2.1. Linux user applications (usr)

In addition to the contents defined in the rootfs, additional applications can be built and deployed in the linux/usr/ directory. Such applications are specific to the agency and do not belong to any external packages.

2.1.1. Deployment in the rootfs

All applications and files which need to be deployed in the rootfs must be first installed in the usr/build/deploy directory. To do so, the current approach is to edit the usr-linux recipe adding the install command, for example:

usr_do_install_file_root "${IB_TARGET}/build/lib/lv_port_linux/lvglsim"

This command will copy the file lvglsim to the usr/build/deploy directory.

2.1.2. Development of modules and deployment

Kernel modules can also be compiled in the usr/module/ directory according to the platform as defined in build/conf/local.conf file.

The modules are automatically deployed in the root/ home directory of the target rootfs. The insmod application can then be used from the shell in order to load the module into the kernel.

A module can be helpful for testing purposes, for example to test kernel functionalities.