atmel-samd: Introduce a nvm module for non-volatile byte-level memory access. (#203)

* atmel-samd: Introduce a nvm module for non-volatile byte-level memory access.

This allows for persisting small configuration values even when the file system
is read-only from CircuitPython.

Fixes #160

* Review feedback:
* Add tests.
* Fix non-zero index.
* Fix len()

1 files changed, 43 insertions, 0 deletions

diff --git a/shared-bindings/nvm/ByteArray.h b/shared-bindings/nvm/ByteArray.h
new file mode 100644
index 000000000..43d942c23
--- /dev/null
+++ b/shared-bindings/nvm/ByteArray.h
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef __MICROPY_INCLUDED_SHARED_BINDINGS_NVM_BYTEARRAY_H__
+#define __MICROPY_INCLUDED_SHARED_BINDINGS_NVM_BYTEARRAY_H__
+
+#include "common-hal/nvm/ByteArray.h"
+
+const mp_obj_type_t nvm_bytearray_type;
+
+uint32_t common_hal_nvm_bytearray_get_length(nvm_bytearray_obj_t *self);
+
+bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t *self,
+    uint32_t start_index, uint8_t* values, uint32_t len);
+// len and values are intentionally swapped to signify values is an output and
+// also leverage the compiler to validate uses are expected.
+void common_hal_nvm_bytearray_get_bytes(nvm_bytearray_obj_t *self,
+    uint32_t start_index, uint32_t len, uint8_t* values);
+
+#endif  // __MICROPY_INCLUDED_SHARED_BINDINGS_NVM_BYTEARRAY_H__