wfjm.w11/tools/oskit/211bsd_rpmin

Notes on oskit: 2.11BSD system on a RP06 volume - minimal memory system

General remarks

See notes in w11a_os_guide.md on

1. I/O emulation setup
2. FPGA Board setup
3. Rlink and Backend Server setup
4. Legal terms

System properties and intended usage

This system is created for usage on systems with limited memory. The kernel is configured with

    NBUF 40         # only 60 blocks disk cache (usual is 160)
    MAXUSERS 10     # this reduces number of file, process, ... slots
    INET NO         # no networking available

The system will boot on as little as 512 kB memory. Will work reasonably with 640 kB if only one or two sessions are active. Usage of tcsh should be avoided because it has a large memory footprint.

History

For history see CHANGELOG.md.

Installation

A disk set is available from http://www.retro11.de/data/oc_w11/oskits/211bsd_rpminset.tgz

Download, unpack and copy the disk images (*.dsk), e.g.

       cd $RETROBASE/tools/oskit/211bsd_rpmin/
       wget http://www.retro11.de/data/oc_w11/oskits/211bsd_rpminset.tgz
       tar -xzf 211bsd_rpminset.tgz

Usage

• Start backend server and boot system (see section Rlink in w11a_os_guide.md)

       boot script:  211bsd_rpmin_boot.tcl
       example:      ti_w11 <opt> @211bsd_rpmin_boot.tcl
                     where <opt> is the proper option set for the board.
  

• Hit <ENTER> in the xterm window to connnect to backend server. System with as low as 512 kB memory can be used, like in example below. The boot dialog in the console xterm window will look like (required input is in {..}, with {<CR>} denoting a carriage return:

       70Boot from xp(0,0,0) at 0176700
       : {<CR>}
       : xp(0,0,0)unix
       Boot: bootdev=05000 bootcsr=0176700
  
       2.11 BSD UNIX #1: Fri May 26 12:48:54 PDT 2017
           root@w11a:/usr/src/sys/RETRONFPMIN
  
       phys mem  = 524288
       avail mem = 313536
       user mem  = 307200
  
       May 26 12:49:35 init: configure system
  
       dz ? csr 160100 vector 310 skipped:  No CSR.
       lp 0 csr 177514 vector 200 attached
       rk 0 csr 177400 vector 220 attached
       rl 0 csr 174400 vector 160 attached
       tm 0 csr 172520 vector 224 attached
       xp 0 csr 176700 vector 254 attached
       cn 1 csr 176500 vector 300 attached
       erase, kill ^U, intr ^C
  

  In first '#' prompt the system is in single-user mode. Just enter a ^D to continue the system startup to multi-user mode:

       #^D
       Fast boot ... skipping disk checks
       checking quotas: done.
       Assuming non-networking system ...
       checking for core dump... 
       preserving editor files
       clearing /tmp
       standard daemons: update cron accounting.
       starting lpd
       starting local daemons:Fri May 26 12:50:44 PDT 2017
  
  
       2.11 BSD UNIX (w11a) (console)
  
       login:
  

  The login prompt is sometimes mangled with system messages, if its not visible just hit <ENTER> to get a fresh one.

       login: {root}
       erase, kill ^U, intr ^C
  

  Now the system is in multi-user mode, daemons runnng. You can explore the system, e.g. with a pstat -T or a mount command. The second xterm can be activated too, it will connect to a second emulated DL11. At the end is important to shutdown properly with a halt:

       # {pstat -T}
        15/122 files
        47/128 inodes
         9/ 80 processes
         8/ 36 texts active,  32 used
         6/ 72 swapmap entries,  475 kB used, 3704 kB free, 3673 kB max
        15/ 80 coremap entries,  107 kB free,   43 kB max
         1/ 10  ub_map entries,   25    free,   25    max
       # {mount}
       /dev/xp0a on /
       /dev/xp0c on /tmp
       /dev/xp0d on /home
       /dev/xp0e on /usr
       # {halt}
       syncing disks... done
       halting
  

  While the system was running the server process display the

       cpu0> 
  

  prompt. When the w11 has halted after 211bsd shutdown a message like

  
       CPU down attention
       Processor registers and status:
         PS: 030350 cm,pm=k,u s,p,t=0,7,0 NZVC=1000  rust: 01 HALTed
         R0: 177560  R1: 010330  R2: 056172  R3: 000010
         R4: 005000  R5: 147510  SP: 147466  PC: 000014
  

  will be visible. Now the server process can be stopped with ^D.