The Neutrino boot process can dynamically add block I/O (i.e., disk) drivers, letting you boot on systems with newer controllers. The mechanism is simple and not proprietary to QNX Software Systems, so third parties can offer enhanced block drivers without any intervention on our part.
The driver update consists of the drivers themselves (devb-* only) and a simple configuration file. The configuration file is in plain text (DOS or UNIX line endings accepted), with the following format:
drvr_name|type|timeout|add_args
The first three fields are mandatory. The fields are as follows:
The configuration file must be called drivers.cfg, and you must supply the update on a physical medium, currently a CD-ROM or a USB flash drive. The boot process looks in the root of the filesystem first, and then in a directory called qnxdrvr. This can help reduce clutter in the root of the filesystem.
The source filesystem can be any of the supported filesystems. These filesystems are known to work:
If the update is distributed over the web in zip or tar format with the qnxdrvr structure preserved, an end user simply has to download the archive, unzip it to a USB drive, and insert the USB drive on booting.
You can apply a driver update by pressing Space during booting and selecting F2. The system then completes the startup of the standard block drivers, giving a source filesystem to apply the update from. You're then prompted to choose the filesystem and insert the update media.
Once the files have been copied, you're prompted to reinsert the installation CD if applicable. The block drivers are then restarted.
This mechanism also lets you update existing drivers or simply modify their arguments (e.g., PCI ID specification).
If you're installing, then the installation program copies the updated drivers to /sbin and the configuration file to /boot/sys. It then makes copies of the standard build files in /boot/build (except multicore ones) and calls them qnxbase-drvrup.build and qnxbasedma-drvrup.build. These files are then used to create new image files called qnxbase-drvrup.ifs and qnxbasedma-drvrup.ifs in /boot/fs. The DMA version of this new file is copied to /.boot, and the non-DMA version is copied to /.altboot.