[U-Boot] [PATCH 05/24] SPL: tiny-printf: add "l" modifier

[Simon Glass]

Hi,

On 23 November 2016 at 20:19, Siarhei Siamashka
<siarhei.siamashka at gmail.com> wrote:
> On Sun, 20 Nov 2016 14:56:59 +0000
> Andre Przywara <andre.przywara at arm.com> wrote:
>
>> tiny-printf does not know about the "l" modifier so far, which breaks
>> the crash dump on AArch64, because it uses %lx to print the registers.
>> Add an easy way of handling longs correctly.
>
> I can't help but notice that the changes of this kind are in a way
> defeating the original purpose of tiny-printf. And it is surely not
> the first patch adding features to tiny-printf. I guess, in the end
> we may end up with a large and bloated printf implementation again :-)
>
> A possible solution might be just a strict check when parsing format
> modifiers and abort with an error message (yeah, this will introduce
> some size increase, but hopefully the last one). This way we
> acknowledge the fact that tiny-printf is a reduced incomplete
> implementation, and that the callers need to take this into account.
>
> As for the "l" modifier. How much does it add to the code size? IMHO
> this information should be mentioned in the commit message. Can the
> AArch64 crash dump code be modified to avoid using it? Or can we have
> the "l" modifier supported on 64-bit platforms only?
>
>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>> ---
>>  lib/tiny-printf.c | 43 +++++++++++++++++++++++++++++++++----------
>>  1 file changed, 33 insertions(+), 10 deletions(-)

I think I tested this patch as adding 36 bytes on Thumb2 so not too
terrible. But I do agree with the sentiment.

Why is aarch64 using tiny-printf? Surely all though chips have heaps of space?!

Regards,
Simon