From ef5f55f6e4e069af70f001d2dca3980a0f2b9bfa Mon Sep 17 00:00:00 2001
From: keton <keton@users.noreply.github.com>
Date: Thu, 6 Oct 2016 21:49:14 +0200
Subject: [PATCH] Optimize memory usage for ARM Cortex M and similar embedded
 systems (#578)

* Changed ge_precomp data to const to reduce RAM usage on embedded systems.
* Add configuration option "WOLFSSL_NRF5x" for Nordic nRF5x platform in settings.h
---
 wolfcrypt/src/ge_operations.c |  6 +++---
 wolfssl/wolfcrypt/settings.h  | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/wolfcrypt/src/ge_operations.c b/wolfcrypt/src/ge_operations.c
index 40dd4c7b1..99eaeb2dc 100644
--- a/wolfcrypt/src/ge_operations.c
+++ b/wolfcrypt/src/ge_operations.c
@@ -758,7 +758,7 @@ static unsigned char negative(signed char b)
 }
 
 
-static void cmov(ge_precomp *t,ge_precomp *u,unsigned char b)
+static void cmov(ge_precomp *t,const ge_precomp *u,unsigned char b)
 {
   fe_cmov(t->yplusx,u->yplusx,b);
   fe_cmov(t->yminusx,u->yminusx,b);
@@ -767,7 +767,7 @@ static void cmov(ge_precomp *t,ge_precomp *u,unsigned char b)
 
 
 /* base[i][j] = (j+1)*256^i*B */
-static ge_precomp base[32][8] = {
+static const ge_precomp base[32][8] = {
 {
  {
   { 25967493,-14356035,29566456,3660896,-12694345,4014787,27544626,-11754271,-6079156,2047605 },
@@ -2222,7 +2222,7 @@ static void slide(signed char *r,const unsigned char *a)
 }
 
 
-static ge_precomp Bi[8] = {
+static const ge_precomp Bi[8] = {
  {
   { 25967493,-14356035,29566456,3660896,-12694345,4014787,27544626,-11754271,-6079156,2047605 },
   { -12545711,934262,-2722910,3049990,-727428,9406986,12720692,5043384,19500929,-15469378 },
diff --git a/wolfssl/wolfcrypt/settings.h b/wolfssl/wolfcrypt/settings.h
index 134920f87..cc5283fac 100644
--- a/wolfssl/wolfcrypt/settings.h
+++ b/wolfssl/wolfcrypt/settings.h
@@ -124,6 +124,9 @@
 /* Uncomment next line if building for VxWorks */
 /* #define WOLFSSL_VXWORKS */
 
+/* Uncomment next line if building for Nordic nRF5x platofrm */
+/* #define WOLFSSL_NRF5x */
+
 /* Uncomment next line to enable deprecated less secure static DH suites */
 /* #define WOLFSSL_STATIC_DH */
 
@@ -401,6 +404,23 @@
     #define SINGLE_THREADED         /* Not ported at this time */
 #endif
 
+#ifdef WOLFSSL_NRF5x
+		#define SIZEOF_LONG 4
+		#define SIZEOF_LONG_LONG 8
+		#define NO_ASN_TIME
+		#define NO_DEV_RANDOM
+		#define NO_FILESYSTEM
+		#define NO_MAIN_DRIVER
+		#define NO_WRITEV
+		#define SINGLE_THREADED
+		#define USE_FAST_MATH
+		#define TFM_TIMING_RESISTANT
+		#define USE_WOLFSSL_MEMORY
+		#define WOLFSSL_NRF51
+		#define WOLFSSL_USER_IO
+		#define NO_SESSION_CACHE
+#endif
+
 /* Micrium will use Visual Studio for compilation but not the Win32 API */
 #if defined(_WIN32) && !defined(MICRIUM) && !defined(FREERTOS) && \
 	!defined(FREERTOS_TCP) && !defined(EBSNET) && !defined(WOLFSSL_EROAD) && \