[io] Refactor IOStream to use an external printf implementation

.gitmodules

@@ -16,3 +16,6 @@
 [submodule "ext/gcc/libstdc++"]
 	path = ext/gcc/libstdc++
 	url = https://github.com/modm-io/avr-libstdcpp.git
+[submodule "ext/mpaland/printf"]
+	path = ext/mpaland/printf
+	url = https://github.com/modm-ext/printf.git

examples/arduino_uno/basic/read_analog_voltage/project.xml

@@ -2,6 +2,7 @@
   <extends>modm:arduino-uno</extends>
   <options>
     <option name="modm:build:build.path">../../../../build/arduino_uno/basic/read_analog_voltage</option>
+    <option name="modm:io:with_float">True</option>
   </options>
   <modules>
     <module>modm:platform:adc</module>

examples/avr/block_device_mirror/project.xml

@@ -3,6 +3,7 @@
     <option name="modm:target">atmega644</option>
     <option name="modm:platform:clock:f_cpu">14745600</option>
     <option name="modm:build:build.path">../../../build/avr/block_device_mirror</option>
+    <option name="modm:io:with_printf">True</option>
   </options>
   <modules>
     <module>modm:debug</module>

examples/avr/can/mcp2515/project.xml

@@ -3,6 +3,7 @@
     <option name="modm:target">atmega644</option>
     <option name="modm:platform:clock:f_cpu">14745600</option>
     <option name="modm:build:build.path">../../../../build/avr/can/mcp2515</option>
+    <option name="modm:io:with_printf">True</option>
   </options>
   <modules>
     <module>modm:driver:mcp2515</module>

examples/avr/can/mcp2515_uart/project.xml

@@ -3,6 +3,7 @@
     <option name="modm:target">atmega644</option>
     <option name="modm:platform:clock:f_cpu">14745600</option>
     <option name="modm:build:build.path">../../../../build/avr/can/mcp2515_uart</option>
+    <option name="modm:io:with_printf">True</option>
   </options>
   <modules>
     <module>modm:architecture:interrupt</module>

examples/avr/xpcc/receiver/project.xml

@@ -5,6 +5,8 @@
     <option name="modm:build:build.path">../../../../build/avr/xpcc/receiver</option>
     <option name="modm::xpcc:generator:source">../../../xpcc/xml/communication.xml</option>
     <option name="modm::xpcc:generator:container">receiver</option>
+    <option name="modm:io:with_printf">True</option>
+    <option name="modm:io:with_float">True</option>
   </options>
   <modules>
     <module>modm:communication:xpcc:generator</module>

examples/avr/xpcc/sender/project.xml

@@ -5,6 +5,8 @@
     <option name="modm:build:build.path">../../../../build/avr/xpcc/sender</option>
     <option name="modm::xpcc:generator:source">../../../xpcc/xml/communication.xml</option>
     <option name="modm::xpcc:generator:container">sender</option>
+    <option name="modm:io:with_printf">True</option>
+    <option name="modm:io:with_float">True</option>
   </options>
   <modules>
     <module>modm:communication:xpcc:generator</module>

ext/mpaland/printf.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+// empty include header for printf.c
+#include <stdarg.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void _putchar(char character);
+
+#ifdef __cplusplus
+}
+#endif

src/modm/architecture/interface/accessor_flash.hpp

@@ -37,7 +37,7 @@
 
 /// Declare a flash string inline
 /// @ingroup modm_architecture_accessor
-#define PSTR(s) ((const char *)(s))
+#define IFSS(s) ((const char *)(s))
 
 #else // !__DOXYGEN__