[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS/Demo/ARM7_LPC2138_Rowley/mainISR.c

@@ -0,0 +1,76 @@
+/*
+ * 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
+ *
+ */
+#include "FreeRTOS.h"
+#include "semphr.h"
+
+#define isrCLEAR_EINT_1 2
+
+/*
+ * Interrupt routine that simply wakes vButtonHandlerTask on each interrupt
+ * generated by a push of the built in button.  The wrapper takes care of
+ * the ISR entry.  This then calls the actual handler function to perform
+ * the work.  This work should not be done in the wrapper itself unless
+ * you are absolutely sure that no stack space is used.
+ */
+void vButtonISRWrapper( void ) __attribute__ ((naked));
+void vButtonHandler( void ) __attribute__ ((noinline));
+
+void vButtonHandler( void )
+{
+extern SemaphoreHandle_t xButtonSemaphore;
+portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
+
+	xSemaphoreGiveFromISR( xButtonSemaphore, &xHigherPriorityTaskWoken );
+
+	if( xHigherPriorityTaskWoken )
+	{
+		/* We have woken a task.  Calling "yield from ISR" here will ensure
+		the interrupt returns to the woken task if it has a priority higher
+		than the interrupted task. */
+		portYIELD_FROM_ISR();
+	}
+
+    EXTINT = isrCLEAR_EINT_1;
+    VICVectAddr = 0;
+}
+/*-----------------------------------------------------------*/
+
+void vButtonISRWrapper( void )
+{
+	/* Save the context of the interrupted task. */
+	portSAVE_CONTEXT();
+
+	/* Call the handler to do the work.  This must be a separate function to
+	the wrapper to ensure the correct stack frame is set up. */
+	__asm volatile( "bl vButtonHandler" );
+
+	/* Restore the context of whichever task is going to run once the interrupt
+	completes. */
+	portRESTORE_CONTEXT();
+}
+
+
+