[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS/Demo/PIC18_MPLAB/serial/serial.c

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+/*
+ * FreeRTOS V202212.01
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+/*
+Changes from V1.2.5
+
+	+  Clear overrun errors in the Rx ISR.  Overrun errors prevent any further
+	   characters being received.
+
+Changes from V2.0.0
+
+	+ Use TickType_t in place of unsigned pdLONG for delay periods.
+	+ cQueueReieveFromISR() used in place of xQueueReceive() in ISR.
+*/
+
+/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */
+
+/* Scheduler header files. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "serial.h"
+#include "queue.h"
+
+/*
+ * Prototypes for ISR's.  The PIC architecture means that these functions
+ * have to be called from port.c.  The prototypes are not however included
+ * in the header as the header is common to all ports.
+ */
+void vSerialTxISR( void );
+void vSerialRxISR( void );
+
+/* Hardware pin definitions. */
+#define serTX_PIN	TRISCbits.TRISC6
+#define serRX_PIN	TRISCbits.TRISC7
+
+/* Bit/register definitions. */
+#define serINPUT				( 1 )
+#define serOUTPUT				( 0 )
+#define serTX_ENABLE			( ( unsigned short ) 1 )
+#define serRX_ENABLE			( ( unsigned short ) 1 )
+#define serHIGH_SPEED			( ( unsigned short ) 1 )
+#define serCONTINUOUS_RX		( ( unsigned short ) 1 )
+#define serCLEAR_OVERRUN		( ( unsigned short ) 0 )
+#define serINTERRUPT_ENABLED 	( ( unsigned short ) 1 )
+#define serINTERRUPT_DISABLED 	( ( unsigned short ) 0 )
+
+/* All ISR's use the PIC18 low priority interrupt. */
+#define							serLOW_PRIORITY ( 0 )
+
+/*-----------------------------------------------------------*/
+
+/* Queues to interface between comms API and interrupt routines. */
+static QueueHandle_t xRxedChars;
+static QueueHandle_t xCharsForTx;
+
+/*-----------------------------------------------------------*/
+
+xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
+{
+unsigned long ulBaud;
+
+	/* Calculate the baud rate generator constant.
+	SPBRG = ( (FOSC / Desired Baud Rate) / 16 ) - 1 */
+	ulBaud = configCPU_CLOCK_HZ / ulWantedBaud;
+	ulBaud /= ( unsigned long ) 16;
+	ulBaud -= ( unsigned long ) 1;
+
+	/* Create the queues used by the ISR's to interface to tasks. */
+	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
+	xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
+
+	portENTER_CRITICAL();
+	{
+		/* Start with config registers cleared, so we can just set the wanted
+		bits. */
+		TXSTA = ( unsigned short ) 0;
+		RCSTA = ( unsigned short ) 0;
+
+		/* Set the baud rate generator using the above calculated constant. */
+		SPBRG = ( unsigned char ) ulBaud;
+
+		/* Setup the IO pins to enable the USART IO. */
+		serTX_PIN = serOUTPUT;
+		serRX_PIN = serINPUT;
+
+		/* Set the serial interrupts to use the same priority as the tick. */
+		IPR1bits.TXIP = serLOW_PRIORITY;
+		IPR1bits.RCIP = serLOW_PRIORITY;
+
+		/* Setup Tx configuration. */
+		TXSTAbits.BRGH = serHIGH_SPEED;
+		TXSTAbits.TXEN = serTX_ENABLE;
+
+		/* Setup Rx configuration. */
+		RCSTAbits.SPEN = serRX_ENABLE;
+		RCSTAbits.CREN = serCONTINUOUS_RX;
+
+		/* Enable the Rx interrupt now, the Tx interrupt will get enabled when
+		we have data to send. */
+		PIE1bits.RCIE = serINTERRUPT_ENABLED;
+	}
+	portEXIT_CRITICAL();
+
+	/* Unlike other ports, this serial code does not allow for more than one
+	com port.  We therefore don't return a pointer to a port structure and
+	can	instead just return NULL. */
+	return NULL;
+}
+/*-----------------------------------------------------------*/
+
+xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength )
+{
+	/* This is not implemented in this port.
+	Use xSerialPortInitMinimal() instead. */
+}
+/*-----------------------------------------------------------*/
+
+portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
+{
+	/* Get the next character from the buffer.  Return false if no characters
+	are available, or arrive before xBlockTime expires. */
+	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
+	{
+		return pdTRUE;
+	}
+	else
+	{
+		return pdFALSE;
+	}
+}
+/*-----------------------------------------------------------*/
+
+portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
+{
+	/* Return false if after the block time there is no room on the Tx queue. */
+	if( xQueueSend( xCharsForTx, ( const void * ) &cOutChar, xBlockTime ) != pdPASS )
+	{
+		return pdFAIL;
+	}
+
+	/* Turn interrupt on - ensure the compiler only generates a single
+	instruction for this. */
+	PIE1bits.TXIE = serINTERRUPT_ENABLED;
+
+	return pdPASS;
+}
+/*-----------------------------------------------------------*/
+
+void vSerialClose( xComPortHandle xPort )
+{
+	/* Not implemented for this port.
+	To implement, turn off the interrupts and delete the memory
+	allocated to the queues. */
+}
+/*-----------------------------------------------------------*/
+
+#pragma interruptlow vSerialRxISR save=PRODH, PRODL, TABLAT, section(".tmpdata")
+void vSerialRxISR( void )
+{
+char cChar;
+portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
+
+	/* Get the character and post it on the queue of Rxed characters.
+	If the post causes a task to wake force a context switch as the woken task
+	may have a higher priority than the task we have interrupted. */
+	cChar = RCREG;
+
+	/* Clear any overrun errors. */
+	if( RCSTAbits.OERR )
+	{
+		RCSTAbits.CREN = serCLEAR_OVERRUN;
+		RCSTAbits.CREN = serCONTINUOUS_RX;
+	}
+
+	xQueueSendFromISR( xRxedChars, ( const void * ) &cChar, &xHigherPriorityTaskWoken );
+
+	if( xHigherPriorityTaskWoken )
+	{
+		taskYIELD();
+	}
+}
+/*-----------------------------------------------------------*/
+
+#pragma interruptlow vSerialTxISR save=PRODH, PRODL, TABLAT, section(".tmpdata")
+void vSerialTxISR( void )
+{
+char cChar, cTaskWoken = pdFALSE;
+
+	if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
+	{
+		/* Send the next character queued for Tx. */
+		TXREG = cChar;
+	}
+	else
+	{
+		/* Queue empty, nothing to send. */
+		PIE1bits.TXIE = serINTERRUPT_DISABLED;
+	}
+}
+
+
+