fix nvm rewrite

Author: microdev1

ports/raspberrypi/common-hal/nvm/ByteArray.c

@@ -32,26 +32,54 @@
 #include "src/rp2_common/hardware_flash/include/hardware/flash.h"
 
 extern uint32_t __flash_binary_start;
+static const uint32_t flash_binary_start = (uint32_t) &__flash_binary_start;
+
+#define RMV_OFFSET(addr) addr - flash_binary_start
 
 uint32_t common_hal_nvm_bytearray_get_length(nvm_bytearray_obj_t* self) {
     return self->len;
 }
 
 static void write_page(uint32_t page_addr, uint32_t offset, uint32_t len, uint8_t* bytes) {
-    // Write a whole page to flash, buffering it first and then erasing and rewriting
-    // it since we can only clear a whole page at a time.
+    // Write a whole page to flash, buffering it first and then erasing and rewriting it
+    // since we can only write a whole page at a time.
     if (offset == 0 && len == FLASH_PAGE_SIZE) {
-        flash_range_program(page_addr - (uint32_t) &__flash_binary_start, bytes, FLASH_PAGE_SIZE);
+        flash_range_program(RMV_OFFSET(page_addr), bytes, FLASH_PAGE_SIZE);
     } else {
         uint8_t buffer[FLASH_PAGE_SIZE];
         memcpy(buffer, (uint8_t*) page_addr, FLASH_PAGE_SIZE);
         memcpy(buffer + offset, bytes, len);
-        flash_range_program(page_addr - (uint32_t) &__flash_binary_start, buffer, FLASH_PAGE_SIZE);
+        flash_range_program(RMV_OFFSET(page_addr), buffer, FLASH_PAGE_SIZE);
     }
 }
 
+static void write_sector(uint32_t address, uint32_t len, uint8_t* bytes) {
+    // Write a whole sector to flash, buffering it first and then erasing and rewriting it
+    // since we can only erase a whole sector at a time.
+    uint8_t buffer[FLASH_SECTOR_SIZE];
+    memcpy(buffer, (uint8_t*) CIRCUITPY_INTERNAL_NVM_START_ADDR, FLASH_SECTOR_SIZE);
+    memcpy(buffer + address, bytes, len);
+    flash_range_erase(RMV_OFFSET(CIRCUITPY_INTERNAL_NVM_START_ADDR), FLASH_SECTOR_SIZE);
+    flash_range_program(RMV_OFFSET(CIRCUITPY_INTERNAL_NVM_START_ADDR), buffer, FLASH_SECTOR_SIZE);
+}
+
+void common_hal_nvm_bytearray_get_bytes(nvm_bytearray_obj_t* self,
+        uint32_t start_index, uint32_t len, uint8_t* values) {
+    memcpy(values, self->start_address + start_index, len);
+}
+
 bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t* self,
         uint32_t start_index, uint8_t* values, uint32_t len) {
+    uint8_t values_in[len];
+    common_hal_nvm_bytearray_get_bytes(self, start_index, len, values_in);
+
+    for (uint32_t i = 0; i < len; i++) {
+        if (values_in[i] != UINT8_MAX) {
+            write_sector(start_index, len, values);
+            return true;
+        }
+    }
+
     uint32_t address = (uint32_t) self->start_address + start_index;
     uint32_t offset = address % FLASH_PAGE_SIZE;
     uint32_t page_addr = address - offset;
@@ -67,8 +95,3 @@ bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t* self,
 
     return true;
 }
-
-void common_hal_nvm_bytearray_get_bytes(nvm_bytearray_obj_t* self,
-        uint32_t start_index, uint32_t len, uint8_t* values) {
-    memcpy(values, self->start_address + start_index, len);
-}