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

Wolfgang Denk wd at denx.de
Sun Feb 13 01:15:12 CET 2005

In message <2da76b6505021215452596cc8a at 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

> 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_

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