[U-Boot-Users] U-Boot-NG ?

[Wolfgang Denk <wd@denx.de>]

In message <468AA145.8090404@smiths-aerospace.com> you wrote:
>
> One technique I've used in the past that has worked well is to output 
> successive characters at critical points in the code.  (It became known 
> around here as "alphabet soup.")  If the board stopped spitting out 
> characters prematurely, you have a clue what is wrong.

This is definitely useful for debugging. We often do similar  things;
like  ust  writing  characters  or  a  counter  to some static memory
location for post mortem analysis with a debugger.

> > MPC8260 Clock Configuration
> >  - Bus-to-Core Mult 4.5x, VCO Div 2, 60x Bus Freq  22-65 , Core Freq
> > 100-300
> >  - dfbrg 0, corecnf 0x17, busdf 5, cpmdf 1, plldf 0, pllmf 5
> >  - vco_out  597196800, scc_clk  149299200, brg_clk  149299200
> >  - cpu_clk  447897600, cpm_clk  298598400, bus_clk   99532800
> >  - pci_clk   49766400
> 
> One or two of these may be useful, but even that is debatable.

I consider it very useful.  We  had  several  cases  where  customers
reported  on  strange problems, and by just checking the printed data
we wre able to see that they either used a wrong board  configuration
for U-Boot, or that the syctem clock was off, or ...

> * Some of these, if wrong, will cause complete board failure and the
>      above won't be printed anyway.
> * Most can be deferred till after RAM reloc

No, it cannot, because then you might never  see  these  messages  at
all.

> > CPU:   MPC8280 (HiP7 Rev 14, Mask 1.0 1K49M) at 447.897 MHz
> > Board: Innovative Systems AP2, CPU1
> > Build: $SvnTreeRevision: 89 $
> Defer till after RAM reloc

NO! Please, please DON'T!

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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