Readme - Web Server Software ExampleDESCRIPTION:	A Web Server running from a file system in flash memory.REQUIREMENTS:This example will run on the following Nios II harware example designs:- Standard- Full FeaturedIn addition, one of the following Nios development boards is required:- Nios II Development Board, Stratix II Edition- Nios II Development Board, Cyclone II Edition- Nios Development Board, Stratix Professional Edition- Nios Development Board, Stratix Edition- Nios Development Board, Cyclone EditionPERIPHERALS USED:This example exercises the following peripherals:- Ethernet MAC (named "lan91c111" in SOPC Builder)- STDOUT device (UART or JTAG UART)- LCD Display (named "lcd_display" in SOPC Builder)SOFTWARE SOURCE FILES:This example includes the following software source files:- web_server.c: Contains main() and LWIP callback to install tasks once LWIP   has been properly initialized.- http.c: Implementation of an HTTP server including all necessary sockets  calls to handle a multiple connections and parsing basic HTTP commands to   handle GET and POST requests. Requests for files via HTTP GET requests direct  the server to fetch the file, if available, from the flash file system and   send it to the client requesting it.- http.h: Header information defining HTTP server implementation and common  HTTP server strings & constants.- user.h: Definitions for the entire example application.- network_utilities.c: Contains MAC address, IP address, and DHCP routines to  manage addressing. These are used by LWIP during initialization, but are  implementation-specific (for any implementation of this example not an Altera   Nios development board, Stratix, Stratix Professional, or Cyclone edition,   this file will need to be modified to control addressing in your system).BOARD/HOST REQUIREMENTS:This example requires an Ethernet cable connected to the development board's RJ-45 jack, and a JTAG connection with the development board. If the host communication settings are changed from JTAG UART (default) to use aconventional UART, a serial cable between board DB-9 connector  and the host isrequired. If DHCP is available, the application will attempt to obtain an IPaddress from a DHCP server. Otherwise, a static IP address (defined in user.h) will be assigned after a 120-second timeout. The DHCP timeout can be adjusted in user.h. KNOWN ISSUES/LIMITATIONSThe read-only zip filesystem must be set to a flash memory device whose baseaddress is 0x0 (note that you may place read-only zip file system contents at any offset within the flash memory device). This limitation is scheduledto be corrected in a future Nios development kit release.ADDITIONAL INFORMATION:This is an example HTTP server using LWIP on MicroC/OS-II. The server can process basic requests to serve HTML, JPEG, and GIF files from the Altera read-only zip file system. It is in no way a complete implementation of a full-featured HTTP server.LWIP has two API's, a callback interface and "standard" sockets. This exampleuses the sockets interface. A good introduction to sockets programming is thebook Unix Network Programming by Richard Stevens. Additionally, the text"Sockets in C", by Donahoo & Calvert, is an concise & inexpensive text forgetting started with sockets programming.To run the HTTP server, you must first program the file system using the Flash Programmer utility of the Nios II IDE. The read-only zip file system contents come from a .zip file ("ro_zipfs.zip" by default) in your application "syslib" library project by default. When the web-server application is built, the contents of this zip file are extracted and converted into a flash programmingfile, "filesys.flash", located in the "<system library>/Release" folder of yourweb-server. This file will be programmed into flash allowing the HTTP serverto fetch content at runtime. To build & run the web-server application, perform the following steps:   === I.  BUILD PROJECT ===1. After creating a new "Web Server" software example project and referring to    a Nios II "standard" or "full_featured" hardware example design .ptf file,    you may build it by choosing "Build All" from the Nios II IDE "Project"    menu.  2. Wait for the build process to complete. During the software build, the   files necessary to run this example are generated.   === II. PROGRAM FLASH === 1. Select the web-server application project (the default project name is    "web_server_0" unless specified otherwise during project creation).   2. From the "Tools" menu, select "Flash Programmer".2. Select "Flash Programmer" under the list of "Configurations:".3. Press New.4. Press Program Flash.   Flash on your development board will now be programmed with the    web-server application, read-only zip file system contents, and a    boot-copier program. When your board is programmed with the standard   or full_featured .sof file, the web-server application will boot and   serve web content from flash in the read-only zip file system.   === III. DEBUG ===   The above instructions will allow you to run the web server when the FPGA   has been configured. If you wish to manually download the web-server    application (for example, after making an edit and re-compiling), or if you   wish to debug the web-server application, the following steps apply:1. Program the standard or full_featured design (.sof file) into the FPGA    using the Quartus II Programmer.   2. In the Nios II IDE, again select the web server application project.3. From the "Run" menu, select "Debug..." (to launch the debugger) or    "Run..." (to   download software to RAM and execute).4. Select a "Nios II Hardware".5. Press "New".6. Press "Run" or "Debug" as appropriate.Note: This example will not run on the Instruction Set Simulator (ISS).