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--- acpi [2014/11/12 13:48]
lionelsambuc created
+++ acpi [2014/11/12 13:48] (current)
lionelsambuc created
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+===== ACPI =====
+Support for [[http://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface|ACPI]] in Minix has 2 parts, in-kernel code and a userspace driver.
+==== Kernel ====
+The in-kernel code is used to locate the ACPI information in memory and export this to userland, discover IO APICs and all CPU in a multi-processor system.
+==== Userspace ACPI driver ====
+The userspace driver is based on the [[http://www.acpica.org/|ACPI CA]] library. The library covers the whole ACPI functionality which means that in theory Minix can uses any of the ACPI feature, the functionality is limited though.
+  * Currently the driver provides interface to discover PCI interrupts routing information only
+  * Does not register interrupt hooks to handle events
+It is fairly easy to add interfaces to any other functions as need be. Minix does not have any use for this yet.
+The main disadvantage of the ACPI driver is that it can access **//any//** system memory and IO ports which is a **//possible vulnerability//**. It is not possible to limit the memory acces in the sense of the the isolation policies as implemented in current Minix.