Boot code of linuxppc v. netbsd

[Dan Jacobowitz <youngdrow%geocities.com@localhost>]

First of all, if anyone wants to look at it, linux-pmac/arch/ppc can be
found both loose and as a .tgz under
http://www.drow.net/netbsd/linux_arch_ppc and
http://www.drow.net/netbsd/linux_arch_ppc.tgz .

Looking at coffboot, their xcoff boot loader, I noticed something very
interesting.  It calls first crt0 - some cache flushing only, as far as I
can tell - and then start(int a1, int a2, void *promptr).

Our ofwboot on the other hand begins right at:
__dead void
_start(vpd, res, openfirm, arg, argl)
        void *vpd;
        int res;
        int (*openfirm)(void *);
        char *arg;
        int argl;

Notice that we are expecting five parameters instead of three.  Could it
possibly be that Apple's OF is not providing five?


As an aside, in arch/powerpc/powerpc/ofwmagic.S we say:
/*
 * Magic note section used by OpenFirmware.
 */
[snip]
        # note descriptor

        # real mode (-1) or virtual mode (0)
        .long   0

Is this ignored?  Also, I note that a vmlinux.coff has only a .text, .data,
and .bss while we have seven or so sections.  Cutting corners for poor old
Apple again?


Dan.

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| Dan Jacobowitz                 | drow%drow.net@localhost                    |
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