Modify TC3xx HAL flash erase to support arbitrary offsets and sizes

Author: bigbrett

hal/aurix_tc3xx.c

@@ -459,25 +459,91 @@ int RAMFUNCTION hal_flash_erase(uint32_t address, int len)
 {
     LED_ON(LED_ERASE);
 
-    const uint32_t sectorAddr = GET_SECTOR_ADDR(address);
-    const size_t   numSectors =
-        (len == 0) ? 0 : ((len - 1) / WOLFBOOT_SECTOR_SIZE) + 1;
-    const IfxFlash_FlashType type = getFlashTypeFromAddr(address);
+    /* Handle zero length case */
+    if (len <= 0) {
+        LED_OFF(LED_ERASE);
+        return 0;
+    }
 
-    /* Disable ENDINIT protection */
-    const uint16 endInitSafetyPassword =
+    const uint32_t           startSectorAddr = GET_SECTOR_ADDR(address);
+    const uint32_t           endAddress      = address + len - 1;
+    const uint32_t           endSectorAddr   = GET_SECTOR_ADDR(endAddress);
+    const IfxFlash_FlashType type            = getFlashTypeFromAddr(address);
+    const uint16             endInitSafetyPassword =
         IfxScuWdt_getSafetyWatchdogPasswordInline();
-    IfxScuWdt_clearSafetyEndinitInline(endInitSafetyPassword);
+    uint32_t currentSectorAddr;
 
-    IfxFlash_eraseMultipleSectors(sectorAddr, numSectors);
+    /* If address and len are both sector-aligned, perform simple bulk erase */
+    if ((address == startSectorAddr) &&
+        (endAddress == endSectorAddr + WOLFBOOT_SECTOR_SIZE - 1)) {
+        const size_t numSectors =
+            (endSectorAddr - startSectorAddr) / WOLFBOOT_SECTOR_SIZE + 1;
 
-    /* Reenable ENDINIT protection */
-    IfxScuWdt_setSafetyEndinitInline(endInitSafetyPassword);
+        /* Disable ENDINIT protection */
+        IfxScuWdt_clearSafetyEndinitInline(endInitSafetyPassword);
 
-    IfxFlash_waitUnbusy(FLASH_MODULE, type);
+        IfxFlash_eraseMultipleSectors(startSectorAddr, numSectors);
 
-    LED_OFF(LED_ERASE);
+        /* Reenable ENDINIT protection */
+        IfxScuWdt_setSafetyEndinitInline(endInitSafetyPassword);
 
+        IfxFlash_waitUnbusy(FLASH_MODULE, type);
+    }
+    /* For non-sector aligned erases, handle each sector carefully */
+    else {
+        /* Process each affected sector */
+        for (currentSectorAddr = startSectorAddr;
+             currentSectorAddr <= endSectorAddr;
+             currentSectorAddr += WOLFBOOT_SECTOR_SIZE) {
+
+            /* Check if this is a partial sector erase */
+            const int isFirstSector = (currentSectorAddr == startSectorAddr);
+            const int isLastSector  = (currentSectorAddr == endSectorAddr);
+            const int isPartialStart =
+                isFirstSector && (address > startSectorAddr);
+            const int isPartialEnd =
+                isLastSector &&
+                (endAddress < (endSectorAddr + WOLFBOOT_SECTOR_SIZE - 1));
+
+            /* For partial sectors, need to read-modify-write */
+            if (isPartialStart || isPartialEnd) {
+                /* Read the sector into the sector buffer */
+                cacheSector(currentSectorAddr, type);
+
+                /* Calculate which bytes within the sector to erase */
+                uint32_t eraseStartOffset =
+                    isPartialStart ? (address - currentSectorAddr) : 0;
+
+                uint32_t eraseEndOffset = isPartialEnd
+                                              ? (endAddress - currentSectorAddr)
+                                              : (WOLFBOOT_SECTOR_SIZE - 1);
+
+                uint32_t eraseLen = eraseEndOffset - eraseStartOffset + 1;
+
+                /* Fill the section to be erased with the erased byte value */
+                memset((uint8_t*)sectorBuffer + eraseStartOffset,
+                       FLASH_BYTE_ERASED, eraseLen);
+
+                /* Erase the sector */
+                IfxScuWdt_clearSafetyEndinitInline(endInitSafetyPassword);
+                IfxFlash_eraseSector(currentSectorAddr);
+                IfxScuWdt_setSafetyEndinitInline(endInitSafetyPassword);
+                IfxFlash_waitUnbusy(FLASH_MODULE, type);
+
+                /* Program the modified buffer back */
+                programCachedSector(currentSectorAddr, type);
+            }
+            /* For full sector erase, just erase directly */
+            else {
+                IfxScuWdt_clearSafetyEndinitInline(endInitSafetyPassword);
+                IfxFlash_eraseSector(currentSectorAddr);
+                IfxScuWdt_setSafetyEndinitInline(endInitSafetyPassword);
+                IfxFlash_waitUnbusy(FLASH_MODULE, type);
+            }
+        }
+    }
+
+    LED_OFF(LED_ERASE);
     return 0;
 }
 

src/image.c

@@ -1359,7 +1359,6 @@ static int copy_flash_buffered(uintptr_t src_addr, uintptr_t dst_addr,
     static uint8_t buffer[FLASHBUFFER_SIZE];
 #endif
 
-#if 0
 #ifdef WOLFBOOT_FLASH_MULTI_SECTOR_ERASE
 /* Mass erase destination flash in one go before writing */
 #ifdef EXT_FLASH
@@ -1376,7 +1375,6 @@ static int copy_flash_buffered(uintptr_t src_addr, uintptr_t dst_addr,
         hal_flash_lock();
     }
 #endif /* WOLFBOOT_FLASH_MULTI_SECTOR_ERASE */
-#endif
 
     /* Loop until all requested bytes are copied */
     while (bytes_copied < total_size) {