VAX 11/.750 Boot ROM code makes non-longword memory references to MassBus and Unibus register space. Minor changes were necessary to allow this behavior which was architecturally undefined behavior, but had real code which depended on it.
Added a BOOTDEV option to the CPU to reflect the 4 position boot device selection switch on real VAX 11/750 hardware.
The UBA750 initial state started with the UBA map registers validly mapping the first 256KB of RAM to Unibus space.
Added simulated PCS/WCS memory which boot code on some operating systems (Ultrix and other BSD derived systems) automatically loaded on the VAX 11/750. PCS/WCS was also automatically loaded by the newer versions of the BOOT ROMs.
The goals here being to simplify calling code while getting consistent output delivered everywhere it may be useful.
Modified most places which explicitly used sim_log or merely called printf to now avoid doing that and merely call sim_printf().
scp.c,scp.h - Gave priority to a command message handler to determine what values result in displayed messages and exported run_cmd_message for use by simulators which add simulator specific BOOT commands which leverage the run_cmd logic and should also leverage the run_cmd_message for message display
VAX/vax610_sysdev.c, vax730_sys.c, vax750_cmi.c, vax780_sbi.c - Added BOOT command message dispatch to run_cmd_message for simulators which perform preprocessing on BOOT activities but otherwise then dispatch to run_cmd.
