From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Date: Fri, 20 Apr 2012 18:16:41 +0200
Subject: [U-Boot] [PATCH v3] Add support for MINI2440 (s3c2440).
	Documentation about the product can be found on:
	http://www.friendlyarm.net/products/mini2440
In-Reply-To: <CABi8O6bhzKVQme4ObKHL7iMrBkpjr-3pMdjFnXxpbSvjiQ=Ysg@mail.gmail.com>
References: <20120416174633.GA7463@debian> <201204201608.56158.marex@denx.de>
	<CABi8O6bhzKVQme4ObKHL7iMrBkpjr-3pMdjFnXxpbSvjiQ=Ysg@mail.gmail.com>
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Dear Ilya Averyanov,

> 2012/4/20 Marek Vasut <marex@denx.de>
> 
> > Dear Ilya Averyanov,
> > 
> > > 2012/4/20 Marek Vasut <marex@denx.de>
> > > 
> > > > Dear Ilya Averyanov,
> > > > 
> > > > [...]
> > > > 
> > > > > > > > > > > .word 0x32
> > > > > > > > > > > +    .word 0x30
> > > > > > > > > > > +    .word 0x30
> > > > > > > > > > 
> > > > > > > > > > What this undocumented stuff?
> > > > > > > > > 
> > > > > > > > > SoC specific, I pasted it from smdk2410, it's for
> > > > > > > > > initialize the
> > > > > > 
> > > > > > DRAM.
> > > > > > 
> > > > > > > > Can't you init DRAM in some more fitting place? Also document
> > > > > > > > this?
> > > > > > > 
> > > > > > > I don't know, this part is a bit difficult for me, but I'm
> > > > > > > going
> > 
> > to
> > 
> > > > try
> > > > 
> > > > > > > to document it with the help of the SoC documentation.
> > > > > > > 
> > > > > > > For the place, should I move it to mini2440.c in
> > > > > > > arch_cpu_init()
> > 
> > or
> > 
> > > > > > > board_early_init_f() ? I don't really know the difference.
> > > > > > 
> > > > > > dram_init() maybe ?
> > > > > 
> > > > > You propose to initialize the SDRAM controller in dram_init ()?
> > > > 
> > > > Well yes, ain't it more fitting ?
> > > > 
> > > > Best regards,
> > > > Marek Vasut
> > > 
> > > No. We have to two reasons why this is not the case.
> > > 1) Open u-boot/arch/arm/cpu/arm920t/start.S:328
> > > cpu_init_crit
> > > ......
> > > line 346
> > > 
> > >     /*
> > >     
> > >      * before relocating, we have to setup RAM timing
> > >      * because memory timing is board-dependend, you will
> > >      * find a lowlevel_init.S in your board directory.
> > >      */
> > 
> > Well don't setup run in lowlevel_init.S then ?
> > 
> > > 2) NAND controller must be initialized before C code run.
> > 
> > Why?
> > 
> > Best regards,
> > Marek Vasut
> 
> mmm...
> Because we need a stack.
> The stack is in RAM.

mmm...
You can lock cache entries to create space for stack in cache. That's how it's 
done on PXA, check it.

Best regards,
Marek Vasut