Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!genrad!mit-eddi!mit-vax!eagle!harpo!seismo!hao!hplabs!sri-unix!lwa@mit-csr From: lwa%mit-csr@sri-unix.UUCP Newsgroups: net.unix-wizards Subject: Re: pdp11 loader options Message-ID: <2047@sri-arpa.UUCP> Date: Sat, 11-Jun-83 13:17:00 EDT Article-I.D.: sri-arpa.2047 Posted: Sat Jun 11 13:17:00 1983 Date-Received: Sun, 12-Jun-83 22:07:46 EDT Lines: 21 The -i and -n options to the pdp-11 loader actually do different things. -n produces a load image with separate "text" and "data" segments, such that the text segment is read-only and can be shared. The data segment is relocated to begin at the next 4K word boundary above the end of the text segment (_etext) so that it will mapped by a different mapping register - this allows the text and data segments to be non-contiguous in physical memory. The -i option goes further - it produces a program linked to run with separated instruction and data (I and D) spaces. In this case both the text segment and the data segment are relocated to begin at virtual address 0; the processor determines from the type of reference (instruction fetch or not) whether the address is to be mapped using the I-space mapping registers or the D-space mapping registers. Programs linked with -n can be run on any pdp-11; programs linked with -i can be larger, but will only run on 11/44's, 45's, 50's, 55's, and 70's. -Larry Allen -------