[U-Boot] [RFC PATCH 4/6] porter_defconfig: Enable tiny printf

[Vignesh R]

Hi Marek, Simon

On 29/11/18 3:20 AM, Marek Vasut wrote:
> On 11/28/2018 09:34 PM, Simon Goldschmidt wrote:
>> On 28.11.2018 18:52, Marek Vasut wrote:
>>> On 11/28/2018 06:26 PM, Vignesh R wrote:
>>>> Enable tiny printf to reduce SPL foot print
>>> This should be enabled already on Gen2, no ?

Right, its already enabled, please ignore this particular patch. I saw
sram overflow with this config when running buildman and therefore
though this change might help.

>>> Anyway, what's the size growth on Gen2 with the new Linux SF framework ?
>>
>> After downloading the missing patch 1/6 from github and testing it on
>> socfpga gen5, my SPL got ~2500 byte larger.
>>

I guess patch 1/6 took a bit more time to get across. I can see it in
patchworks: https://patchwork.ozlabs.org/patch/1004836/

>> While I think porting this from Linux is the right thing to do, I can't
>> say I'm happy with losing yet another 2.5 kB for SPL when it is already
>> too stuffed to add secure boot via FIT signatures.
> 
> Indeed. Can we somehow trim things down a bit for SPL ?
> 

I am able to trim overall size delta to within 1KB for porter_defconfig.
Pushed new set of patches to github[1]

With new this new SF framework and porter_defconfig:
size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  15749	    184	   1100	  17033	   4289	spl/u-boot-spl

Current mainline:
size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  14881	    184	   1100	  16165	   3f25	spl/u-boot-spl

Typical increase in code delta is ~1K to ~1.2KB wrt SPL on different
platforms depending on flash devices supports enabled.

I am not sure if its possible to trim this down further, as there is
addition of new code to handle 4 Byte addressing feature and moving to
spi-mem framework to support direct mapping capable SPI controllers.
These features will add to code size and I hope that's an acceptable
tradeoff.

I believe, once SPI NOR is completely integrated with MTD framework,
there will be some size reduction(such as due to getting rid of sf_mtd.c
and spi_flash_* APIs completely. Also, loading of U-Boot images across
NAND/SPI NOR can be consolidated).

I will post revised patches to mailing list after travis ci report.

[1] https://github.com/r-vignesh/u-boot.git spi-nor-mig-v2

-- 
Regards
Vignesh