From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Date: Mon, 23 Apr 2012 16:07:37 +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: <CABi8O6Ys0D4kyCj=z=Rrj+K_K_G9FF__UhH2m7HpBgMuuPkdcQ@mail.gmail.com>
References: <20120416174633.GA7463@debian> <201204211519.30964.marex@denx.de>
	<CABi8O6Ys0D4kyCj=z=Rrj+K_K_G9FF__UhH2m7HpBgMuuPkdcQ@mail.gmail.com>
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Dear Ilya Averyanov,

> Dear Marek Vasut,
> 
> Would you please explain, why do you want to initialize the sdram has been
> in C code.

Ok, no problem:
- You'll be able to call get_ram_size() to scan for ram size as any other board
- SDRAM driver will fit properly into the driver model once it's in place (WIP, 
wanna volunteer for review process?)
- It's much cleaner

> If for provide this feature should be written assembly code. And it would
> sometimes even harder than the initialization code sdram?

What do you mean?

Ah yes, just a remark, please don't top-post. Notice how other people don't do 
it -- I know gmail does it out-of-the-box, but that doesn't mean it's correct.

> 2012/4/21 Marek Vasut <marex@denx.de>
> 
> > Dear Ilya Averyanov,
> > 
> > > 2012/4/21 Vasily Khoruzhick <anarsoul@gmail.com>
> > > 
> > > > 2012/4/21 Ilya Averyanov <averyanovin+uboot@gmail.com>:
> > > > > No have problem.
> > > > > Available only if you boot from NOR flash.
> > > > > If you boot from the NAND 4kb of SRAM (steppingstone) not
> > > > > available.
> > > > 
> > > > For NAND boot it's mapped at 0x0
> > > > For NOR boot it's mapped at 0x40000000
> > > > 
> > > > NAND controller uses it for booting purpose, but anyway for SPL we
> > > > should fit code into
> > > > 4k (hardware limitation), so I think using assembly here for SDRAM
> > > > init is OK.
> > > > 
> > > > And how will you use the internal SRAM when you boot from NAND, if
> > > > the SoC
> > > 
> > > writes in the SDRAM read data from NAND, and your data will be
> > 
> > overwritten.
> > 
> > Why? You'll load SPL into SRAM, then in SPL you'll copy the rest of uboot
> > from
> > NAND to - then already inited - SDRAM and execute it. We even have
> > ready-to-use
> > NAND SPL.
> > 
> > > > Regards
> > > > Vasily
> > 
> > Best regards,
> > Marek Vasut

Best regards,
Marek Vasut