[coreboot] Servo debug uart in Linux?

Trammell Hudson hudson at trmm.net
Thu Oct 6 19:56:52 CEST 2016

Is it possible to use the Skylake Servo debug UART in Linux or Xen?
It doesn't show up as a normal 16550 (setserial reports "uart type
unknown"), which is making debugging the payload kernel a little

I've added lots of "outb $0x80" calls to trace the Xen hypervisor and
have figured out that the Skylake doesn't work with the x2apic, the xsave
instruction or the MCE handler, but would prefer a higher bandwidth way
to report progress/errors.


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