query: per-opcode filters/logging? about avatar2 HOT 2 OPEN

Hi,

If I understand correctly, you would like to do some hardware-in-the-loop to debug the reboot issue on hardware, but you have troubles booting the firmware in QEMU up to the same point as with the hardware?

In this case, I think you could start the execution on the hardware, breakpoint somewhere after the point where QEMU has difficulties to emulate (POST codes), migrate the state of the firmware in QEMU and continue from there?

from avatar2.

No, the post codes are not really that big of an issue, but it would be nice to have.

The real issue is that on vendor firmware, something happens on the x86 side
(there's also arm code execution on ryzen chips) that prevents the boot loop from
happening, so maybe by emulating the vendor bios and watching 'what it does'
will reveal the secret I need.

Suppose this is theoretically doable. Question now would be, how? Serial target? GDB target? Jtag is off the table 100%, and as far as I know there's no x86 gdbstub in 'bios' out there.

from avatar2.