From 2ce7e221e70214b094e2e54d0e6dc9491a742dd3 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Fri, 3 Jan 2014 19:57:26 +0000
Subject: [PATCH] OvmfPkg: QemuFwCfgLib: extract stateful implementation
The current implementation of QemuFwCfgLib is:
- stateful
- implicitly initialized in the library constructor.
OVMF's SEC runs from read-only memory/flash. When the library is linked
into a SEC binary (which currently never happens), the
"mQemuFwCfgSupported" global variable becomes read-only, making the
library non-functional.
Extract the stateful, implicitly initialized library implementation into a
separate file, making room for a stateless, explicitly queried
implementation that's usable in SEC. Restrict the stateful implementation
to the current, non-SEC clients.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15045 6f19259b-4bc3-4df7-8a09-765794883524
---
OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c | 74 ---------------
OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf | 6 +-
.../Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c | 92 +++++++++++++++++++
3 files changed, 97 insertions(+), 75 deletions(-)
create mode 100644 OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
index 985b383c26..3c5963f31b 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -22,8 +22,6 @@
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
-STATIC BOOLEAN mQemuFwCfgSupported = FALSE;
-
/**
Reads an 8-bit I/O port fifo into a block of memory.
@@ -78,26 +76,6 @@ IoWriteFifo8 (
);
-/**
- Returns a boolean indicating if the firmware configuration interface
- is available or not.
-
- This function may change fw_cfg state.
-
- @retval TRUE The interface is available
- @retval FALSE The interface is not available
-
-**/
-BOOLEAN
-EFIAPI
-QemuFwCfgIsAvailable (
- VOID
- )
-{
- return InternalQemuFwCfgIsAvailable ();
-}
-
-
/**
Selects a firmware configuration item for reading.
@@ -265,39 +243,6 @@ QemuFwCfgRead64 (
}
-RETURN_STATUS
-EFIAPI
-QemuFwCfgInitialize (
- VOID
- )
-{
- UINT32 Signature;
- UINT32 Revision;
-
- //
- // Enable the access routines while probing to see if it is supported.
- //
- mQemuFwCfgSupported = TRUE;
-
- QemuFwCfgSelectItem (QemuFwCfgItemSignature);
- Signature = QemuFwCfgRead32 ();
- DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
- QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
- Revision = QemuFwCfgRead32 ();
- DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
- if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
- (Revision < 1)
- ) {
- DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
- mQemuFwCfgSupported = FALSE;
- return RETURN_SUCCESS;
- }
-
- DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));
- return RETURN_SUCCESS;
-}
-
-
/**
Find the configuration item corresponding to the firmware configuration file.
@@ -349,22 +294,3 @@ QemuFwCfgFindFile (
return RETURN_NOT_FOUND;
}
-
-
-/**
- Returns a boolean indicating if the firmware configuration interface is
- available for library-internal purposes.
-
- This function never changes fw_cfg state.
-
- @retval TRUE The interface is available internally.
- @retval FALSE The interface is not available internally.
-**/
-BOOLEAN
-EFIAPI
-InternalQemuFwCfgIsAvailable (
- VOID
- )
-{
- return mQemuFwCfgSupported;
-}
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf
index e6910c76bb..071737edef 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf
@@ -1,5 +1,8 @@
## @file
#
+# Stateful, implicitly initialized fw_cfg library.
+#
+# Copyright (C) 2013, Red Hat, Inc.
# Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
#
# This program and the accompanying materials
@@ -18,7 +21,7 @@
FILE_GUID = fdd53716-31e1-4acc-9007-8bd5d877c96f
MODULE_TYPE = BASE
VERSION_STRING = 1.0
- LIBRARY_CLASS = QemuFwCfgLib
+ LIBRARY_CLASS = QemuFwCfgLib|PEIM DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER
CONSTRUCTOR = QemuFwCfgInitialize
@@ -30,6 +33,7 @@
[Sources]
QemuFwCfgLib.c
+ QemuFwCfgPeiDxe.c
[Sources.IA32]
Ia32/IoLibExAsm.asm
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c
new file mode 100644
index 0000000000..f693cff29e
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c
@@ -0,0 +1,92 @@
+/** @file
+
+ Stateful and implicitly initialized fw_cfg library implementation.
+
+ Copyright (C) 2013, Red Hat, Inc.
+ Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
+
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/QemuFwCfgLib.h>
+
+STATIC BOOLEAN mQemuFwCfgSupported = FALSE;
+
+
+/**
+ Returns a boolean indicating if the firmware configuration interface
+ is available or not.
+
+ This function may change fw_cfg state.
+
+ @retval TRUE The interface is available
+ @retval FALSE The interface is not available
+
+**/
+BOOLEAN
+EFIAPI
+QemuFwCfgIsAvailable (
+ VOID
+ )
+{
+ return InternalQemuFwCfgIsAvailable ();
+}
+
+
+RETURN_STATUS
+EFIAPI
+QemuFwCfgInitialize (
+ VOID
+ )
+{
+ UINT32 Signature;
+ UINT32 Revision;
+
+ //
+ // Enable the access routines while probing to see if it is supported.
+ //
+ mQemuFwCfgSupported = TRUE;
+
+ QemuFwCfgSelectItem (QemuFwCfgItemSignature);
+ Signature = QemuFwCfgRead32 ();
+ DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
+ QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
+ Revision = QemuFwCfgRead32 ();
+ DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
+ if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
+ (Revision < 1)
+ ) {
+ DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
+ mQemuFwCfgSupported = FALSE;
+ return RETURN_SUCCESS;
+ }
+
+ DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));
+ return RETURN_SUCCESS;
+}
+
+
+/**
+ Returns a boolean indicating if the firmware configuration interface is
+ available for library-internal purposes.
+
+ This function never changes fw_cfg state.
+
+ @retval TRUE The interface is available internally.
+ @retval FALSE The interface is not available internally.
+**/
+BOOLEAN
+EFIAPI
+InternalQemuFwCfgIsAvailable (
+ VOID
+ )
+{
+ return mQemuFwCfgSupported;
+}