[U-Boot] [PATCH v2 01/40] vsprintf: Add modifier for phys_addr_t

[Thierry Reding]

On Tue, Aug 26, 2014 at 05:14:17PM -0600, Simon Glass wrote:
> Hi Thierry,
> 
> On 26 August 2014 09:33, Thierry Reding <thierry.reding at gmail.com> wrote:
> >
> > From: Thierry Reding <treding at nvidia.com>
> >
> > Provide a new modifier to vsprintf() to print phys_addr_t variables to
> > avoid having to cast or #ifdef when printing them out. The %pa modifier
> > is used for this purpose, so phys_addr_t variables need to be passed by
> > reference, like so:
> >
> >         phys_addr_t start = 0;
> >
> >         printf("start: %pa\n", &start);
> >
> > Depending on the size of phys_addr_t this will print out the address
> > with 8 or 16 hexadecimal digits following a 0x prefix.
> 
> Would it be better to use %#pa to get the 0x prefix so we have the
> option? Hex is the default in U-Boot.

Yeah, that's very confusing since there's no way to tell apart a
hexadecimal number from a decimal one since there's no decimal
equivalent of the 0x prefix.

If you insist I can change that (it should be a simple matter of
dropping the SPECIAL flag in the 'a' case).

> > Signed-off-by: Thierry Reding <treding at nvidia.com>
> > ---
> >  lib/vsprintf.c | 16 ++++++++++++++--
> >  1 file changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> > index 7ec758e40fc5..044d5551bdd0 100644
> > --- a/lib/vsprintf.c
> > +++ b/lib/vsprintf.c
> > @@ -518,6 +518,8 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
> >  static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> >                 int field_width, int precision, int flags)
> >  {
> > +       u64 num = (uintptr_t)ptr;
> > +
> 
> Will this impact code size much? I suppose it is vsprintf() so it
> doesn't matter too much?

Doing only this change and the corresponding change in the call to
number() results in the exact sizes:

	$ size build/jetson-tk1.{before,after}/u-boot
	   text    data     bss     dec     hex filename
	 310434   10872  309184  630490   99eda build/jetson-tk1.before/u-boot
	 310434   10872  309184  630490   99eda build/jetson-tk1.after/u-boot

Given that the num parameter of the number() function is already a u64
the compiler will presumably automatically handle the ptr argument as a
64-bit value.

Thierry
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