Hi,
ruiktest ~ # /tmp/acpidump Could not get ACPI tables, AE_BAD_HEADER
It seems there is a bug in ACPICA, coreboot is using revision 0 (ACPI 1.0) if there is no XSDT. But ACPICA expect always ACPI 2.0 style which have a len record. This is bit more complicated, coreboot creates a header with revision 0, but provides all other fields as it would be ACPI 2.0, but SeaBIOS correctly strips that.
I created a bug report at ACPICA:
https://bugs.acpica.org/show_bug.cgi?id=1097
Thanks Rudolf