[U-Boot] [PATCH V2 06/10] fat: ffconf.h changes for U-Boot port

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/15/2015 07:07 AM, Tom Rini wrote:
> On Fri, Aug 14, 2015 at 09:40:48PM -0600, Stephen Warren wrote:
>> On 08/14/2015 12:47 PM, Tom Rini wrote:
>>> On Tue, Aug 11, 2015 at 08:55:41AM -0600, Stephen Warren
>>> wrote:
>>>> Turn on _FS_NORTC: This means we don't have to implement 
>>>> get_fattime() which simplifies life for now.
>>>> 
>>>> Automatically set _FS_READONLY based on CONFIG_FAT_WRITE.
>>>> This requires including <config.h> since we reference
>>>> CONFIG_*.
>>>> 
>>>> Set _USE_LFN to enable long filename handling; an essential 
>>>> feature.
>>>> 
>>>> Set _FS_RPATH so that paths components "." and ".." are
>>>> correctly parsed and handled. This enables paths such as
>>>> "/extlinux/../foo" to work.
>>>> 
>>>> Set _USE_LABEL so that volume labels can be read.
>>> 
>>> Hmm, is there some way to wrap volume label support in
>>> Kconfig? I'm sure this is useful in some cases, but maybe
>>> something that boards that are already on the cusp of their
>>> size limit would want off?
>> 
>> It's certainly possible; ffconf.h's definition of _FS_READONLY
>> is already driven by CONFIG_FAT_WRITE in this series.
>> 
>> I'm not sure if it's worth it though; on the RPi, turning off
>> volume label support only saves ~0.5K of .text, 0 .data, and 8
>> bytes .bss. If so, I can certainly throw in another patch to
>> allow it to be configured.
> 
> Yeah, OK, that's not a big enough savings to bother with I think.
> On the boards where we're seeing a bigger size growth can you
> investigate a little?  Thanks!

I haven't built a lot of boards, but I think that large size increase
may have been limited to sandbox. For some reason, its config.mk
doesn't contain:

PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden

If I add that to arch/sandbox/config.mk, then I see a much smaller
size increase when switching to the new FAT implementation.

There are obviously a few functions that aren't used in ff.c, but
aren't ifdef'd out.