From: PaytonX Hsieh <paytonx.hs...@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4427
1. Since UART speed is slower than CPU, BIOS need to check the write
buffer is empty, to avoid overwrite the buffer content.
2. LPSS UART might disable MMIO space for Windows debug usage during
ExitBootServices event. BIOS need to avoid access the MMIO space
after ExitBootServices.
Cc: Guo Dong <guo.d...@intel.com>
Cc: Ray Ni <ray...@intel.com>
Cc: Sean Rhodes <sean@starlabs.systems>
Cc: James Lu <james...@intel.com>
Cc: Gua Guo <gua....@intel.com>
Signed-off-by: PaytonX Hsieh <paytonx.hs...@intel.com>
---
UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c | 13
+++++
UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c | 55
++++++++++++++++++++
UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf | 41
+++++++++++++++
UefiPayloadPkg/UefiPayloadPkg.dsc | 11
+++-
4 files changed, 118 insertions(+), 2 deletions(-)
diff --git a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
index 8216195c62..88981a0863 100644
--- a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
@@ -53,6 +53,7 @@ typedef struct {
UART_INFO mUartInfo[MAX_SIZE];
UINT8 mUartCount = 0;
+BOOLEAN mBaseSerialPortLibHobAtRuntime = FALSE;
/**
Reads an 8-bit register. If UseMmio is TRUE, then the value is read from
@@ -285,6 +286,11 @@ SerialPortWrite (
UseMmio = mUartInfo[Count].UseMmio;
Stride = mUartInfo[Count].RegisterStride;
+ if (UseMmio && mBaseSerialPortLibHobAtRuntime) {
+ Count++;
+ continue;
+ }
+
if (BaseAddress == 0) {
Count++;
continue;
@@ -294,6 +300,13 @@ SerialPortWrite (
BytesLeft = NumberOfBytes;
while (BytesLeft != 0) {
+ //
+ // Wait for the serial port to be ready, to make sure both the transmit
FIFO
+ // and shift register empty.
+ //
+ while ((SerialPortReadRegister (BaseAddress, R_UART_LSR, UseMmio,
Stride) & B_UART_LSR_TXRDY) == 0) {
+ }
+
//
// Fill the entire Tx FIFO
//
diff --git
a/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c
b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c
new file mode 100644
index 0000000000..dbbc02dcee
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c
@@ -0,0 +1,55 @@
+/** @file
+ UART Serial Port library functions.
+
+ Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+#include <Uefi.h>
+
+extern BOOLEAN mBaseSerialPortLibHobAtRuntime;
+
+/**
+ Set mSerialIoUartLibAtRuntime flag as TRUE after ExitBootServices.
+
+ @param[in] Event The Event that is being processed.
+ @param[in] Context The Event Context.
+
+**/
+STATIC
+VOID
+EFIAPI
+BaseSerialPortLibHobExitBootServicesEvent (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ mBaseSerialPortLibHobAtRuntime = TRUE;
+}
+
+/**
+ The constructor function registers a callback for the ExitBootServices event.
+
+ @param[in] ImageHandle The firmware allocated handle for the EFI image.
+ @param[in] SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The operation completed successfully.
+ @retval other Either the serial port failed to initialize or the
+ ExitBootServices event callback registration failed.
+**/
+EFI_STATUS
+EFIAPI
+DxeBaseSerialPortLibHobConstructor (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_EVENT SerialPortLibHobExitBootServicesEvent;
+ return SystemTable->BootServices->CreateEvent (
+ EVT_SIGNAL_EXIT_BOOT_SERVICES,
+ TPL_NOTIFY,
+
BaseSerialPortLibHobExitBootServicesEvent,
+ NULL,
+ &SerialPortLibHobExitBootServicesEvent
+ );
+}
diff --git
a/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
new file mode 100644
index 0000000000..7bb3a6ae96
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
@@ -0,0 +1,41 @@
+## @file
+# SerialPortLib instance for UART information retrieved from bootloader.
+#
+# Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = DxeBaseSerialPortLibHob
+ FILE_GUID = c8def0c5-48e7-45b8-8299-485ea2e63b2c
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = SerialPortLib|DXE_CORE DXE_DRIVER
DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_APPLICATION UEFI_DRIVER
+ CONSTRUCTOR = DxeBaseSerialPortLibHobConstructor
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+ PcdLib
+ IoLib
+ HobLib
+ TimerLib
+
+[Sources]
+ DxeBaseSerialPortLibHob.c
+ BaseSerialPortLibHob.c
+
+[Pcd]
+ gEfiMdeModulePkgTokenSpaceGuid.PcdSerialLineControl
+ gEfiMdeModulePkgTokenSpaceGuid.PcdSerialFifoControl
+ gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate
+ gEfiMdeModulePkgTokenSpaceGuid.PcdSerialExtendedTxFifoSize
+ gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl
+
+[Guids]
+ gUniversalPayloadSerialPortInfoGuid
diff --git a/UefiPayloadPkg/UefiPayloadPkg.dsc
b/UefiPayloadPkg/UefiPayloadPkg.dsc
index 9847f189ff..998d222909 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.dsc
+++ b/UefiPayloadPkg/UefiPayloadPkg.dsc
@@ -256,7 +256,11 @@
SerialPortLib|UefiPayloadPkg/Library/CbSerialPortLib/CbSerialPortLib.inf
PlatformHookLib|MdeModulePkg/Library/BasePlatformHookLibNull/BasePlatformHookLibNull.inf
!else
-
SerialPortLib|MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+ !if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
+
SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
+ !else
+
SerialPortLib|MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+ !endif
PlatformHookLib|UefiPayloadPkg/Library/PlatformHookLib/PlatformHookLib.inf
!endif
PlatformBootManagerLib|UefiPayloadPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
@@ -313,6 +317,9 @@
PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
DxeHobListLib|UefiPayloadPkg/Library/DxeHobListLibNull/DxeHobListLibNull.inf
DebugLib|MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
+!if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
+
SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
+!endif
[LibraryClasses.common.DXE_CORE]
DxeHobListLib|UefiPayloadPkg/Library/DxeHobListLibNull/DxeHobListLibNull.inf
@@ -617,7 +624,7 @@
<LibraryClasses>
!if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
DebugLib|MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
-
SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
+
SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
!endif
NULL|MdeModulePkg/Library/LzmaCustomDecompressLib/LzmaCustomDecompressLib.inf
}
--
2.39.2.windows.1
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