Memory optimization for static const data. (#30)

Makefile

@@ -4,6 +4,7 @@ AR := $(TOOLCHAIN_PREFIX)ar
 LD := $(TOOLCHAIN_PREFIX)gcc
 OBJCOPY := $(TOOLCHAIN_PREFIX)objcopy
 
+MFORCE32 := $(shell $(CC) --help=target | grep mforce-l32)
 
 XTENSA_LIBS ?= $(shell $(CC) -print-sysroot)
 
@@ -43,6 +44,14 @@ LDFLAGS  += 	-L$(XTENSA_LIBS)/lib \
 CFLAGS+=-std=c99 -DESP8266
 
 CFLAGS += -Wall -Os -g -O2 -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mno-text-section-literals  -D__ets__ -DICACHE_FLASH
+
+ifneq ($(MFORCE32),)
+    # Your compiler supports the -mforce-l32 flag which means that 
+    # constants can be stored in flash (program) memory instead of SRAM.
+    # See: https://www.arduino.cc/en/Reference/PROGMEM
+    CFLAGS += -DPROGMEM="__attribute__((aligned(4))) __attribute__((section(\".irom.text\")))" -mforce-l32
+endif
+
 BIN_DIR := bin
 AXTLS_AR := $(BIN_DIR)/libaxtls.a
 

crypto/aes.c

@@ -75,7 +75,7 @@
 /*
  * AES S-box
  */
-static const uint8_t aes_sbox[256] =
+static const uint8_t aes_sbox[256] PROGMEM =
 {
 	0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5,
 	0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76,
@@ -114,7 +114,7 @@ static const uint8_t aes_sbox[256] =
 /*
  * AES is-box
  */
-static const uint8_t aes_isbox[256] = 
+static const uint8_t aes_isbox[256] PROGMEM = 
 {
     0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,
     0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb,

crypto/crypto_misc.c

@@ -309,7 +309,7 @@ EXP_FUNC void STDCALL print_blob(const char *format, const unsigned char *data,
 
 #if defined(CONFIG_SSL_HAS_PEM) || defined(CONFIG_HTTP_HAS_AUTHORIZATION)
 /* base64 to binary lookup table */
-static const uint8_t map[128] =
+static const uint8_t map[128] PROGMEM =
 {
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

crypto/sha512.c

@@ -42,7 +42,7 @@
 #define SIGMA4(x) (ROR64(x, 19) ^ ROR64(x, 61) ^ SHR64(x, 6))
 #define MIN(x, y) ((x) < (y) ? x : y)
  
-static const uint8_t padding[128] =
+static const uint8_t padding[128] PROGMEM =
 {
     0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

ssl/os_port.h

@@ -230,6 +230,10 @@ void exit_now(const char *format, ...);
 #define SSL_CTX_UNLOCK(A)
 #endif
 
+#ifndef PROGMEM
+#define PROGMEM
+#endif
+
 #ifdef __cplusplus
 }
 #endif