[coreboot] IMB-A180 based design question regarding interrupts

Scott Duplichan scott at notabs.org
Wed Jun 11 23:03:55 CEST 2014

Mark C. Mason [mailto:mark at edt.com] wrote:

]We are testing coreboot with our new IMB-A180 based AGESA design,
]and DMA interrupts are not functioning.  I am looking into the Coreboot
]Options, but is there a recipie for enabling legacy interrupts in AGESA?
]We configure in Linux at IRQ 17.
]Thanks in advance,
]Mark Mason
]Engineering Design Team

By legacy interrupts, do you mean the interrupt configuration
when PIC mode interrupt handling is in use, or do you mean
the routing of interrupts from a legacy device to an I/O
APIC interrupt number? You mention Linux so I think the latter.

It looks like agesa programs only APIC mode interrupt
routing, and not the PIC mode routing used by older
operating systems. The agesa programming is not configurable,
as far as I can tell (see FchInternalDeviceIrqForApicMode[]
in file HwAcpiLate.c).

Your own code reprogram this routing. See IOC00 Pci_Intr_Index
in the Kabini BKDG:


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