# libp7 - Casio Communication Protocol 7.00 implementation
## Introduction
Protocol 7.00 (or "Protocol 7") is the communication protocol used by CASIO
FX calculators, between them and with a PC (serial and USB). It allows model
identification, file interaction (with main memory and flash/SD storage
devices), screenstreaming and OS updating.

This library, under [LGPL](https://www.gnu.org/licenses/lgpl-3.0.fr.html),
brings functions to send and receive packets, and packet flows
such as file getting/sending, remote file interaction (listing, copying,
deleting), filesystem optimization, screen receiving and OS Update-related
(backup, executable sending). No interaction with the main memory is
implemented yet.

Screen receiving is only supported for monochrome calculator as the format for
other calculators are yet to be known.

This library has two main parts: find the devices to communicate with, through
cross-platform streams (P7 streams, a superset of local streams, including libc
and libusb ones), and talk P7 with them.

This library require environment knowledges because of protocol failure. Those
are hardcoded; for each newly discovered environment (new calculator, ...),
entry must be added in the `src/core/devices.c` file, in the
`known_environments` list, using and updating command masks if necessary.
A precise environment listing is required to have a clean detection of what
commands and devices we can or cannot run so we don't have any surprise.

More on the [P7 homepage](https://p7.planet-casio.com/en.html).

## Prerequisites
Side note: the library might work with older versions of these dependencies,
I took these as a reference because these are the ones I work with.

### Making-only dependencies
| Name                                               | Version  |
| -------------------------------------------------- | -------- |
| [make](https://www.gnu.org/software/make/)         | >= 4.0   |
| [gcc](https://gcc.gnu.org/)                        | >= 4.9   |
| [binutils](https://www.gnu.org/software/binutils/) | >= 2.25  |
| [asciidoc](http://asciidoc.org/)                   | >= 8.6.9 |
| [gzip](https://www.gnu.org/software/gzip/)         | >= 1.6   |

### Making and runtime dependencies
| Name                                               | Version  |
| -------------------------------------------------- | -------- |
| [libusb](http://libusb.info/)                      | >= 1.0   |

## Configuring
First of all, the configure script has a help message where all of the
options are listed. The defaults should be appropriate for a native build,
just `./configure` if that's what you want to do, but you should read at
least the next paragraph.

If you're installing on or packaging for a GNU/Linux distribution, you might
want to install the `udev` rule to let the access to the direct calculator
connexions to normal users. As calculators can be connected as serial devices,
which are attributed to the `uucp` group (on Manjaro GNU/Linux), I chose to
attribute the `uucp` group to calculators plugged directly as USB. If you
agree with that, just add the `--udev` option to the configuration command
line; otherwise, make your own, or make nothing, I don't really care.

Building for the MS-Windows platform is supported, just use a `-mingw32`
target.

Also, building a static library, for both PC and embedded systems, is
supported : just use the `--static` option. If you want to build a static
library so that a cross-compiler that uses Microsoft Windows static library
formats, add the `--windows` option (notice that for a `-mingw32` target and
a dynamic library generation, this option is automatically added).

## Building and installing
Once configuring is done, just `make`.
To install, use `make install`.

To build and install only the lib, use `all-lib` and `install-lib`.  
To build and install only the docs, use `all-doc` and `install-doc`.  

If you ought to package this library, use the `DESTDIR` Makefile variable,
e.g. `make install DESTDIR=./package-root`. Do **not** use the `--root`
configure options for this, as configure tools (`libp7-config` and the
`pkg-config` configuration file) will add what's in the `--root` option value
but not in the `DESTDIR` option.

Other useful targets:

- `uninstall`, `uninstall-lib`, `uninstall-bin` `uninstall-doc`: will try to
  uninstall using the current configuration;
- `mostlyclean`, `clean`, `clean-doc`, `mclean-lib`, `clean-lib`: remove
  built files at different levels;
- `re`, `re-lib`, `re-doc`: regenerate built files at different levels
  (clean and build) -- useful when configuration changes.