> There are a lot more information on the Devname architecture > that we have not discussed so far.
BACKGROUND Solaris devices are represented in two name spaces: /dev and /devices. The /devices namespace represents the physical path to a hardware device, a pseudo device, or a bus nexus device. It reflects the kernel device tree and is managed by the devfs filesystem. The /dev namespace contains logical device names used by applications. The names are either symbolic links to the physical path names under /devices or, in rare cases, device special files created via the mknod(1M) command or the mknod(2) system call. Most of the /dev names are automatically generated by devfsadmd(1M) in response to physical device configuration events. These naming rules are delivered by driver developers through link generator modules for devfsadm and entries in /etc/devlink.tab. It is also possible for system administrators and applications to create device special files and symbolic links directly, bypassing the devfsadm framework. The global /dev namespace resides under the system root /dev directory. Some Solaris applications like ftpd create a chroot'ed environment and export a restricted subset of the system device names into its chroot'ed /dev directory. Solaris zones create virtualized Solaris instance and provide a subset of the system device names inside the virtualized /dev namespace. COMPONENTS delivered with Devname Project: The Devname project builds the foundation for a simplified Solaris device naming model. The project implements an in-memory file system that exports the /dev namespace. This approach brings the flexibilities needed in exporting a subset of the /dev namespaces, intercepting individual /dev name lookup request thus achieving /dev name resoltuion through optionally customized mechanisms. The Devname project delivers the following components: 1. The dev File System – This file system exports the /dev namespace, supports multiple file system instances, intercepts file system operations on /dev names and supports the existing Solaris /dev naming system. 2. Simplified Zones Device Support - The project removes zones dependency on devfsadm[d], and encapsulates the device special file details inside the file system. 3. Simplified /dev/pts Namespace Implementation - This is the feature that demonstrates the directory based device name resolution architecture to achieve better system observability in local pty devices, simpler implementation, and a more reliable pseudo-terminal subsystem. 4. Directory Based device Name Resolution – This is the infrastructure provided by Devname to support flexible device naming scheme inside a /dev subdirectory. A plug-in mechanism is also provided for future delivery of directory based device naming scheme through kernel modules. FUTURE Leverage of Devname Project: 1. /dev/net namespace implementation (on-going with ClearView project); 2. Centralized Tape Device Naming (future project); 3. Anonymous FTP support in Local Zone (rfe); 4. /etc/logindevperm enhancements (future project); 5. EFI disk labeling (preliminary prototype is done) - this is also answering Tao's question. lucy This message posted from opensolaris.org _______________________________________________ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
