diff --git a/include/bx/inline/readerwriter.inl b/include/bx/inline/readerwriter.inl
index 7a8ded1..27051bd 100644
--- a/include/bx/inline/readerwriter.inl
+++ b/include/bx/inline/readerwriter.inl
@@ -356,23 +356,38 @@ namespace bx
 		return result;
 	}
 
-	inline int32_t writePrintf(WriterI* _writer, const char* _format, ...)
+	inline int32_t writePrintfVargs(WriterI* _writer, const char* _format, va_list _argList)
 	{
-		va_list argList;
-		va_start(argList, _format);
+		va_list argListCopy;
+		va_copy(argListCopy, _argList);
 
 		char temp[2048];
-		char* out = temp;
+		char*   out = temp;
 		int32_t max = sizeof(temp);
-		int32_t len = vsnprintf(out, max, _format, argList);
+		int32_t len = vsnprintf(out, max, _format, argListCopy);
+
+		va_end(argListCopy);
+
 		if (len > max)
 		{
+			va_copy(argListCopy, _argList);
+
 			out = (char*)alloca(len);
-			len = vsnprintf(out, len, _format, argList);
+			len = vsnprintf(out, len, _format, argListCopy);
+
+			va_end(argListCopy);
 		}
 
 		int32_t size = write(_writer, out, len);
 
+		return size;
+	}
+
+	inline int32_t writePrintf(WriterI* _writer, const char* _format, ...)
+	{
+		va_list argList;
+		va_start(argList, _format);
+		int32_t size = writePrintfVargs(_writer, _format, argList);
 		va_end(argList);
 
 		return size;
diff --git a/include/bx/readerwriter.h b/include/bx/readerwriter.h
index c7b2d63..c5f2fd4 100644
--- a/include/bx/readerwriter.h
+++ b/include/bx/readerwriter.h
@@ -280,6 +280,9 @@ namespace bx
 	template<typename Ty>
 	int32_t writeBE(WriterI* _writer, const Ty& _value, Error* _err = NULL);
 
+	/// Write formated string.
+	int32_t writePrintfVargs(WriterI* _writer, const char* _format, va_list _argList);
+
 	/// Write formated string.
 	int32_t writePrintf(WriterI* _writer, const char* _format, ...);
 
diff --git a/src/crtnone.cpp b/src/crtnone.cpp
index 79c6dd8..fd1d202 100644
--- a/src/crtnone.cpp
+++ b/src/crtnone.cpp
@@ -5,9 +5,9 @@
 
 #include "bx_p.h"
 #include <bx/debug.h>
+#include <bx/file.h>
 #include <bx/math.h>
 #include <bx/sort.h>
-#include <bx/readerwriter.h>
 
 #if BX_CRT_NONE
 
@@ -286,8 +286,12 @@ extern "C" int snprintf(char* _out, size_t _max, const char* _format, ...)
 
 extern "C" int printf(const char* _format, ...)
 {
-	BX_UNUSED(_format);
-	return -1;
+	va_list argList;
+	va_start(argList, _format);
+	bx::WriterI* writer = bx::getStdOut();
+	int32_t len = bx::writePrintfVargs(writer, _format, argList);
+	va_end(argList);
+	return len;
 }
 
 struct FILE
@@ -429,6 +433,7 @@ extern "C" int prctl(int _option, unsigned long _arg2, unsigned long _arg3, unsi
 extern "C" int chdir(const char* _path)
 {
 	BX_UNUSED(_path);
+	bx::debugPrintf("chdir(%s) not implemented!\n", _path);
 	return -1;
 }
 
@@ -441,18 +446,21 @@ extern "C" char* getcwd(char* _buf, size_t _size)
 extern "C" char* getenv(const char* _name)
 {
 	BX_UNUSED(_name);
-	return NULL;
+	bx::debugPrintf("getenv(%s) not implemented!\n", _name);
+	return (char*)"";
 }
 
 extern "C" int setenv(const char* _name, const char* _value, int _overwrite)
 {
 	BX_UNUSED(_name, _value, _overwrite);
+	bx::debugPrintf("setenv(%s, %s, %d) not implemented!\n", _name, _value, _overwrite);
 	return -1;
 }
 
 extern "C" int unsetenv(const char* _name)
 {
 	BX_UNUSED(_name);
+	bx::debugPrintf("unsetenv(%s) not implemented!\n", _name);
 	return -1;
 }
 
@@ -565,17 +573,17 @@ namespace __cxxabiv1
 
 	__extension__ typedef int __guard __attribute__( (mode(__DI__) ) );
 
-	extern "C" int __cxa_guard_acquire (__guard* _g)
+	extern "C" int __cxa_guard_acquire(__guard* _g)
 	{
 		return !*(char*)(_g);
 	}
 
-	extern "C" void __cxa_guard_release (__guard* _g)
+	extern "C" void __cxa_guard_release(__guard* _g)
 	{
 		*(char*)_g = 1;
 	}
 
-	extern "C" void __cxa_guard_abort (__guard* _g)
+	extern "C" void __cxa_guard_abort(__guard* _g)
 	{
 		BX_UNUSED(_g);
 	}
diff --git a/src/file.cpp b/src/file.cpp
index 44bc85a..ab29663 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -305,6 +305,7 @@ namespace bx
 			int32_t size = crt0::read(m_fd, _data, _size);
 			if (size != _size)
 			{
+				BX_UNUSED(_err);
 //				if (0 != feof(m_file) )
 //				{
 //					BX_ERROR_SET(_err, BX_ERROR_READERWRITER_EOF, "FileReader: EOF.");