[U-Boot] [PATCH] ppc: transform init_sequence into a function.

Wolfgang Denk wd at denx.de
Mon Dec 6 23:36:21 CET 2010


Dear Joakim Tjernlund,

In message <OFEE7ADEEA.47556DD1-ONC12577F1.006FAF8D-C12577F1.0071C097 at transmode.se> you wrote:
>
> > This is indeed much uglier.  What exactly is your problem with
> > debugging the existing code?
> 
> Whenever I screw up so that one of the init funcs crashes, often without
> any trace on the RS232 port you don't know which one. Single stepping

Well, we turn on the serial ports as early as possible, so ther eis
only a pretty small collection that is candidate for such a situation.

> though the loop is cumbersome and not easy as BDI tends to
> flush the cache when it stops so you loose your stack.

Does it? On which architecture / processor is this?

> The other way is to look up one those funs and set a BP there and hope
> for the best. Then repeat with the next function and so on.
> Compare that with just setting a BP in the new init_sequence(), it is
> fast and easy to move around.

...but ugly to read.  And if you really want to introduce this style,
it has to be done for all architectures, as I want to see this code to
become common across architectures.

> I don't think you have been chasing bugs in this area for a long time,
> if you had, you would appreciate how easy it is with functions
> compared with a bunch of function ptrs.

I haven't, lately, that's true, or when I had, I always knew pretty
well where I had to expect the issues.  But I've been there before,
many, many times.

> I don't think this is much uglier, just a bit, but far more
> useful and I have a hard time buying into "beautiful trumps usefulness".

I'm not convinced that your code is actually a general improvement.  I
understand that it's useful for you, and your style of debugging.
If you are really hanging in this area, then maybe a debug() is more
prowerfull - and less invasive.

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
In a survey taken several years ago, all  incoming  freshmen  at  MIT
were  asked  if  they  expected  to graduate in the top half of their
class. Ninety-seven percent responded that they did.


More information about the U-Boot mailing list