fiasco boot sequence on arm

Adam Lackorzynski adam at
Sun Oct 19 21:27:52 CEST 2008


On Fri Oct 17, 2008 at 01:39:18 +0800, Qmo (Yi-Sheng) wrote:
> I am working on a project which porting fiasco to a ARM&DSP platform.
> Now I have questions about the fiasco boot sequence in arm side.
> First, when doing a workable kernel image, we should use the l4
> package *[1]"bootstrap"
> (l4/pkg/bootstrap)*
>  to encapsulate the needed modules, for example: roottask, sigma0, and the
> real fiasco kernel(it means the building image in
> kernel/fiasco/builddir/fiasco.image).
> And we find the file "l4/pkg/bootstrap/server/src/", there are
> some source code lines like:
> #elif defined(ARCH_arm)
>          typedef void (*startup_func)(void);
>         * startup_func f = (startup_func)boot_info.kernel_start;*
>           f();
>  #else
> the command line says that "setup the L4 kernel info page before booting the
> L4 microkernel",
> but we want to know what is the entry point about
> *boot_info.kernel_start*in the real fiasco kernel(fiasco.image) source
> codes?

_start, and then bootstrap_main.

> And we also find that there is also a file named *[2]bootstrap in
> kernel/fiasco/src/kern/arm/bootstrap.cpp*, this file seems to steup the
> memory mapping.
> So we guess the first bootstrap*[1]* is used to arrange the roottask,
> sigma0, etc... in the memory space, then jump to the second

Just sigma0 and roottask are moved to their final place, others are left
where they are.

> bootstrap*[2]*in fiasco kernel
> to setup the needed memory mapping, and finally give the control to the real
> fiasco kernel. We want to confirm the steps, or something is wrong?

Yes, sounds good!

> And the last question, what is the coding style about *IMPLEMENTATION [arm]:
> *
> in kernel/fiasco/src/kern/arm/ directory, is there any effect when compiling
> them?

Yes, the preprocess tools takes or not takes those parts, depending
which tags are used, those tags are defined by the configuration.

Adam                 adam at

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