OvmfPkg QemuFwCfgLib: determine if S3 support is explicitly enabled
Such a packaged query function will come in handy in the following
patches.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
[jordan.l.justen@intel.com: check for enabled rather than disabled]
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15292 6f19259b-4bc3-4df7-8a09-765794883524
diff --git a/OvmfPkg/Include/Library/QemuFwCfgLib.h b/OvmfPkg/Include/Library/QemuFwCfgLib.h
index 2519fc2..8d3b835 100644
--- a/OvmfPkg/Include/Library/QemuFwCfgLib.h
+++ b/OvmfPkg/Include/Library/QemuFwCfgLib.h
@@ -214,5 +214,19 @@
VOID
);
+
+/**
+ Determine if S3 support is explicitly enabled.
+
+ @retval TRUE if S3 support is explicitly enabled.
+ FALSE otherwise. This includes unavailability of the firmware
+ configuration interface.
+**/
+BOOLEAN
+EFIAPI
+QemuFwCfgS3Enabled (
+ VOID
+ );
+
#endif
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
index 3c5963f..92c85c1 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -294,3 +294,31 @@
return RETURN_NOT_FOUND;
}
+
+
+/**
+ Determine if S3 support is explicitly enabled.
+
+ @retval TRUE if S3 support is explicitly enabled.
+ FALSE otherwise. This includes unavailability of the firmware
+ configuration interface.
+**/
+BOOLEAN
+EFIAPI
+QemuFwCfgS3Enabled (
+ VOID
+ )
+{
+ RETURN_STATUS Status;
+ FIRMWARE_CONFIG_ITEM FwCfgItem;
+ UINTN FwCfgSize;
+ UINT8 SystemStates[6];
+
+ Status = QemuFwCfgFindFile ("etc/system-states", &FwCfgItem, &FwCfgSize);
+ if (Status != RETURN_SUCCESS || FwCfgSize != sizeof SystemStates) {
+ return FALSE;
+ }
+ QemuFwCfgSelectItem (FwCfgItem);
+ QemuFwCfgReadBytes (sizeof SystemStates, SystemStates);
+ return (BOOLEAN) (SystemStates[3] & BIT7);
+}