#13370: Haiku doesn't mbr boot on AMD Ryzen systems
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Reporter: kallisti5 | Owner: nobody
Type: bug | Status: assigned
Priority: normal | Milestone: Unscheduled
Component: System/Boot Loader | Version: R1/Development
Resolution: | Keywords: boot-failure
Blocked By: | Blocking: 13953, 14325
Has a Patch: 0 | Platform: All
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Comment (by mmlr):
The syslog shows that there is a problem with finding an interrupt routing
for the IO-MMU and therefore switching to IO-APICs is aborted:
https://dev.haiku-os.org/attachment/ticket/13370/20180918-RR-wacom-
previous_syslog.txt#L1548
Using modern systems without IO-APICs isn't really a good idea as it will
lead to lots of shared interrupts and is generally not well tested (by
hardware vendors and in Haiku).
I don't think the IO-MMU should get an interrupt line at all, but it looks
like the interrupt pin is still set in the PCI registers (causing the IO-
APIC setup code to try and find a routing). The interrupt line is however
unset. It may be a good idea to ignore a failure to find an interrupt
routing for devices that previously weren't assigned an interrupt at all,
because they wouldn't have an interrupt line under the PIC either.
The code avoids using IO-APICs in case anything does not add up. This made
sense at the time this code was written as IO-APICs were sometimes just
buggy and using them instead of the traditional PIC would generally make
things worse. In todays systems however using the IO-APIC is the expected
norm and using the PIC is the neglected option that will probably make
things worse. So alternatively the IO-APIC code could be made less
conservative overall.
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Ticket URL: <https://dev.haiku-os.org/ticket/13370#comment:21>
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