[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS/Demo/HCS12_GCC_banked/startup.c

@@ -0,0 +1,80 @@
+/*
+ * 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
+ *
+ */
+
+
+/*
+ * startup.c
+ * Author Jefferson L Smith, Robotronics Inc.
+ *
+ * __premain() is the startup code to init hardware and ram to execute the
+ *             C application.
+ *
+ */
+
+#include <sys/ports.h>
+#include "cpu.h"
+
+void ATTR_NEAR __premain (void);
+
+void
+__premain (void)
+{
+	// in case special mode enabled, avoid conflict on PORTE
+	PEAR |= NECLK;
+	// bgnd mode stops COP and RTI clocks
+	COPCTL = RSBCK;
+	// stops TCNT counter when debugging stops
+	TSCR1 |= (1<<5);			// TFRZ
+
+	// PLL
+	CLKSEL = 0;				// disable PLL to configure
+	// xtal 16MHz, bus 24MHz
+	SYNR  = 3 - 1;
+	REFDV = 2 - 1;
+	while (!(CRGFLG & 0x08))    // wait for PLL LOCK
+	cop_optional_reset();
+	CLKSEL |= 0x80;             // use PLL
+
+	// init switch inputs
+	PERH = 0xff;				// pullups
+
+	// outputs
+#if PORT_LED==M6811_PORTB		//PORTB
+	DDRB = 0xff;	// init LED
+#elif PORT_LED==M6811_PORTA		//PORTA
+	DDRA = 0xff;
+#elif PORT_LED==M6811_PTT	//PTT
+	DDRT = 0xff;
+#elif PORT_LED==M6811_PTM	//PTM
+	DDRM = 0xff;
+#elif PORT_LED==M6811_PTP	//PTP
+	DDRP = 0xff;
+#elif PORT_LED==M6811_PTH	//PTH
+	DDRH = 0xff;
+#endif
+
+}
+