[U-Boot] [PATCH v3] Add support for MINI2440 (s3c2440). Documentation about the product can be found on: http://www.friendlyarm.net/products/mini2440

From: Ilya Averyanov <averyanovin+uboot@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3] Add support for MINI2440 (s3c2440). Documentation about the product can be found on: http://www.friendlyarm.net/products/mini2440
Date: Fri, 20 Apr 2012 18:35:57 +0400	[thread overview]
Message-ID: <CABi8O6Yduf2ezgaXzQ5tLMr_MyZt+UfZPE2DWYc2Xnttg-m=3w@mail.gmail.com> (raw)
In-Reply-To: <CABi8O6bhzKVQme4ObKHL7iMrBkpjr-3pMdjFnXxpbSvjiQ=Ysg@mail.gmail.com>

2012/4/20 Ilya Averyanov <averyanovin+uboot@gmail.com>

>
>
> 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.
>
>2) NAND controller must be initialized before C code run.
Sorry made ??a mistake. SDRAM! Not NAND!