Exclude LWIP_FEATURES and float printf/scanf

Author: CapnBry

src/python/build_flags.py

@@ -176,6 +176,26 @@ def get_version():
         target_name != "NATIVE":
     build_flags = [f for f in build_flags if "Regulatory_Domain_ISM_2400" not in f]
 
+# Slim down the ESP8266 targets by not force-including float in scanf/printf
+if env.get('PIOPLATFORM', '') == 'espressif8266':
+    env.Replace(LINKFLAGS=[
+        "-Os",
+        "-nostdlib",
+        "-Wl,--no-check-sections",
+        "-Wl,-static",
+        "-Wl,--gc-sections",
+        "-Wl,-wrap,system_restart_local",
+        "-Wl,-wrap,spi_flash_read",
+        "-u", "app_entry",
+        #"-u", "_printf_float",
+        #"-u", "_scanf_float",
+        "-u", "_DebugExceptionVector",
+        "-u", "_DoubleExceptionVector",
+        "-u", "_KernelExceptionVector",
+        "-u", "_NMIExceptionVector",
+        "-u", "_UserExceptionVector"
+    ])
+
 env['OPTIONS_JSON'] = json_flags
 env['BUILD_FLAGS'] = build_flags
 sys.stdout.write("\nbuild flags: %s\n\n" % build_flags)

src/targets/common.ini

@@ -139,9 +139,7 @@ build_flags =
 	-D PLATFORM_ESP8266=1
 	-D VTABLES_IN_FLASH=1
 	-D PIO_FRAMEWORK_ARDUINO_MMU_CACHE16_IRAM48
-	-D CONFIG_TCPIP_LWIP=1
-	-D BEARSSL_SSL_BASIC
-	-O2
+	-D PIO_FRAMEWORK_ARDUINO_LWIP2_LOW_MEMORY_LOW_FLASH
 	-I ${PROJECTSRC_DIR}/hal
 board_build.f_cpu = 160000000L
 board_build.ldscript = eagle.flash.1m.ld