Mike Loptien (mike.loptien@se-eng.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2684
-gerrit
commit 11b7528420451d75da381e77e9fdadf417d16451 Author: Mike Loptien mike.loptien@se-eng.com Date: Tue Mar 12 10:21:24 2013 -0600
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 --- src/mainboard/amd/persimmon/dsdt.asl | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/src/mainboard/amd/persimmon/dsdt.asl b/src/mainboard/amd/persimmon/dsdt.asl index 148d7b0..dff5917 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) }