OvmfPkg/QemuFwCfgLib: Provide Pei and Dxe specific library

[mirror_edk2.git] / OvmfPkg / Library / QemuFwCfgLib / QemuFwCfgDxe.c

diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgDxe.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgDxe.c
new file mode 100644 (file)
index 0000000..ac05f4c
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgDxe.c
@@ -0,0 +1,116 @@
+/** @file\r
+\r
+  Stateful and implicitly initialized fw_cfg library implementation.\r
+\r
+  Copyright (C) 2013, Red Hat, Inc.\r
+  Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>\r
+\r
+  This program and the accompanying materials are licensed and made available\r
+  under the terms and conditions of the BSD License which accompanies this\r
+  distribution.  The full text of the license may be found at\r
+  http://opensource.org/licenses/bsd-license.php\r
+\r
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+**/\r
+\r
+#include <Library/DebugLib.h>\r
+#include <Library/QemuFwCfgLib.h>\r
+\r
+#include "QemuFwCfgLibInternal.h"\r
+\r
+STATIC BOOLEAN mQemuFwCfgSupported = FALSE;\r
+STATIC BOOLEAN mQemuFwCfgDmaSupported;\r
+\r
+\r
+/**\r
+  Returns a boolean indicating if the firmware configuration interface\r
+  is available or not.\r
+\r
+  This function may change fw_cfg state.\r
+\r
+  @retval    TRUE   The interface is available\r
+  @retval    FALSE  The interface is not available\r
+\r
+**/\r
+BOOLEAN\r
+EFIAPI\r
+QemuFwCfgIsAvailable (\r
+  VOID\r
+  )\r
+{\r
+  return InternalQemuFwCfgIsAvailable ();\r
+}\r
+\r
+\r
+RETURN_STATUS\r
+EFIAPI\r
+QemuFwCfgInitialize (\r
+  VOID\r
+  )\r
+{\r
+  UINT32 Signature;\r
+  UINT32 Revision;\r
+\r
+  //\r
+  // Enable the access routines while probing to see if it is supported.\r
+  // For probing we always use the IO Port (IoReadFifo8()) access method.\r
+  //\r
+  mQemuFwCfgSupported = TRUE;\r
+  mQemuFwCfgDmaSupported = FALSE;\r
+\r
+  QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r
+  Signature = QemuFwCfgRead32 ();\r
+  DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));\r
+  QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r
+  Revision = QemuFwCfgRead32 ();\r
+  DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));\r
+  if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r
+      (Revision < 1)\r
+     ) {\r
+    DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));\r
+    mQemuFwCfgSupported = FALSE;\r
+    return RETURN_SUCCESS;\r
+  }\r
+\r
+  if ((Revision & FW_CFG_F_DMA) == 0) {\r
+    DEBUG ((DEBUG_INFO, "QemuFwCfg interface (IO Port) is supported.\n"));\r
+  } else {\r
+    mQemuFwCfgDmaSupported = TRUE;\r
+    DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n"));\r
+  }\r
+  return RETURN_SUCCESS;\r
+}\r
+\r
+\r
+/**\r
+  Returns a boolean indicating if the firmware configuration interface is\r
+  available for library-internal purposes.\r
+\r
+  This function never changes fw_cfg state.\r
+\r
+  @retval    TRUE   The interface is available internally.\r
+  @retval    FALSE  The interface is not available internally.\r
+**/\r
+BOOLEAN\r
+InternalQemuFwCfgIsAvailable (\r
+  VOID\r
+  )\r
+{\r
+  return mQemuFwCfgSupported;\r
+}\r
+\r
+/**\r
+  Returns a boolean indicating whether QEMU provides the DMA-like access method\r
+  for fw_cfg.\r
+\r
+  @retval    TRUE   The DMA-like access method is available.\r
+  @retval    FALSE  The DMA-like access method is unavailable.\r
+**/\r
+BOOLEAN\r
+InternalQemuFwCfgDmaIsAvailable (\r
+  VOID\r
+  )\r
+{\r
+  return mQemuFwCfgDmaSupported;\r
+}\r