[ros-dev] APIC support on uniprocessor machines

[James Tabor]

Hi!
Hartmut Birr wrote:
> Hi,   
> 
> if your machine can run M$ windows in APIC mode, you can use the SMP
> build. For using the apic mode, the bios must provide an MP structure.
> The acpi structures doesn't contain the wiring between the apic and the
> physical interrupt lines. But sharing of interrupts in non apic mode
> should also work. I've a test machine which does share one interrupt
> with two scsi controllers and one network card. The scsi cards work
> perfectly. The nic driver is loaded, but it didn't work properly. I
> think this has nothing to do with the interrupt.
> 
> - Hartmut
> 

I'm run Linux with APIC uniprocessor compiled w/o smp support. But would
that make a difference? I'll try compiling smp to see.

Here is a interrupt list dump from linux,

root at rosbox:/proc# cat interrupts
            CPU0
   0:  688709406    IO-APIC-edge  timer
   1:     227899    IO-APIC-edge  i8042
   3:   37547817    IO-APIC-edge  serial
   7:    2888974    IO-APIC-edge  parport0
   9:          1   IO-APIC-level  acpi
  12:    3308666    IO-APIC-edge  i8042
  14:     345459    IO-APIC-edge  ide0
  15:         25    IO-APIC-edge  ide1
  17:         21   IO-APIC-level  ide2
  19:    7669945   IO-APIC-level  eth0
  21:          0   IO-APIC-level  ehci_hcd, uhci_hcd, uhci_hcd, uhci_hcd
  22:     728139   IO-APIC-level  VIA8233
NMI:          0
LOC:  688695128
ERR:          0
MIS:          0

With apic you can reassign irq and do not need to share them. The only
one is usb and thats for good reason.

Thanks Hartmut,
James