[U-Boot] [PATCH v4] Switch from archive libraries to partial linking

Detlev Zundel
2010-11-17T12:30:52Z

Hi Mike,

> On Tuesday, November 16, 2010 09:58:48 Detlev Zundel wrote:
>> > On Monday, November 15, 2010 07:13:03 Sebastien Carlier wrote:
>> >> On 2010-11-15 11:54:07, Wolfgang Denk wrote:
>> >> > I notice that the patch affects the size of the resulting U-Boot
>> >> > images.
>> >> >
>> >> > For example:
>> >> >
>> >> > Configuring for MiniFAP - Board: TQM5200, Options: MINIFAP
>> >> >
>> >> > text data bss dec hex filename
>> >> >
>> >> > 358144 35208 303248 696600 aa118 ./u-boot before
>> >> > 361340 35824 303332 700496 ab050 ./u-boot after
>> >> >
>> >> > -------------------------------
>> >> >
>> >> > Delta: +3896 Bytes
>> >> >
>> >> > For other boards it's only a few hundred bytes, but why do we see
>> >> > such big increase here?
>> >>
>> >> In this case, these libraries contribute 3260 bytes in unused
>> >> definitions:
>> >>
>> >> In each case, a whole object file contains exactly the unused
>> >> definitions, and could be excluded in the respective Makefile.
>> >
>> > or just use -ffunction-sections/-fdata-sections/-Wl,--gc-sections and
>> > dont worry about it. which is what we do for the Blackfin port.
>>
>> If you do worry, you can use the "--gc-sections" together with
>> "--print-gc-sections" to actually find out what is unused[1].
>
> the u-boot.map also mentions which input sections are discarded without
> needing --print-gc-sections ...

Intersting, I didn't realize this. Thanks!
Detlev

--
While the list of different methods is not endless, it is certainly
pretty long, with new ones being dreamed up all the time. Fortunately,
space limitations prevent us from looking at all of them.
-- Andrew S. Tanenbaum
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de