[Skiboot] Skiboot on qemu questions

Marty E. Plummer hanetzer-skiboot at use.startmail.com
Fri Oct 9 19:36:13 AEDT 2020


On Thu, Oct 08, 2020 at 10:59:37PM -0500, Marty E. Plummer wrote:
> 'you in this case' means the firmware (coreboot) I'm running?
> I don't recall explicitly enabling MMU but this is all very early work,
> so perhaps I did.
> 
> So 0xe40 illegal instructions, got it. Should have RTFM'd a bit more but
> I'm pretty excited about current progress and glazed over a bit.
Inspection of the hsrr0 and hsrr1 registers at the time of exception
leads me to believe an all zero instruction is attempting to be
executed. I *think* this may be to do with abi elfv2 toc stuff, since
the coreboot flow is basically bootblock calls romstage calls ramstage,
which is mostly 'read from boot media to some kind of memory, and jump
to it', so its basically executing three elf binaries in a row.

I assume each one should have its own toc & toc pointer set up prior to
their equivalent of `int main()`, or at the very least close to it?


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