[U-Boot] RFC: U-Boot OneNAND IPL TEXT_BASE

[Marek Vasut]

Dne Ne 2. května 2010 13:07:13 Kyungmin Park napsal(a):
> On Sun, May 2, 2010 at 3:39 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> > Dne Ne 2. května 2010 05:54:41 Kyungmin Park napsal(a):
> >> Hi,
> >> 
> >> Which CPU do you use? In most ARM cpu, CPU load the IPL into its
> >> internal SRAM, and runs at here.
> > 
> > PXA270 ... the BootRAM is mapped to 0x0 and the code runs from there.
> > 
> >> But in your case it's not. So you maybe redefine IPL address.
> >> 
> >> Instead of modifying the config.mk, how about to define IPL_TEXT_BASE.
> >> 
> >> e.g.,
> >> 
> >> In OneNAND IPL code,
> >> 
> >> #ifndef BOARD_IPL_TEXT_BASE
> >> #define ONENAND_IPL_TEXT_BASE BOARD_IPL_TEXT_BASE
> >> #endif
> > 
> > That won't help -- TEXT_BASE is used while compiling start.S (to setup
> > stack under TEXT_BASE) and the config.mk prepares the gcc options for
> > start.S (the TEXT_BASE is defined in the gcc options).So modifying
> > config.mk is unavoidable I fear.
> 
> Sorry my mistake. It's already supported at current drivers. Now I
> works on s5pc100 and s5pc110 and each define it's TEXT_BASE at
> onenand_ipl/board/samsung/${board_name}/config.mk. and it's used at
> start.S
> 
I noticed the config.mk in onenand-ipl/board/... were meant to be used, but in 
my case, those were not used. Instead, the board/... config.mk was used (and 
from what I saw in config.mk, that's understandable).

Also, see the Makefile in onenand-ipl/board/apollon/Makefile -- onenand-
ipl/board/apollon/config.mk defines the TEXT_BASE in Makefile, but right before 
that it includes the system-wide config.mk, which configures the compiler 
options and amongst those is -DTEXT_BASE and that one is set to one defined in 
board/apollon/config.mk . Obviously when compiling start.S, that one is used.

Cheers

> No need to modify config.mk and Makefile. If you need I can't send a
> sample files to you.
> 
> Thank you,
> Kyungmin Park
> 
> > The thing we can do is define STACK_TOP_BASE and that'd certainly do the
> > trick! This would allow me to point stack into SRAM, while running the
> > IPL code from BootRAM. Of course, in case STACK_TOP_BASE wasn't defined,
> > it'd fall back to the old code in start.S. This would of course work
> > without modifying config.mk and I start to like such a solution.
> > 
> > Hm?
> > 
> >> load IPL code ONENAND_IPL_TEXT_BASE instead of current code.
> >> 
> >> Thank you,
> >> Kyungmin Park
> > 
> > Thanks!
> > 
> >> On Sat, May 1, 2010 at 11:48 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
> >> > Hey,
> >> > 
> >> > I've been tinkering with OneNAND IPL in uboot. I found out it wan't to
> >> > load itself to the address specified in board/$(BOARDDIR)/config.mk .
> >> > That's fine in most cases, but in my case that wasn't possible.
> >> > 
> >> > In my case, SDRAM init didn't fit into the IPL, so I had to copy
> >> > U-Boot into SRAM, then execute it and let it relocate itself into
> >> > SDRAM. One more time: IPL: OneNAND->SRAM
> >> > U-Boot: SRAM->SDRAM
> >> > 
> >> > It all works fine, but when compiling the IPL, I had to alter
> >> > TEXT_BASE not to point into SDRAM but SRAM too (because of stack). I
> >> > introduced a variable called IPL which allows using config.mk from
> >> > (for example) onenand-
> >> > ipl/board/$(BOARDDIR)/config.mk rather than the
> >> > board/$(BOARDDIR)/config.mk one, which is in my opinion a correct
> >> > behaviour.
> >> > 
> >> > Any opinions?
> >> > 
> >> > Thanks in advance.
> >> > 
> >> > diff --git a/config.mk b/config.mk
> >> > index 73b5195..8639580 100644
> >> > --- a/config.mk
> >> > +++ b/config.mk
> >> > @@ -130,9 +130,13 @@ BOARDDIR = $(VENDOR)/$(BOARD)
> >> >  else
> >> >  BOARDDIR = $(BOARD)
> >> >  endif
> >> > +ifdef  IPL
> >> > +sinclude $(TOPDIR)/$(IPL)/board/$(BOARDDIR)/config.mk  # include IPL
> >> > specific rules
> >> > +else
> >> >  ifdef  BOARD
> >> >  sinclude $(TOPDIR)/board/$(BOARDDIR)/config.mk # include board
> >> > specific rules endif
> >> > +endif
> >> > 
> >> >  #####################################################################
> >> > ### #
> >> > 
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