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>

p448.h

@@ -0,0 +1,15 @@
+#define N_REDUNDANT_LIMBS 16
+typedef struct p448_t
+{
+  uint32_t limb[N_REDUNDANT_LIMBS];
+} p448_t;
+
+void p448_add (p448_t *x, const p448_t *a, const p448_t *b);
+void p448_sub (p448_t *x, const p448_t *a, const p448_t *b);
+void p448_mul (p448_t *__restrict__ x, const p448_t *a, const p448_t *b);
+void p448_mul_39081 (p448_t *x, const p448_t *a);
+void p448_sqr (p448_t *__restrict__ c, const p448_t *a);
+void p448_inv (p448_t *__restrict__ x, const p448_t *a);
+void p448_serialize (uint8_t serial[56], const p448_t *x);
+void p448_deserialize (p448_t *x, const uint8_t serial[56]);
+void p448_strong_reduce (p448_t *a);