genode

History

Alexander Boettcher 35a96e1101 acpi: parse RMRR structures and print DMA regions The regions reported by the RMRR structure are used by legacy devices for DMA requests. Theses would need to be added to the device_pd to avoid DMAR faults when used in legacy mode. For now parse and print them, so that one has a clue about why we get DMAR faults. Issue #683		2013-08-30 13:34:14 +02:00
..
x86	Coding style fixes	2013-03-23 13:37:57 +01:00
README	ACPI: Remove quota checking	2012-03-16 18:22:52 +01:00
acpi.cc	acpi: parse RMRR structures and print DMA regions	2013-08-30 13:34:14 +02:00
acpi.h	Coding style fixes	2013-03-23 13:37:57 +01:00
main.cc	Attach affinity information to session requests	2013-08-13 17:08:25 +02:00

README

This directory contains an implementation of a simple ACPI parser

Behavior
--------

This server should be used when using a kernel (like Fiasco.OC or Nova) that
takes advantage of x86's APIC. The server traverses the ACPI tables and sets the
interrupt line of devices within the PCI config space to the GSIs found in the
ACPI tables. The 'MADT' table is parsed by the server as well, enabling clients
to use the correct IRQ when 'Interrupt Override' structures are found wihtin the
table.

Usage
-----

Start the 'acpi_drv' in your Genode environment. Do not start the 'pci_drv'
since this will be used as a slave of the 'acpi_drv'. You still must load the
'pci_drv' in your boot loader.

Configuration snipped (please note that IRQ service requests of the 'timer' are
routed to the ACPI-driver):

!<start name="acpi">
!  <resource name="RAM" quantum="2M"/>
!    <binary name="acpi_drv"/>
!    <provides>
!      <service name="PCI"/>
!      <service name="IRQ" />
!    </provides>
!    <route>
!      <service name="PCI"> <any-child /> </service>
!      <any-service> <parent/> <any-child /> </any-service>
!    </route>
!</start>
!
!<start name="timer">
!  <resource name="RAM" quantum="1M"/>
!  <provides><service name="Timer"/></provides>
!  <route>
!    <service name="IRQ"><child name="acpi" /></service>
!    <any-service> <parent /> <any-child /></any-service>
!  </route>
!</start>

Limitations and known issues
----------------------------

Currently there is no interface to set the interrupt mode for Irq_sessions
(e.g., level or edge triggered). This is required by Fiasco.OCs kernel
interface. We regard this as future work.