The Barracuda App Server is an embeddable C code library with support for the following platforms: Embedded Linux, Zephyr, FreeRTOS+TCP or lwIP, VxWorks, QNX, INTEGRITY, Windows & Win CE, Azure RTOS (ThreadX/NetX), Nucleus RTOS, embOS, RTXC, SMX, MQX, RTOS-32, Mac, and UNIX/POSIX. The Barracuda App Server (BAS) runs on anything from tiny FPGA's to online cloud servers.

Programming language: C
License: GNU General Public License v3.0 or later
Tags: Networking     HTTP     WebSocket     MQTT     WebDAV    

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BAS Amalgamated

Barracuda App Server Amalgamated

The Barracuda App Server is an embeddable C code library with support for the following platforms: Embedded Linux, Zephyr, FreeRTOS+TCP or lwIP, VxWorks, QNX, INTEGRITY, Windows & Win CE, Azure RTOS (ThreadX/NetX), Nucleus RTOS, embOS, RTXC, SMX, MQX, RTOS-32, Mac, and UNIX/POSIX.

Check out the tutorial Embedded Web Server vs. Embedded Application Server if you are new to application server technology.

Barracuda App Server Amalgamated

The Barracuda App Server (BAS) runs on anything from tiny FPGA's to online cloud servers. Refer to the Barracuda App Server's Product Page for details.

Lua Server Pages (LSP for short) is a Lua API that includes a compact and efficient Lua web framework, non-blocking asynchronous sockets, and many (I)IoT protocols.


BAS Amalgamated is a compact version of BAS, extracted from the BAS SDK. BAS Amalgamated includes all APIs found in the BAS SDK, but with a limited set of examples and tools. BAS Amalgamated includes the following source code components.

  • BAS.c: Platform independent code (amalgamation of many files)
  • ThreadLib.c: Kernel porting layer
  • SoDisp.c: TCP/IP porting layer (the socket dispatcher)
  • BaFile.c: File system porting layer (optional)
  • BWS.c: The Barracuda Embedded Web Server is also included and the [C++ WebSocket example project](examples/C-WebSockets/README.md) is configured to link with BWS.c. The SharkSSL ESP32 IDE includes BWS and the WebSocket example.

Who Can Use BAS Amalgamated

BAS Amalgamated runs efficiently on a Cortex M4 running @100Mhz and up; however, most microcontrollers will need external memory. See the Memory section in the Porting Barracuda to an Embedded System for details.

Before Downloading the Source Code

The Barracuda App Server is a complex product with many options. Before downloading the source code, consider downloading one of the pre-compiled binaries with included Lua tutorials. For FreeRTOS users, check out the super easy to use ESP32 IDE designed for educational purposes.

How To Compile

To compile BAS, include BAS.c, src/arch/XXX/ThreadLib.c, src/arch/NET/XXX/SoDisp.c, and optionally src/DiskIo/XXX/BaFile.c, where XXX is the required porting layer. In addition, the compiler's include path must include inc/arch/XXX, inc/arch/NET/XXX, and optionally inc/DiskIo/XXX

BAS is extremely flexible and can, for example, be used as follows:

  • Compiled and integrated with RTOS powered monolithic firmware
  • Compiled and run as a process on a High Level Operating System (HLOS) such as embedded Linux
  • Compiled and integrated with a standard (desktop) application

BAS Amalgamated is very easy to compile and several command line compilation examples are shown below. You can add the code to any IDE and Makefile system.

BAS Amalgamated Examples

BAS Amalgamated includes three examples from the BAS SDK: the Mako Server, the LSP Application Manager, and the [C++ WebSocket Server Example](examples/C-WebSockets/README.md).

  • The Mako Server is designed for HLOS, and the LSP Application Manager is designed for RTOS. Both examples provide a Lua foundation enabling rapid interactive development of web, IoT, and business logic (high level logic).
  • The C++ WebSocket Server Example shows how to implement everything using C code (no Lua). With this example, you are effectively using the Barracuda Embedded Web Server component.

Mako Server (HLOS)

The Mako Server Example can be compiled for Windows, (embedded) Linux, QNX, and VxWorks.


Use the Visual Studio project file found in: BAS/examples/MakoServer/VcMake; however, make sure to download SQLite or disable the SQLite build in the project file.


See the tutorial Embedded Linux Web Interface Design for details; however, the server can be downloaded and compiled for Linux as follows:

wget -O - https://raw.githubusercontent.com/RealTimeLogic/BAS/main/LinuxBuild.sh | bash

Download and cross-compile the code for (embedded) Linux as follows:

export CC=/opt/gcc-linaro-7.1.1-2017.08-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc
wget -O - https://raw.githubusercontent.com/RealTimeLogic/BAS/main/LinuxBuild.sh | bash
Change the above CC environment variable to your cross-compiler.


The following example builds the Mako Server without SQLite for HLOS. You can copy and paste the command into a Linux shell. Note that you can also download pre-compiled Mako Server versions for many operating systems on the Mako Server Web Site.

gcc -o examples/MakoServer/mako -fmerge-all-constants -O3 -Os\
    -Iinc -Iinc/arch/Posix -Iinc/arch/NET/Posix\
    src/arch/Posix/ThreadLib.c src/arch/NET/generic/SoDisp.c src/DiskIo/posix/BaFile.c\
    -lpthread -lm -ldl

The above command works for any HLOS with a GCC compiler (and derivatives), including cross compiling for embedded Linux, compiling for QNX, and compiling for VxWorks 7. Simply replace 'gcc' with the applicable compiler. Note that VxWorks is a cross between HLOS and RTOS; thus, you may consider using the LSP Application Manager instead (details below). BAS supports VxWorks 5 and up.

See the Mako Server's Build Documentation for details on macros and other important information, but note that the amalgamated version in the standard SDK works differently.

After running the above compilation command, start the server as follows:


Mako Server. Version 3.7
BAS lib 4920. Build date: Dec  2 2021
Copyright (c) Real Time Logic.

Mounting /tmp/BAS/examples/MakoServer/mako.zip
Server listening on IPv6 port 9357
Server listening on IPv4 port 9357
Loading certificate MakoServer
SharkSSL server listening on IPv6 port 9443
SharkSSL server listening on IPv4 port 9443

Compiling for Windows

The following example compiles and links the server as a 64 bit Windows application using the Visual Studio command line compiler (cl). Note that we include two additional C files. These two C files make it possible to run the server as a Windows service. Note that the pre-compiled Mako Server for Windows is compiled as a 32 bit application.

cl /O2^
 /Iinc /Iinc/arch/Windows /Iinc/arch/NET/Windows^
 src/arch/Windows/ThreadLib.c src/arch/NET/generic/SoDisp.c src/DiskIo/windows/BaFile.c^
 examples/MakoServer/src/Windows/MakoWinMain.c examples/MakoServer/src/Windows/servutil.c^
 ws2_32.lib kernel32.lib User32.lib Gdi32.lib advapi32.lib ole32.lib oleaut32.lib shell32.lib^
 /link /machine:X64 /OUT:examples/MakoServer/mako.exe

The above command requires setting up the command line for 64 bit compilation. The above can be copied and pasted "as is" into a command window.

Including SQLite in the Build

The Mako Server can optionally be linked with the SQLite database engine. The following command shows how to include SQLite and activate the Lua SQLite bindings. However, before running the compilation command, download SQLite and copy sqlite3.c and sqlite3.h to the BAS/src directory.

gcc -o examples/MakoServer/mako -fmerge-all-constants -O3 -Os\
    -Iinc -Iinc/arch/Posix -Iinc/arch/NET/Posix\
    src/arch/Posix/ThreadLib.c src/arch/NET/generic/SoDisp.c src/DiskIo/posix/BaFile.c\
    src/ls_sqlite3.c src/luasql.c src/sqlite3.c\
    -lpthread -lm -ldl

LSP Application Manager (RTOS)

The LSP Application Manager turns the Barracuda App Server into an interactive development tool. See the Online LSP Application Manager Documentation for details.

LSP Application Manager

The LSP Application Manager is designed for RTOS devices, but can also be compiled for non embedded as is shown in the following compile examples.

The LSP Application Manager is typically run from a dedicated RTOS thread, but for HLOS we can create a startup file as follows:

echo "extern void barracuda(void); int main() {barracuda(); return 0;}" > main.c

The following example shows how to compile the LSP Application Manager for HLOS and include file system support.

gcc -o examples/lspappmgr/lspappmgr -Iinc -Iinc/arch/Posix -Iinc/arch/NET/Posix\
    src/arch/Posix/ThreadLib.c src/arch/NET/generic/SoDisp.c src/DiskIo/posix/BaFile.c\
    main.c examples/lspappmgr/src/LspAppMgr.c examples/lspappmgr/src/led.c\
    examples/lspappmgr/obj/LspZip.c -lpthread -lm

The file LspZip.c is the LSP Application Manager's resources converted to a C file. You find the resources in the same directory in lsp.zip. The tutorial Rapid Firmware Development shows how to initially use the provided LSP Application Manager to develop your own application and how to replace LspZip.c with your own application when it is ready for deployment. The tools directory includes the bin2c tool used for converting ZIP files to C files. Embedding the resources in the firmware is convenient, but not required.

If you run the server after compiling it, you will see no printouts. The server tries to open port 80 and if that fails, it tries to open port 9357. Embedded systems with a console can enable the trace library by providing a callback for the data being printed. You can also view the trace in a browser by navigating to http://ip-addr/rtl/tracelogger/. See the TraceLogger Documentation for details and our online tutorial server for a demo: https://tutorial.realtimelogic.com/rtl/tracelogger/

The LSP Application Manager does not require a file system, and the following example shows how to compile the LSP Application Manager without including BaFile.c

gcc -o examples/lspappmgr/lspappmgr -DNO_BAIO_DISK -Iinc -Iinc/arch/Posix -Iinc/arch/NET/Posix\
    src/arch/Posix/ThreadLib.c src/arch/NET/generic/SoDisp.c
    main.c examples/lspappmgr/src/LspAppMgr.c examples/lspappmgr/src/led.c\
    examples/lspappmgr/obj/LspZip.c -lpthread -lm

The macro NO_BAIO_DISK is used by the LSP Application Manager's C startup code LspAppMgr.c.

Cross Compiling the LSP Application Manager for Embedded Systems

Include the files as instructed above in your IDE or Makefile. Most embedded systems require an efficient allocator, which is included. See, for example, the [FreeRTOS Readme File](src/arch/FreeRTOS/README.txt) for how to set up all required components. Most embedded RTOSs require the same setup.

A recommendation is to initially try the server on an ESP32 using FreeRTOS and lwIP even if you plan on using another RTOS and/or device. The ESP32 is very easy to set up and is an excellent RTOS learning platform.

Enabling Additional Features

BAS Amalgamated (BAS.c) includes features that are by default not compiled. These features can be enabled by the following macros. The macros can be enabled on any platform, including RTOS, unless stated otherwise.

The following macros are required if you plan on using the Let's Encrypt plugin. The macros are pre-set for the following ports: POSIX (Linux/QNX), Windows, VxWorks, and INtime.


The following Mako Server specific macro enables loading external Lua modules. When not using a pre-built Mako Server and when using the source code you can instead choose to integrate additional Lua bindings directly with your build.


All porting layers, except POSIX and Windows, have the following pre-set:


The above construction makes Lua use integer only and excludes floating point numbers. To re-enable floating point, compile the code with:


See inc/arch/XXX/luaconf.h for details.

Porting Layers

OS+TCP include source
Digi inc/arch/Digi src/arch/Digi/ThreadLib.c src/arch/NET/generic/SoDisp.c
embOS inc/arch/NET/embOSIP inc/arch/embOS src/arch/embOS/ThreadLib.c src/arch/NET/embOSIP/SoDisp.c
FreeRTOS+lwIP inc/arch/NET/LwIP inc/arch/FreeRTOS src/arch/FreeRTOS/ThreadLib.c src/arch/NET/LwIP/SoDisp.c
FreeRTOS+TCP inc/arch/FreeRTOS src/arch/FreeRTOS/ThreadLib.c src/arch/FreeRTOS/SoDisp.c
INTEGRITY inc/arch/NET/Posix inc/arch/INTEGRITY src/arch/INTEGRITY/ThreadLib.c src/arch/NET/generic/SoDisp.c
INtime inc/arch/NET/INtime inc/arch/INtime src/arch/INtime/ThreadLib.c src/arch/NET/generic/SoDisp.c
Linux+epoll inc/arch/NET/epoll inc/arch/Posix src/arch/Posix/ThreadLib.c src/arch/NET/epoll/SoDisp.c
MQX inc/arch/NET/MQX inc/arch/MQX src/arch/MQX/ThreadLib.c src/arch/NET/MQX/SoDisp.c
Nucleus inc/arch/NET/Nucleus inc/arch/Nucleus src/arch/Nucleus/ThreadLib.c src/arch/NET/Nucleus/SoDisp.c
Posix (Linux, Mac, QNX) inc/arch/NET/Posix inc/arch/Posix src/arch/Posix/ThreadLib.c src/arch/NET/generic/SoDisp.c
Quadros inc/arch/Quadros src/arch/Quadros/ThreadLib.c src/arch/NET/generic/SoDisp.c
SMX inc/arch/NET/SMX-NET inc/arch/SMX src/arch/SMX/ThreadLib.c src/arch/NET/generic/SoDisp.c
ThreadX+NetX inc/arch/ThreadX src/arch/ThreadX/ThreadLib.c src/arch/ThreadX/SoDisp.c
VxWorks inc/arch/VxWorks src/arch/VxWorks/ThreadLib.c src/arch/NET/generic/SoDisp.c
Windows inc/arch/NET/Windows inc/arch/Windows src/arch/Windows/ThreadLib.c src/arch/NET/generic/SoDisp.c
Windows CE inc/arch/NET/CE inc/arch/Windows src/arch/Windows/ThreadLib.c src/arch/NET/generic/SoDisp.c
Zephyr inc/arch/Zephyr src/arch/Zephyr/ThreadLib.c src/arch/NET/generic/SoDisp.c

The generic directory 'inc' must also be in the include path.

Additional Build Examples


The following example shows how to compile Mako Server for VxWorks 7. Use the LSP Application Manager example if you are using an older VxWorks version.

wr-cc -o examples/MakoServer/mako -static -fmerge-all-constants -O3 -Os\
    -Iinc -Iinc/arch/VxWorks -Iinc/arch/NET/Posix\
    src/arch/VxWorks/ThreadLib.c src/arch/NET/generic/SoDisp.c src/DiskIo/posix/BaFile.c\

Note that we are not including SQLite support. You can include SQLite by using the SQLite version provided by Wind River.

ThreadX/NetX using IAR

The following example shows how to compile the generic BAS library for ThreadX and NetX using IAR for ARM. We have the following directories tx (ThreadX), nx (NetX), and BAS.

iccarm -e -c^
  -Itx -Inx^
  -IBAS/inc -IBAS/inc/arch/ThreadX^

Using the above compilation settings, you would also need to include src/arch/ThreadX/ThreadLib.c, src/arch/ThreadX/SoDisp.c, and optionally src/DiskIo/FileX/BaFile.c.


i.MX RT1020

Download a ready to compile and run project for i.MX RT1020.

IoT ESP32 Educational Kit

Check out the SharkSSL ESP32 IDE if you are interested in testing the Barracuda App Server on a FreeRTOS powered ESP32. The ESP32 is great for educational purposes.


Barracuda App Server Tutorials

DZone BAS and Mako Server Tutorials