Adding the rest of files:

- ASM is disabled
- Neug needs full rewrite
- Flash is based on PiMoroni 4MB flash (needs adjust)

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

sha256.h

@@ -0,0 +1,17 @@
+#define SHA256_DIGEST_SIZE  32
+#define SHA256_BLOCK_SIZE   64
+
+typedef struct
+{
+  uint32_t total[2];
+  uint32_t state[8];
+  uint32_t wbuf[16];
+} sha256_context;
+
+void sha256 (const unsigned char *input, unsigned int ilen,
+	     unsigned char output[32]);
+void sha256_start (sha256_context *ctx);
+void sha256_finish (sha256_context *ctx, unsigned char output[32]);
+void sha256_update (sha256_context *ctx, const unsigned char *input,
+		    unsigned int ilen);
+void sha256_process (sha256_context *ctx);