riscv: Add exception codes

Update #3433.

cpukit/score/cpu/riscv/include/rtems/score/cpu.h

@@ -220,6 +220,45 @@ extern void _CPU_Fatal_halt(uint32_t source, uint32_t error) RTEMS_NO_RETURN;
 
 typedef uint16_t Priority_bit_map_Word;
 
+/*
+ * See The RISC-V Instruction Set Manual, Volume II: RISC-V Privileged
+ * Architectures V1.10, Table 3.6: Machine cause register (mcause) values after
+ * trap.
+ */
+typedef enum {
+  RISCV_INTERRUPT_SOFTWARE_USER = 0,
+  RISCV_INTERRUPT_SOFTWARE_SUPERVISOR = 1,
+  RISCV_INTERRUPT_SOFTWARE_MACHINE = 3,
+  RISCV_INTERRUPT_TIMER_USER = 4,
+  RISCV_INTERRUPT_TIMER_SUPERVISOR = 5,
+  RISCV_INTERRUPT_TIMER_MACHINE = 7,
+  RISCV_INTERRUPT_EXTERNAL_USER = 8,
+  RISCV_INTERRUPT_EXTERNAL_SUPERVISOR = 9,
+  RISCV_INTERRUPT_EXTERNAL_MACHINE = 11
+} RISCV_Interrupt_code;
+
+/*
+ * See The RISC-V Instruction Set Manual, Volume II: RISC-V Privileged
+ * Architectures V1.10, Table 3.6: Machine cause register (mcause) values after
+ * trap.
+ */
+typedef enum {
+  RISCV_EXCEPTION_INSTRUCTION_ADDRESS_MISALIGNED = 0,
+  RISCV_EXCEPTION_INSTRUCTION_ACCESS_FAULT = 1,
+  RISCV_EXCEPTION_ILLEGAL_INSTRUCTION = 2,
+  RISCV_EXCEPTION_BREAKPOINT = 3,
+  RISCV_EXCEPTION_LOAD_ADDRESS_MISALIGNED = 4,
+  RISCV_EXCEPTION_LOAD_ACCESS_FAULT = 5,
+  RISCV_EXCEPTION_STORE_OR_AMO_ADDRESS_MISALIGNED = 6,
+  RISCV_EXCEPTION_STORE_OR_AMO_ACCESS_FAULT = 7,
+  RISCV_EXCEPTION_ENVIRONMENT_CALL_FROM_U_MODE = 8,
+  RISCV_EXCEPTION_ENVIRONMENT_CALL_FROM_S_MODE = 9,
+  RISCV_EXCEPTION_ENVIRONMENT_CALL_FROM_M_MODE = 11,
+  RISCV_EXCEPTION_INSTRUCTION_PAGE_FAULT = 12,
+  RISCV_EXCEPTION_LOAD_PAGE_FAULT = 13,
+  RISCV_EXCEPTION_STORE_OR_AMO_PAGE_FAULT = 15
+} RISCV_Exception_code;
+
 typedef struct {
   unsigned long x[32];;
 } CPU_Exception_frame;