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+/******************************************************************************
+ * console.h
+ *
+ * Console I/O interface for Xen guest OSes.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (c) 2005, Keir Fraser
+ */
+
+#ifndef __XEN_PUBLIC_IO_CONSOLE_H__
+#define __XEN_PUBLIC_IO_CONSOLE_H__
+
+typedef UINT32 XENCONS_RING_IDX;
+
+#define MASK_XENCONS_IDX(idx, ring) ((idx) & (sizeof(ring)-1))
+
+struct xencons_interface {
+ char in[1024];
+ char out[2048];
+ XENCONS_RING_IDX in_cons, in_prod;
+ XENCONS_RING_IDX out_cons, out_prod;
+};
+
+#endif /* __XEN_PUBLIC_IO_CONSOLE_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
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+/** @file
+ Xen console SerialPortLib instance
+
+ Copyright (c) 2015, Linaro Ltd. 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 <Base.h>
+#include <Uefi/UefiBaseType.h>
+
+#include <Library/BaseLib.h>
+#include <Library/SerialPortLib.h>
+#include <Library/XenHypercallLib.h>
+
+#include <IndustryStandard/Xen/io/console.h>
+#include <IndustryStandard/Xen/hvm/params.h>
+#include <IndustryStandard/Xen/event_channel.h>
+
+//
+// The code below expects these global variables to be mutable, even in the case
+// that we have been incorporated into SEC or PEIM phase modules (which is
+// allowed by our INF description). While this is a dangerous assumption to make
+// in general, it is actually fine for the Xen domU (guest) environment that
+// this module is intended for, as UEFI always executes from DRAM in that case.
+//
+STATIC evtchn_send_t mXenConsoleEventChain;
+STATIC struct xencons_interface *mXenConsoleInterface;
+
+RETURN_STATUS
+EFIAPI
+SerialPortInitialize (
+ VOID
+ )
+{
+ if (!mXenConsoleInterface) {
+ mXenConsoleEventChain.port = (UINT32)XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_EVTCHN);
+ mXenConsoleInterface = (struct xencons_interface *)(UINTN)
+ (XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_PFN) << EFI_PAGE_SHIFT);
+
+ //
+ // No point in ASSERT'ing here as we won't be seeing the output
+ //
+ }
+ return RETURN_SUCCESS;
+}
+
+/**
+ Write data to serial device.
+
+ @param Buffer Point of data buffer which need to be written.
+ @param NumberOfBytes Number of output bytes which are cached in Buffer.
+
+ @retval 0 Write data failed.
+ @retval !0 Actual number of bytes written to serial device.
+
+**/
+UINTN
+EFIAPI
+SerialPortWrite (
+ IN UINT8 *Buffer,
+ IN UINTN NumberOfBytes
+ )
+{
+ XENCONS_RING_IDX Consumer, Producer;
+ UINTN Sent;
+
+ if (!mXenConsoleInterface) {
+ return 0;
+ }
+
+ Consumer = mXenConsoleInterface->out_cons;
+ Producer = mXenConsoleInterface->out_prod;
+
+ MemoryFence ();
+
+ Sent = 0;
+ while (Sent < NumberOfBytes && ((Producer - Consumer) < sizeof (mXenConsoleInterface->out)))
+ mXenConsoleInterface->out[MASK_XENCONS_IDX(Producer++, mXenConsoleInterface->out)] = Buffer[Sent++];
+
+ MemoryFence ();
+
+ mXenConsoleInterface->out_prod = Producer;
+
+ if (Sent > 0) {
+ XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);
+ }
+
+ return Sent;
+}
+
+/**
+ Read data from serial device and save the data in buffer.
+
+ @param Buffer Point of data buffer which need to be written.
+ @param NumberOfBytes Size of Buffer[].
+
+ @retval 0 Read data failed.
+ @retval !0 Actual number of bytes read from serial device.
+
+**/
+UINTN
+EFIAPI
+SerialPortRead (
+ OUT UINT8 *Buffer,
+ IN UINTN NumberOfBytes
+)
+{
+ XENCONS_RING_IDX Consumer, Producer;
+ UINTN Received;
+
+ if (!mXenConsoleInterface) {
+ return 0;
+ }
+
+ Consumer = mXenConsoleInterface->in_cons;
+ Producer = mXenConsoleInterface->in_prod;
+
+ MemoryFence ();
+
+ Received = 0;
+ while (Received < NumberOfBytes && Consumer < Producer)
+ Buffer[Received++] = mXenConsoleInterface->in[MASK_XENCONS_IDX(Consumer++, mXenConsoleInterface->in)];
+
+ MemoryFence ();
+
+ mXenConsoleInterface->in_cons = Consumer;
+
+ XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);
+
+ return Received;
+}
+
+/**
+ Check to see if any data is available to be read from the debug device.
+
+ @retval TRUE At least one byte of data is available to be read
+ @retval FALSE No data is available to be read
+
+**/
+BOOLEAN
+EFIAPI
+SerialPortPoll (
+ VOID
+ )
+{
+ return mXenConsoleInterface &&
+ mXenConsoleInterface->in_cons != mXenConsoleInterface->in_prod;
+}
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+#/** @file
+#
+# Component description file for XenConsoleSerialPortLib module
+#
+# Copyright (c) 2015, Linaro Ltd. 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.
+#
+#**/
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = XenConsoleSerialPortLib
+ FILE_GUID = 401406DD-BCAC-4B91-9F4E-72A7FEBE4762
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = SerialPortLib
+ CONSTRUCTOR = SerialPortInitialize
+
+[Sources.common]
+ XenConsoleSerialPortLib.c
+
+[LibraryClasses]
+ BaseLib
+ XenHypercallLib
+
+[Packages]
+ MdePkg/MdePkg.dec
+ OvmfPkg/OvmfPkg.dec