daj@ (Dean A. Jones) (10/26/90)
I'm having a bit of trouble understanding what sash does. i.e. what is it really useful for, under what circumstances is it loaded etc. Any help would be appreciated. Dean A. Jones. daj@godzilla.cgl.rmit.oz.au
olson@anchor.esd.sgi.com (Dave Olson) (10/27/90)
In <daj.656899089@godzilla> daj@ (Dean A. Jones) writes: | I'm having a bit of trouble understanding what sash does. i.e. what is it | really useful for, under what circumstances is it loaded etc. Any help would | be appreciated. sash (Stand Alone SHell) is used to load /unix, and other 'standalone' programs from the filesystem. The PROM only understands the special (i.e., simple) volume-header and tapedirectory 'filesystems'. For systems with newer PROMs (almost all 4D's, except for the 4D60, and possibly a few other older systems), when the system is set to autoboot, the PROM loads sash automatically, and sash loads the file listed in the volume header as the boot file. This file is most commonly unix, but could conceivably be other programs. The other thing sash is commonly used for is to load the standalone fx program from /stand/fx. When you say: boot somefile (e.g., boot dksc(0,1,0)stand/fx) to the PROM, it first loads the program listed in the NVRAM environment variable 'bootfile', which is typically dkip(0,0,8)sash for ESDI drives, and dksc(0,1,8)sash for SCSI drives; that program is passed the remaining arguments, and tries to load that file. Finally, if you have a PI, or a newer 4D[23]X0, then the 'install' menu choice invokes sash -m, which looks for an installation device, and if found, tries to load the miniroot from it, and then load the appropriate kernel from the miniroot. (Actually, sash.IP6, sash.IP5, or sash.IP4 is normally what is loaded in this case, depending on machine type). I don't think we have much documentation on the standalone environment available... -- Dave Olson Life would be so much easier if we could just look at the source code.