[U-Boot] [PATCH] env_mmc: fix buffer allocation for armv7

Wolfgang Denk wd at denx.de
Mon Oct 7 15:58:02 CEST 2013


Dear Tom,

In message <20131007122020.GT15917 at bill-the-cat> you wrote:
> 
> > But malloc() is drawing from the very same resource as the stack, even
> > more so: with a buffer on the stack, the memory isfreed completeky
> > upon return from the fucntion, with no reminders left.  With malloc()
> > you need to statically allocate the malloc pool size for the whole
> > runtime, and allocating the buffers may fragment tha area, so even
> > after freeing the buffers there is less space left for other purposes.
> > 
> > Especially in memory-tight situations you want to avoid malloc().
>
> Ah, but in these cases we don't have stack room, period.  We have a
> malloc pool.  So unless we make SPL move its stack pointer into DDR from
> wherever we set the initial one to, the other option here is to just
> restrict real env support to NOR (and we already don't allow embedded
> env, since that's embedded within U-Boot, not SPL).

Well, if we have DDR such that we can use it for the malloc arena, we
also should use it for the stack.  Or is there a good reason for not
doing this?  It would solve all these issues at the root...

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Q:  Do you know what the death rate around here is?
A:  One per person.


More information about the U-Boot mailing list