Hi,
Can I use current seabios with old qemu which does not provide the separate ACPI tables? For example, does current bios contain these tables too, so they're both separate and embedded?
Yes. The i440fx acpi tables are compiled in and will be used as fallback in case qemu doesn't provide acpi tables.
And the reverse, can I use old bios with new qemu which do provide the separate tables?
Yes. Old seabios will simply ignore the qemu-provides tables and use the compiled-in ones. That is limited to the 'pc' machine type though, q35 will not work this way. q35 needs other tables and this was the reason to let qemu provide the tables in the first place.
cheers, Gerd