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

[Ilya Averyanov]

2012/4/20 Marek Vasut <marex at denx.de>

> Dear Ilya Averyanov,
>
> > 2012/4/20 Ilya Averyanov <averyanovin+uboot at gmail.com>
> >
> > > 2012/4/20 Marek Vasut <marex at denx.de>
> > >
> > >> Dear Ilya Averyanov,
> > >>
> > >> > 2012/4/20 Marek Vasut <marex at 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!
>
> Which doesn't matter, either way you need stack ... and you can have the
> stack
> in cache ;-)
>
> Best regards,
> Marek Vasut
>
Why do you insist on sdram initialization code in C?
If you simply do as done in the other boards on this architecture?