added correct interrupt handler initialization in RISC-V-Qemu-virt_GCC (#864)

* added correct trap_handler initialization in main.c

Co-authored-by: Joseph Julicher <jjulicher@mac.com>
Co-authored-by: Kody Stribrny <kstribrn@amazon.com>
Co-authored-by: Aniruddha Kanhere <60444055+AniruddhaKanhere@users.noreply.github.com>

FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/Makefile

@@ -47,7 +47,7 @@ SRCS = main.c main_blinky.c riscv-virt.c ns16550.c \
 	$(RTOS_SOURCE_DIR)/portable/MemMang/heap_4.c \
 	$(RTOS_SOURCE_DIR)/portable/GCC/RISC-V/port.c
 
-ASMS = start.S \
+ASMS = start.S vector.S\
 	$(RTOS_SOURCE_DIR)/portable/GCC/RISC-V/portASM.S
 
 OBJS = $(SRCS:%.c=$(BUILD_DIR)/%.o) $(ASMS:%.S=$(BUILD_DIR)/%.o)

FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/main.c

@@ -20,7 +20,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  * https://www.FreeRTOS.org
- * https://www.github.com/FreeRTOS
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -30,6 +30,10 @@
 
 /* Run a simple demo just prints 'Blink' */
 #define DEMO_BLINKY	1
+#define mainVECTOR_MODE_DIRECT	1
+
+extern void freertos_risc_v_trap_handler( void );
+extern void freertos_vector_table( void );
 
 void vApplicationMallocFailedHook( void );
 void vApplicationIdleHook( void );
@@ -43,6 +47,16 @@ int main_blinky( void );
 int main( void )
 {
 	int ret;
+	// trap handler initialization
+		#if( mainVECTOR_MODE_DIRECT == 1 )
+	{
+		__asm__ volatile( "csrw mtvec, %0" :: "r"( freertos_risc_v_trap_handler ) );
+	}
+	#else
+	{
+		__asm__ volatile( "csrw mtvec, %0" :: "r"( ( uintptr_t )freertos_vector_table | 0x1 ) );
+	}
+	#endif
 
 #if defined(DEMO_BLINKY)
 	ret = main_blinky();

FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/vector.S

@@ -0,0 +1,62 @@
+/*
+ * FreeRTOS V202112.00
+ * 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
+ *
+ */
+
+.balign 128, 0
+.option norvc
+.global freertos_vector_table
+freertos_vector_table:
+IRQ_0:
+        j freertos_risc_v_exception_handler
+IRQ_1:
+        j freertos_risc_v_interrupt_handler
+IRQ_2:
+        j freertos_risc_v_interrupt_handler
+IRQ_3:
+        j freertos_risc_v_interrupt_handler
+IRQ_4:
+        j freertos_risc_v_interrupt_handler
+IRQ_5:
+        j freertos_risc_v_interrupt_handler
+IRQ_6:
+        j freertos_risc_v_interrupt_handler
+IRQ_7:
+        j freertos_risc_v_mtimer_interrupt_handler
+IRQ_8:
+        j freertos_risc_v_interrupt_handler
+IRQ_9:
+        j freertos_risc_v_interrupt_handler
+IRQ_10:
+        j freertos_risc_v_interrupt_handler
+IRQ_11:
+        j freertos_risc_v_interrupt_handler
+IRQ_12:
+        j freertos_risc_v_interrupt_handler
+IRQ_13:
+        j freertos_risc_v_interrupt_handler
+IRQ_14:
+        j freertos_risc_v_interrupt_handler
+IRQ_15:
+        j freertos_risc_v_interrupt_handler