README This directory contains source and a Makefile for the umbrella downloader and uploader commands. The umbrella commands, like "download" and "upload" examine the machine database to determine which of several possible micros the user will be assigned, allocates the micro, and then invokes a machine- specific downloader/uploader command, depending on what is specified in the machine database. An example database is contained in file machines.example; the copy actually used resides in {Xinu-directory}/lib/machines. The subdirectories are structured as follows: cmd contains the source for umbrella commands. These are the commands that users invoke from the shell level to download or upload a microcomputer. h contains include files used by the umbrella commands and elsewhere. There are links to files in this directory from several lower level h directories. lib contains the source for all the database search routines and device reservation routines. Files in this directory are compiled to produce libd.a, which is referenced in Makefiles for both umbrella commands and device-specific routines. lsi11 contains the source for serial-line and Ethernet-based Vax-to-LSI 11 downloaders. Both the LSI-resident code as well as code that runs under UNIX on the host (vax) is included. vax contains the source for serial and Ethernet VAX-to-VAX downloaders (usually used for VAX-to-microvax, but can be used to download almost any Vax through the console port, including machines like 8600s. The makefile here calls make on the cmd, Lsi11, and Vax subdirectories. If you add downloading code for other target micros, add a new subdirectory under this one with all the downloading source code related to that machine (including source for boot loaders that executes on the micro as well as source for the downloader itself).