From: Laszlo Ersek <lersek@redhat.com>
Date: Tue, 4 Mar 2014 08:01:49 +0000 (+0000)
Subject: OvmfPkg QemuFwCfgLib: determine if S3 support is explicitly enabled
X-Git-Tag: edk2-stable201903~11672
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=14eb7a5be2d6415ca614fb62c28fd165eed3c572

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 2519fc297f..8d3b835d43 100644
--- a/OvmfPkg/Include/Library/QemuFwCfgLib.h
+++ b/OvmfPkg/Include/Library/QemuFwCfgLib.h
@@ -214,5 +214,19 @@ InternalQemuFwCfgIsAvailable (
   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 3c5963f31b..92c85c1d3d 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -294,3 +294,31 @@ QemuFwCfgFindFile (
 
   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);
+}