[U-Boot-Users] Need help booting an unsupported OS on ARM

[U-Boot-Users] Need help booting an unsupported OS on ARM

[Rod Landers]

I am trying to use U-Boot to start up a home grown OS.  How can I make
my OS a little more U-Boot friendly, or visa-versa?  The specific
problem I'm having is that when I issue a SWI on the arm, the U-Boot
interrupt routines get used instead of mine.

I can see why that is happening because the vectors in the flash
address point to the U-Boot routines, but I'm wondering if there is a
way to set a secondary jump so that my routines are used.

Thanks,

Rod Landers

[U-Boot-Users] Need help booting an unsupported OS on ARM

[Wolfgang Denk]

In message <2da76b6505021215452596cc8a@mail.gmail.com> you wrote:
> I am trying to use U-Boot to start up a home grown OS.  How can I make
> my OS a little more U-Boot friendly, or visa-versa?  The specific

You can do both, but in general you don't have to.

The most trivial thing is to start your OS using the "go"  command  -
assuming that the OS does not require to receive any information from
the  boot loader. Or, assuming the OS uses ELF files, you can use the
"bootelf" copmmand, too.

> problem I'm having is that when I issue a SWI on the arm, the U-Boot
> interrupt routines get used instead of mine.

Your OS is expected  to  install  it's  own  interrupt  handlers,  of
course.

> I can see why that is happening because the vectors in the flash
> address point to the U-Boot routines, but I'm wondering if there is a

This is only before relocation.

> way to set a secondary jump so that my routines are used.

You may want to peek for example at the  Linux  kernel  code  how  to
install your own interrupt handlers.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
In accord with UNIX philosophy, Perl gives you enough  rope  to  hang
yourself.              - L. Wall & R. L. Schwartz, _Programming Perl_

[U-Boot-Users] Need help booting an unsupported OS on ARM

[Rod Landers]

Thanks Wolfgang,

That only seems logical.  I'm not exactly sure why I didn't think of
checking out Linux for examples.

-Rod


On Sun, 13 Feb 2005 01:15:12 +0100, Wolfgang Denk <wd@denx.de> wrote:
> In message <2da76b6505021215452596cc8a@mail.gmail.com> you wrote:
> > I am trying to use U-Boot to start up a home grown OS.  How can I make
> > my OS a little more U-Boot friendly, or visa-versa?  The specific
> 
> You can do both, but in general you don't have to.
> 
> The most trivial thing is to start your OS using the "go"  command  -
> assuming that the OS does not require to receive any information from
> the  boot loader. Or, assuming the OS uses ELF files, you can use the
> "bootelf" copmmand, too.
> 
> > problem I'm having is that when I issue a SWI on the arm, the U-Boot
> > interrupt routines get used instead of mine.
> 
> Your OS is expected  to  install  it's  own  interrupt  handlers,  of
> course.
> 
> > I can see why that is happening because the vectors in the flash
> > address point to the U-Boot routines, but I'm wondering if there is a
> 
> This is only before relocation.
> 
> > way to set a secondary jump so that my routines are used.
> 
> You may want to peek for example at the  Linux  kernel  code  how  to
> install your own interrupt handlers.
> 
> Best regards,
> 
> Wolfgang Denk
> 
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> In accord with UNIX philosophy, Perl gives you enough  rope  to  hang
> yourself.              - L. Wall & R. L. Schwartz, _Programming Perl_
>

[U-Boot-Users] Need help booting an unsupported OS on ARM

[Roger Larsson]

On Sunday 13 February 2005 19.36, Rod Landers wrote:
> Thanks Wolfgang,
>
> That only seems logical.  I'm not exactly sure why I didn't think of
> checking out Linux for examples.
>

Maybe because Linux code is GPL:ed?
And that after you have fixed all your OS problems by copying code from
Linux you might en up in a questionable licensing situation...
But of cause that is no problem if your OS is GPLed too.

/RogerL