Merge pull request #10534 from OpenNuvoton/nuvoton_nano130_fix-vectab-virtual

NANO130: Fix optimization error with NVIC_SetVector/NVIC_GetVector on ARMC6

Author: 0xc0170

targets/TARGET_NUVOTON/TARGET_NANO100/device/TOOLCHAIN_IAR/NANO130.icf

@@ -19,14 +19,15 @@ define memory mem with size = 4G;
 define region ROM_region   = mem:[from __ICFEDIT_region_ROM_start__   to __ICFEDIT_region_ROM_end__];
 define region IRAM_region  = mem:[from __ICFEDIT_region_IRAM_start__  to __ICFEDIT_region_IRAM_end__];
 
+define block ROMVEC    with alignment = 8                                   { readonly section .intvec };
 define block CSTACK    with alignment = 8, size = __ICFEDIT_size_cstack__   { };
 define block HEAP      with alignment = 8, size = __ICFEDIT_size_heap__     { };
 
 
 initialize by copy { readwrite };
 do not initialize  { section .noinit };
 
-place at address mem:__ICFEDIT_intvec_start__ { readonly section .intvec };
+place at address mem:__ICFEDIT_intvec_start__ { block ROMVEC };
 
 place in ROM_region   { readonly };
 place at start of IRAM_region   { block CSTACK };

targets/TARGET_NUVOTON/TARGET_NANO100/device/cmsis_nvic.h

@@ -23,18 +23,26 @@
 #define NVIC_USER_IRQ_NUMBER 32
 #define NVIC_NUM_VECTORS     (NVIC_USER_IRQ_OFFSET + NVIC_USER_IRQ_NUMBER)
 
-#if defined(__CC_ARM) || (defined(__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050))
-#   define NVIC_RAM_VECTOR_ADDRESS  ((uint32_t) &Image$$ER_IRAMVEC$$ZI$$Base)
+/* Avoid optimization error on e.g. ARMC6
+ *
+ * If NVIC_FLASH_VECTOR_ADDRESS is directly defined as 0, the compiler would see it
+ * as NULL, and deliberately optimize NVIC_GetVector to an undefined instruction -
+ * trapping because we're accessing an array at NULL.
+ *
+ * A suggested solution by Arm is to define NVIC_FLASH_VECTOR_ADDRESS as a symbol
+ * instead to avoid such unwanted optimization.
+ */
+#if defined(__ARMCC_VERSION)
+extern uint32_t Image$$ER_IROM1$$Base;
+#define NVIC_FLASH_VECTOR_ADDRESS   ((uint32_t) &Image$$ER_IROM1$$Base)
 #elif defined(__ICCARM__)
-#   pragma section = "IRAMVEC"
-#   define NVIC_RAM_VECTOR_ADDRESS  ((uint32_t) __section_begin("IRAMVEC"))
+#pragma section = "ROMVEC"
+#define NVIC_FLASH_VECTOR_ADDRESS   ((uint32_t) __section_begin("ROMVEC"))
 #elif defined(__GNUC__)
-#   define NVIC_RAM_VECTOR_ADDRESS  ((uint32_t) &__start_vector_table__)
+extern uint32_t __vector_table;
+#define NVIC_FLASH_VECTOR_ADDRESS   ((uint32_t) &__vector_table)
 #endif
 
-
-#define NVIC_FLASH_VECTOR_ADDRESS 0
-
 #ifdef __cplusplus
 extern "C" {
 #endif