Dear Tom Rini,
On 09/18/12 12:25, Marek Vasut wrote:
Dear Tom Rini,
On 09/18/12 12:19, Marek Vasut wrote:
Dear Tom Rini,
On 09/18/12 11:33, Marek Vasut wrote:
Dear Scott Wood,
[snip]
> I think I got some wires crossed and was thinking about > printf/puts. We want those to be optimized away at > compile time (not pointed to a stub at link time) on an > SPL that has no output support, but once that's done the > low level serial functions shouldn't be referenced > anymore, right?
But if you point them to stubs, that's OK. The compiler will GC these useless stubs anyway. But wait, we're getting to LTO here, right?
So the safest bet really is macro in serial.h ?
Due to the gcc bug I've mentioned before, yes. Dummy functions will, I bet, keep the string constants around. do {} while(0) will drop them out entirely.
Damn, not much gain on m28evk (with C functionss/with macros), using gcc 4.7.1:
Configuring for m28evk board... text data bss dec hex filename 418994 7780 288632 715406 aea8e ./u-boot 11773 788 12 12573 311d ./spl/u-boot-spl
Configuring for m28evk board... text data bss dec hex filename 418998 7780 288628 715406 aea8e ./u-boot 11765 788 12 12565 3115 ./spl/u-boot-spl
Right, didn't have many strings. But do you see what I mean now about not needing this patch as it stands currently?
No, I don't. If I remove this patch, the build breaks either because serial_* is defined twice or not defined at all.
m28evk currently, needlessly, defines serial_puts/putc. I locally patched master to drop them from arch/arm/cpu/arm926ejs/mxs/spl_boot.c and the references in common/libcommon.o are correctly garbage-collected. They are in fact unused functions today as they're garbage collected without patching, see spl/u-boot-spl.map after building.
I'd love to, this is what I get with my patchset when I remove the #ifdef from serial.c:
$ ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- ./MAKEALL m28evk Configuring for m28evk board... make[1]: *** [/home/marex/U-Boot/u-boot-marex/spl/u-boot-spl] Error 1 make: *** [spl/u-boot-spl.bin] Error 2 arm-linux-gnueabi-size: './u-boot': No such file common/libcommon.o: In function `get_current': /home/marex/U-Boot/u-boot-marex/common/serial.c:229: undefined reference to `default_serial_console' make[1]: *** [/home/marex/U-Boot/u-boot-marex/spl/u-boot-spl] Error 1 make: *** [spl/u-boot-spl.bin] Error 2 make: *** Waiting for unfinished jobs....
So someone still has to implement default_serial_console() call. Is that fine ?
So again I say, if common/serial.o is NOT being discard in your series on m28evk there is a bug in your series to fix or a change to better understand and document
Ok, I spent hours documenting this series. What else is there to document?
Besides, my team is starting to collect dead weight and we're running behind the schedule a lot ... I'm fucked, I'm desperate and I really don't know what to do anymore. Pardon if I'm a bit unpleasant to deal with recently.
(and then see if we can change since as Scott notes, this needs to work for 4kb boards and that is tight).
What exactly are the 4k boards?
One more question -- if I have two __weak functions and one non-weak, the non- weak wins and noone complains, right?
Best regards, Marek Vasut