fix - added proper code of cmsis_nvic.c for regular nrf51 target

Author: nvlsianpu

targets/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF51822_UNIFIED/device/cmsis_nvic.c

@@ -30,74 +30,14 @@
  */
 #include "cmsis_nvic.h"
 
-/* In the M0, there is no VTOR. In the LPC range such as the LPC11U,
- * whilst the vector table may only be something like 48 entries (192 bytes, 0xC0), 
- * the SYSMEMREMAP register actually remaps the memory from 0x10000000-0x100001FF 
- * to adress 0x0-0x1FF. In this case, RAM can be addressed at both 0x10000000 and 0x0
- * 
- * If we just copy the vectors to RAM and switch the SYSMEMMAP, any accesses to FLASH
- * above the vector table before 0x200 will actually go to RAM. So we need to provide 
- * a solution where the compiler gets the right results based on the memory map
- *
- * Option 1 - We allocate and copy 0x200 of RAM rather than just the table
- *  - const data and instructions before 0x200 will be copied to and fetched/exec from RAM
- *  - RAM overhead: 0x200 - 0xC0 = 320 bytes, FLASH overhead: 0
- * 
- * Option 2 - We pad the flash to 0x200 to ensure the compiler doesn't allocate anything there  
- *  - No flash accesses will go to ram, as there will be nothing there
- *  - RAM only needs to be allocated for the vectors, as all other ram addresses are normal
- *  - RAM overhead: 0, FLASH overhead: 320 bytes
- *
- * Option 2 is the one to go for, as RAM is the most valuable resource
- */
-
-
-#define NVIC_RAM_VECTOR_ADDRESS   (0x10000000)  // Location of vectors in RAM
-#define NVIC_FLASH_VECTOR_ADDRESS (0x0)       // Initial vector position in flash
-/*
-void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector) {
-    uint32_t *vectors = (uint32_t*)SCB->VTOR;
-    uint32_t i;
+extern uint32_t nrf_dispatch_vector[NVIC_NUM_VECTORS];
 
-    // Copy and switch to dynamic vectors if the first time called
-    if (SCB->VTOR == NVIC_FLASH_VECTOR_ADDRESS) {
-        uint32_t *old_vectors = vectors;
-        vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS;
-        for (i=0; i<NVIC_NUM_VECTORS; i++) {
-            vectors[i] = old_vectors[i];
-        }
-        SCB->VTOR = (uint32_t)NVIC_RAM_VECTOR_ADDRESS;
-    }
-    vectors[IRQn + 16] = vector;
+void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector)
+{
+    nrf_dispatch_vector[IRQn + NVIC_USER_IRQ_OFFSET] = vector;
 }
 
-uint32_t NVIC_GetVector(IRQn_Type IRQn) {
-    uint32_t *vectors = (uint32_t*)SCB->VTOR;
-    return vectors[IRQn + 16];
-}*/
-
-void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector) {
-   // int i;
-    // Space for dynamic vectors, initialised to allocate in R/W
-    static volatile uint32_t* vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS;
-    /*
-    // Copy and switch to dynamic vectors if first time called
-    if((LPC_SYSCON->SYSMEMREMAP & 0x3) != 0x1) {     
-      uint32_t *old_vectors = (uint32_t *)0;         // FLASH vectors are at 0x0
-      for(i = 0; i < NVIC_NUM_VECTORS; i++) {    
-            vectors[i] = old_vectors[i];
-        }
-        LPC_SYSCON->SYSMEMREMAP = 0x1; // Remaps 0x0-0x1FF FLASH block to RAM block
-    }*/
-
-    // Set the vector 
-    vectors[IRQn + 16] = vector; 
-}
-
-uint32_t NVIC_GetVector(IRQn_Type IRQn) {
-    // We can always read vectors at 0x0, as the addresses are remapped
-    uint32_t *vectors = (uint32_t*)0; 
-
-    // Return the vector
-    return vectors[IRQn + 16];
+uint32_t NVIC_GetVector(IRQn_Type IRQn)
+{
+    return nrf_dispatch_vector[IRQn + NVIC_USER_IRQ_OFFSET];
 }