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authorMike Loptien <mike.loptien@se-eng.com>2013-03-12 10:21:24 -0600
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-03-15 17:06:23 +0100
commite31c0ed9b5f789cb0207740c588c769f7eda5f0e (patch)
treea73d64418b7663c57dc053de9ce72997c4219ddd /src/mainboard/amd
parent35c2f4fd4aac8b14421ee73be490bde06dbcef56 (diff)
Persimmon DSDT: Add OSC method
The _OSC method is used to tell the OS what capabilities it can take control over from the firmware. This method is described in chapter 6.2.9 of the ACPI spec v3.0. The method takes 4 inputs (UUID, Rev ID, Input Count, and Capabilities Buffer) and returns a Capabilites Buffer the same size as the input Buffer. This Buffer is generally 3 Dwords long consisting of an Errors Dword, a Supported Capabilities Dword, and a Control Dword. The OS will request control of certain capabilities and the firmware must grant or deny control of those features. We do not want to have control over anything so let the OS control as much as it can. The _OSC method is required for PCIe devices and dmesg checks for its existence and issues an error if it is not found. Change-Id: I1494285def7440972f0549b7cb73eb94dafc72c2 Signed-off-by: Mike Loptien <mike.loptien@se-eng.com> Reviewed-on: http://review.coreboot.org/2684 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/mainboard/amd')
-rw-r--r--src/mainboard/amd/persimmon/dsdt.asl14
1 files changed, 13 insertions, 1 deletions
diff --git a/src/mainboard/amd/persimmon/dsdt.asl b/src/mainboard/amd/persimmon/dsdt.asl
index 148d7b074b..dff59170de 100644
--- a/src/mainboard/amd/persimmon/dsdt.asl
+++ b/src/mainboard/amd/persimmon/dsdt.asl
@@ -1157,8 +1157,20 @@ DefinitionBlock (
Device(PCI0) {
External (TOM1)
External (TOM2)
- Name(_HID, EISAID("PNP0A03"))
+ Name(_HID, EISAID("PNP0A08")) /* PCI Express Root Bridge */
+ Name(_CID, EISAID("PNP0A03")) /* PCI Root Bridge */
Name(_ADR, 0x00180000) /* Dev# = BSP Dev#, Func# = 0 */
+
+ /* Operating System Capabilities Method */
+ Method(_OSC,4)
+ { /* Check for proper PCI/PCIe UUID */
+ If(LEqual(Arg0,ToUUID("33DB4D5B-1FF7-401C-9657-7441C03DD766")))
+ {
+ /* Let OS control everything */
+ Return (Arg3)
+ }
+ }
+
Method(_BBN, 0) { /* Bus number = 0 */
Return(0)
}