[U-Boot] uboot for MIPS: need help to skip relocate uboot and start uboot from RAM

[Pandurang Kale]

Hi Wolfgang Denk,

 Thanks a lot for all the clarification and help. I really appreciate your
support.

 I have few question with reards to the start.S file for MIPS. What is the
significance of CONFIG_SYS_MONITOR_BASE ?? why is this used as the
base/source address in relocate_code in mips start.S file while for ARM we
use the _start as base/source address?

secondly for ARM we compare the source and destination address and skip the
copy_loop(in ARM specific start.S file) if both are same, while this has not
been implemented for MIPS.

I had to make similar changes in the start.S file (MIPS version) to skip the
copying section.

Thanks,
Pandu.

P.S: I am aware that you are out till 14th but I thought of posting it as
these are valid arguments.

On Fri, Mar 4, 2011 at 6:23 AM, Wolfgang Denk <wd at denx.de> wrote:

> Dear Pandurang Kale,
>
> In message <AANLkTinTqxJPU9Gwye_8pT2PcUxR8E36=zm78ypc1740 at mail.gmail.com>
> you wrote:
> >
> > For MIPS I do not find the TEXT_BASE symbol, there is
> SYS_CFG_MONITOR_BASE
>
> Please check again. MIPS uses CONFIG_SYS_TEXT_BASE like all other
> architectures.
>
> > which it uses to relocate the code from the define symbol to high RAM
> > address. how can I avoid this?  As I see we have a switch defined for
> ARM,
>
> You should not try to avoid this.  It is a useful feature, even if you
> load U-Boot to RAM separately.
>
> > CONFIG_SKIP_RELOCATE_UBOOT,  to skip the code relocation I cant find a
> > similar instance in MIPS code. Can you please throw some light on getting
> > the TEXT_BASE setting correctly for MIPS code? how can I do that?
>
> You did not understand what I wrote:
>
> > > > I can see there is a switch for ARM processor,
> > > CONFIG_SKIP_RELOCATE_UBOOT,
> > >
> > > Are you looking at recent code and working boards?
> > >
> > I have recent uboot code for MIPS and I cant find any similar switch for
> > MIPS codebase. arch/mips/lib/board.c and arch/mips/cpu/start.S
>
> I meant: do you see CONFIG_SKIP_RELOCATE_UBOOT in recent ARM code, on
> working (compilable) ARM boards?
>
> > > Do do not want to skip relocation.  U-Boot may need to auto-adjust
> > > it's start address dynamically, depending on configuration, system
> > > requirements and/or environment settings.
> > >
> > The uboot is already loaded in the RAM (by the primary boot loader) so I
> > dont want uboot to again relocate itself from one location of RAM to its
> > predefined high-memory region in RAM which I have explained in my first
> > mail.
>
> Please re-read what I wrote.  In general, U-Boot's load address cannot
> be determined at compile time, at least not without crippeling it from
> some interesting features.  You should really not try doing things
> differently to everybody else.  We had similar discussins not so long
> ago for AMR, so please just re-read this in the archives.
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
>