that you noticed dead code elimination > (-ffunction-sections -fdata-sections, --gc-sections) > does not work if the same symbol names are used > in the conventional incremental linking > Linux kernel used to use. > > As you notice, this is a potential problem > of CONFIG_PBL_MULTI_IMAGES, > and I know the right solution. > > > Since Linux v4.13 (commit 98ced886dd79a), > Linux kernel build system uses thin archive, > where Kbuild uses $(AR) rcSTP instead of $(LD) -r > to combine built-in objects. > > With this, the final link stage does the right thing to do > for --gc-sections. > > Besides, thin archive is faster, > and saves disk spaces. > > If you sync core Makefiles with Linux, > your problem will be solved. That's really nice, thanks for noting this. I had a short look into it, unfortunately syncing the Makefile doesn't appear to be an easy job. I think we stick to the current patch for now until someone finds time to do it. It's good to know there's a proper solution to the problem though Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
