288 lines
8.0 KiB
C

/*********************************************************************
* (c) SEGGER Microcontroller GmbH *
* The Embedded Experts *
* www.segger.com *
**********************************************************************
-------------------------- END-OF-HEADER -----------------------------
Purpose : Implementation of low-level functions for I/O with the
SEGGER Runtime Library
using a UART (SEGGER's BSP UART module)
*/
/*********************************************************************
*
* #include section
*
**********************************************************************
*/
#include "__SEGGER_RTL_Int.h"
#include "stdio.h"
#include "Bsp.h"
/*********************************************************************
*
* Local types
*
**********************************************************************
*/
struct __SEGGER_RTL_FILE_impl { // NOTE: Provides implementation for FILE
int stub; // only needed so impl has size != 0.
};
/*********************************************************************
*
* Static data
*
**********************************************************************
*/
static FILE __SEGGER_RTL_stdin_file = { 0 }; // stdin reads from UART
static FILE __SEGGER_RTL_stdout_file = { 0 }; // stdout writes to UART
static FILE __SEGGER_RTL_stderr_file = { 0 }; // stderr writes to UART
static unsigned int _UART_Port = TTY_COM;
static int _stdin_ungot = EOF;
/*********************************************************************
*
* Public data
*
**********************************************************************
*/
FILE *stdin = &__SEGGER_RTL_stdin_file; // NOTE: Provide implementation of stdin for RTL.
FILE *stdout = &__SEGGER_RTL_stdout_file; // NOTE: Provide implementation of stdout for RTL.
FILE *stderr = &__SEGGER_RTL_stderr_file; // NOTE: Provide implementation of stderr for RTL.
void *__aeabi_read_tp(void) {
return 0; // 单线程环境下直接返回 0
}
/*********************************************************************
*
* Static code
*
**********************************************************************
*/
/*********************************************************************
*
* _stdin_getc()
*
* Function description
* Get character from standard input.
*
* Return value
* Character received.
*
* Additional information
* This function never fails to deliver a character.
*/
static char _stdin_getc(void) {
unsigned char c;
if (_stdin_ungot != EOF) {
c = _stdin_ungot;
_stdin_ungot = EOF;
} else {
c = UsartReceiveChar(_UART_Port);
}
return c;
}
/*********************************************************************
*
* Public code
*
**********************************************************************
*/
/*********************************************************************
*
* RTL_UART_Init()
*
* Function description
* Initialize RTL to use given UART for stdio.
*
* Parameters
* Unit : UART unit number (typically zero-based).
* Baudrate : Baud rate to configure [Hz].
* NumDataBits: Number of data bits to use.
* Parity : One of the following values:
* * BSP_UART_PARITY_NONE
* * BSP_UART_PARITY_ODD
* * BSP_UART_PARITY_EVEN
* NumStopBits: Number of stop bits to use.
*
* Additional description
* Parameters are same as for BSP_UART_Init().
* This also sets appropriate RX and TX interrupt handlers.
*/
void RTL_UART_Init(unsigned int Unit, unsigned long Baudrate, unsigned char NumDataBits, unsigned char Parity, unsigned char NumStopBits) {
_UART_Port = Unit;
UsartStdConfig(_UART_Port, Baudrate);
}
/*********************************************************************
*
* __SEGGER_RTL_X_file_stat()
*
* Function description
* Get file status.
*
* Parameters
* stream - Pointer to file.
*
* Additional information
* Low-overhead test to determine if stream is valid. If stream
* is a valid pointer and the stream is open, this function must
* succeed. If stream is a valid pointer and the stream is closed,
* this function must fail.
*
* The implementation may optionally determine whether stream is
* a valid pointer: this may not always be possible and is not
* required, but may assist debugging when clients provide wild
* pointers.
*
* Return value
* < 0 - Failure, stream is not a valid file.
* >= 0 - Success, stream is a valid file.
*/
int __SEGGER_RTL_X_file_stat(FILE *stream) {
if (stream == stdin || stream == stdout || stream == stderr) {
return 0; // NOTE: stdin, stdout, and stderr are assumed to be valid.
} else {
return EOF;
}
}
/*********************************************************************
*
* __SEGGER_RTL_X_file_bufsize()
*
* Function description
* Get stream buffer size.
*
* Parameters
* stream - Pointer to file.
*
* Additional information
* Returns the number of characters to use for buffered I/O on
* the file stream. The I/O buffer is allocated on the stack
* for the duration of the I/O call, therefore this value should
* not be set arbitrarily large.
*
* For unbuffered I/O, return 1.
*
* Return value
* Nonzero number of characters to use for buffered I/O; for
* unbuffered I/O, return 1.
*/
int __SEGGER_RTL_X_file_bufsize(FILE *stream) {
(void)stream;
return 1;
}
/*********************************************************************
*
* __SEGGER_RTL_X_file_read()
*
* Function description
* Read data from file.
*
* Parameters
* stream - Pointer to file to read from.
* s - Pointer to object that receives the input.
* len - Number of characters to read from file.
*
* Return value
* >= 0 - Success, amount of data read.
* < 0 - Failure.
*
* Additional information
* Reading from any stream other than stdin results in an error.
*/
int __SEGGER_RTL_X_file_read(FILE *stream, char *s, unsigned len) {
int c;
if (stream == stdin) {
c = 0;
while (len > 0) {
*s = _stdin_getc();
++s;
++c;
--len;
}
} else {
c = EOF;
}
return c;
}
/*********************************************************************
*
* __SEGGER_RTL_X_file_write()
*
* Function description
* Write data to file.
*
* Parameters
* stream - Pointer to file to write to.
* s - Pointer to object to write to file.
* len - Number of characters to write to the file.
*
* Return value
* >= 0 - Success.
* < 0 - Failure.
*
* Additional information
* this version is NOT reentrant!
* stdout and stderr are directed to UART;
* writing to any stream other than stdout or stderr results in an error
*/
int __SEGGER_RTL_X_file_write(FILE *stream, const char *s, unsigned len) {
if ((stream == stdout) || (stream == stderr)) {
UsartSendStr(_UART_Port, (uint8_t* ) s, len);
return len;
} else {
return EOF;
}
}
/*********************************************************************
*
* __SEGGER_RTL_X_file_unget()
*
* Function description
* Push character back to stream.
*
* Parameters
* stream - Pointer to file to push back to.
* c - Character to push back.
*
* Return value
* >= 0 - Success.
* < 0 - Failure.
*
* Additional information
* Push-back is only supported for standard input, and
* only a single-character pushback buffer is implemented.
*/
int __SEGGER_RTL_X_file_unget(FILE *stream, int c) {
if (stream == stdin) {
if (c != EOF && _stdin_ungot == EOF) {
_stdin_ungot = c;
} else {
c = EOF;
}
} else {
c = EOF;
}
return c;
}
/*************************** End of file ****************************/