SeaBIOS won't execute (unimplemented opcode that should exist)

[ghost]

The opcodes sgdt and pause are unimplemented, so JPC fails when starting SeaBIOS Git or 1.10.2 with an UnimplementedOpcodeException. However, I do see code for sgdt at least.

I was able to workaround pause by changing it in code to nop, but what is wrong with sgdt?

[ianopolous]

It is probably sgdt in a different operating mode? I'm happy to accept prs if you get it working. The opcode implementations are generated from an xml meta description.

[ghost]

Ah, I think I understand the classes now. the opcodes.vm, pm, and rm classes are the respective operating modes of the processor. So I need to port the sgdt to whatever mode SeaBIOS is using?

…

On Thu, Jul 13, 2017 at 4:33 PM, Ian Preston ***@***.***> wrote: It is probably sgdt in a different operating mode? I'm happy to accept prs if you get it working. The opcode implementations are generated from an xml meta description. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#5 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ASVvX0lnRnqoSjJlYRv87TjjiAkjf2Cuks5sNn8SgaJpZM4OU-1I> .

[ianopolous]

That's correct. I haven't looked at this in a while so I don't remember in which modes it is implemented. sgdt might be a little involved, but you can check the intel documentation and also the equivalent source code in Bochs and Qemu for comparison after implementing it.