[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/riscv-virt.h

@@ -0,0 +1,54 @@
+/*
+ * 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://www.github.com/FreeRTOS
+ *
+ */
+
+#ifndef RISCV_VIRT_H_
+#define RISCV_VIRT_H_
+
+#include "riscv-reg.h"
+
+#ifdef __ASSEMBLER__
+#define CONS(NUM, TYPE)NUM
+#else
+#define CONS(NUM, TYPE)NUM##TYPE
+#endif /* __ASSEMBLER__ */
+
+#define PRIM_HART			0
+
+#define CLINT_ADDR			CONS(0x02000000, UL)
+#define CLINT_MSIP			CONS(0x0000, UL)
+#define CLINT_MTIMECMP		CONS(0x4000, UL)
+#define CLINT_MTIME			CONS(0xbff8, UL)
+
+#define NS16550_ADDR		CONS(0x10000000, UL)
+
+#ifndef __ASSEMBLER__
+
+int xGetCoreID( void );
+void vSendString( const char * s );
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* RISCV_VIRT_H_ */