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

Wolfgang Denk
2007-07-03T21:11:30Z

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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