From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,55958fd991db66fe X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-09-13 09:00:35 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!paloalto-snf1.gtei.net!chcgil2-snh1.gtei.net!chcgil2-snf1.gtei.net!news.gtei.net!news.binc.net!kilgallen From: Kilgallen@SpamCop.net (Larry Kilgallen) Newsgroups: comp.lang.ada Subject: Re: Advantage of XML based GUI? (was Re: Ada-inspired OS/Language) Date: 13 Sep 2002 11:00:18 -0600 Organization: LJK Software Message-ID: <2nbgXSBE2fdF@eisner.encompasserve.org> References: <4519e058.0209101828.cb5ff85@posting.google.com> <3d7f9d3f.920665532@news.cis.dfn.de> <3d80b566.992395741@news.cis.dfn.de> <3d81400c.1027894993@news.cis.dfn.de> NNTP-Posting-Host: eisner.encompasserve.org X-Trace: grandcanyon.binc.net 1031931491 15023 192.135.80.34 (13 Sep 2002 15:38:11 GMT) X-Complaints-To: abuse@binc.net NNTP-Posting-Date: Fri, 13 Sep 2002 15:38:11 +0000 (UTC) Xref: archiver1.google.com comp.lang.ada:28940 Date: 2002-09-13T11:00:18-06:00 List-Id: In article <3d81400c.1027894993@news.cis.dfn.de>, nickroberts@blueyonder.co.uk (Nick Roberts) writes: > On 12 Sep 2002 11:23:11 -0600, Kilgallen@SpamCop.net (Larry Kilgallen) > strongly typed: >>Existing device drivers that follow what model ? > > Various and many. Maybe Linux. Maybe Windows. Probably a good plan would be > to start with one that is relatively simple (but still works), and work > towards the more sophisticated ones. I believe such an approach would lead to a "tacked on" result such as Windows NT, 2000, etc., with GUI from one heritage tacked onto an operating system kernal from another. >>Certainly that is fundamental to the design of the "native" device >>driver system. > > A device driver may require: port I/O; memory mapped I/O; interrupt handler > installation (and communication); communication with higher levels of > software. What else? The design of AdaOS is very flexible. I suspect most > DD environments would fit into AdaOS with little difficulty. A Port and Class driver architecture, allowing in the simplest case multiple drivers to share a single SCSI bus and in more complex cases multiple ports to access the same device on a remote controller. For a sanity check, I would suggest desk checking any design against contemporary Fibre Channel hardware specifications to ensure that IO to a specified disk can be handled over multiple paths. >>Unless you design it from the start, for instance, >>it would be difficult to deliver ASTs. > > What is an 'AST' in this context, please? Execution of code provided by the user, in user process context and user processor mode when an IO request completes, independent of the normal code flow of the user program. ====================== Of course I can only mention considerations I know about, I am sure there are others with experience in other environments (IBM Parallel sysplex, etc.) who should be consulted to understand high end device driver environments.