[U-Boot] [PATCH] post: new parallel nor flash test

[Mike Frysinger]

On Tuesday, May 10, 2011 17:59:42 Wolfgang Denk wrote:
> Mike Frysinger 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?

"parallel" is the connection type to the processor meaning it may be directly 
addressed (has dedicated address and data lines).  "NOR" is simply the 
technology type.

serial flashes tend to be NOR flashes connected via a SPI bus.

then there are NAND flashes which tend to be connected via a dedicated NAND 
flash controller (NFC), but that isnt a hard line anymore either.  ive seen 
serial NAND flashes which means they connect via SPI.

> I mean, I have never heard anybody use this term before.  Maybe we can just
> omit it - I find it more confusing than helpful.

*shrug* i cant say i found that to be the same, but doesnt matter to me.  the 
point of saying "parallel nor" was to be explicit ... this post test is only 
for nor flashes connected directly to the processor using the u-boot 
include/flash.h standard.  it is not for spi nor flashes, nor is it for nand 
flashes of any type.

> > 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().

considering the current test design blasts away at entire sectors, i didnt 
think putting a 128KiB buffer on the stack was kosher.  should be trivial to 
change it to malloc() ...
-mike
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