Nanopb is a plain-C implementation of Google's Protocol Buffers data

format. It is targeted at 32 bit microcontrollers, but is also fit for
other embedded systems with tight (2-10 kB ROM, <1 kB RAM) memory
constraints.(http://koti.kapsi.fi/jpa/nanopb/)

How to use the example:
	1. move examples/nanopb to bsp/xxxx/
	2. enable macro RT_USING_NANOPB in rtconfig.h
	3. regenerate the project file (scons --target=xxxx)
	4. rebuild the project

bsp/stm32f10x/rtconfig.h

@@ -184,4 +184,7 @@
 // <bool name="RT_USING_BSP_CMSIS" description="Using CMSIS in BSP" default="true" />
 // #define RT_USING_BSP_CMSIS
 
+/* nanopb support */
+/* #define RT_USING_NANOPB */
+
 #endif

components/external/nanopb/CHANGELOG.txt

@@ -0,0 +1,183 @@
+nanopb-0.3.1 (2014-09-11)
+ Fix security issue due to size_t overflows. (issue 132)
+ Fix memory leak with duplicated fields and PB_ENABLE_MALLOC
+ Fix crash if pb_release() is called twice.
+ Fix cyclic message support (issue 130)
+ Fix error in generated initializers for repeated pointer fields.
+ Improve tests (issues 113, 126)
+
+nanopb-0.3.0 (2014-08-26)
+ NOTE: See docs/migration.html or online at
+ http://koti.kapsi.fi/~jpa/nanopb/docs/migration.html
+ for changes in this version. Most importantly, you need to add
+ pb_common.c to the list of files to compile.
+
+ Separated field iterator logic to pb_common.c (issue 128)
+ Change the _count fields to use pb_size_t datatype (issue 82)
+ Added PB_ prefix to macro names (issue 106)
+ Added #if version guard to generated files (issue 129)
+ Added migration document
+
+nanopb-0.2.9 (2014-08-09)
+ NOTE: If you are using the -e option with the generator, you have
+ to prepend . to the argument to get the same behaviour as before.
+
+ Do not automatically add a dot with generator -e option. (issue 122)
+ Fix problem with .options file and extension fields. (issue 125)
+ Don't use SIZE_MAX macro, as it is not in C89. (issue 120)
+ Generate #defines for initializing message structures. (issue 79)
+ Add skip_message option to generator. (issue 121)
+ Add PB_PACKED_STRUCT support for Keil MDK-ARM toolchain (issue 119)
+ Give better messages about the .options file path. (issue 124)
+ Improved tests
+
+nanopb-0.2.8 (2014-05-20)
+ Fix security issue with PB_ENABLE_MALLOC. (issue 117)
+ Add option to not add timestamps to .pb.h and .pb.c preambles. (issue 115)
+ Documentation updates
+ Improved tests
+
+nanopb-0.2.7 (2014-04-07)
+ Fix bug with default values for extension fields (issue 111)
+ Fix some MISRA-C warnings (issue 91)
+ Implemented optional malloc() support (issue 80)
+ Changed pointer-type bytes field datatype
+ Add a "found" field to pb_extension_t (issue 112)
+ Add convenience function pb_get_encoded_size() (issue 16)
+
+nanopb-0.2.6 (2014-02-15)
+ Fix generator error with bytes callback fields (issue 99)
+ Fix warnings about large integer constants (issue 102)
+ Add comments to where STATIC_ASSERT is used (issue 96)
+ Add warning about unknown field names on .options (issue 105)
+ Move descriptor.proto to google/protobuf subdirectory (issue 104)
+ Improved tests
+
+nanopb-0.2.5 (2014-01-01)
+ Fix a bug with encoding negative values in int32 fields (issue 97)
+ Create binary packages of the generator + dependencies (issue 47)
+ Add support for pointer-type fields to the encoder (part of issue 80)
+ Fixed path in FindNanopb.cmake (issue 94)
+ Improved tests
+
+nanopb-0.2.4 (2013-11-07)
+ Remove the deprecated NANOPB_INTERNALS functions from public API.
+ Document the security model.
+ Check array and bytes max sizes when encoding (issue 90)
+ Add #defines for maximum encoded message size (issue 89)
+ Add #define tags for extension fields (issue 93)
+ Fix MISRA C violations (issue 91)
+ Clean up pb_field_t definition with typedefs.
+
+nanopb-0.2.3 (2013-09-18)
+ Improve compatibility by removing ternary operator from initializations (issue 88)
+ Fix build error on Visual C++ (issue 84, patch by Markus Schwarzenberg)
+ Don't stop on unsupported extension fields (issue 83)
+ Add an example pb_syshdr.h file for non-C99 compilers
+ Reorganize tests and examples into subfolders (issue 63)
+ Switch from Makefiles to scons for building the tests
+ Make the tests buildable on Windows
+
+nanopb-0.2.2 (2013-08-18)
+ Add support for extension fields (issue 17)
+ Fix unknown fields in empty message (issue 78)
+ Include the field tags in the generated .pb.h file.
+ Add pb_decode_delimited and pb_encode_delimited wrapper functions (issue 74)
+ Add a section in top of pb.h for changing compilation settings (issue 76)
+ Documentation improvements (issues 12, 77 and others)
+ Improved tests
+
+nanopb-0.2.1 (2013-04-14)
+ NOTE: The default callback function signature has changed.
+       If you don't want to update your code, define PB_OLD_CALLBACK_STYLE.
+ 
+ Change the callback function to use void** (issue 69)
+ Add support for defining the nanopb options in a separate file (issue 12)
+ Add support for packed structs in IAR and MSVC (in addition to GCC) (issue 66)
+ Implement error message support for the encoder side (issue 7)
+ Handle unterminated strings when encoding (issue 68)
+ Fix bug with empty strings in repeated string callbacks (issue 73)
+ Fix regression in 0.2.0 with optional callback fields (issue 70)
+ Fix bugs with empty message types (issues 64, 65)
+ Fix some compiler warnings on clang (issue 67)
+ Some portability improvements (issues 60, 62)
+ Various new generator options
+ Improved tests
+
+nanopb-0.2.0 (2013-03-02)
+ NOTE: This release requires you to regenerate all .pb.c
+       files. Files generated by older versions will not
+       compile anymore.
+
+ Reformat generated .pb.c files using macros (issue 58)
+ Rename PB_HTYPE_ARRAY -> PB_HTYPE_REPEATED
+ Separate PB_HTYPE to PB_ATYPE and PB_HTYPE
+ Move STATIC_ASSERTs to .pb.c file
+ Added CMake file (by Pavel Ilin)
+ Add option to give file extension to generator (by Michael Haberler)
+ Documentation updates
+
+nanopb-0.1.9 (2013-02-13)
+ Fixed error message bugs (issues 52, 56)
+ Sanitize #ifndef filename (issue 50)
+ Performance improvements
+ Add compile-time option PB_BUFFER_ONLY
+ Add Java package name to nanopb.proto
+ Check for sizeof(double) == 8 (issue 54)
+ Added generator option to ignore some fields. (issue 51)
+ Added generator option to make message structs packed. (issue 49)
+ Add more test cases.
+
+nanopb-0.1.8 (2012-12-13)
+ Fix bugs in the enum short names introduced in 0.1.7 (issues 42, 43)
+ Fix STATIC_ASSERT macro when using multiple .proto files. (issue 41)
+ Fix missing initialization of istream.errmsg
+ Make tests/Makefile work for non-gcc compilers (issue 40)
+
+nanopb-0.1.7 (2012-11-11)
+ Remove "skip" mode from pb_istream_t callbacks. Example implementation had a bug. (issue 37)
+ Add option to use shorter names for enum values (issue 38)
+ Improve options support in generator (issues 12, 30)
+ Add nanopb version number to generated files (issue 36)
+ Add extern "C" to generated headers (issue 35)
+ Add names for structs to allow forward declaration (issue 39)
+ Add buffer size check in example (issue 34)
+ Fix build warnings on MS compilers (issue 33)
+
+nanopb-0.1.6 (2012-09-02)
+ Reorganize the field decoder interface (issue 2)
+ Improve performance in submessage decoding (issue 28)
+ Implement error messages in the decoder side (issue 7)
+ Extended testcases (alltypes test is now complete).
+ Fix some compiler warnings (issues 25, 26, 27, 32).
+
+nanopb-0.1.5 (2012-08-04)
+ Fix bug in decoder with packed arrays (issue 23).
+ Extended testcases.
+ Fix some compiler warnings.
+
+nanopb-0.1.4 (2012-07-05)
+ Add compile-time options for easy-to-use >255 field support.
+ Improve the detection of missing required fields.
+ Added example on how to handle union messages.
+ Fix generator error with .proto without messages.
+ Fix problems that stopped the code from compiling with some compilers.
+ Fix some compiler warnings.
+
+nanopb-0.1.3 (2012-06-12)
+ Refactor the field encoder interface.
+ Improve generator error messages (issue 5)
+ Add descriptor.proto into the #include exclusion list
+ Fix some compiler warnings.
+
+nanopb-0.1.2 (2012-02-15)
+ Make the generator to generate include for other .proto files (issue 4).
+ Fixed generator not working on Windows (issue 3)
+
+nanopb-0.1.1 (2012-01-14)
+ Fixed bug in encoder with 'bytes' fields (issue 1).
+ Fixed a bug in the generator that caused a compiler error on sfixed32 and sfixed64 fields.
+ Extended testcases.
+
+nanopb-0.1.0 (2012-01-06)
+ First stable release.

components/external/nanopb/README.txt

@@ -0,0 +1,61 @@
+Nanopb is a small code-size Protocol Buffers implementation in ansi C. It is
+especially suitable for use in microcontrollers, but fits any memory
+restricted system.
+
+Homepage: http://kapsi.fi/~jpa/nanopb/
+
+
+
+
+Using the nanopb library
+========================
+To use the nanopb library, you need to do two things:
+
+1) Compile your .proto files for nanopb, using protoc.
+2) Include pb_encode.c and pb_decode.c in your project.
+
+The easiest way to get started is to study the project in "examples/simple".
+It contains a Makefile, which should work directly under most Linux systems.
+However, for any other kind of build system, see the manual steps in
+README.txt in that folder.
+
+
+
+Using the Protocol Buffers compiler (protoc)
+============================================
+The nanopb generator is implemented as a plugin for the Google's own protoc
+compiler. This has the advantage that there is no need to reimplement the
+basic parsing of .proto files. However, it does mean that you need the
+Google's protobuf library in order to run the generator.
+
+If you have downloaded a binary package for nanopb (either Windows, Linux or
+Mac OS X version), the 'protoc' binary is included in the 'generator-bin'
+folder. In this case, you are ready to go. Simply run this command:
+
+    generator-bin/protoc --nanopb_out=. myprotocol.proto
+
+However, if you are using a git checkout or a plain source distribution, you
+need to provide your own version of protoc and the Google's protobuf library.
+On Linux, the necessary packages are protobuf-compiler and python-protobuf.
+On Windows, you can either build Google's protobuf library from source or use
+one of the binary distributions of it. In either case, if you use a separate
+protoc, you need to manually give the path to nanopb generator:
+
+    protoc --plugin=protoc-gen-nanopb=nanopb/generator/protoc-gen-nanopb ...
+
+
+
+Running the tests
+=================
+If you want to perform further development of the nanopb core, or to verify
+its functionality using your compiler and platform, you'll want to run the
+test suite. The build rules for the test suite are implemented using Scons,
+so you need to have that installed. To run the tests:
+
+    cd tests
+    scons
+
+This will show the progress of various test cases. If the output does not
+end in an error, the test cases were successful.
+
+

components/external/nanopb/SConscript

@@ -0,0 +1,14 @@
+Import('RTT_ROOT')
+Import('rtconfig')
+from building import *
+
+src	= Split('''
+pb_common.c
+pb_decode.c
+pb_encode.c
+''')
+CPPPATH = [RTT_ROOT + '/components/external/nanopb']
+
+group = DefineGroup('Nanopb', src, depend = ['RT_USING_NANOPB'], CPPPATH = CPPPATH)
+
+Return('group')

components/external/nanopb/pb_common.c

@@ -0,0 +1,90 @@
+/* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
+ *
+ * 2014 Petteri Aimonen <jpa@kapsi.fi>
+ */
+
+#include "pb_common.h"
+
+bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
+{
+    iter->start = fields;
+    iter->pos = fields;
+    iter->required_field_index = 0;
+    iter->dest_struct = dest_struct;
+    iter->pData = (char*)dest_struct + iter->pos->data_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
+    
+    return (iter->pos->tag != 0);
+}
+
+bool pb_field_iter_next(pb_field_iter_t *iter)
+{
+    const pb_field_t *prev_field = iter->pos;
+
+    if (prev_field->tag == 0)
+    {
+        /* Handle empty message types, where the first field is already the terminator.
+         * In other cases, the iter->pos never points to the terminator. */
+        return false;
+    }
+    
+    iter->pos++;
+    
+    if (iter->pos->tag == 0)
+    {
+        /* Wrapped back to beginning, reinitialize */
+        (void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
+        return false;
+    }
+    else
+    {
+        /* Increment the pointers based on previous field size */
+        size_t prev_size = prev_field->data_size;
+    
+        if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
+            PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
+        {
+            /* In static arrays, the data_size tells the size of a single entry and
+             * array_size is the number of entries */
+            prev_size *= prev_field->array_size;
+        }
+        else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
+        {
+            /* Pointer fields always have a constant size in the main structure.
+             * The data_size only applies to the dynamically allocated area. */
+            prev_size = sizeof(void*);
+        }
+        
+        if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
+        {
+            /* Count the required fields, in order to check their presence in the
+             * decoder. */
+            iter->required_field_index++;
+        }
+    
+        iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
+        iter->pSize = (char*)iter->pData + iter->pos->size_offset;
+        return true;
+    }
+}
+
+bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
+{
+    const pb_field_t *start = iter->pos;
+    
+    do {
+        if (iter->pos->tag == tag &&
+            PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
+        {
+            /* Found the wanted field */
+            return true;
+        }
+        
+        (void)pb_field_iter_next(iter);
+    } while (iter->pos != start);
+    
+    /* Searched all the way back to start, and found nothing. */
+    return false;
+}
+
+

components/external/nanopb/pb_common.h

@@ -0,0 +1,42 @@
+/* pb_common.h: Common support functions for pb_encode.c and pb_decode.c.
+ * These functions are rarely needed by applications directly.
+ */
+
+#ifndef PB_COMMON_H_INCLUDED
+#define PB_COMMON_H_INCLUDED
+
+#include "pb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Iterator for pb_field_t list */
+struct pb_field_iter_s {
+    const pb_field_t *start;       /* Start of the pb_field_t array */
+    const pb_field_t *pos;         /* Current position of the iterator */
+    unsigned required_field_index; /* Zero-based index that counts only the required fields */
+    void *dest_struct;             /* Pointer to start of the structure */
+    void *pData;                   /* Pointer to current field value */
+    void *pSize;                   /* Pointer to count/has field */
+};
+typedef struct pb_field_iter_s pb_field_iter_t;
+
+/* Initialize the field iterator structure to beginning.
+ * Returns false if the message type is empty. */
+bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct);
+
+/* Advance the iterator to the next field.
+ * Returns false when the iterator wraps back to the first field. */
+bool pb_field_iter_next(pb_field_iter_t *iter);
+
+/* Advance the iterator until it points at a field with the given tag.
+ * Returns false if no such field exists. */
+bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
+

components/external/nanopb/pb_decode.h

@@ -0,0 +1,149 @@
+/* pb_decode.h: Functions to decode protocol buffers. Depends on pb_decode.c.
+ * The main function is pb_decode. You also need an input stream, and the
+ * field descriptions created by nanopb_generator.py.
+ */
+
+#ifndef PB_DECODE_H_INCLUDED
+#define PB_DECODE_H_INCLUDED
+
+#include "pb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Structure for defining custom input streams. You will need to provide
+ * a callback function to read the bytes from your storage, which can be
+ * for example a file or a network socket.
+ * 
+ * The callback must conform to these rules:
+ *
+ * 1) Return false on IO errors. This will cause decoding to abort.
+ * 2) You can use state to store your own data (e.g. buffer pointer),
+ *    and rely on pb_read to verify that no-body reads past bytes_left.
+ * 3) Your callback may be used with substreams, in which case bytes_left
+ *    is different than from the main stream. Don't use bytes_left to compute
+ *    any pointers.
+ */
+struct pb_istream_s
+{
+#ifdef PB_BUFFER_ONLY
+    /* Callback pointer is not used in buffer-only configuration.
+     * Having an int pointer here allows binary compatibility but
+     * gives an error if someone tries to assign callback function.
+     */
+    int *callback;
+#else
+    bool (*callback)(pb_istream_t *stream, uint8_t *buf, size_t count);
+#endif
+
+    void *state; /* Free field for use by callback implementation */
+    size_t bytes_left;
+    
+#ifndef PB_NO_ERRMSG
+    const char *errmsg;
+#endif
+};
+
+/***************************
+ * Main decoding functions *
+ ***************************/
+ 
+/* Decode a single protocol buffers message from input stream into a C structure.
+ * Returns true on success, false on any failure.
+ * The actual struct pointed to by dest must match the description in fields.
+ * Callback fields of the destination structure must be initialized by caller.
+ * All other fields will be initialized by this function.
+ *
+ * Example usage:
+ *    MyMessage msg = {};
+ *    uint8_t buffer[64];
+ *    pb_istream_t stream;
+ *    
+ *    // ... read some data into buffer ...
+ *
+ *    stream = pb_istream_from_buffer(buffer, count);
+ *    pb_decode(&stream, MyMessage_fields, &msg);
+ */
+bool pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+
+/* Same as pb_decode, except does not initialize the destination structure
+ * to default values. This is slightly faster if you need no default values
+ * and just do memset(struct, 0, sizeof(struct)) yourself.
+ *
+ * This can also be used for 'merging' two messages, i.e. update only the
+ * fields that exist in the new message.
+ *
+ * Note: If this function returns with an error, it will not release any
+ * dynamically allocated fields. You will need to call pb_release() yourself.
+ */
+bool pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+
+/* Same as pb_decode, except expects the stream to start with the message size
+ * encoded as varint. Corresponds to parseDelimitedFrom() in Google's
+ * protobuf API.
+ */
+bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+
+#ifdef PB_ENABLE_MALLOC
+/* Release any allocated pointer fields. If you use dynamic allocation, you should
+ * call this for any successfully decoded message when you are done with it. If
+ * pb_decode() returns with an error, the message is already released.
+ */
+void pb_release(const pb_field_t fields[], void *dest_struct);
+#endif
+
+
+/**************************************
+ * Functions for manipulating streams *
+ **************************************/
+
+/* Create an input stream for reading from a memory buffer.
+ *
+ * Alternatively, you can use a custom stream that reads directly from e.g.
+ * a file or a network socket.
+ */
+pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
+
+/* Function to read from a pb_istream_t. You can use this if you need to
+ * read some custom header data, or to read data in field callbacks.
+ */
+bool pb_read(pb_istream_t *stream, uint8_t *buf, size_t count);
+
+
+/************************************************
+ * Helper functions for writing field callbacks *
+ ************************************************/
+
+/* Decode the tag for the next field in the stream. Gives the wire type and
+ * field tag. At end of the message, returns false and sets eof to true. */
+bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof);
+
+/* Skip the field payload data, given the wire type. */
+bool pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type);
+
+/* Decode an integer in the varint format. This works for bool, enum, int32,
+ * int64, uint32 and uint64 field types. */
+bool pb_decode_varint(pb_istream_t *stream, uint64_t *dest);
+
+/* Decode an integer in the zig-zagged svarint format. This works for sint32
+ * and sint64. */
+bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest);
+
+/* Decode a fixed32, sfixed32 or float value. You need to pass a pointer to
+ * a 4-byte wide C variable. */
+bool pb_decode_fixed32(pb_istream_t *stream, void *dest);
+
+/* Decode a fixed64, sfixed64 or double value. You need to pass a pointer to
+ * a 8-byte wide C variable. */
+bool pb_decode_fixed64(pb_istream_t *stream, void *dest);
+
+/* Make a limited-length substream for reading a PB_WT_STRING field. */
+bool pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

components/external/nanopb/pb_encode.h

@@ -0,0 +1,154 @@
+/* pb_encode.h: Functions to encode protocol buffers. Depends on pb_encode.c.
+ * The main function is pb_encode. You also need an output stream, and the
+ * field descriptions created by nanopb_generator.py.
+ */
+
+#ifndef PB_ENCODE_H_INCLUDED
+#define PB_ENCODE_H_INCLUDED
+
+#include "pb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Structure for defining custom output streams. You will need to provide
+ * a callback function to write the bytes to your storage, which can be
+ * for example a file or a network socket.
+ *
+ * The callback must conform to these rules:
+ *
+ * 1) Return false on IO errors. This will cause encoding to abort.
+ * 2) You can use state to store your own data (e.g. buffer pointer).
+ * 3) pb_write will update bytes_written after your callback runs.
+ * 4) Substreams will modify max_size and bytes_written. Don't use them
+ *    to calculate any pointers.
+ */
+struct pb_ostream_s
+{
+#ifdef PB_BUFFER_ONLY
+    /* Callback pointer is not used in buffer-only configuration.
+     * Having an int pointer here allows binary compatibility but
+     * gives an error if someone tries to assign callback function.
+     * Also, NULL pointer marks a 'sizing stream' that does not
+     * write anything.
+     */
+    int *callback;
+#else
+    bool (*callback)(pb_ostream_t *stream, const uint8_t *buf, size_t count);
+#endif
+    void *state;          /* Free field for use by callback implementation. */
+    size_t max_size;      /* Limit number of output bytes written (or use SIZE_MAX). */
+    size_t bytes_written; /* Number of bytes written so far. */
+    
+#ifndef PB_NO_ERRMSG
+    const char *errmsg;
+#endif
+};
+
+/***************************
+ * Main encoding functions *
+ ***************************/
+
+/* Encode a single protocol buffers message from C structure into a stream.
+ * Returns true on success, false on any failure.
+ * The actual struct pointed to by src_struct must match the description in fields.
+ * All required fields in the struct are assumed to have been filled in.
+ *
+ * Example usage:
+ *    MyMessage msg = {};
+ *    uint8_t buffer[64];
+ *    pb_ostream_t stream;
+ *
+ *    msg.field1 = 42;
+ *    stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
+ *    pb_encode(&stream, MyMessage_fields, &msg);
+ */
+bool pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct);
+
+/* Same as pb_encode, but prepends the length of the message as a varint.
+ * Corresponds to writeDelimitedTo() in Google's protobuf API.
+ */
+bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct);
+
+/* Encode the message to get the size of the encoded data, but do not store
+ * the data. */
+bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct);
+
+/**************************************
+ * Functions for manipulating streams *
+ **************************************/
+
+/* Create an output stream for writing into a memory buffer.
+ * The number of bytes written can be found in stream.bytes_written after
+ * encoding the message.
+ *
+ * Alternatively, you can use a custom stream that writes directly to e.g.
+ * a file or a network socket.
+ */
+pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize);
+
+/* Pseudo-stream for measuring the size of a message without actually storing
+ * the encoded data.
+ * 
+ * Example usage:
+ *    MyMessage msg = {};
+ *    pb_ostream_t stream = PB_OSTREAM_SIZING;
+ *    pb_encode(&stream, MyMessage_fields, &msg);
+ *    printf("Message size is %d\n", stream.bytes_written);
+ */
+#ifndef PB_NO_ERRMSG
+#define PB_OSTREAM_SIZING {0,0,0,0,0}
+#else
+#define PB_OSTREAM_SIZING {0,0,0,0}
+#endif
+
+/* Function to write into a pb_ostream_t stream. You can use this if you need
+ * to append or prepend some custom headers to the message.
+ */
+bool pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count);
+
+
+/************************************************
+ * Helper functions for writing field callbacks *
+ ************************************************/
+
+/* Encode field header based on type and field number defined in the field
+ * structure. Call this from the callback before writing out field contents. */
+bool pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field);
+
+/* Encode field header by manually specifing wire type. You need to use this
+ * if you want to write out packed arrays from a callback field. */
+bool pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number);
+
+/* Encode an integer in the varint format.
+ * This works for bool, enum, int32, int64, uint32 and uint64 field types. */
+bool pb_encode_varint(pb_ostream_t *stream, uint64_t value);
+
+/* Encode an integer in the zig-zagged svarint format.
+ * This works for sint32 and sint64. */
+bool pb_encode_svarint(pb_ostream_t *stream, int64_t value);
+
+/* Encode a string or bytes type field. For strings, pass strlen(s) as size. */
+bool pb_encode_string(pb_ostream_t *stream, const uint8_t *buffer, size_t size);
+
+/* Encode a fixed32, sfixed32 or float value.
+ * You need to pass a pointer to a 4-byte wide C variable. */
+bool pb_encode_fixed32(pb_ostream_t *stream, const void *value);
+
+/* Encode a fixed64, sfixed64 or double value.
+ * You need to pass a pointer to a 8-byte wide C variable. */
+bool pb_encode_fixed64(pb_ostream_t *stream, const void *value);
+
+/* Encode a submessage field.
+ * You need to pass the pb_field_t array and pointer to struct, just like
+ * with pb_encode(). This internally encodes the submessage twice, first to
+ * calculate message size and then to actually write it out.
+ */
+bool pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

examples/nanopb/SConscript

@@ -0,0 +1,13 @@
+Import('RTT_ROOT')
+Import('rtconfig')
+from building import *
+
+src	= Split('''
+simple.c
+simple.pb.c
+''')
+CPPPATH = [RTT_ROOT + '/examples/nanopb']
+
+group = DefineGroup('Nanopb_test', src, depend = ['RT_USING_NANOPB'], CPPPATH = CPPPATH)
+
+Return('group')

examples/nanopb/simple.c

@@ -0,0 +1,73 @@
+#include <rthw.h>
+#include <stm32f10x.h>
+#include <pb_encode.h>
+#include <pb_decode.h>
+#include "simple.pb.h"
+
+int nanopb_test()
+{
+    /* This is the buffer where we will store our message. */
+    uint8_t buffer[128];
+    size_t message_length;
+    bool status;
+
+    /* Encode our message */
+    {
+        /* Allocate space on the stack to store the message data.
+         *
+         * Nanopb generates simple struct definitions for all the messages.
+         * - check out the contents of simple.pb.h! */
+        SimpleMessage message = SimpleMessage_init_zero;
+
+        /* Create a stream that will write to our buffer. */
+        pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
+
+        /* Fill in the lucky number */
+        message.lucky_number = 13;
+
+        /* Now we are ready to encode the message! */
+        status = pb_encode(&stream, SimpleMessage_fields, &message);
+        message_length = stream.bytes_written;
+
+        /* Then just check for any errors.. */
+        if (!status)
+        {
+            rt_kprintf("Encoding failed: %s\n", PB_GET_ERROR(&stream));
+            return 1;
+        }
+    }
+
+    /* Now we could transmit the message over network, store it in a file or
+     * wrap it to a pigeon's leg.
+     */
+
+    /* But because we are lazy, we will just decode it immediately. */
+
+    {
+        /* Allocate space for the decoded message. */
+        SimpleMessage message;
+
+        /* Create a stream that reads from the buffer. */
+        pb_istream_t stream = pb_istream_from_buffer(buffer, message_length);
+
+        /* Now we are ready to decode the message. */
+        status = pb_decode(&stream, SimpleMessage_fields, &message);
+
+        /* Check for errors... */
+        if (!status)
+        {
+            rt_kprintf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
+            return 1;
+        }
+
+        /* Print the data contained in the message. */
+        rt_kprintf("Your lucky number was %d!\n", message.lucky_number);
+    }
+
+    return 0;
+}
+
+#ifdef RT_USING_FINSH
+#include <finsh.h>
+FINSH_FUNCTION_EXPORT(nanopb_test, nanopb encode/decode test.)
+#endif

examples/nanopb/simple.options

@@ -0,0 +1 @@
+SimpleMessage.name		max_size:16

examples/nanopb/simple.pb.c

@@ -0,0 +1,18 @@
+/* Automatically generated nanopb constant definitions */
+/* Generated by nanopb-0.3.1 at Tue Mar 10 01:16:15 2015. */
+
+#include "simple.pb.h"
+
+#if PB_PROTO_HEADER_VERSION != 30
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+
+
+const pb_field_t SimpleMessage_fields[3] = {
+    PB_FIELD(  1, INT32   , REQUIRED, STATIC  , FIRST, SimpleMessage, lucky_number, lucky_number, 0),
+    PB_FIELD(  2, BYTES   , REQUIRED, STATIC  , OTHER, SimpleMessage, name, lucky_number, 0),
+    PB_LAST_FIELD
+};
+
+

examples/nanopb/simple.pb.h

@@ -0,0 +1,45 @@
+/* Automatically generated nanopb header */
+/* Generated by nanopb-0.3.1 at Tue Mar 10 01:16:15 2015. */
+
+#ifndef PB_SIMPLE_PB_H_INCLUDED
+#define PB_SIMPLE_PB_H_INCLUDED
+#include <pb.h>
+
+#if PB_PROTO_HEADER_VERSION != 30
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Enum definitions */
+/* Struct definitions */
+typedef PB_BYTES_ARRAY_T(16) SimpleMessage_name_t;
+
+typedef struct _SimpleMessage {
+    int32_t lucky_number;
+    SimpleMessage_name_t name;
+} SimpleMessage;
+
+/* Default values for struct fields */
+
+/* Initializer values for message structs */
+#define SimpleMessage_init_default               {0, {0, {0}}}
+#define SimpleMessage_init_zero                  {0, {0, {0}}}
+
+/* Field tags (for use in manual encoding/decoding) */
+#define SimpleMessage_lucky_number_tag           1
+#define SimpleMessage_name_tag                   2
+
+/* Struct field encoding specification for nanopb */
+extern const pb_field_t SimpleMessage_fields[3];
+
+/* Maximum encoded size of messages (where known) */
+#define SimpleMessage_size                       29
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

examples/nanopb/simple.proto

@@ -0,0 +1,10 @@
+// A very simple protocol definition, consisting of only
+// one message.
+
+message SimpleMessage {
+    required int32 lucky_number = 1;
+	required bytes name = 2;
+}
+
+
+