diff --git a/.hg_archival.txt b/.hg_archival.txt
index fbea688..18f075c 100644
--- a/.hg_archival.txt
+++ b/.hg_archival.txt
@@ -1,4 +1,4 @@
 repo: 74e97a8352b0714d95edee6a4e88879188f84695
-node: e4ffcdf1b68d181b4fd4053628f0039dd190aba7
+node: 8c6fd17949c867af77d3cb932e5fb19ac040984c
 branch: default
-tag: R2101
+tag: R2102
diff --git a/ChangeLog b/ChangeLog
index 77d0d7d..c3670c4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+Release R2102:
+==============
+- fix: potential bus error with write_u64 on little endian
+- fix: do not set valid flag when parsing ascii fails
+- fix: stringtype handling may fallback to C type
+- fix: multiple options handling
+- fix: return type must be ssize_t if function returns <0
+- fix: build fixes for examples
+- enhancement: support for setting bytes with hex encoded data
+- enhancement: updated syscfg example to demo setByName
+- enhancement: added doxygen comments to the generated files
+- enhancement: opimization for use of empty string as invalid value
+
 Release R2101:
 ==============
 - enhancement: support option used for messages
diff --git a/examples/ascii_output/ip4_output.cpp b/examples/ascii_output/ip4_output.cpp
index 6a7e904..970d87a 100644
--- a/examples/ascii_output/ip4_output.cpp
+++ b/examples/ascii_output/ip4_output.cpp
@@ -75,15 +75,18 @@ int main()
 
 	// print ASCII representation
 	nc.toASCII(cout);
+	cout << endl;
 
 	// modification of contents can also be done by setting by name
 	nc.setByName("hostname","myhost");
 	nc.setByName("degC","19.8");
 	nc.toASCII(cout);
+	cout << endl;
+	cout << endl;
 
 	// binary output:
 	cout << "encoded binary has " << nc.calcSize() << " bytes\n"
-		"binary output:\n\n";
+		"binary output:\n";
 
 	uint8_t buf[nc.calcSize()];
 	nc.toMemory(buf,sizeof(buf));	// serialze to buffer
diff --git a/examples/datatypes/Makefile b/examples/datatypes/Makefile
index dc9fed6..ed45982 100644
--- a/examples/datatypes/Makefile
+++ b/examples/datatypes/Makefile
@@ -2,7 +2,7 @@ WFC	= ../../bin/wfc
 CXX	= g++
 CXXFLAGS= -I../../include -Os
 
-CXXSRC	= datatypes.cpp test_dt.cpp ../../lib/wfc_support.cpp
+CXXSRC	= datatypes.cpp test_dt.cpp
 CXXOBJ	= $(CXXSRC:%.cpp=%.o)
 
 test_dt: $(CXXOBJ)
diff --git a/examples/syscfg/Makefile b/examples/syscfg/Makefile
index 30e5632..5d203b0 100644
--- a/examples/syscfg/Makefile
+++ b/examples/syscfg/Makefile
@@ -1,9 +1,13 @@
 CXXFLAGS	= -Os -g -I../../include
 CXXSRCS		= main_stream.cpp syscfg_efix.cpp syscfg_edyn.cpp
 CXXOBJS		= $(CXXSRCS:%.cpp=%.o)
+DEPS		= $(CXXSRCS:%.cpp=.%.d)
 
 all: pc edyn efix
 
+.%.d: %.cpp
+	$(CXX) $(CXXFLAGS) -MG -MT$(@:.%.d=%.o) -MM $< > $@
+
 syscfg_pc.cpp: syscfg.wfc
 	../../bin/wfc -tpc -o syscfg_pc syscfg.wfc
 
@@ -22,7 +26,7 @@ main_efix.o: main_posix.cpp syscfg_efix.cpp
 
 
 pc: syscfg_pc.o main_stream.o
-	$(CXX) $(CXXFLAGS) -I../../include main_stream.o syscfg_pc.o ../../lib/wfc_support.cpp -o $@
+	$(CXX) $(CXXFLAGS) -I../../include main_stream.o syscfg_pc.o -o $@
 
 edyn: syscfg_edyn.o main_edyn.o
 	$(CXX) $(CXXFLAGS) -I../../include main_edyn.o syscfg_edyn.o -o $@
@@ -30,3 +34,10 @@ edyn: syscfg_edyn.o main_edyn.o
 efix: syscfg_efix.o main_efix.o
 	$(CXX) $(CXXFLAGS) -I../../include main_efix.o syscfg_efix.o -o $@
 
+clean:
+	rm -f $(CXXOBJS) syscfg_pc.* syscfg_edy.* syscfg_efix.*
+
+.depend: syscfg_pc.cpp syscfg_edyn.cpp syscfg_efix.cpp | $(DEPS)
+	cat $(DEPS) > .depend
+
+include .depend
diff --git a/examples/syscfg/ip4ascii.h b/examples/syscfg/ip4ascii.h
new file mode 100644
index 0000000..0b93752
--- /dev/null
+++ b/examples/syscfg/ip4ascii.h
@@ -0,0 +1,21 @@
+#include <iostream>
+#include <stdlib.h>
+
+inline void ip4_ascii(std::ostream &str, uint32_t ip)
+{
+	str << (ip & 0xff) << '.' << ((ip >> 8) & 0xff) << '.' << ((ip >> 16) & 0xff) << '.' << ((ip >> 24 ) & 0xff);
+}
+
+
+static int parse_ipv4(uint32_t *ip, const char *str)
+{
+	uint8_t b[4];
+	int n = 0;
+	int r = sscanf(str,"%hhu.%hhu.%hhu.%hhu%n",b+0,b+1,b+2,b+3,&n);
+	if (4 == r) {
+		*ip = ((uint32_t)b[0]) | ((uint32_t)b[1]<<8) | ((uint32_t)b[2]<<16) | ((uint32_t)b[3]<<24);
+		return n;
+	}
+	std::cerr << "parser error " << n << "\n";
+	return -1;
+}
diff --git a/examples/syscfg/main_stream.cpp b/examples/syscfg/main_stream.cpp
index 5f3cb20..cd51822 100644
--- a/examples/syscfg/main_stream.cpp
+++ b/examples/syscfg/main_stream.cpp
@@ -29,9 +29,9 @@ void saveConfig(const Config &cfg)
 	out.open(CfgName);	// open file
 	out << str;		// write to file
 	if (out.good())
-		cout << "writing config successful\n";
+		cout << "\nwriting config successful\n";
 	else
-		cerr << "error writing config\n";
+		cerr << "\nerror writing config\n";
 }
 
 
@@ -56,6 +56,18 @@ int readConfig(Config &cfg)
 }
 
 
+static uint32_t str_to_ip(const char *str)
+{
+	uint8_t b[4];
+	int n = sscanf(str,"%hhu.%hhu.%hhu.%hhu",b+0,b+1,b+2,b+3);
+	if (4 == n) {
+		uint32_t ip = ((uint32_t)b[0]<<24) | ((uint32_t)b[1]<<16) | ((uint32_t)b[2]<<8) | (uint32_t)b[3];
+		return ip;
+	}
+	return 0;
+}
+
+
 int main()
 {
 	Config cfg;
@@ -69,7 +81,51 @@ int main()
 	// do some work here
 	// e.g. produce ASCII output
 	cfg.toASCII(std::cout);
+
+	cout << "\nNow continue interactively, by setting gateway and netmask.\n"
+		"Therefore, enter parameter name and its argument separated by a singel space.\n"
+		"e.g. type 'netmask 24'\n";
+	char line[80];
+	do {
+		cin.getline(line,sizeof(line));
+		char *sp = strchr(line,' ');
+		if (sp) {
+			*sp = 0;
+			if (0 > cfg.setByName(line,sp+1))
+				cerr << "error parsing '" << line << "' = '" << sp+1 << "'\n";
+		}
+	} while (line[0] != 0);
 	
+	// without setByName
+	/*
+	char line[80];
+	do {
+
+		// this code misses necessary checks to be more readable as an example
+		if (!memcmp(line,"gateway ",8)) {
+			uint32_t ip = str_to_ip(line+8);
+			if (ip)
+				cfg.set_gateway(ip);
+			else
+				cerr << "invalid IP address\n";
+		} else if (!memcmp(line,"ipv4 ",5)) {
+			uint32_t ip = str_to_ip(line+5);
+			if (ip)
+				cfg.set_ipv4(ip);
+			else
+				cerr << "invalid IP address '" << line+4 << "'\n";
+		} else if (!memcmp(line,"netmask ",8)) {
+			long v = strtol(line+8,0,0);
+			cfg.set_netmask(v);
+		} else if (line[0] != 0) {
+			cerr << "invalid parameter\n";
+		}
+		// ...
+	} while (line[0] != 0);
+	*/
+	
+	cfg.toASCII(std::cout);
+	cout << "\n";
 	// save the config before terminating
 	saveConfig(cfg);
 	return 0;
diff --git a/examples/syscfg/syscfg.wfc b/examples/syscfg/syscfg.wfc
index 9f63e27..b72558d 100644
--- a/examples/syscfg/syscfg.wfc
+++ b/examples/syscfg/syscfg.wfc
@@ -21,15 +21,18 @@ option embedded_dyn : embedded {
 
 option embedded_fix : embedded {
 	header=<fstring.h>;
-	/Config/hostname : stringtype = "FString<16>";
-	/Config/wifi_ssid: stringtype = "FString<32>";
-	/Config/wifi_pass: stringtype = "FString<32>";
+	/Config/hostname :	stringtype = "FString<16>";
+	/Config/wifi_ssid:	stringtype = "FString<32>";
+	/Config/wifi_pass:	stringtype = "FString<32>";
 }
 
 option pc {
 	toASCII = toASCII;
 	endian = little;
 	optimize = speed;
+	header="ip4ascii.h";
+	/Config/ipv4: 		to_ascii = ip4_ascii, parse_ascii = parse_ipv4;
+	/Config/gateway: 	to_ascii = ip4_ascii, parse_ascii = parse_ipv4;
 }
 
 message Config
diff --git a/include/bytes.h b/include/bytes.h
index 71edf9b..bf77c6b 100644
--- a/include/bytes.h
+++ b/include/bytes.h
@@ -21,6 +21,7 @@
 #define _BYTES_H
 
 #include <inttypes.h>
+#include <stdlib.h>
 
 struct Bytes
 {
@@ -29,14 +30,43 @@ struct Bytes
 	, len(0)
 	{ }
 
+	explicit Bytes(const char *d)
+	: len(strlen(d))
+	{
+		bytes = (char *)malloc(len);
+		memcpy(bytes,d,len);
+	}
+
 	Bytes(const char *d, size_t l)
-	: bytes(d)
+	: bytes((char *)malloc(l))
 	, len(l)
-	{ }
+	{ memcpy(bytes,d,l); }
+
+	Bytes(const Bytes &b)
+	: bytes((char *)malloc(b.len))
+	, len(b.len)
+	{ memcpy(bytes,b.bytes,len); }
+	
+	~Bytes()
+	{ free(bytes); }
 
+	Bytes &operator = (const Bytes &b)
+	{
+		assign(b.bytes,b.len);
+		return *this;
+	}
+	
+	Bytes &operator = (const char *cstr)
+	{
+		size_t l = strlen(cstr);
+		assign(cstr,l);
+		return *this;
+	}
+	
 	void assign(const char *d, size_t l)
 	{
-		bytes = d;
+		bytes = (char*)realloc((void*)bytes,l);
+		memcpy(bytes,d,l);
 		len = l;
 	}
 
@@ -51,15 +81,39 @@ struct Bytes
 
 	void clear()
 	{
+		free((void*)bytes);
 		bytes = 0;
 		len = 0;
 	}
 
+	void push_back(char c)
+	{
+		size_t at = len;
+		++len;
+		bytes = (char *) realloc((void*)bytes,len);
+		bytes[at] = c;
+	}
+
 	bool operator != (const Bytes &r) const
 	{ return (len != r.len) || (0 != memcmp(bytes,r.bytes,len)); }
 
+	bool operator == (const Bytes &r) const
+	{ return (len == r.len) && (0 == memcmp(bytes,r.bytes,len)); }
+
+	bool operator == (const char *cstr) const
+	{
+		size_t l = strlen(cstr);
+		return (l == len) && (0 == memcmp(bytes,cstr,l));
+	}
+
+	bool operator != (const char *cstr) const
+	{
+		size_t l = strlen(cstr);
+		return (l != len) || (0 != memcmp(bytes,cstr,l));
+	}
+
 	private:
-	const char *bytes;
+	char *bytes;
 	size_t len;
 };
 
diff --git a/include/fstring.h b/include/fstring.h
index 082657b..82215e8 100644
--- a/include/fstring.h
+++ b/include/fstring.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2020, Thomas Maier-Komor
+ *  Copyright (C) 2020-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -44,13 +44,11 @@ class FString
 			l = len-1;
 		memcpy(str,s,l);
 		str[l] = 0;
-		str[len-1] = 0;
 	}
 
 	FString(const FString &a)
 	{
 		strcpy(str,a.str);
-		str[len-1] = 0;
 	}
 
 	FString &operator = (const FString &a)
@@ -61,8 +59,8 @@ class FString
 
 	FString &operator += (const FString &a)
 	{
-		strncat(str,a.str,len-1);
-		str[len-1] = 0;
+		size_t l = strlen(str);
+		strncat(str,a.str,len-l-1);
 		return *this;
 	}
 
diff --git a/share/parse_ascii.cct b/share/parse_ascii.cct
index d203d25..04c5898 100644
--- a/share/parse_ascii.cct
+++ b/share/parse_ascii.cct
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2018, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -27,14 +27,12 @@ int parse_ascii_u8(uint8_t *v, const char *ascii)
 {
 	char *eptr;
 	long d = strtol(ascii,&eptr,0);
-	if ((d < 0) || (d > UINT8_MAX)) {
+	if (eptr == ascii)
 		$handle_error;
-	}
-	if (eptr != ascii) {
-		*v = (uint8_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if ((d < 0) || (d > UINT8_MAX))
+		$handle_error;
+	*v = (uint8_t) d;
+	return eptr-ascii;
 }
 
 
@@ -46,14 +44,12 @@ int parse_ascii_u16(uint16_t *v, const char *ascii)
 {
 	char *eptr;
 	long d = strtol(ascii,&eptr,0);
-	if ((d < 0) || (d > UINT16_MAX)) {
+	if (eptr == ascii)
 		$handle_error;
-	}
-	if (eptr != ascii) {
-		*v = (uint16_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if ((d < 0) || (d > UINT16_MAX))
+		$handle_error;
+	*v = (uint16_t) d;
+	return eptr-ascii;
 }
 
 
@@ -65,13 +61,12 @@ int parse_ascii_u32(uint32_t *v, const char *ascii)
 {
 	char *eptr;
 	long long d = strtoll(ascii,&eptr,0);
+	if (eptr == ascii)
+		$handle_error;
 	if ((d < 0) || (d > UINT32_MAX))
 		$handle_error;
-	if (eptr != ascii) {
-		*v = (uint32_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	*v = (uint32_t) d;
+	return eptr-ascii;
 }
 
 
@@ -83,11 +78,10 @@ int parse_ascii_u64(uint64_t *v, const char *ascii)
 {
 	char *eptr;
 	unsigned long long d = strtoull(ascii,&eptr,0);
-	if (eptr != ascii) {
-		*v = (uint64_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if (eptr == ascii)
+		$handle_error;
+	*v = (uint64_t) d;
+	return eptr-ascii;
 }
 
 
@@ -99,14 +93,12 @@ int parse_ascii_s8(int8_t *v, const char *ascii)
 {
 	char *eptr;
 	long d = strtol(ascii,&eptr,0);
-	if ((d < INT8_MIN) || (d > INT8_MAX)) {
+	if (eptr == ascii)
 		$handle_error;
-	}
-	if (eptr != ascii) {
-		*v = (uint8_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if ((d < INT8_MIN) || (d > INT8_MAX))
+		$handle_error;
+	*v = (uint8_t) d;
+	return eptr-ascii;
 }
 
 
@@ -118,14 +110,12 @@ int parse_ascii_s16(int16_t *v, const char *ascii)
 {
 	char *eptr;
 	long d = strtol(ascii,&eptr,0);
-	if ((d < INT16_MIN) || (d > INT16_MAX)) {
+	if (eptr == ascii)
 		$handle_error;
-	}
-	if (eptr != ascii) {
-		*v = (uint16_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if ((d < INT16_MIN) || (d > INT16_MAX))
+		$handle_error;
+	*v = (uint16_t) d;
+	return eptr-ascii;
 }
 
 
@@ -137,14 +127,12 @@ int parse_ascii_s32(int32_t *v, const char *ascii)
 {
 	char *eptr;
 	long long d = strtoll(ascii,&eptr,0);
-	if ((d < INT32_MIN) || (d > INT32_MAX)) {
+	if (eptr == ascii)
 		$handle_error;
-	}
-	if (eptr != ascii) {
-		*v = (uint32_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if ((d < INT32_MIN) || (d > INT32_MAX))
+		$handle_error;
+	*v = (uint32_t) d;
+	return eptr-ascii;
 }
 
 
@@ -156,11 +144,10 @@ int parse_ascii_s64(int64_t *v, const char *ascii)
 {
 	char *eptr;
 	unsigned long long d = strtoull(ascii,&eptr,0);
-	if (eptr != ascii) {
-		*v = (int64_t) d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if (eptr == ascii)
+		$handle_error;
+	*v = (int64_t) d;
+	return eptr-ascii;
 }
 
 
@@ -172,11 +159,10 @@ int parse_ascii_flt(float *v, const char *ascii)
 {
 	char *eptr;
 	float f = strtof(ascii,&eptr);
-	if (eptr != ascii) {
-		*v = f;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if (eptr == ascii)
+		$handle_error;
+	*v = f;
+	return eptr-ascii;
 }
 
 
@@ -188,11 +174,10 @@ int parse_ascii_dbl(double *v, const char *ascii)
 {
 	char *eptr;
 	double d = strtod(ascii,&eptr);
-	if (eptr != ascii) {
-		*v = d;
-		return eptr-ascii;
-	}
-	$handle_error;
+	if (eptr == ascii)
+		$handle_error;
+	*v = d;
+	return eptr-ascii;
 }
 
 
@@ -269,11 +254,9 @@ int parse_ascii_bool(bool *v, const char *ascii)
  */
 int parse_enum(varint_t *v, const char *n)
 {
-	if ((n[0] >= '0') && (n[0] <= '9')) {
-		char *e;
-		long ll = strtoll(n,&e,0);
-		if ((ll == 0) && (e == n))
-			$handle_error;
+	char *e;
+	long ll = strtoll(n,&e,0);
+	if (e != n) {
 		*v = ll;
 		return e-n;
 	}
@@ -283,3 +266,43 @@ int parse_enum(varint_t *v, const char *n)
 	*v = i->second;
 	return strlen(n);
 }
+
+/* wfc-template:
+ * function: parse_ascii_bytes
+ * sysinclude: map
+ */
+template <typename T>
+int parse_ascii_bytes(T &b, const char *ascii)
+{
+	const char *at = ascii;
+	while (*at) {
+		char c0 = *at++;
+		while ((c0 == ' ') || (c0 == '\t') || (c0 == '\n') || (c0 == '\r'))
+			c0 = *at++;
+		char c1 = *at++;
+		while ((c1 == ' ') || (c1 == '\t') || (c1 == '\n') || (c1 == '\r'))
+			c1 = *at++;
+		if (c1 == 0)
+			$handle_error;
+		uint8_t v;
+		if ((c0 >= '0') && (c0 <= '9'))
+			v = c0-'0';
+		else if ((c0 >= 'a') && (c0 <= 'f'))
+			v = c0-'a'+10;
+		else if ((c0 >= 'A') && (c0 <= 'F'))
+			v = c0-'A'+10;
+		else
+			return at-ascii-1;
+		v <<= 4;
+		if ((c1 >= '0') && (c1 <= '9'))
+			v |= c1-'0';
+		else if ((c1 >= 'a') && (c1 <= 'f'))
+			v |= c1-'a'+10;
+		else if ((c1 >= 'A') && (c1 <= 'F'))
+			v |= c1-'A'+10;
+		else
+			$handle_error;
+		b.push_back(v);
+	}
+	return at-ascii;
+}
diff --git a/share/write_mem.cc b/share/write_mem.cc
index cbbd91b..1cc611e 100644
--- a/share/write_mem.cc
+++ b/share/write_mem.cc
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2018, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -36,14 +36,25 @@ union mangle_double
 };
 
 
+/* wfc-template:
+ * function: write_u64
+ * endian: little
+ * Optimize: speed
+ */
+#define write_u64_le(w,v) (*(uint64_t*)w) = v
+
+
 /* wfc-template:
  * function: write_u64
  */
 void write_u64_generic(uint8_t *wire, uint64_t v)
 {
 #if defined __BYTE_ORDER__ && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
-	*(uint64_t*)wire = v;
-#else
+	if (((off_t)wire & 0x7) == 0) {
+		*(uint64_t*)wire = v;
+		return;
+	}
+#endif
 	*wire++ = v & 0xff;
 	v >>= 8;
 	*wire++ = v & 0xff;
@@ -59,7 +70,6 @@ void write_u64_generic(uint8_t *wire, uint64_t v)
 	*wire++ = v & 0xff;
 	v >>= 8;
 	*wire++ = v;
-#endif
 }
 
 
@@ -139,14 +149,6 @@ void write_u64_Os2(uint8_t *wire, uint64_t v)
 #define write_u32_le(w,v) (*(uint32_t*)w) = v
 
 
-/* wfc-template:
- * function: write_u64
- * endian: little
- * Optimize: speed
- */
-#define write_u64_le(w,v) (*(uint64_t*)w) = v
-
-
 /* wfc-template:
  * function: write_u64
  * endian: little
@@ -162,6 +164,12 @@ void write_u64_le_fun(uint8_t *wire, uint64_t v)
  */
 void write_u32_0(uint8_t *wire, uint32_t v)
 {
+#if defined __BYTE_ORDER__ && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+	if (((off_t)wire & 0x3) == 0) {
+		*(uint32_t*)wire = v;
+		return;
+	}
+#endif
 	*wire++ = v & 0xff;
 	v >>= 8;
 	*wire++ = v & 0xff;
diff --git a/src/CodeGenerator.cc b/src/CodeGenerator.cc
index 074e888..c007c6a 100644
--- a/src/CodeGenerator.cc
+++ b/src/CodeGenerator.cc
@@ -56,7 +56,9 @@ CodeGenerator::CodeGenerator(PBFile *p, Options *o)
 		impl = new XmlGenerator(p,o);
 	} else
 		abort();
-	License = "\nCode generated with Wire-Format-Compiler " VERSION "\n\n";
+	License = "\nCode generated by Wire-Format-Compiler (WFC)\n"
+		"WFC Version: " VERSION "\n"
+		"WFC is Copyright 2015-2021, Thomas Maier-Komor\n\n";
 	if (p) {
 		License += "Source Information:\n===================\n";
 		License += "Filename : ";
diff --git a/src/CodeTemplate.cc b/src/CodeTemplate.cc
index a9c86c3..37d2c27 100644
--- a/src/CodeTemplate.cc
+++ b/src/CodeTemplate.cc
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2020, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -44,6 +44,7 @@ const char *Functions[] = {
 	"decode_early",
 	"decode_union",
 	"parse_ascii_bool",
+	"parse_ascii_bytes",
 	"parse_ascii_dbl",
 	"parse_ascii_flt",
 	"parse_ascii_s16",
diff --git a/src/CppGenerator.cc b/src/CppGenerator.cc
index 20b34a5..867064d 100644
--- a/src/CppGenerator.cc
+++ b/src/CppGenerator.cc
@@ -221,7 +221,8 @@ void CppGenerator::setTarget(const char *t)
 	do {
 		const map<string,KVPair*> &nodeopts = no->getNodeOptions();
 		for (map<string,KVPair*>::const_iterator i(nodeopts.begin()),e(nodeopts.end()); i != e; ++i) {
-			applyNodeOption(i->first.c_str(),i->second);
+			KVPair *p = i->second;
+			applyNodeOption(i->first.c_str(),p);
 		}
 		no = no->getParent();
 	} while (no);
@@ -233,40 +234,52 @@ void CppGenerator::setTarget(const char *t)
 
 void CppGenerator::applyNodeOption(const char *nodepath, KVPair *kvp)
 {
-	diag("appyNodeOption(%s,[%s,%s])",nodepath,kvp->getKey().c_str(),kvp->getValue().c_str());
+	diag("appyNodeOption(%s,[%s,%s,...])",nodepath,kvp->getKey().c_str(),kvp->getValue().c_str());
 	if (nodepath[0] != '/')
 		error("invalid node path '%s'",nodepath);
 	const char *node = nodepath+1;
-	const char *slash = strchr(node,'/');
 	Message *m = 0;	// needed for '/message' case
 	do {
-		string msgname(node,slash?slash-node:strlen(node));
+		char *slash = strchr((char*)node,'/');
+		string msgname(node,slash ? slash-node : strlen(node));
 		diag("appyNodeOption: msg %s",msgname.c_str());
-		if (m) {
-			m = m->getMessage(msgname.c_str());
-		} else {
+		if (m == 0) {
 			m = file->getMessage(msgname.c_str());
+		} else if (Message *sm = m->getMessage(msgname.c_str())) {
+			m = sm;
+		} else {
+			// this is a field or a enum
+			break;
 		}
 		if (m == 0) {
 			warn("Ignoring unknwon message '%s' in nodepath '%s'",msgname.c_str(),nodepath);
 			return;
 		}
-		if (slash) {
+		if (slash == 0)
+			node = 0;
+		else
 			node = slash+1;
-			slash = strchr(slash+1,'/');
-		}
-	} while (slash);
+	} while (node);
 	
 	if (Enum *e = m ? m->getEnum(node) : file->getEnum(node)) {
 		diag("appyNodeOption: enum %s",node);
-		e->setOption(kvp->getKey(),kvp->getValue());
+		do {
+			e->setOption(kvp->getKey(),kvp->getValue());
+			kvp = kvp->getNext();
+		} while (kvp);
 	} else if (m == 0) {
 		warn("Unable to resolve node path %s. Ignoring option '%s'.",nodepath,kvp->getKey().c_str());
 	} else if (Field *f = m->getField(node)) {
-		diag("appyNodeOption: field %s",node);
-		f->setOption(kvp->getKey(),kvp->getValue());
+		do {
+			diag("appyNodeOption: field %s, key %s",node,kvp->getKey().c_str());
+			f->setOption(kvp->getKey(),kvp->getValue());
+			kvp = kvp->getNext();
+		} while (kvp);
 	} else {
-		m->setOption(kvp->getKey().c_str(),kvp->getValue().c_str());
+		do {
+			m->setOption(kvp->getKey().c_str(),kvp->getValue().c_str());
+			kvp = kvp->getNext();
+		} while (kvp);
 	}
 }
 
@@ -290,13 +303,17 @@ string CppGenerator::getValid(Field *f, bool invalid)
 	}
 	int vbit = f->getValidBit();
 	if (const char *invValue = f->getInvalidValue()) {
-		assert(vbit < 0);
-		ret += "m_$(fname)";
-		if (invalid)
-			ret += " == ";
-		else
-			ret += " != ";
-		ret += invValue;
+			assert(vbit < 0);
+		if ((type == ft_string) && (!strcmp(invValue,"\"\""))) {
+			ret += "!m_$(fname).empty()";
+		} else {
+			ret += "m_$(fname)";
+			if (invalid)
+				ret += " == ";
+			else
+				ret += " != ";
+			ret += invValue;
+		}
 		return ret;
 	}
 	assert(vbit >= 0);
@@ -475,6 +492,8 @@ void CppGenerator::init()
 
 void CppGenerator::scanRequirements(Message *m)
 {
+	if (!m->getGenerate())
+		return;
 	if (optmode == optreview)
 		hasVarInt = true;	// tags are then always generated as varint
 	for (auto i : m->getFields()) {
@@ -685,6 +704,7 @@ static void allHelpers(vector<unsigned> &funcs, bool VarIntBits64)
 	funcs.push_back(ct_to_dblstr);
 
 	funcs.push_back(ct_parse_ascii_bool);
+	funcs.push_back(ct_parse_ascii_bytes);
 	funcs.push_back(ct_parse_ascii_dbl);
 	funcs.push_back(ct_parse_ascii_flt);
 	funcs.push_back(ct_parse_ascii_s8);
@@ -1252,32 +1272,67 @@ void CppGenerator::writeClass(Generator &G, Message *m)
 		G << "bool operator != (const $(msg_name) &r) const;\n";
 	if (target->getFlag("withEqual"))
 		G << "bool operator == (const $(msg_name) &r) const;\n";
-	G <<	"void $(msg_clear)();\n"
+	G <<	"\n"
+		"//! function for resetting all members to their default values\n"
+		"void $(msg_clear)();\n"
+		"\n"
+		"//! Calculate the required number of bytes for serializing this object.\n"
+		"//! If the data of the object change, the number ob bytes needed for\n"
+		"//! serialization, may change, too.\n"
 		"size_t $calcSize() const;\n";
 	if (G.hasValue("fromMemory"))
-		G << "ssize_t $(fromMemory)(const void *b, ssize_t s);\n";
+		G <<	"\n"
+			"//! Function for parsing memory with serialized data to append and update this object.\n"
+			"//! @param b buffer of serialized data\n"
+			"//! @param s number of bytes available in the buffer\n"
+			"//! @return number of bytes parsed or negative value if an error occured\n"
+			"ssize_t $(fromMemory)(const void *b, ssize_t s);\n";
 	if (G.hasValue("toMemory"))
-		G << "size_t $(toMemory)(uint8_t *, ssize_t) const;\n";
+		G << 	"\n"
+			"\t//! Serialize the object to memory.\n"
+			"\t//! param b buffer the data should be written to\n"
+			"\t//! param s number of bytes available in the buffer\n"
+			"\t//! return number of bytes written\n"
+			"ssize_t $(toMemory)(uint8_t *, ssize_t) const;\n";
 	if (G.hasValue("toWire")) {
 		G.setMode(gen_wire);
-		G <<	"void $(toWire)($putparam) const;\n";
+		G <<	"\n"
+			"//! Serialize the object using a function for transmitting individual bytes.\n"
+			"//! @param put function to put individual bytes for transmission on the wire\n"
+			"void $(toWire)($putparam) const;\n";
 	}
 	if (G.hasValue("toSink")) {
 		G.setMode(gen_sink);
-		G <<	"$(sink_template)void $(toSink)($putparam) const;\n";
+		G <<	"\n"
+			"//! Function for serializing the object using the Sink class.\n"
+			"$(sink_template)void $(toSink)($putparam) const;\n";
 	}
 	if (G.hasValue("toString")) {
 		G.setMode(gen_string);
-		G <<	"void $(toString)($putparam) const;\n";
+		G <<	"\n"
+			"//! Function for serializing the object to a string.\n"
+			"void $(toString)($putparam) const;\n";
 	}
 	if (G.hasValue("toJSON"))
-		G << "void $(toJSON)($(streamtype) &json, unsigned indLvl = 0) const;\n";
+		G <<	"\n"
+			"//! Function for writing the JSON representation of this object to a stream.\n"
+			"void $(toJSON)($(streamtype) &json, unsigned indLvl = 0) const;\n";
 	if (PrintOut)
-		G << "void $(toASCII)($(streamtype) &o, size_t indent = 0) const;\n";
+		G <<	"\n"
+			"//! Function for writing an ASCII representation of this object to a stream.\n"
+			"void $(toASCII)($(streamtype) &o, size_t indent = 0) const;\n";
 	if (G.hasValue("getMaxSize"))
-		G << "static size_t $getMaxSize();\n";
+		G <<	"\n"
+			"//! Function for determining the maximum size that the object may need for\n"
+		       	"//! its serialized representation\n"
+			"static size_t $getMaxSize();\n";
 	if (target->getOption("SetByName") != "")
-		G << "int $(set_by_name)(const char *, const char *);\n";
+		G <<	"\n"
+			"//! Function for setting a parameter by its ASCII name using an ASCII representation of value.\n"
+			"//! @param param parameter name\n"
+			"//! @param value ASCII representation of the value\n"
+			"//! @return number of bytes parsed from value or negative value if an error occurs\n"
+			"int $(set_by_name)(const char *param, const char *value);\n";
 	G << '\n';
 	if (SubClasses) {
 		for (unsigned i = 0, e = m->numEnums(); i != e; ++i) {
@@ -1502,13 +1557,24 @@ void CppGenerator::writeHeader(const string &bn)
 			"{\n"
 			"	public:\n"
 			"	virtual ~" << bcn << "() = 0;\n"
+			"\n"
+			"	//! calculate the number ob bytes needed for a serialized representation\n"
 			"	virtual size_t $calcSize() const = 0;\n";
 		if (G.hasValue("toString"))
-			G << 	"\tvirtual void $toString($(stringtype) &) const = 0;\n";
+			G << 	"\n"
+				"\t//! serialize the object to a string\n"
+				"\tvirtual void $toString($(stringtype) &) const = 0;\n";
 		if (G.hasValue("toSink") && !SinkToTemplate)
-			G << 	"\tvirtual void $toSink(Sink &) const = 0;\n";
+			G << 	"\n"
+				"\t//! serialize the object to an object derived from class Sink\n"
+				"\tvirtual void $toSink(Sink &) const = 0;\n";
 		if (G.hasValue("toMemory"))
-			G << 	"\tvirtual size_t $toMemory(uint8_t *, ssize_t) const = 0;\n";
+			G << 	"\n"
+				"\t//! serialize the object to memory\n"
+				"\t//! @param b buffer the data should be written to\n"
+				"\t//! @param s number of bytes available in the buffer\n"
+				"\t//! @return number of bytes written\n"
+				"\tvirtual ssize_t $toMemory(uint8_t *, ssize_t) const = 0;\n";
 		G <<	"};\n\n";
 	}
 	for (unsigned i = 0, n = file->numEnums(); i != n; ++i) {
@@ -1756,7 +1822,7 @@ void CppGenerator::writeSetByNameR(Generator &G, Field *f)
 			"}\n";
 		return;
 	}
-	if (!f->getOption("parse_ascii").empty()) {
+	if (!f->getParseAsciiFunction().empty()) {
 		G <<	"return $parse_ascii(&m_$fname[x],value);\n"
 			"}\n"
 			"}\n";
@@ -1857,7 +1923,14 @@ void CppGenerator::writeSetByName(Generator &G, Message *m)
 {
 	if (target->getOption("SetByName").empty())
 		return;
-	G <<	"int $(prefix)$(msg_name)::$(set_by_name)(const char *name, const char *value)\n"
+	G <<	"/*\n"
+		" * Function for setting an element in dot notation with an ASCII value.\n"
+		" * It will call the specified parse_ascii function for parsing the value.\n"
+		" *\n"
+		" * @return number of bytes successfully parsed or negative value indicating\n"
+		" *         an error.\n"
+		" */\n"
+		"int $(prefix)$(msg_name)::$(set_by_name)(const char *name, const char *value)\n"
 		"{\n";
 	unsigned n = 0;
 	for (auto i : m->getFields()) {
@@ -1865,15 +1938,18 @@ void CppGenerator::writeSetByName(Generator &G, Message *m)
 		if ((f == 0) || !f->isUsed() || f->isObsolete())
 			continue;
 		uint32_t t = f->getType();
-		if ((t == ft_bytes) || (t == ft_cptr))
+		if (t == ft_cptr)
 			continue;
-		G.setField(f);
 		++n;
 		if (q_repeated == f->getQuantifier()) {
+			if (t == ft_bytes)
+				continue;
+			G.setField(f);
 			writeSetByNameR(G,f);
 			G.setField(0);
 			continue;
 		}
+		G.setField(f);
 		if ((t & ft_filter) == ft_msg) {
 			if (f->getValidBit() >= 0) {
 				G <<	"if (0 == memcmp(name,\"$(fname)\",$fnamelen)) {\n"
@@ -1903,9 +1979,11 @@ void CppGenerator::writeSetByName(Generator &G, Message *m)
 				"return 0;\n"
 				"}\n";
 		}
-		if (!f->getOption("parse_ascii").empty()) {
+		if (!f->getParseAsciiFunction().empty()) {
+			G <<	"int r = $parse_ascii(&m_$fname,value);\n"
+				"if (r > 0)\n";
 			writeSetValid(G,f->getValidBit());
-			G <<	"return $parse_ascii(&m_$fname,value);\n"
+			G <<	"return r;\n"
 				"}\n";
 			G.setField(0);
 			continue;
@@ -1932,62 +2010,67 @@ void CppGenerator::writeSetByName(Generator &G, Message *m)
 			G.setField(0);
 			continue;
 		}
-		writeSetValid(G,f->getValidBit());
 		switch (t) {
 		case ft_string:
 			G <<	"m_$fname = value;\n"
-				"return m_$(fname).size();\n";
+				"int r = m_$(fname).size();\n";
+			break;
+		case ft_bytes:
+			G <<	"int r = parse_ascii_bytes(m_$(fname),value);\n";
 			break;
 		case ft_float:
-			G <<	"return parse_ascii_flt(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_flt(&m_$(fname),value);\n";
 			break;
 		case ft_double:
-			G <<	"return parse_ascii_dbl(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_dbl(&m_$(fname),value);\n";
 			break;
 		case ft_int8:
 		case ft_sint8:
 		case ft_sfixed8:
-			G <<	"return parse_ascii_s8(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_s8(&m_$(fname),value);\n";
 			break;
 		case ft_int16:
 		case ft_sint16:
 		case ft_sfixed16:
-			G <<	"return parse_ascii_s16(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_s16(&m_$(fname),value);\n";
 			break;
 		case ft_int32:
 		case ft_sint32:
 		case ft_sfixed32:
-			G <<	"return parse_ascii_s32(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_s32(&m_$(fname),value);\n";
 			break;
 		case ft_int64:
 		case ft_sint64:
 		case ft_sfixed64:
-			G <<	"return parse_ascii_s64(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_s64(&m_$(fname),value);\n";
 			break;
 		case ft_fixed8:
 		case ft_uint8:
-			G <<	"return parse_ascii_u8(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_u8(&m_$(fname),value);\n";
 			break;
 		case ft_uint16:
 		case ft_fixed16:
-			G <<	"return parse_ascii_u16(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_u16(&m_$(fname),value);\n";
 			break;
 		case ft_uint32:
 		case ft_fixed32:
-			G <<	"return parse_ascii_u32(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_u32(&m_$(fname),value);\n";
 			break;
 		case ft_uint64:
 		case ft_fixed64:
-			G <<	"return parse_ascii_u64(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_u64(&m_$(fname),value);\n";
 			break;
 		case ft_bool:
-			G <<	"return parse_ascii_bool(&m_$(fname),value);\n";
+			G <<	"int r = parse_ascii_bool(&m_$(fname),value);\n";
 			break;
 		case ft_signed:
 		case ft_unsigned:
 		default:
 			abort();
 		}
+		G << "if (r > 0)\n";
+		writeSetValid(G,f->getValidBit());
+		G << "return r;\n";
 		G.setField(0);
 		G <<	"}\n";
 	}
@@ -2000,8 +2083,12 @@ void CppGenerator::writeClear(Generator &G, Field *f)
 	uint8_t q = f->getQuantifier();
 	if (q == q_required)
 		return;
-	G	<< "$(inline)void $(prefix)$(msg_name)::$(field_clear)()\n"
-		   "{\n";
+	G <<	"/*!\n"
+		" * Function for clearing the associated member variable.\n"
+		" * It will reset the value to the default value.\n"
+		" */\n"
+		"$(inline)void $(prefix)$(msg_name)::$(field_clear)()\n"
+		"{\n";
 	uint32_t type = f->getType();
 	int vbit = f->getValidBit();
 	if (vbit >= 0) {
@@ -2284,8 +2371,13 @@ void CppGenerator::writeCalcSize(Generator &G, Field *f)
 
 void CppGenerator::writeCalcSize(Generator &G, Message *m)
 {
-	G	<< "size_t $(prefix)$(msg_name)::$calcSize() const\n"
-		<< "{\n";
+	G <<	"/*!\n"
+		" * Function for calculating the number of bytes needed for serializing\n"
+		" * the related object with its associated data.\n"
+		" * Changing the data may change the size of the serialized object.\n"
+		" */\n"
+		"size_t $(prefix)$(msg_name)::$calcSize() const\n"
+		"{\n";
 	size_t n = 0;
 	for (auto i : m->getFields()) {
 		Field *f = i.second;
@@ -3229,7 +3321,14 @@ void CppGenerator::writeToX(Generator &G, Field *f)
 
 void CppGenerator::writeFromMemory(Generator &G, Message *m)
 {
-	G <<	"ssize_t $(prefix)$(msg_name)::$(fromMemory)(const void *b, ssize_t s)\n"
+	G <<	"/*!\n"
+		" * Function for parsing an object from serialized data.\n"
+		" * @param b buffer containg the data to be parsed\n"
+		" * @param s number of bytes in buffer\n"
+		" * @return number of bytes successfully parsed (can be < s)\n"
+		" *         or a negative value indicating the error encountered\n"
+		" */\n"
+		"ssize_t $(prefix)$(msg_name)::$(fromMemory)(const void *b, ssize_t s)\n"
 		"{\n"
 		"const uint8_t *a = (const uint8_t *)b;\n"
 		"const uint8_t *e = a + s;\n";
@@ -3328,7 +3427,13 @@ void CppGenerator::writeFromMemory(Generator &G, Message *m)
 
 void CppGenerator::writeToMemory(Generator &G, Message *m)
 {
-	G <<	"size_t $(prefix)$(msg_name)::$toMemory(uint8_t *b, ssize_t s) const\n"
+	G <<	"/*!\n"
+		" * Function for serializing the object to memory.\n"
+		" * @param b buffer to serialize the object to\n"
+		" * @param s number of bytes available in the buffer\n"
+		" * @return number of bytes successfully serialized\n"
+		" */\n"
+		"ssize_t $(prefix)$(msg_name)::$toMemory(uint8_t *b, ssize_t s) const\n"
 		"{\n";
 	if (Debug)
 		G << "std::cout << \"$(prefix)$(msg_name)::$toMemory(\" << (void*)b << \", \" << s << \")\\n\";\n";
@@ -3546,7 +3651,12 @@ void CppGenerator::writeToJson(Generator &G, Message *m)
 		break;
 	}
 	G.addVariable("json_indent",resolve_esc(target->getOption("json_indent")));
-	G <<	"void $(prefix)$(msg_name)::$(toJSON)($(streamtype) &json, unsigned indLvl) const\n"
+	G <<	"/*!\n"
+		" * Function for writing a JSON representation of the object to a stream.\n"
+		" * @param json stream object the data should be serialized to\n"
+		" * @param indLvl the indention level that should be used\n"
+		" */\n"
+		"void $(prefix)$(msg_name)::$(toJSON)($(streamtype) &json, unsigned indLvl) const\n"
 		"{\n";
 	if (fsep == 0)
 		G <<	"char fsep = '{';\n";
@@ -3604,7 +3714,10 @@ void CppGenerator::writeToX(Generator &G, Message *m)
 
 void CppGenerator::writeClear(Generator &G, Message *m)
 {
-	G <<	"void $(prefix)$(msg_name)::$(msg_clear)()\n"
+	G <<	"/*!\n"
+		" * Function for resetting all members of this object to their default values.\n"
+		" */\n"
+		"void $(prefix)$(msg_name)::$(msg_clear)()\n"
 		"{\n";
 	for (auto i : m->getFields()) {
 		Field *f = i.second;
@@ -3818,7 +3931,6 @@ void CppGenerator::writePrint(Generator &G, Field *f)
 		} else
 			G <<	"o << $(field_value) << ';';\n";
 	} else if (!f->getAsciiFunction().empty()) {
-		G << ";\n";
 		G << f->getAsciiFunction() << "(o,$(field_value));\n";
 		G << "o << ';';\n";
 	} else switch (type) {
@@ -3972,15 +4084,29 @@ void CppGenerator::writeFunctions(Generator &G, Message *m)
 	if (G.hasValue("toWire")) {
 		G.setMode(gen_wire);
 		G.setVariable("toX",G.getVariable("toWire"));
+		G << 	"/*!\n"
+			" * Function for serializing the object directly to a transmission stream.\n"
+			" * @param put function for putting a byte on the transmitting wire\n"
+			" */\n";
 		writeToX(G,m);
 	}
 	if (G.hasValue("toSink") && !SinkToTemplate) {
 		G.setMode(gen_sink);
+		G << 	"/*!\n"
+			" * Function for serializing the object using a Sink object.\n"
+			" * Derive a class from the Sink base class to provide custom methods\n"
+			" * for sending the objects' data.\n"
+			" * @param s object of the class derived from Sink\n"
+			" */\n";
 		G.setVariable("toX",G.getVariable("toSink"));
 		writeToX(G,m);
 	}
 	if (G.hasValue("toString")) {
 		G.setMode(gen_string);
+		G << 	"/*!\n"
+			" * Function for serializing the object to a string.\n"
+			" * @param s string object the data should be written to\n"
+			" */\n";
 		G.setVariable("toX",G.getVariable("toString"));
 		writeToX(G,m);
 	}
@@ -4066,6 +4192,8 @@ void CppGenerator::writeHelpers(vector<unsigned> &funcs)
 			funcs.push_back(ct_parse_ascii_s16);
 		if (hasS8)
 			funcs.push_back(ct_parse_ascii_s8);
+		if (hasBytes)
+			funcs.push_back(ct_parse_ascii_bytes);
 		if (hasBool)
 			funcs.push_back(ct_parse_ascii_bool);
 	}
diff --git a/src/Field.cc b/src/Field.cc
index a86a5ad..37e9c7f 100644
--- a/src/Field.cc
+++ b/src/Field.cc
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2020, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -935,18 +935,23 @@ static bool is_xid(const string &v)
 	else if (c == '_');
 	else
 		return false;
+	unsigned nest = 0;
 	while (*s) {
 		c = *s++;
 		if ((c >= 'a') && (c <= 'z'));
 		else if ((c >= 'A') && (c <= 'Z'));
 		else if ((c >= '0') && (c <= '9'));
 		else if (c == '_');
-		else if (c == '>');
-		else if (c == '<');
+		else if (c == '>')
+			--nest;
+		else if (c == '<')
+			++nest;
+		else if (c == ',');
+		else if (c == ':');
 		else
 			return false;
 	}
-	return true;
+	return nest == 0;
 }
 
 
@@ -1004,6 +1009,19 @@ void Field::setOption(const string &option, const string &value)
 			} else {
 				stringtype = st_class;
 				type = ft_string;
+				size_t n = value.size();
+				const char *d = value.data();
+				string v;
+				if (d[0] == '"') {
+					assert(d[n-1] == '"');	// must be true due to lexical analysis
+					v.assign(d+1,n-2);
+				} else {
+					v = value;
+				}
+				
+				if (!is_xid(v))
+					error("invalid argument to stringtype: %s",value.c_str());
+				options->setOption("stringtype",v.c_str());
 			}
 		} else
 			error("invalid option stringtype for field '%s' of type '%s'",name.c_str(),getTypeName());
diff --git a/src/Field.h b/src/Field.h
index dbe9f1c..1fdb8b4 100644
--- a/src/Field.h
+++ b/src/Field.h
@@ -195,6 +195,9 @@ class Field
 	const std::string &getJsonFunction() const
 	{ return json_value_func; }
 
+	const std::string &getParseAsciiFunction() const
+	{ return parse_ascii_func; }
+
 	const char *getInvalidValue() const
 	{ return invvalue.empty() ? 0 : invvalue.c_str(); }
 
diff --git a/src/Generator.cc b/src/Generator.cc
index bd676db..00b627f 100644
--- a/src/Generator.cc
+++ b/src/Generator.cc
@@ -577,7 +577,7 @@ void Generator::setField(const Field *f)
 		addVariable("ptype",ptype);
 		sprintf(tmp,"%u",f->getTagSize());
 		addVariable("tagsize",tmp);
-		addVariable("parse_ascii",f->getOption("parse_ascii"));
+		addVariable("parse_ascii",f->getParseAsciiFunction());
 		if (Enum *e = f->toEnum())
 			setEnum(e);
 	} else {
diff --git a/src/Message.cc b/src/Message.cc
index 8143e9c..9972f1b 100644
--- a/src/Message.cc
+++ b/src/Message.cc
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2020, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -107,6 +107,8 @@ void Message::addReservation(unsigned lb, unsigned ub)
 
 Field *Message::getField(const char *n) const
 {
+	if (n == 0)
+		return 0;
 	for (auto i(m_fields.begin()), e(m_fields.end()); i != e; ++i) {
 		Field *f = i->second;
 		if ((f != 0) && (0 == strcmp(n, f->getName())))
diff --git a/src/Options.cc b/src/Options.cc
index bb10238..5c94ae9 100644
--- a/src/Options.cc
+++ b/src/Options.cc
@@ -1080,8 +1080,7 @@ KVPair::~KVPair()
 
 void KVPair::setNext(KVPair *n)
 {
-	assert(n->next == 0);
-	n->next = next;
+	assert(next == 0);
 	next = n;
 }
 
diff --git a/src/codeid.h b/src/codeid.h
index c14801b..63ba7ec 100644
--- a/src/codeid.h
+++ b/src/codeid.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2017-2020, Thomas Maier-Komor
+ *  Copyright (C) 2017-2021, Thomas Maier-Komor
  *
  *  This source file belongs to Wire-Format-Compiler.
  *
@@ -35,6 +35,7 @@ typedef enum {
 	ct_decode_early,
 	ct_decode_union,
 	ct_parse_ascii_bool,
+	ct_parse_ascii_bytes,
 	ct_parse_ascii_dbl,
 	ct_parse_ascii_flt,
 	ct_parse_ascii_s16,
diff --git a/src/wfc.cc b/src/wfc.cc
index 518f829..67372c9 100644
--- a/src/wfc.cc
+++ b/src/wfc.cc
@@ -50,7 +50,7 @@ const char *InstallDir = 0;
 void printVersion(ostream &out)
 {
 	out <<	"Wire Format Compiler (WFC), Version " VERSION "\n"
-		"Copyright 2015-2020, Thomas Maier-Komor\n"
+		"Copyright 2015-2021, Thomas Maier-Komor\n"
 		"License: GPLv3 (see file LICENSE for details)\n";
 }
 
diff --git a/src/xproto.y b/src/xproto.y
index 9556f32..a2b474c 100644
--- a/src/xproto.y
+++ b/src/xproto.y
@@ -153,7 +153,7 @@ OptionList_P
 	: Option_P
 	{ $$ = $1; }
 	| OptionList_P COMMA Option_P
-	{ $1->setNext($3); $$ = $1; }
+	{ $3->setNext($1); $$ = $3; }
 	;
 
 OptionArg_P
diff --git a/testsuite/genwfc.mk b/testsuite/genwfc.mk
index f7a7ce4..ac8a686 100644
--- a/testsuite/genwfc.mk
+++ b/testsuite/genwfc.mk
@@ -1,5 +1,5 @@
 #
-#  Copyright (C) 2019-2020, Thomas Maier-Komor
+#  Copyright (C) 2019-2021, Thomas Maier-Komor
 #
 #  This file belongs to Wire-Format-Compiler.
 #
@@ -25,7 +25,7 @@ WFCSRCS = testcases/empty_elements.wfc testcases/enumtest.wfc testcases/validbit
 	  testcases/reference.wfc testcases/validbits2.wfc testcases/tt.wfc \
 	  testcases/unused.wfc testcases/fixed_only.wfc testcases/novarint.wfc \
 	  testcases/packed.wfc testcases/virtual.wfc testcases/byname.wfc \
-	  testcases/inv_def.wfc testcases/arraycheck.wfc
+	  testcases/inv_def.wfc testcases/arraycheck.wfc testcases/binformats.wfc
 
 
 CXXSRCS	= $(WFCSRCS:testcases/%.wfc=$(ODIR)/%.cpp) $(ODIR)/referencev2.cpp
@@ -58,3 +58,9 @@ $(ODIR)/comp_v2.cpp: testcases/compatibility.wfc
 
 $(ODIR)/referencev2.cpp: testcases/reference.wfc
 	"$(WFC)" $(WFCFLAGS) -trev2 -o $(ODIR)/referencev2 $^
+
+$(ODIR)/binformats.cpp: testcases/binformats.wfc
+	"$(WFC)" $(WFCFLAGS) -tpc -o $(ODIR)/binformats_pc $^
+	"$(WFC)" $(WFCFLAGS) -tesp8266 -o $(ODIR)/binformats_esp8266 $^
+	"$(WFC)" $(WFCFLAGS) -tesp32 -o $(ODIR)/binformats_esp32 $^
+
diff --git a/testsuite/ip4funcs.h b/testsuite/ip4funcs.h
new file mode 100644
index 0000000..3294dfe
--- /dev/null
+++ b/testsuite/ip4funcs.h
@@ -0,0 +1,20 @@
+#include <iostream>
+#include <stdlib.h>
+
+inline void ip4_ascii(std::ostream &str, uint32_t ip)
+{
+	str << (ip & 0xff) << '.' << ((ip >> 8) & 0xff) << '.' << ((ip >> 16) & 0xff) << '.' << ((ip >> 24 ) & 0xff);
+}
+
+
+static int parse_ipv4(uint32_t *ip, const char *str)
+{
+	uint8_t b[4];
+	int n = sscanf(str,"%hhu.%hhu.%hhu.%hhu",b+0,b+1,b+2,b+3);
+	if (4 == n) {
+		*ip = ((uint32_t)b[0]) | ((uint32_t)b[1]<<8) | ((uint32_t)b[2]<<16) | ((uint32_t)b[3]<<24);
+		return 1;
+	}
+	std::cerr << "parser error " << n << "\n";
+	return -1;
+}
diff --git a/testsuite/testcases/binformats.wfc b/testsuite/testcases/binformats.wfc
new file mode 100644
index 0000000..3ceaf06
--- /dev/null
+++ b/testsuite/testcases/binformats.wfc
@@ -0,0 +1,640 @@
+/*
+ *  Copyright (C) 2018-2021, Thomas Maier-Komor
+ *  Atrium Firmware Package for ESP
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+option common {
+	id0=true;
+	header="support.h";
+	header="stream.h";
+	header="estring.h";
+	streamtype=stream;
+	stringtype=estring;
+	bytestype=estring;
+}
+
+option pc : common {
+	toSink="";
+	toASCII=toASCII;
+	optimize=speed;
+}
+
+option esp : common {
+	withEqual=true;
+	toString="";
+	toSink="";
+	toWire="";
+	toASCII=toASCII;
+	intsize=32;
+	varintbits=32;
+	//header="astring.h";
+	//stringtype=AString;
+	//ascii_indent=null_indent;
+}
+
+option esp32 : esp {
+	optimize=speed;
+	endian=little;		// not for esp8266, does not allow unaligned access
+	withUnequal=true;
+	/AdcConfig/mode:		used = false;
+	/AdcConfig/clk_div:		used = false;
+}
+
+option esp8266 : esp {
+	ssize_t=_ssize_t;
+	optimize=size;
+	withUnequal=false;
+	/TouchpadConfig:		used = false;
+	/TouchChannelConfig:		used = false;
+	/AdcChannel:			used = false;
+	/HardwareConfig/uart:		used = false;
+	/HardwareConfig/touchpad:	used = false;
+	/HardwareConfig/tp_channel:	used = false;
+	/Bme280Config/freq:		used = false;
+	/UartConfig/tx_gpio:		used = false;
+	/UartConfig/rx_gpio:		used = false;
+	/UartConfig/cts_gpio:		used = false;
+	/UartConfig/rts_gpio:		used = false;
+	/AdcConfig/adc1_bits:		used = false;
+	/AdcConfig/adc2_bits:		used = false;
+	/AdcConfig/hall_name:		used = false;
+	/AdcConfig/channels:		used = false;
+	/Ws2812bConfig/ch:		used = false;
+}
+
+option esp8285 : esp8266 {
+	//header="astring.h";
+	//stringtype=AString;
+	/OwDeviceConfig:		used = false;
+	/NodeConfig/httpd:		used = false;
+	/NodeConfig/app_params:		used = false;
+	/NodeConfig/signals:		used = false;
+	/NodeConfig/functions:		used = false;
+	/NodeConfig/owdevices:		used = false;
+	/HardwareConfig/max7219:	used = false;
+	/HardwareConfig/tlc5947:	used = false;
+	/HardwareConfig/ws2812b:	used = false;
+	/HardwareConfig/hcsr04:		used = false;
+	/HardwareConfig/onewire:	used = false;
+}
+
+option s20 : esp8285 {
+	/HardwareConfig/dht:		used = false;
+	/HardwareConfig/terminal:	used = false;
+}
+
+option dht_term : esp8285 {
+	/NodeConfig/holidays:		used = false;
+	/NodeConfig/at_actions:		used = false;
+}
+
+option d1_lite : esp8266 {
+	withUnequal=false;
+}
+
+option termserv : d1_lite {
+	/NodeConfig/holidays:		used = false;
+	/NodeConfig/at_actions:		used = false;
+}
+
+
+enum rstrsn_t {
+	unknown = 0;
+	powerup = 1;
+	external = 2;
+	software = 3;
+	panic = 4;
+	internal_wdt = 5;
+	task_wdt = 6;
+	watchdog = 7;
+	deepsleep = 8;
+	brownout = 9;
+	sdio = 10;
+	option toString=strReset;
+}
+
+
+message WifiConfig
+{
+	string ssid = 1			[ unset = "" ];
+	string pass = 2			[ unset = "" ];
+	bytes mac = 3;
+	required bool activate = 4	[ unset = false ];
+	fixed32 addr4 = 5		[ to_ascii=ip4_to_ascii, to_json=ip4_to_ascii, parse_ascii=parse_ipv4 ];
+	fixed8 netmask4 = 6;
+	fixed32 gateway4 = 7		[ to_ascii=ip4_to_ascii, to_json=ip4_to_ascii, parse_ascii=parse_ipv4 ];
+}
+
+
+message MQTT
+{
+	string uri = 1			[ unset = "" ];
+	bool enable = 2			[ unset = false ];
+	string username = 3		[ unset = "" ];
+	string password = 4		[ unset = "" ];
+	repeated string subscribtions = 5;	// qos0 subscribptions
+}
+
+
+message Date
+{
+	fixed8 day = 1		[ unset = 0 ];
+	fixed8 month = 2	[ unset = 0 ];
+	fixed16 year = 3	[ unset = 0 ];
+	fixed8 endday = 4	[ unset = 0 ];
+	fixed8 endmonth = 5	[ unset = 0 ];
+	fixed8 endyear = 6	[ unset = 0 ];
+}
+
+
+enum WeekDay 
+{ 
+	Sunday = 0; 
+	Monday = 1; 
+	Tuesday = 2; 
+	Wednesday = 3; 
+	Thursday = 4;
+	Friday = 5;
+	Saturday = 6;
+	WorkDay = 7;
+	WeekEnd = 8;
+	EveryDay = 9;
+	Holiday = 10;
+}
+
+
+message AtAction
+{
+	optional WeekDay day = 1;
+	unsigned min_of_day = 2		[ to_json = min_of_day_to_ascii ];
+	string action = 3;
+	required bool enable = 4        [ default = true ];
+}
+
+
+message Influx
+{
+	string hostname = 1	[ unset = "" ];
+	fixed16 port = 2	[ unset = 0 ];
+	string measurement = 3	[ unset = "" ];
+	unsigned interval = 4	[ default = 60000, usage = deprecated ];
+}
+
+
+message UartSettings
+{
+	uint8 port = 1;
+	unsigned baudrate = 2;
+	// bit0,1: uart_word_length_t		[ 5..8 ]
+	// bit2,3: uart_stop_bits_t		[ 1=1, 2=1.5, 3=2 ]
+	// bit4,5: uart_hw_flowcontrol_t	[ 0=none, 1=rts, 2=cts, 3=cts+rts ]
+	// bit6,7: uart_parity_t		[ 0=none, 2=even, 3=odd ]
+	// bit8,9: reserved for future uart_parity_t extension
+	// bit10: ref_tick
+	// bit11-15: reserved
+	fixed16 config = 3		[ unset = 0 ];
+	fixed8 rx_thresh = 4		[ unset = 0 ];
+	unsigned tx_bufsize = 6;
+	unsigned rx_bufsize = 7;
+}
+
+
+message FtpdConfig
+{
+	fixed16 port = 1	[ unset = 0 ];
+	bool start = 2;
+	string root = 3		[ unset = "" ];
+}
+
+
+message HttpdConfig
+{
+	fixed16 port = 1	[ default = 80 ];
+	bool start = 2		[ default = true ];
+	string root = 3		[ unset = "" ];
+	string uploaddir = 4	[ unset = "" ];
+}
+
+
+message TerminalConfig
+{
+	sint8 uart_rx = 1	[ unset = -1 ];
+	sint8 uart_tx = 2	[ unset = -1 ];
+	string name = 3;
+}
+
+
+message Trigger
+{
+	string event = 1;
+	string action = 2;
+}
+
+
+message AppParam
+{
+	string key = 1;
+	unsigned uValue = 2;
+	string sValue = 3;
+	signed dValue = 4;
+	double fValue = 5;
+}
+
+
+message EventTimer
+{
+	string name = 1		[ unset = "" ];
+	unsigned time = 2;	// in msec
+	// bit0: repeat, bit1: autostart
+	unsigned config = 3	[ unset = 0 ];
+}
+
+
+message FunctionConfig
+{
+	string name = 1;
+	string func = 2;
+	repeated string params = 3;
+}
+
+
+enum sigtype_t
+{
+	st_invalid = 0;
+	st_int = 1;
+	st_float = 2;
+	st_string = 3;
+}
+
+
+message SignalConfig
+{
+	string name = 1		[ unset = "" ];
+	sigtype_t type = 2	[ unset = st_invalid ];
+	string iv = 3		[ unset = "" ];
+	// TODO
+	//bool persistent = 4	[ unset = false ];	// store every update to NVS
+}
+
+
+message OwDeviceConfig
+{
+	fixed64 id = 1		[ to_ascii = id64_to_ascii ];
+	string name = 2;
+}
+
+
+message NodeConfig
+{
+	fixed32 magic = 0;	// should always be set to 0xAE54EDC0
+	string nodename = 1		[ unset = "" ];
+	bytes pass_hash = 2;
+	unsigned cpu_freq = 3;
+	WifiConfig station = 4;
+	WifiConfig softap = 5;
+	string dns_server = 6		[ unset = "" ];
+	string syslog_host = 7		[ unset = "" ];
+	string sntp_server = 8		[ unset = "" ];
+	string timezone = 9		[ unset = "" ];
+	MQTT mqtt = 10;
+	fixed16 dmesg_size = 11	[ default = 512 ];
+	Influx influx = 12;
+	unsigned station2ap_time = 13;	// failover time from station to ap mode [s]
+	string domainname = 15	[ unset = "" ];
+
+	// action timers
+	repeated Date holidays = 16;
+	repeated AtAction at_actions = 17;
+	// bit0: enable, bit1: enable factory_reset
+	unsigned actions_enable = 18	[ default = 1 ];
+	repeated Trigger triggers = 19;
+
+	repeated UartSettings uart = 20;
+	repeated TerminalConfig terminal = 21;
+
+	// set udp_ctrl_port to 0 to disable this feature
+	fixed16 udp_ctrl_port = 22	[ default = 12719 ];
+
+	repeated string debugs = 23;
+
+	// TODO
+	//FtpdConfig ftpd = 24;
+	HttpdConfig httpd = 25;
+
+	// event timer/timefuse
+	repeated EventTimer timefuses = 30;
+	repeated SignalConfig signals = 31;
+	repeated FunctionConfig functions = 32;
+
+	// relay control (e.g. s20)
+	unsigned max_on_time = 34	[ unset = 0, usage=deprecated ];	// in minutes
+
+	// application: light sensor controlled LED
+	unsigned threshold_off = 35;
+	unsigned threshold_on = 36;
+	unsigned dim_step = 37;		// ms per 1% step
+	bool lightctrl = 38;		// true=auto, false=manual
+	unsigned pwm_freq = 39;		// base PWM frequenzy in Hz - shared for all channels
+
+	repeated AppParam app_params = 40;
+
+	repeated OwDeviceConfig owdevices = 50;
+}
+
+
+message SystemConfig
+{
+	string manufacturer = 1	[ unset = ""];
+	string board_name = 2	[ unset = ""];
+	string board_rev = 3	[ unset = ""];
+	sint8 diag_uart = 4	[ unset = 0 ];
+	sint8 console_rx = 5	[ default = 0 ];
+	sint8 console_tx = 6	[ default = 0 ];
+	string model_name = 7	[ unset = ""];
+	string model_number = 8	[ unset = ""];
+}
+
+
+message TouchpadConfig
+{
+	bool fsm_mode = 1	[ unset = false ];
+	sint8 lvolt = 2		[ unset = -1 ];
+	sint8 hvolt = 3		[ unset = -1 ];
+	sint8 atten = 4		[ unset = -1 ];
+	unsigned interval = 7;
+}
+
+
+message TouchChannelConfig
+{
+	string name = 1;
+	sint8 channel = 2	[ unset = -1 ];
+	fixed16 threshold = 3;
+	uint8 slope = 4;
+	uint8 tieopt = 5;
+}
+
+
+enum pull_mode_t
+{
+	option allow_alias = true;
+	pull_none = 0;
+	pull_en = 1;
+	pull_dir = 2;
+	pull_down = 1;
+	pull_up = 3;
+}
+
+
+message ButtonConfig
+{
+	string name = 1			[ unset = "" ];
+	sint8 gpio = 2			[ unset = -1 ];
+	bool presslvl = 3		[ unset = 0 ];
+	pull_mode_t pull_mode = 4	[ unset = pull_none ];
+}
+
+
+enum relay_cfg_t
+{
+	rc_active_low = 0;
+	rc_active_high = 1;
+	rc_init_on = 2;
+	rc_persistent = 4;	// store state in NVS and restore state on boot
+	rc_open_drain = 8;
+	rc_mqtt = 16;
+}
+
+
+message RelayConfig
+{
+	string name = 1		[ unset = "" ];
+	sint8 gpio = 2		[ unset = -1 ];
+	relay_cfg_t config = 3	[ unset = rc_active_low ];
+	unsigned min_itv = 4	[ default = 0 ];	// minimum interval
+	sint8 interlock = 5	[ unset = -1 ];		// index of relay to interlock with
+}
+
+
+message Max7219Config
+{
+	sint8 clk = 1		[ unset = -1 ];
+	sint8 dout = 2		[ unset = -1 ];
+	sint8 cs = 3		[ unset = -1 ];
+	bool odrain = 4		[ unset = false ];
+	uint8 digits = 5	[ unset = 0 ];
+}
+
+
+message Tlc5947Config
+{
+	sint8 sin = 1		[ unset = -1 ];
+	sint8 sclk = 2		[ unset = -1 ];
+	sint8 xlat = 3		[ unset = -1 ];
+	sint8 blank = 4		[ unset = -1 ];
+	uint8 ntlc = 5		[ unset = 0 ];
+}
+
+
+message Ws2812bConfig
+{
+	sint8 gpio = 1		[ unset = -1 ];
+	sint8 ch = 2		[ unset = -1 ];
+	uint8 nleds = 3		[ unset = 0 ];
+}
+
+
+enum dht_model_t
+{
+	DHT_NONE = 0;
+	RHT03 = 3;
+	DHT11 = 11;
+	DHT21 = 21;
+	DHT22 = 22;
+	AM2301 = 2301;
+	AM2302 = 2302;
+}
+
+
+message DhtConfig
+{
+	dht_model_t model = 1	[ unset = DHT_NONE ];
+	sint8 gpio = 2		[ unset = -1 ];
+}
+
+
+message Bme280Config
+{
+	uint8 port = 1		[ default = 0 ];
+	sint8 sda = 2		[ unset = -1 ];
+	sint8 scl = 3		[ unset = -1 ];
+	unsigned freq = 4	[ default = 100000 ];
+}
+
+
+message HcSr04Config
+{
+	sint8 trigger = 1	[ unset = -1 ];
+	sint8 echo = 2		[ unset = -1 ];
+}
+
+
+message LedConfig
+{
+	sint8 gpio = 1		[ unset = -1 ];
+	// bit 0: active high
+	// bit 1: open drain
+	uint8 config = 2;
+	string name = 3		[ unset = "" ];
+	sint8 pwm_ch = 4	[ unset = -1 ];
+}
+
+
+message OneWireConfig
+{
+	sint8 gpio = 1		[ unset = -1 ];
+	bool pullup = 2		[ unset = false ];	// pull-up the gpio
+	sint8 power = 3		[ unset = -1 ];
+}
+
+
+message UartConfig
+{
+	sint8 port = 1;
+	sint8 tx_gpio = 2;
+	sint8 rx_gpio = 3;
+	sint8 cts_gpio = 4;
+	sint8 rts_gpio = 5;
+}
+
+
+message AdcChannel
+{
+	string name = 1		[ unset = "" ];
+
+	// ADC1 or ADC2 - ADC2 cannot be used with WiFi started
+	uint8 unit = 2		[ unset = 0 ];
+
+	// valid channels: 0-9
+	sint8 ch = 3		[ unset = -1 ];
+
+	// adc_atten_t: 0 = 0dB, 1=2,5dB, 2=6dB, 3=11dB
+	uint8 atten = 4		[ default = 0 ];	
+}
+
+
+message AdcConfig
+{
+	// esp8266: set name to enable
+	// esp32: not used
+	string adc_name = 1	[ unset = "" ];
+
+	// adc_width_t: 0=9bit .. 3=12bit, adc is disabled if not set
+	uint8 adc1_bits = 2	[ default = 0 ];
+	uint8 adc2_bits = 3	[ default = 0 ];
+
+	uint8 mode = 4;		// esp8266 only (adc_mode_t: TOUT_MODE=0, VDD_MODE=1)
+	uint8 clk_div = 5;	// esp8266 only
+
+	// name of hall sensor
+	string hall_name = 6	[ unset = "" ];
+
+	repeated AdcChannel channels = 7;
+}
+
+
+message GpioConfig
+{
+	string name = 1;
+	sint8 gpio = 2		[ unset = -1 ];
+	// bit 1,0: gpio_mode_t: disable, input, output, output_od
+	// bit 4..2: gpio_int_type_t
+	//	{0=none, 1=pos dge, 2=neg edge, 3=both edge
+	//	, 4=lolevel, 5=hilevel}
+	// bit 5: set initial level
+	// bit 6: init level
+	// bit 7: pull-up enable
+	// bit 8: pull-down enable
+	unsigned config = 3;
+}
+
+
+message HardwareConfig
+{
+	fixed32 magic = 0;	// should always be set to 0xAE54EDCB
+	// core hardware
+	SystemConfig system = 1;
+	repeated UartConfig uart = 3;
+	AdcConfig adc = 4;
+	TouchpadConfig touchpad = 5;
+	repeated TouchChannelConfig tp_channel = 6;
+	repeated GpioConfig gpio = 7;
+
+	// direct gpio drivers
+	repeated ButtonConfig button = 16;
+	repeated RelayConfig relay = 17;
+	repeated LedConfig led = 18;
+
+	// high level applicaton drivers
+	Max7219Config max7219 = 32;	// for 7-segment clock
+	Tlc5947Config tlc5947 = 33;	// for nightsky LEDs
+	Ws2812bConfig ws2812b = 34;	// for ws2812b LED strips
+	DhtConfig dht = 35;
+	Bme280Config bme280 = 36;
+	HcSr04Config hcsr04 = 37;
+	OneWireConfig onewire = 38;
+}
+
+
+/*
+// draft/idea - maybe better direct structs for mmap access
+enum ledaction_t
+{
+	la_nop = 0;	// no operation
+	la_set = 1;	// set specific led
+	la_mask = 2;	// set color mask
+	la_setall = 3;	// set all leds to value
+	la_delay = 4;	// delay ms
+	la_dim = 5;	// r/g/b delta as int8
+	la_jump = 6;	// index of next action to execute
+	la_random = 7;	// generate random arg
+}
+
+message LedAction
+{
+	ledaction_t action = 1;
+	// 0xff000000	: led mask
+	// 0x00ff0000	: red mask
+	// 0x0000ff00	: green mask
+	// 0x000000ff	: blue mask
+	unsigned arg = 2;
+}
+
+
+message LedStripMode
+{
+	string name = 1;
+	repeated LedAction actions = 2;
+}
+
+
+message LedStripData
+{
+	fixed32 magic = 0;
+	repeated LedStripMode modes = 1;
+
+}
+*/
diff --git a/testsuite/testcases/byname.wfc b/testsuite/testcases/byname.wfc
index 6834759..e807e98 100644
--- a/testsuite/testcases/byname.wfc
+++ b/testsuite/testcases/byname.wfc
@@ -1,4 +1,5 @@
 //option toASCII=toASCII;
+option header = "ip4funcs.h";
 
 message Pair
 {
@@ -32,4 +33,10 @@ message M
 
 	bool B = 11;
 	repeated bool RB = 12;
+
+	bytes data = 13;
+
+	fixed32 ipv4 = 14	[ to_ascii = ip4_ascii, parse_ascii = parse_ipv4 ];
+
+	repeated bytes sectors = 15;
 }
diff --git a/testsuite/testcases/bynametest.cpp b/testsuite/testcases/bynametest.cpp
index bb73048..1a8fae9 100644
--- a/testsuite/testcases/bynametest.cpp
+++ b/testsuite/testcases/bynametest.cpp
@@ -30,6 +30,18 @@ int main()
 	assert(x > 0);
 	assert(tb.kvpair1().key() == "key");
 	runcheck(tb);
+	x = tb.setByName("BYTESO","deadbeef feed\raa\n00\tcc");
+	assert(x > 0);
+	uint8_t data[] = {0xde,0xad,0xbe,0xef,0xfe,0xed,0xaa,0x00,0xcc};
+	assert(tb.BYTESO().size() == sizeof(data));
+	assert(0 == memcmp(tb.BYTESO().data(),data,sizeof(data)));
+	runcheck(tb);
+	x = tb.setByName("ipv4","10.158.66.3");
+	assert(x > 0);
+	runcheck(tb);
+	stringstream ss;
+	ip4_ascii(ss,tb.ipv4());
+	assert(ss.str() == "10.158.66.3");
 
 	// invalid settings
 	x = tb.setByName("SI8","-129");
@@ -45,6 +57,8 @@ int main()
 	assert(x > 0);
 	assert(tb.PackedMsg().Bool() == false);
 	runcheck(tb);
+	x = tb.setByName("BYTESO","deanbeeffeedaa00cc");
+	assert(x < 0);
 
 	// arrays
 	x = tb.setByName("kvpairs[+]","");
diff --git a/testsuite/testcases/reference.wfc b/testsuite/testcases/reference.wfc
index b9aedd4..88cc163 100644
--- a/testsuite/testcases/reference.wfc
+++ b/testsuite/testcases/reference.wfc
@@ -5,6 +5,7 @@ option SortMembers=type;
 option toString="toString";
 option toJSON="toJSON";
 option header="cstring.h";
+option header="ip4funcs.h";
 
 option rev2 {
 	withEqual=true;
@@ -14,6 +15,7 @@ option rev2 {
 	toString=toString;
 	toJSON=toJSON;
 	header="cstring.h";
+	header="ip4funcs.h";
 	/TestBench/VI32:	usage = obsolete;
 	/TestBench/STR:		usage = obsolete;
 	/TestBench/STRV:	usage = obsolete;
@@ -149,4 +151,6 @@ message TestBench
 	sint16 SI16 = 0x75;
 	sint32 SI32 = 0x76;
 	sint64 SI64 = 0x77;
+
+	fixed32 ipv4 = 0x80	[ to_ascii = ip4_ascii, parse_ascii = parse_ipv4 ];
 }
diff --git a/testsuite/testcases/validbits2.wfc b/testsuite/testcases/validbits2.wfc
index 9a674d3..d96110f 100644
--- a/testsuite/testcases/validbits2.wfc
+++ b/testsuite/testcases/validbits2.wfc
@@ -3,6 +3,7 @@
 
 option header="math.h";
 option header="cstring.h";
+option header="bytes.h";
 option withEqual=true;
 option withUnequal=true;
 
@@ -25,8 +26,8 @@ message M
 	string s3i = 6		[ stringtype=CString, unset="" ];
 	bytes b1e = 11		[ bytestype=std::string ];
 	bytes b1i = 12		[ bytestype=std::string, unset="" ];
-	bytes b2e = 13		[ bytestype=CString];
-	bytes b2i = 14		[ bytestype=CString, unset="" ];
+	bytes b2e = 13		[ bytestype=Bytes];
+	bytes b2i = 14		[ bytestype=Bytes, unset="" ];
 	finger_t e1e = 20;
 	finger_t e1i = 21	[ unset=nofinger ];
 	float f1e = 30;