/** @file | |
Serial I/O Port library functions with no library constructor/destructor | |
Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR> | |
Copyright (c) 2021, Arm Limited. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <Uefi.h> | |
#include <Library/DebugLib.h> | |
#include <Library/SemihostLib.h> | |
#include <Library/SerialPortLib.h> | |
/* | |
Programmed hardware of Serial port. | |
@return Always return EFI_UNSUPPORTED. | |
**/ | |
RETURN_STATUS | |
EFIAPI | |
SerialPortInitialize ( | |
VOID | |
) | |
{ | |
if (SemihostConnectionSupported ()) { | |
return RETURN_SUCCESS; | |
} else { | |
return RETURN_UNSUPPORTED; | |
} | |
} | |
/** | |
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. | |
**/ | |
#define PRINT_BUFFER_SIZE 512 | |
#define PRINT_BUFFER_THRESHOLD (PRINT_BUFFER_SIZE - 4) | |
UINTN | |
EFIAPI | |
SerialPortWrite ( | |
IN UINT8 *Buffer, | |
IN UINTN NumberOfBytes | |
) | |
{ | |
UINT8 PrintBuffer[PRINT_BUFFER_SIZE]; | |
UINTN SourceIndex; | |
UINTN DestinationIndex; | |
UINT8 CurrentCharacter; | |
SourceIndex = 0; | |
DestinationIndex = 0; | |
while (SourceIndex < NumberOfBytes) { | |
CurrentCharacter = Buffer[SourceIndex++]; | |
switch (CurrentCharacter) { | |
case '\r': | |
continue; | |
case '\n': | |
PrintBuffer[DestinationIndex++] = ' '; | |
// fall through | |
default: | |
PrintBuffer[DestinationIndex++] = CurrentCharacter; | |
break; | |
} | |
if (DestinationIndex > PRINT_BUFFER_THRESHOLD) { | |
PrintBuffer[DestinationIndex] = '\0'; | |
SemihostWriteString ((CHAR8 *)PrintBuffer); | |
DestinationIndex = 0; | |
} | |
} | |
if (DestinationIndex > 0) { | |
PrintBuffer[DestinationIndex] = '\0'; | |
SemihostWriteString ((CHAR8 *)PrintBuffer); | |
} | |
return NumberOfBytes; | |
} | |
/** | |
Read data from serial device and save the datas in buffer. | |
@param Buffer Point of data buffer which need to be written. | |
@param NumberOfBytes Number of output bytes which are cached in 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 | |
) | |
{ | |
*Buffer = SemihostReadCharacter (); | |
return 1; | |
} | |
/** | |
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 | |
) | |
{ | |
// Since SemiHosting read character is blocking always say we have a char ready? | |
return SemihostConnectionSupported (); | |
} |