Cours Lua In Embedded Linux, tutoriel & guide de travaux pratiques en pdf.
Lua in San Diego
-Lua is or will be used in several embedded projects. Majority of these projects are Set Top related.
-The purpose of this presentation is to share our work and goals.
Current Use of Lua
-Lua is embedded in the embedded applicationand lua runs as a thread or task in the application. Lua has direct access to the embedded system.
-Lua connects remotely, ( serial or TCP/IP ) to remote user interfaces – hyperterm of telnet client.
-A modest shell interface is written to command line history and interactive command editing.
( This is an important feature )
Lua Environment Continued
-C extensions tie the lua interpreter to hardware and O/S commands
-Lua Scripts are loaded at runtime and transferred from remote connection.
-The C extensions allow various levels of the driver software to be tested.
-Lua Scripts set up the environment for testing as well as provide extensive unit testing capability.
Political Problems
-Very hard to politically to incorporate scripting language in embedded system. ( Even when project is bleeding from lack of testing. )
-May be very successful in one generation and taken out in the next.
-A NASA experience is documented in the following URL’s ( LISP SCRIPTING )
Solution
-Lua needs to be a default tool for embedded systems.
–-Removes the political decision.
-In Embedded Linux there is a way easily do this
–Incorporate Lua into Busybox
–Replace the default Ash Shell with the Lua Intepreter as Command Shell
Added Benefit
-Embedded Applications are being written in scripting languages as seen from cover story in the Linux Journal.
Busy Box Economics
-Lua as shell language makes sense from memory footprint
-Ash Shell 60K
-Lua 130K — ( MIPS processor )
-Full Bash Shell 900K
-With Lua’s Posix , TCP/IP and string pattern matching libraries, the Busy Box environment should be smaller and more modular.
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Lua In Embedded Linux (122 KO) (Cours PDF)