UefiPayloadPkg: Add library for logging to EC

Make use of the SMFI command interface to forward logs from edk2 to
System76 EC.

UefiPayloadPkg/Library/System76EcLib/System76EcLib.c

@@ -0,0 +1,103 @@
+/** @file
+  System76 EC logging
+
+  Copyright (c) 2020 System76, Inc.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/System76EcLib.h>
+#include <Library/IoLib.h>
+#include <Library/TimerLib.h>
+
+#define SYSTEM76_EC_BASE 0xE00
+#define CMD_PRINT 0x4
+
+/**
+  @param  Offset    The offset into the SFMI RAM window to read from.
+
+  @return The value read.
+**/
+STATIC
+UINT8
+System76EcReadByte (
+  UINT8   Offset
+  )
+{
+  return IoRead8 (SYSTEM76_EC_BASE + Offset);
+}
+
+/**
+  @param  Offset    The offset into the SFMI RAM window to write to.
+  @param  Value     The value to write.
+
+  @return The value written back to the I/O port.
+**/
+STATIC
+UINT8
+System76EcWriteByte (
+  UINT8   Offset,
+  UINT8   Value
+  )
+{
+  return IoWrite8 (SYSTEM76_EC_BASE + Offset, Value);
+}
+
+/**
+  Write data to the embedded controller using SMFI command interface.
+
+  @param  Buffer            Pointer to the data buffer to be written.
+  @param  NumberOfBytes     Number of bytes to write.
+
+  @return -1 if the command failed, else the number of data bytes written.
+**/
+INTN
+System76EcWrite (
+  IN UINT8  *Buffer,
+  IN UINTN  NumberOfBytes
+  )
+{
+  UINTN Index;
+  UINTN Index2;
+  UINTN Timeout;
+
+  if (Buffer == NULL) {
+      return 0;
+  }
+
+  for (Index = 0; Index < NumberOfBytes;) {
+    if (System76EcReadByte (0) == 0) {
+
+      // Can write 256 bytes of data at a time
+      for (Index2 = 0; (Index2 < NumberOfBytes) && ((Index2 + 4) < 256); Index++, Index2++) {
+        System76EcWriteByte ((Index + 4), Buffer[Index]);
+      }
+      // Flags
+      System76EcWriteByte (2, 0);
+      // Length
+      System76EcWriteByte (3, Index2);
+      // Command
+      System76EcWriteByte (0, CMD_PRINT);
+
+      // Wait for command completion, for up to 1 second
+      for (Timeout = 1000000; Timeout > 0; Timeout--) {
+        if (System76EcReadByte (0) == 0)
+          break;
+        MicroSecondDelay (1);
+      }
+      if (Timeout == 0) {
+        // Error: Timeout occured
+        return -1;
+      }
+      if (System76EcReadByte (1) != 0) {
+        // Error: Command failed
+        return -1;
+      }
+    } else {
+      // Error: Command already running
+      return -1;
+    }
+  }
+
+  return Index;
+}

UefiPayloadPkg/Library/System76EcLib/System76EcLib.inf

@@ -0,0 +1,29 @@
+## @file
+#  System76 EC logging.
+#
+#  Copyright (c) 2020, System76, Inc.
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = System76EcLib
+  MODULE_UNI_FILE                = System76EcLib.uni
+  FILE_GUID                      = 76ECF0DD-148B-4E48-8589-FC998823F8C2
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 0.1
+  LIBRARY_CLASS                  = System76EcLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  UefiPayloadPkg/UefiPayloadPkg.dec
+
+[LibraryClasses]
+  IoLib
+  TimerLib
+
+[Sources]
+  System76EcLib.c
+
+[Pcd]

UefiPayloadPkg/Library/System76EcLib/System76EcLib.uni

@@ -0,0 +1,13 @@
+// /** @file
+// System76 EC logging.
+//
+// Copyright (c) 2020, System76, Inc.
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "System76 EC logging"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "System76 EC logging."
+

UefiPayloadPkg/Library/System76EcLibNull/System76EcLibNull.c

@@ -0,0 +1,18 @@
+/** @file
+  System76 EC logging
+
+  Copyright (c) 2020 System76, Inc.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/System76EcLib.h>
+
+INTN
+System76EcWrite (
+  IN UINT8  *Buffer,
+  IN UINTN  NumberOfBytes
+  )
+{
+  return 0;
+}

UefiPayloadPkg/Library/System76EcLibNull/System76EcLibNull.inf

@@ -0,0 +1,27 @@
+## @file
+#  System76 EC logging.
+#
+#  Copyright (c) 2020, System76, Inc.
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = System76EcLibNull
+  MODULE_UNI_FILE                = System76EcLibNull.uni
+  FILE_GUID                      = 76ECF0DD-148B-4E48-8589-FC998823F8C2
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 0.1
+  LIBRARY_CLASS                  = System76EcLibNull
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  UefiPayloadPkg/UefiPayloadPkg.dec
+
+[LibraryClasses]
+
+[Sources]
+  System76EcLibNull.c
+
+[Pcd]

UefiPayloadPkg/Library/System76EcLibNull/System76EcLibNull.uni

@@ -0,0 +1,13 @@
+// /** @file
+// System76 EC logging.
+//
+// Copyright (c) 2020, System76, Inc.
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "System76 EC logging"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "System76 EC logging."
+