[coreboot] Libpayload dies with NMI exception on qemu-q35

[Jonathan Neuschäfer]

Hi,

I just tried to boot coreinfo in qemu-q35, and it got an NMI exception
after a second:
> Run img/coreinfo
> Calling addr 0x00100000
>
> <coreinfo starts and shows information>
> Non-Maskable-Interrupt Exception
> Error code: n/a
> EIP:    0x00104175
> CS:     0x0010
> EFLAGS: 0x00000093
> EAX:    0x52797503
> ECX:    0x00000000
> EDX:    0x00000001
> EBX:    0x5a769ba0
> ESP:    0x0015917c
> EBP:    0x0000011a
> ESI:    0x31ef541a
> EDI:    0x00000001
> DS:     0x0018
> ES:     0x0018
> SS:     0x0018
> FS:     0x0018
> GS:     0x0018
> Dumping stack:
> 0x159360: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159340: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159320: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159300: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x1592e0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x1592c0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x1592a0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159280: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159260: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159240: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159220: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x159200: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x1591e0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0x1591c0: 00000000 00000000 00100051 00006fb4 00000000 00000000 00000000 00000000
> 0x1591a0: 001591d0 001591c0 ffe27904 001020d0 0010546b 00104d07 00104f88 001020d0
> 0x159180: 00006fb4 001591d0 001591a8 0010209c 000001f4 00000000 001591d0 00006fb4
> 0x159160: 00000000 001591d0 00006fb4 001591d0 00104175 00000010 00000093 001591d0

This happens reliably both with and without SeaBIOS and in both
qemu-system-i386 and qemu-system-x86_64 (version 2.5.0).

The coreinfo application code is apparently irrelevant: I replaced
coreinfo's main() with a printf and an endless loop and still get the
same result.

What could be causing this?

Jonathan