|
iRMX is a real-time operating system designed specifically for use with the Intel 8080 and Intel 8086 family of processors. It is an acronym for ''Real-time Multitasking eXecutive''. Intel developed iRMX in the 1970s and originally released RMX/80 in 1976 and RMX/86 in 1980 to support and create demand for their processors and Multibus system platforms.〔Real-time Elements, Donald J. Ewing, Professor Emeritus, Electrical Engineering and Computer Science University of Toledo, ''EECS 4170/5170/7170 Class Notes'' ()〕 The functional specification for RMX/86 was authored by Bruce Schafer and Miles Lewitt and was completed in the summer of 1978 soon after Intel relocated the entire Multibus business from Santa Clara California to Aloha, Oregon. Bruce and Miles went on each manage one of the two teams that developed the RMX/86 product for release on schedule in 1980. Effective 2000 iRMX is supported, maintained, and licensed worldwide by TenAsys Corporation, under an exclusive licensing arrangement with Intel. iRMX is a layered design: containing a kernel, nucleus, basic i/o system, extended i/o system and human interface. An installation need include only the components required: intertask synchronization, communication subsystems, a filesystem, extended memory management, command shell, etc. The native filesystem is specific to iRMX, but has many similarities to the original Unix (V6) filesystem, such as 14 character path name components, file nodes, sector lists, application readable directories, etc. iRMX supports multiple processes (known as jobs in RMX parlance) and multiple threads are supported within each process (task). In addition, interrupt handlers and threads exist to run in response to hardware interrupts. Thus, iRMX is a multi-processing, multi-threaded, pre-emptive, real-time operating system (RTOS). ==iRMX variants== Several variations of iRMX have been developed since its original introduction on the Intel 8080: iRMX I, II and III, iRMX-86, iRMX-286, DOS-RMX, iRMX for Windows, and, most recently, INtime. While many of the original variants of iRMX are still in use, only iRMX III, iRMX for Windows, and INtime are currently supported for the development of new real-time applications. Each of these three supported variants of iRMX require an Intel 80386 equivalent or higher processor to run. A significant architectural difference between the INtime RTOS and all other iRMX variants is the support for address segments (see x86 memory segmentation). The original 8086 family of processors relied heavily on segment registers to overcome limitations associated with addressing ''large'' amounts of memory via 16-bit registers. The iRMX operating system and the compilers developed for iRMX include features to exploit the segmented addressing features of the original x86 architecture. The INtime variant of iRMX does not include explicit support for segmentation, opting instead to support only the simpler and more common 32-bit flat addressing scheme. Note: despite the fact that native processes written for INtime can only operate using unsegmented flat-mode addressing, it is possible to port and run some older iRMX applications that use segmented addressing to the INtime kernel. When Intel introduced the Intel 80386 processor, in addition to expanding the iRMX RTOS to support 32-bit registers, iRMX III also included support for the four distinct protection rings (named rings 0 through 3) which ''describe'' the protected-mode mechanism of the Intel 32-bit architecture. In practice very few systems have ever used more than rings 0 and 3 to implement protection schemes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「RMX (operating system)」の詳細全文を読む スポンサード リンク
|