avr-shell-cmd

Small helper library for creating shell commands on an AVR, when using avr-gcc. Requires adding an augmented linker script.

Linker script augmentation

This repository includes an augmented linker script: cmdtables.ld. Tell the linker to augment the linker script with this file (use the -T command line option). In Atmel/Microchip Studio this is done in the project properties (Alt+F7), Toolchain, AVR/GNU Linker, Miscellaneous, Other Linker Flags. Add the line:

-T $(ProjectDir)\lib\avr-shell-cmd\cmdtables.ld

Change the path to match where you've included this repo.

If you don't use Atmel/Microchip Studio, add the linker option in your makefile.

Using avr-shell-cmd

First, include the files here in your build. This repo can be included as a submodule.
Then add the linker script as described above.

Creating a shell command

Wherever you want a shell command, include cmd.h. Then make a static function with the command you want (name it the command followed by "Cmd"), and then put it in a CMD macro. Here is a command called "example":

static void exampleCmd(uint8_t argc, char *argv[])
{
    // Your command code goes here
}

CMD(example, "Put helptext here");

That is all that's needed.

Executing a shell command

Collect input from a serial port (or anywhere else you want to expose a shell). Once a full line has been read, call cmd_split_exec with the line. The correct command function will be called.

One command is already provided: help. It will print a list of all commands and their helptext.