From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfgang Denk <wd@denx.de>
Date: Tue, 10 May 2011 23:59:42 +0200
Subject: [U-Boot] [PATCH] post: new parallel nor flash test
In-Reply-To: <201105101711.07625.vapier@gentoo.org>
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	<20110510201700.A8D4AD6F237@gemini.denx.de>
	<201105101711.07625.vapier@gentoo.org>
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To: u-boot@lists.denx.de

Dear Mike Frysinger,

In message <201105101711.07625.vapier@gentoo.org> you wrote:
>
> > > This adds a simple parallel nor flash test to automatically verify
> > > erasing/writing/reading of sectors.  The code is based on existing
> > > Blackfin tests but generalized for everyone to use.
> > 
> > What exactly does the "parallel" in "parallel nor flash test" mean?
> 
> how it is connected to the processor

Are there any other types of NOR flashes?  I mean, I have never heard
anybody use this term before.  Maybe we can just omit it - I find it
more confusing than helpful.

> > > +	unsigned char *ret = (void *)CONFIG_SYS_SDRAM_BASE;
> > 
> > This will not work on many systems.  For example, on PPC you will
> > overwrite the exception vectors in low memory, thus crashing the
> > system.
> 
> this is how the default memory post test works.  it writes all memory from
> CONFIG_SYS_SDRAM_BASE to CONFIG_SYS_SDRAM_BASE+MIN(1GiB,bd->memsize).  so how 
> does this work on ppc systems ?

The RAM test runs before relocation to RAM, i. e. whenRAM is still not
used by anything.

> i didnt think calling malloc() would be OK since i need enough memory to hold 
> one sector ...

Just grabbing a random address in RAM is certainly not a proper way
to allocate I/O buffers.  If you need them, and if your code design
makes it even necessary to pass these buffers around (so you can not
just put them on the stack which is what I would try to do) you have
to use malloc().

Best regards,

Wolfgang Denk

-- 
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