The implementation looks good.
But it limits the usage of SerialPortRead/Write to be called only from BSP
because GetFirstGuidHob() can not be called from APs.
An alternative implementation is to cache the UART instances data into a
library global array so SerialPortRead/Write don't need to call
GetFirstGuidHob() again. Such change allows APs call the APIs.
> -----Original Message-----
> From: Sravanthi, K KavyaX <k.kavyax.sravan...@intel.com>
> Sent: Thursday, July 14, 2022 12:31 PM
> To: devel@edk2.groups.io
> Cc: Sravanthi, K KavyaX <k.kavyax.sravan...@intel.com>; Dong, Guo
> <guo.d...@intel.com>; Ni, Ray <ray...@intel.com>;
> Maurice Ma <maurice...@intel.com>; You, Benjamin <benjamin....@intel.com>;
> Rhodes, Sean
> <sean@starlabs.systems>
> Subject: [PATCH 2/3] UefiPayloadPkg: Implement a new SerialPortLib instance
>
> Add new Serial port library instance that consumes the HOB defined
> in MdeModulePkg/Include/UniversalPayload/SerialPortInfo.h to support
> multiple UART's.
>
> Cc: Guo Dong <guo.d...@intel.com>
> Cc: Ray Ni <ray...@intel.com>
> Cc: Maurice Ma <maurice...@intel.com>
> Cc: Benjamin You <benjamin....@intel.com>
> Cc: Sean Rhodes <sean@starlabs.systems>
> Signed-off-by: Kavya <k.kavyax.sravan...@intel.com>
> ---
> UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c | 802
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf | 39
> +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 841 insertions(+)
>
> diff --git
> a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
> b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
> new file mode 100644
> index 0000000000..6f62b2a5d2
> --- /dev/null
> +++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
> @@ -0,0 +1,802 @@
> +/** @file
> + UART Serial Port library functions.
> +
> + Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +#include <PiDxe.h>
> +#include <Base.h>
> +#include <Library/PcdLib.h>
> +#include <Library/IoLib.h>
> +#include <Library/BaseLib.h>
> +#include <Library/HobLib.h>
> +#include <Library/TimerLib.h>
> +#include <Protocol/SerialIo.h>
> +#include <UniversalPayload/SerialPortInfo.h>
> +
> +//
> +// 16550 UART register offsets and bitfields
> +//
> +#define R_UART_RXBUF 0 // LCR_DLAB = 0
> +#define R_UART_TXBUF 0 // LCR_DLAB = 0
> +#define R_UART_BAUD_LOW 0 // LCR_DLAB = 1
> +#define R_UART_BAUD_HIGH 1 // LCR_DLAB = 1
> +#define R_UART_IER 1 // LCR_DLAB = 0
> +#define R_UART_FCR 2
> +#define B_UART_FCR_FIFOE BIT0
> +#define B_UART_FCR_FIFO64 BIT5
> +#define R_UART_LCR 3
> +#define B_UART_LCR_DLAB BIT7
> +#define R_UART_MCR 4
> +#define B_UART_MCR_DTRC BIT0
> +#define B_UART_MCR_RTS BIT1
> +#define R_UART_LSR 5
> +#define B_UART_LSR_RXRDY BIT0
> +#define B_UART_LSR_TXRDY BIT5
> +#define B_UART_LSR_TEMT BIT6
> +#define R_UART_MSR 6
> +#define B_UART_MSR_CTS BIT4
> +#define B_UART_MSR_DSR BIT5
> +#define B_UART_MSR_RI BIT6
> +#define B_UART_MSR_DCD BIT7
> +
> +/**
> + Reads an 8-bit register. If UseMmio is TRUE, then the value is read from
> + MMIO space. If UseMmio is FALSE, then the value is read from I/O space. The
> + parameter Offset is added to the base address of the register.
> +
> + @param Base The base address register of UART device.
> + @param Offset The offset of the register to read.
> + @param UseMmio Check if value has to be read from MMIO space or IO space.
> +
> + @return The value read from the register.
> +
> +**/
> +UINT8
> +SerialPortReadRegister (
> + UINTN Base,
> + UINTN Offset,
> + BOOLEAN UseMmio
> + )
> +{
> + if (UseMmio) {
> + return MmioRead8 (Base + Offset/4);
> + } else {
> + return IoRead8 (Base + Offset);
> + }
> +}
> +
> +/**
> + Writes an 8-bit register.. If UseMmio is TRUE, then the value is written to
> + MMIO space. If UseMmio is FALSE, then the value is written to I/O space.
> The
> + parameter Offset is added to the base address of the registers.
> +
> + @param Base The base address register of UART device.
> + @param Offset The offset of the register to write.
> + @param Value Value to be written.
> + @param UseMmio Check if value has to be written to MMIO space or IO
> space.
> +
> + @return The value written to the register.
> +
> +**/
> +UINT8
> +SerialPortWriteRegister (
> + UINTN Base,
> + UINTN Offset,
> + UINT8 Value,
> + BOOLEAN UseMmio
> + )
> +{
> + if (UseMmio) {
> + return MmioWrite8 (Base + Offset/4, Value);
> + } else {
> + return IoWrite8 (Base + Offset, Value);
> + }
> +}
> +
> +/**
> + Initialize the serial device hardware.
> +
> + If no initialization is required, then return RETURN_SUCCESS.
> + If the serial device was successfully initialized, then return
> RETURN_SUCCESS.
> + If the serial device could not be initialized, then return
> RETURN_DEVICE_ERROR.
> + If gUniversalPayloadSerialPortInfoGuid not found, then return
> RETURN_NOT_FOUND.
> +
> + @retval RETURN_SUCCESS The serial device was initialized.
> + @retval RETURN_DEVICE_ERROR The serial device could not be initialized.
> + @retval RETURN_NOT_FOUND GuidHob not found.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortInitialize (
> + VOID
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN SerialRegisterBase;
> + UINT32 Divisor;
> + UINT32 CurrentDivisor;
> + UINT32 BaudRate;
> + BOOLEAN Initialized;
> + BOOLEAN MmioEnable;
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + if (GuidHob == NULL) {
> + return RETURN_NOT_FOUND;
> + }
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + SerialRegisterBase = SerialPortInfo->RegisterBase;
> + MmioEnable = SerialPortInfo->UseMmio;
> + BaudRate = SerialPortInfo->BaudRate;
> +
> + if (SerialRegisterBase == 0) {
> + return RETURN_DEVICE_ERROR;
> + }
> +
> + Divisor = PcdGet32 (PcdSerialClockRate) / (BaudRate * 16);
> + if ((PcdGet32 (PcdSerialClockRate) % (BaudRate * 16)) >= BaudRate * 8) {
> + Divisor++;
> + }
> +
> + //
> + // See if the serial port is already initialized
> + //
> + Initialized = TRUE;
> + if ((SerialPortReadRegister (SerialRegisterBase, R_UART_LCR, MmioEnable)
> & 0x3F) != (PcdGet8 (PcdSerialLineControl)
> & 0x3F)) {
> + Initialized = FALSE;
> + }
> +
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR,
> (UINT8)(SerialPortReadRegister (SerialRegisterBase,
> R_UART_LCR, MmioEnable) | B_UART_LCR_DLAB), MmioEnable);
> + CurrentDivisor = SerialPortReadRegister (SerialRegisterBase,
> R_UART_BAUD_HIGH, MmioEnable) << 8;
> + CurrentDivisor |= (UINT32)SerialPortReadRegister (SerialRegisterBase,
> R_UART_BAUD_LOW, MmioEnable);
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR,
> (UINT8)(SerialPortReadRegister (SerialRegisterBase,
> R_UART_LCR, MmioEnable) & ~B_UART_LCR_DLAB), MmioEnable);
> + if (CurrentDivisor != Divisor) {
> + Initialized = FALSE;
> + }
> +
> + if (Initialized) {
> + return RETURN_SUCCESS;
> + }
> +
> + //
> + // Wait for the serial port to be ready.
> + // Verify that both the transmit FIFO and the shift register are empty.
> + //
> + while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR,
> MmioEnable) & (B_UART_LSR_TEMT |
> B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) {
> + }
> +
> + //
> + // Configure baud rate
> + //
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR,
> B_UART_LCR_DLAB, MmioEnable);
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_HIGH,
> (UINT8)(Divisor >> 8), MmioEnable);
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_LOW,
> (UINT8)(Divisor & 0xff), MmioEnable);
> +
> + //
> + // Clear DLAB and configure Data Bits, Parity, and Stop Bits.
> + // Strip reserved bits from PcdSerialLineControl
> + //
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, (UINT8)(PcdGet8
> (PcdSerialLineControl) & 0x3F),
> MmioEnable);
> +
> + //
> + // Enable and reset FIFOs
> + // Strip reserved bits from PcdSerialFifoControl
> + //
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_FCR, 0x00,
> MmioEnable);
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_FCR, (UINT8)(PcdGet8
> (PcdSerialFifoControl) &
> (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)), MmioEnable);
> +
> + //
> + // Set FIFO Polled Mode by clearing IER after setting FCR
> + //
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_IER, 0x00,
> MmioEnable);
> +
> + //
> + // Put Modem Control Register(MCR) into its reset state of 0x00.
> + //
> + SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, 0x00,
> MmioEnable);
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return RETURN_SUCCESS;
> +}
> +
> +/**
> + Write data from buffer to serial device.
> +
> + Writes NumberOfBytes data bytes from Buffer to the serial device.
> + The number of bytes actually written to the serial device is returned.
> + If the return value is less than NumberOfBytes, then the write operation
> failed.
> +
> + If Buffer is NULL, then return 0.
> +
> + If NumberOfBytes is zero, then return 0.
> +
> + @param Buffer Pointer to the data buffer to be written.
> + @param NumberOfBytes Number of bytes to written to the serial device.
> +
> + @retval 0 NumberOfBytes is 0.
> + @retval >0 The number of bytes written to the serial device.
> + If this value is less than NumberOfBytes, then
> the write operation failed.
> +
> +**/
> +UINTN
> +EFIAPI
> +SerialPortWrite (
> + IN UINT8 *Buffer,
> + IN UINTN NumberOfBytes
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> + UINTN BytesLeft;
> + UINTN Index;
> + UINTN FifoSize;
> + UINT8 *DataBuffer;
> +
> + if (Buffer == NULL || NumberOfBytes == 0) {
> + return 0;
> + }
> +
> + //
> + // Compute the maximum size of the Tx FIFO
> + //
> + FifoSize = 1;
> + if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFOE) != 0) {
> + if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFO64) == 0) {
> + FifoSize = 16;
> + } else {
> + FifoSize = PcdGet32 (PcdSerialExtendedTxFifoSize);
> + }
> + }
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + DataBuffer = Buffer;
> + BytesLeft = NumberOfBytes;
> +
> + while (BytesLeft != 0) {
> + //
> + // Fill the entire Tx FIFO
> + //
> + for (Index = 0; Index < FifoSize && BytesLeft != 0; Index++,
> BytesLeft--, DataBuffer++) {
> + //
> + // Write byte to the transmit buffer.
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_TXBUF, *DataBuffer,
> UseMmio);
> + }
> + MicroSecondDelay (20);
> + }
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return NumberOfBytes;
> +}
> +
> +/**
> + Reads data from a serial device into a buffer.
> +
> + @param Buffer Pointer to the data buffer to store the data read
> from the serial device.
> + @param NumberOfBytes Number of bytes to read from the serial device.
> +
> + @retval 0 NumberOfBytes is 0.
> + @retval >0 The number of bytes read from the serial device.
> + If this value is less than NumberOfBytes, then
> the read operation failed.
> +
> +**/
> +UINTN
> +EFIAPI
> +SerialPortRead (
> + OUT UINT8 *Buffer,
> + IN UINTN NumberOfBytes
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> + UINT8 *DataBuffer;
> + UINTN BytesLeft;
> + UINTN Result;
> + UINT8 Mcr;
> +
> + if (Buffer == NULL) {
> + return 0;
> + }
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + DataBuffer = Buffer;
> + BytesLeft = NumberOfBytes;
> +
> + if (BaseAddress == 0) {
> + return 0;
> + }
> +
> + Mcr = (UINT8)(SerialPortReadRegister (BaseAddress, R_UART_MCR, UseMmio)
> & ~B_UART_MCR_RTS);
> +
> + for (Result = 0; BytesLeft-- != 0; Result++, DataBuffer++) {
> + //
> + // Wait for the serial port to have some data.
> + //
> + while ((SerialPortReadRegister (BaseAddress, R_UART_LSR, UseMmio) &
> B_UART_LSR_RXRDY) == 0) {
> + if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
> + //
> + // Set RTS to let the peer send some data
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_MCR, (UINT8)(Mcr |
> B_UART_MCR_RTS), UseMmio);
> + }
> + }
> +
> + if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
> + //
> + // Clear RTS to prevent peer from sending data
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_MCR, Mcr, UseMmio);
> + }
> +
> + //
> + // Read byte from the receive buffer.
> + //
> + *DataBuffer = SerialPortReadRegister (BaseAddress, R_UART_RXBUF,
> UseMmio);
> + }
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return Result;
> +}
> +
> +/**
> + Polls a serial device to see if there is any data waiting to be read.
> +
> + Polls a serial device to see if there is any data waiting to be read.
> + If there is data waiting to be read from the serial device, then TRUE is
> returned.
> + If there is no data waiting to be read from the serial device, then FALSE
> is returned.
> +
> + @retval TRUE Data is waiting to be read from the serial device.
> + @retval FALSE There is no data waiting to be read from the
> serial device.
> +
> +**/
> +BOOLEAN
> +EFIAPI
> +SerialPortPoll (
> + VOID
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + if (BaseAddress == 0) {
> + return FALSE;
> + }
> +
> + //
> + // Read the serial port status
> + //
> + if ((SerialPortReadRegister (BaseAddress, R_UART_LSR, UseMmio) &
> B_UART_LSR_RXRDY) != 0) {
> + if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
> + //
> + // Clear RTS to prevent peer from sending data
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_MCR,
> (UINT8)(SerialPortReadRegister (BaseAddress, R_UART_MCR,
> UseMmio) & ~B_UART_MCR_RTS), UseMmio);
> + }
> + return TRUE;
> + }
> +
> + if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
> + //
> + // Set RTS to let the peer send some data
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_MCR,
> (UINT8)(SerialPortReadRegister (BaseAddress, R_UART_MCR,
> UseMmio) | B_UART_MCR_RTS), UseMmio);
> + }
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> + return FALSE;
> +}
> +
> +/**
> + Sets the control bits on a serial device.
> +
> + @param Control Sets the bits of Control that are settable.
> +
> + @retval RETURN_SUCCESS The new control bits were set on the serial
> device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> + @retval RETURN_NOT_FOUND GuidHob not found.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortSetControl (
> + IN UINT32 Control
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> + UINT8 Mcr;
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + if (GuidHob == NULL) {
> + return RETURN_NOT_FOUND;
> + }
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + if (BaseAddress == 0) {
> + return RETURN_UNSUPPORTED;
> + }
> +
> + //
> + // First determine the parameter is invalid.
> + //
> + if ((Control & (~(EFI_SERIAL_REQUEST_TO_SEND |
> EFI_SERIAL_DATA_TERMINAL_READY |
> + EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE))) != 0)
> + {
> + return RETURN_UNSUPPORTED;
> + }
> +
> + //
> + // Read the Modem Control Register.
> + //
> + Mcr = SerialPortReadRegister (BaseAddress, R_UART_MCR, UseMmio);
> + Mcr &= (~(B_UART_MCR_DTRC | B_UART_MCR_RTS));
> +
> + if ((Control & EFI_SERIAL_DATA_TERMINAL_READY) ==
> EFI_SERIAL_DATA_TERMINAL_READY) {
> + Mcr |= B_UART_MCR_DTRC;
> + }
> +
> + if ((Control & EFI_SERIAL_REQUEST_TO_SEND) ==
> EFI_SERIAL_REQUEST_TO_SEND) {
> + Mcr |= B_UART_MCR_RTS;
> + }
> +
> + //
> + // Write the Modem Control Register.
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_MCR, Mcr, UseMmio);
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return RETURN_SUCCESS;
> +}
> +
> +/**
> + Retrieve the status of the control bits on a serial device.
> +
> + @param Control A pointer to return the current control
> signals from the serial device.
> +
> + @retval RETURN_SUCCESS The control bits were read from the serial
> device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> + @retval RETURN_NOT_FOUND GuidHob not found.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortGetControl (
> + OUT UINT32 *Control
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> + UINT8 Msr;
> + UINT8 Mcr;
> + UINT8 Lsr;
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + if (GuidHob == NULL) {
> + return RETURN_NOT_FOUND;
> + }
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + if (BaseAddress == 0) {
> + return RETURN_UNSUPPORTED;
> + }
> +
> + *Control = 0;
> +
> + //
> + // Read the Modem Status Register.
> + //
> + Msr = SerialPortReadRegister (BaseAddress, R_UART_MSR, UseMmio);
> +
> + if ((Msr & B_UART_MSR_CTS) == B_UART_MSR_CTS) {
> + *Control |= EFI_SERIAL_CLEAR_TO_SEND;
> + }
> +
> + if ((Msr & B_UART_MSR_DSR) == B_UART_MSR_DSR) {
> + *Control |= EFI_SERIAL_DATA_SET_READY;
> + }
> +
> + if ((Msr & B_UART_MSR_RI) == B_UART_MSR_RI) {
> + *Control |= EFI_SERIAL_RING_INDICATE;
> + }
> +
> + if ((Msr & B_UART_MSR_DCD) == B_UART_MSR_DCD) {
> + *Control |= EFI_SERIAL_CARRIER_DETECT;
> + }
> +
> + //
> + // Read the Modem Control Register.
> + //
> + Mcr = SerialPortReadRegister (BaseAddress, R_UART_MCR, UseMmio);
> +
> + if ((Mcr & B_UART_MCR_DTRC) == B_UART_MCR_DTRC) {
> + *Control |= EFI_SERIAL_DATA_TERMINAL_READY;
> + }
> +
> + if ((Mcr & B_UART_MCR_RTS) == B_UART_MCR_RTS) {
> + *Control |= EFI_SERIAL_REQUEST_TO_SEND;
> + }
> +
> + if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
> + *Control |= EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE;
> + }
> +
> + //
> + // Read the Line Status Register.
> + //
> + Lsr = SerialPortReadRegister (BaseAddress, R_UART_LSR, UseMmio);
> +
> + if ((Lsr & (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) == (B_UART_LSR_TEMT |
> B_UART_LSR_TXRDY)) {
> + *Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY;
> + }
> +
> + if ((Lsr & B_UART_LSR_RXRDY) == 0) {
> + *Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
> + }
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return RETURN_SUCCESS;
> +}
> +
> +/**
> + Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
> + data bits, and stop bits on a serial device.
> +
> + @param BaudRate The requested baud rate. A BaudRate value of 0
> will use the
> + device's default interface speed.
> + On output, the value actually set.
> + @param ReveiveFifoDepth The requested depth of the FIFO on the receive
> side of the
> + serial interface. A ReceiveFifoDepth value of 0
> will use
> + the device's default FIFO depth.
> + On output, the value actually set.
> + @param Timeout The requested time out for a single character in
> microseconds.
> + This timeout applies to both the transmit and
> receive side of the
> + interface. A Timeout value of 0 will use the
> device's default time
> + out value.
> + On output, the value actually set.
> + @param Parity The type of parity to use on this serial device.
> A Parity value of
> + DefaultParity will use the device's default
> parity value.
> + On output, the value actually set.
> + @param DataBits The number of data bits to use on the serial
> device. A DataBits
> + vaule of 0 will use the device's default data
> bit setting.
> + On output, the value actually set.
> + @param StopBits The number of stop bits to use on this serial
> device. A StopBits
> + value of DefaultStopBits will use the device's
> default number of
> + stop bits.
> + On output, the value actually set.
> +
> + @retval RETURN_SUCCESS The new attributes were set on the
> serial device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_INVALID_PARAMETER One or more of the attributes has an
> unsupported value.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> + @retval RETURN_NOT_FOUND GuidHob not found.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortSetAttributes (
> + IN OUT UINT64 *BaudRate,
> + IN OUT UINT32 *ReceiveFifoDepth,
> + IN OUT UINT32 *Timeout,
> + IN OUT EFI_PARITY_TYPE *Parity,
> + IN OUT UINT8 *DataBits,
> + IN OUT EFI_STOP_BITS_TYPE *StopBits
> + )
> +{
> + UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *SerialPortInfo;
> + EFI_HOB_GUID_TYPE *GuidHob;
> + UINTN BaseAddress;
> + BOOLEAN UseMmio;
> + UINT32 SerialBaudRate;
> + UINTN Divisor;
> + UINT8 Lcr;
> + UINT8 LcrData;
> + UINT8 LcrParity;
> + UINT8 LcrStop;
> +
> + GuidHob = GetFirstGuidHob (&gUniversalPayloadSerialPortInfoGuid);
> + if (GuidHob == NULL) {
> + return RETURN_NOT_FOUND;
> + }
> + while (GuidHob != NULL) {
> + SerialPortInfo = (UNIVERSAL_PAYLOAD_SERIAL_PORT_INFO *)GET_GUID_HOB_DATA
> (GuidHob);
> + BaseAddress = SerialPortInfo->RegisterBase;
> + UseMmio = SerialPortInfo->UseMmio;
> +
> + if (BaseAddress == 0) {
> + return RETURN_UNSUPPORTED;
> + }
> +
> + //
> + // Check for default settings and fill in actual values.
> + //
> + if (*BaudRate == 0) {
> + *BaudRate = SerialPortInfo->BaudRate;
> + }
> +
> + SerialBaudRate = (UINT32)*BaudRate;
> +
> + if (*DataBits == 0) {
> + LcrData = (UINT8)(PcdGet8 (PcdSerialLineControl) & 0x3);
> + *DataBits = LcrData + 5;
> + } else {
> + if ((*DataBits < 5) || (*DataBits > 8)) {
> + return RETURN_INVALID_PARAMETER;
> + }
> +
> + //
> + // Map 5..8 to 0..3
> + //
> + LcrData = (UINT8)(*DataBits - (UINT8)5);
> + }
> +
> + if (*Parity == DefaultParity) {
> + LcrParity = (UINT8)((PcdGet8 (PcdSerialLineControl) >> 3) & 0x7);
> + switch (LcrParity) {
> + case 0:
> + *Parity = NoParity;
> + break;
> +
> + case 3:
> + *Parity = EvenParity;
> + break;
> +
> + case 1:
> + *Parity = OddParity;
> + break;
> +
> + case 7:
> + *Parity = SpaceParity;
> + break;
> +
> + case 5:
> + *Parity = MarkParity;
> + break;
> +
> + default:
> + break;
> + }
> + } else {
> + switch (*Parity) {
> + case NoParity:
> + LcrParity = 0;
> + break;
> +
> + case EvenParity:
> + LcrParity = 3;
> + break;
> +
> + case OddParity:
> + LcrParity = 1;
> + break;
> +
> + case SpaceParity:
> + LcrParity = 7;
> + break;
> +
> + case MarkParity:
> + LcrParity = 5;
> + break;
> +
> + default:
> + return RETURN_INVALID_PARAMETER;
> + }
> + }
> +
> + if (*StopBits == DefaultStopBits) {
> + LcrStop = (UINT8)((PcdGet8 (PcdSerialLineControl) >> 2) & 0x1);
> + switch (LcrStop) {
> + case 0:
> + *StopBits = OneStopBit;
> + break;
> +
> + case 1:
> + if (*DataBits == 5) {
> + *StopBits = OneFiveStopBits;
> + } else {
> + *StopBits = TwoStopBits;
> + }
> +
> + break;
> +
> + default:
> + break;
> + }
> + } else {
> + switch (*StopBits) {
> + case OneStopBit:
> + LcrStop = 0;
> + break;
> +
> + case OneFiveStopBits:
> + case TwoStopBits:
> + LcrStop = 1;
> + break;
> +
> + default:
> + return RETURN_INVALID_PARAMETER;
> + }
> + }
> +
> + //
> + // Calculate divisor for baud generator
> + // Ref_Clk_Rate / Baud_Rate / 16
> + //
> + Divisor = PcdGet32 (PcdSerialClockRate) / (SerialBaudRate * 16);
> + if ((PcdGet32 (PcdSerialClockRate) % (SerialBaudRate * 16)) >=
> SerialBaudRate * 8) {
> + Divisor++;
> + }
> +
> + //
> + // Configure baud rate
> + //
> + SerialPortWriteRegister (BaseAddress, R_UART_LCR, B_UART_LCR_DLAB,
> UseMmio);
> + SerialPortWriteRegister (BaseAddress, R_UART_BAUD_HIGH, (UINT8)(Divisor
> >> 8), UseMmio);
> + SerialPortWriteRegister (BaseAddress, R_UART_BAUD_LOW, (UINT8)(Divisor &
> 0xff), UseMmio);
> +
> + //
> + // Clear DLAB and configure Data Bits, Parity, and Stop Bits.
> + // Strip reserved bits from line control value
> + //
> + Lcr = (UINT8)((LcrParity << 3) | (LcrStop << 2) | LcrData);
> + SerialPortWriteRegister (BaseAddress, R_UART_LCR, (UINT8)(Lcr & 0x3F),
> UseMmio);
> +
> + GuidHob = GET_NEXT_HOB (GuidHob);
> + GuidHob = GetNextGuidHob (&gUniversalPayloadSerialPortInfoGuid, GuidHob);
> + }
> +
> + return RETURN_SUCCESS;
> +}
> diff --git
> a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
> b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
> new file mode 100644
> index 0000000000..ac857d3eea
> --- /dev/null
> +++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
> @@ -0,0 +1,39 @@
> +## @file
> +# SerialPortLib instance for UART information retrieved from bootloader.
> +#
> +# Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 0x00010005
> + BASE_NAME = BaseSerialPortLibHob
> + FILE_GUID = d8d22930-e8ec-469f-8184-5a069149b2ff
> + MODULE_TYPE = BASE
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = SerialPortLib
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + MdeModulePkg/MdeModulePkg.dec
> +
> +[LibraryClasses]
> + PcdLib
> + IoLib
> + HobLib
> + TimerLib
> +
> +[Sources]
> + BaseSerialPortLibHob.c
> +
> +[Pcd]
> + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialLineControl
> + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialFifoControl
> + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate
> + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialExtendedTxFifoSize
> + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl
> +
> +[Guids]
> + gUniversalPayloadSerialPortInfoGuid
> --
> 2.30.2.windows.1
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#91341): https://edk2.groups.io/g/devel/message/91341
Mute This Topic: https://groups.io/mt/92373403/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
