64K kernel on C64

As for the argument that you can't have a decent kernel in 64K, here is Lunix, Linux for C64's.. http://wwwcip.rus.uni-stuttgart.de/~etk10217/lunix/lunix.html (mirror) http://www.kuai.se/~mage/lunix/ While it does serve as an inspiration, maybe we can steal^H^H^H^H^Hborrow some source? --- snip from README --- .d#M*#MHb\ M? dH*" `Hb. TM. ,MH' `M| 9b. .MH' JM: LUnix-Version 0.1 patchlevel 3b ?M, HM' ?M' =============================== `*M#ML___.__,o#H'' Oct 5, 1996 HH'"'"""*"'' :M' HP ,/# |M' ,. `"` dH .H .. .o. .ov\o\ ., .o, ,, ___. JM' d| H' ``dP `\. |? `H, .d#' .dM#**HMq\. ,MT ,P JT -M| || & `H? ?M' JP' ``9H\?M' || .H' M| || 6 `9b. ,HH' MR `9M6 :? |M M| || M ?H, ?M' HM JM*H\ `booov="9? M| || 9. `MHH" `Hb. _dH' `*9b\. " |MT H. || ,HP>&o. `#H###H"' `*##\. `' ' .,H*' `Hb. `"#Hb\_ _?#*'' "*&#o "*Hbbo\__ __oo##*"" "' Index `"'***M=###booooobd##&*"""" ============ ""' 1. What the hell is LUnix ? 2. How to start LUnix ? 3. Files/Applications comming with LUnix 3.1 The LUnix-Shell (sh0.exe, the default-shell) 3.2 The LUnix-Netdriver 3.3 The LUnix debugger LDB 4. Where can i get the lastest version of LUnix and/or updates, patches ? 5. Can i write my own LUnix-applications ? -------=============#####################################==============---- --- 1. What the hell is LUnix ???? ============================== LUnix is a new operating system for the Commodore64 (or C128 in C64-mode). I started writing LUnix in 1994. The system core is a minimal implementation of a multitasker. I followed an idea of A. Einstein, who said: "Make is as simple as possible, but not simpler" I'd say LUnix tends to be a little bit too simple :-) - LUnix is a operating system for the C64 (no hardware expansions required) (LUnix stands for "little UNIX", well don't expect too much :) LUnix doesn't support additional hardware yet, the next version will be able to support external RAM (assuming someone will write a modul/driver for it). - LUnix provides real multitasking, so there can be more than one process at a time. (Up to 32 processes. LUnix can't swap out stopped processes, so all of them must fit into main memory at once. The next version will support process-data in external RAM) - Using the termial-server "term9600" you can connect a terminal (via RS232) to your C64 and have a second user online on your C64. - Dynamic memory management. (only internal memory, bank0) - A small kernal but multipurpose. (well i hope so :-) What for, why ?? ================ A real C64-freak always wants to do the impossible, thats one of the main reasons, why i started writing LUnix. Many peaople think, that UNIX (multitasking/multiuser) can only run on big workstations with lots of megabytes RAM and gigabytes of discspace. I want to have (a kind of) UNIX on my little C64, having only 64kbyte and a normal 171kbyte-1541floppy. My dream would be, that people agree with me, that this isn't only fun but also makes sense. 2. How to start LUnix : ======================= Get the archivefile "lunix01p3b.c64" into your C64 and run it. Its a self extracting archive. Start it like a normal basic-programm, it will then save all the lunix-files to device 8 of your C64 (e.g. your 1541-floppy). After all the files have been extracted, you can start LUnix by using the boot(-BASIC)-programm called "loader". load"lunix01p3b.c64",8 ... run then load"loader",8 ... run and follow the prompts. 3. Files comming with LUnix: ============================ Systemfiles ----------- loader o A BASIC programm that loads and starts LUnix. lunix.sys o The LUnix system core. bootdrv.drv o The bootdriver that the system will use to load the first command shell. init.exe o The screen manager (console) 3.1 Applications ---------------- sh0.exe - sh0.exe Invokes another (sub-) command shell. a1541 - a1541 Replaces the normal disc-driver by a IRQ-loader. You must enable this driver before accessing the RS232. (eg. before running "term9600"). cat * cat <file> Prints a file to stdout. cd * cd <directory> Changes the working directory. count - count Counts up from <000> to <255> and put the numbers to stdout. Just makes some noise :) disk * disk Prints the disk-status information to stdout. echo * echo <text> Prints text to stdout. hexconv - ... ! hexconv Converts decimal numbers from stdin to hex-numbers (stdout). Usable as a filter. E.g. "ps ! hexconv" the output of the first command will be used as input of the second command. kill - kill <pid> Kills a process. (PID=Process IDentification). You can get the PIDs by using the "ps"-command. ldb - ldb LUnix debugger. Details about its usage below. ls * ls [-l] Prints the disk-directory to stdout. man - man Prints a very little manual to stdout. mem - mem Prints a little statistic about the system-memory usage. memfree - memfree & Shows the amount of free memory in the right corner of the screen. You should start it this way: "memfree &" the command will run in the background and the shell won't wait till the execution is completed. mirror - ... ! mirror It will mirror lines from stdin and put them (mirrored) to the stdout. (should only be used in combination with "!"). more * ... ! more Pass stdin to stdout, asks for a key after printing 11 lines. net.drv - net.drv <NID> Enables access to a local C64/128 network. (NID=Network IDentification of the local computer). netstat - netstat Prints statistics about the C64/128 network. prim - prim <a>,<n> Prints n prime numbers beginning with a. ps - ps [-la] Prints a report about (-a -> "all") processes in the system. The option "-l" will make 'ps' do this in a more detailed way. reboot * reboot Causes a RESET of the computer. renice * renice [<PID>[,<pri>]] Prints/changes the priority of a process. rm * rm <file> Removes (deletes) a file. rsh - rsh <NID> Calls for a shell on an other computer (NID) in the C64/128-net. rshserv - rshserv [-v] & Shellserver, serves shells to other computers in the C64/128-net. (Up to 4 at a time) tee * tee <file> Writes stdin to a file. term9600 - term9600 [-v] & Terminalserver, serves shells to a terminal connected to the RS232. (uses a special userport- RS232-interface 9600Baud 8N1). Never forget to start "a1541" before starting the terminal- server !!! top - top Examines the system and print a sorted list of processes and their use of CPU time. SPACE will restart the examination, any other key ends top. wc - ... ! wc Counts chars, words and line from stdin and prints a report to stdout. write - write [-q] <PID> Writes a massage to an other shell (PID of that shell has to be specified). CTRL+D ends write. Remarks ------- o = file can't be used as a LUnix command. - = commands written by the author himself. * = commands written by Paul Gardner from australia. As you might have noticed, there are no (very) usefull applications. (exept ldb) Thats because i don't have that much fun writing applications than writing kernel-code :-) Usefull may be writing the directory into a file "ls ! tee filename" or calculating some primenumbers and write them into a file "prim 100,10 ! tee primenumers". Maybe you find it usefull to translate all decimals in a textfile into hexadecimals, this would be no problem "cat infile ! hexconv ! tee outfile". I plan to write a TCP/IP-stack for the next version of LUnix, that would be something quite usefull i think. 3.2 The command shell (sh0.exe) =============================== <command> will load and execute a command, wait till its done. <command> ! <command> { ! <command> } load all and execute them parallel, passing stdout of the first to stdin of the second command and so on, wait till the last command is done. ... & A "&" at the end of a command line lets the shell go on without waiting till the command line is done. exit or CTRL+d Ends a shell. ( CTRL+d is the EOF0"end of file" charakter, it also ends wc, write, hexconv,..) 3.3 The LUnix-net-driver : ========================== The net-driver lets you connect up to 6 C64/128 all running LUnix. It sends and receives datapackets. There can be several virtual connections between all stations of the net at the same time. The only service that is implemented yet, is a shell-serving process, it allows remote shells (up to 4 per computer). (The net-sytem supports up to 7 services). What do i need to run this net-driver ? --------------------------------------- - You should have at least one C64/128 (but you'll have much more fun, if there are more of them) - You need at least LUnix_v0.1p2 . and the following files : "net.drv","rshserv","rsh","netstat" you can get all of them (and even more) for free through the Internet (a list of addresses is appended to this file) - And you need a suitable cable ! (if you use more than 1 C64 :) You have to connect (at least) GND, PB0, PB1, PB2, PB3, PB6 (all from the C64's userport) of all C64 in the net, the software supports up to 6 C64 (or C128) in the net. *** if you have only one discdrive you'll need a switch to connect/ disconnect one of the pins to ground (eg. PB0). Use a little resistor (about 470-1000 Ohms) to connect the certain pin to ground. If the connection is switched 'ON' all the communication in the net is disabled. How to start it : ----------------- - First unplug all the computers and discdrives/monitors... - Then connect the userport-pins (you should try to connect each GND-pin first) *** only one discdrive: connect GND to the discdrive (!),to prevent damage when connecting/disconnecting it to one computer after the other later. - Now shitch them all on. - Load and start LUnix, press 'add a session' ,type "net.drv X" X is the ID of the station. This ID ranges from 1 to 6 (don't use the same ID twice !) Then enable logins from other computers to this computer by starting the remote-shell-server process by typing 'rshserv -v &' (-v is not neccessary). <-do this with every computer you have connected . Thats it ! The net is now active. How to use the net ------------------ You can use the net to execute shells on other (or the local) computer. Just type "rsh X" (X- is the ID of the destination computer) and you should get a 'remote shell' from that computer to work with :) The actual 'rshserv' process enables up to 4 remote-logins at a time (it doesn't matter from what computer you are calling) Type 'exit' to logout again. *** only one discdrive: You can use one of the computer to work as server (this will be the only computer with a discdrive later) You just have to start "rsh"s on the other computer in direction to the server. But how to do that, if there is only on discdrive available ? Thats what the mentioned shitch is for ! Switch 'ON' (and block all net actions), then connect the discdrive to one of the other computers and type "rsh Y" (Y is the servers ID) connect the drive to the next computer...and so on...then connect the discdrive to the 'server' and switch 'OFF' !...... 3.4 ldb - LUnix debugger version 1.0 ==================================== Available (commandline-) commands: b break Send character (ascii code 3) to debugged process. c continue Continue process (CTRL+s stopps it) d [[ mid: ] address ] disassemble Disassemble process-code (or any other memory address). With no argument d continues disassembling at the last position. Default for mid is the process' mid. Address is the relative address in the mid-memory area or, if no mid is given the address is relative/absolute/original to the process' startaddress (as defined by the used with the 'm'-command). f dev:filename file Load exacutable file for debugging. h [[ mid: ] address ] hexdump Print a hexdump, syntax like 'd' i info Print process information m[aro] mode ma absolute memory addresses mr relative memory addresses mo original memory addresses (display mode of disassembler) r [ args ] run Run a loaded process with 'args' as commandline parameters. s #signum signal Sends signal #signum to debugged process. t tick Lets the debugged process run for exactly one time slice. (or till there is a 'jsr$$9012' in the code, wich can be used like breakpoints for debugging) NOTE: ldb waits till the process is interrupted while running (if the process is blocked ldb will wait till it is unblocked again) examples: --------- @> ldb LUnix Debug Version 1.0 by Poldi 4.3.1996 ldb> f @:prim { load 'prim' } ldb> r 10000,10 { prim 10000,10 } ldb> i {info} pc=38:0046 sr=00 a=00 x=00 y=00 { mid:reladr ,status register,akku,x-register,y-register } stack 17 90 { $9018=suicide is the return-address, if there is a rts } zp 57 8d 38 35 30 3a 8e 00 59 2f 8d { zero page starting with address $57: ...10 bytes } ldb> d 38:46 { begin disassembling at pc=38:0046 taken from info } $c846 lda#$c8 $c848 jsr$$9051 $c84b jmp$$c991 $c84e rts $c84f lda#$00 $c851 sta$$59 $c853 sta$$5a $c855 sta$$5b $c857 sta$$5c $c859 ldii$57 ldb> mr { switch to relative-address-mode } ldb> h 0 { hexdump starting at relative addr. 0 } $0000 38 f5 fa fa 00 00 00 00 8UZZ.... $0008 00 46 00 00 00 00 00 00 .f...... $0010 00 00 00 00 00 00 00 00 ........ $0018 00 00 4c 1b 90 00 00 00 ..l..... $0020 00 00 00 00 00 00 00 00 ........ $0028 00 00 00 00 00 00 00 00 ........ $0030 00 00 00 00 00 00 00 00 ........ $0038 50 52 49 4d 00 00 00 00 prim.... { 'prim' CMD name in the file } $0040 17 27 00 00 80 00 a9 c8 .'....)h $0048 20 51 90 4c 91 39 60 a9 q.l.9@) ldb> f @:ldb { load 'ldb' } ldb> mo { switch to original address-mode } ldb> d { disassemble code } $7000 38 00 00 00 40 57 06 00 8...@w.. $7008 1c 40 00 00 00 00 00 00 .@...... $7010 00 00 00 00 00 00 00 00 ........ $7018 00 00 4c 48 70 4c 52 70 ..lhPlrP $7020 00 00 00 00 00 00 00 00 ........ $7028 00 00 00 00 00 00 00 00 ........ $7030 00 00 00 00 00 00 00 00 ........ $7038 4c 44 42 00 00 00 00 00 ldb..... $7040 lda#$70 $7042 jsr$$9051 ldb> d { continue disassembling } $7045 jmp$$79aa $7048 se i $7049 lda#$03 $704b ldx$$7001 $704e jsr$$902d $7051 rti $7052 jmp$$901b $7055 pjp$$70a2 $7058 30 31 32 33 34 35 36 37 01234567 $7060 38 39 41 42 43 44 45 46 89abcdef ldb> d { continue disassembling } $7068 01 04 07 0a 0d 10 13 16 ........ $7070 00 00 00 00 00 00 00 00 ........ $7078 00 00 00 00 00 00 00 00 ........ $7080 00 00 00 00 00 00 00 00 ........ $7088 00 00 00 00 00 00 00 00 ........ $7090 00 00 00 00 00 00 00 00 ........ $7098 00 00 00 00 00 00 00 00 ........ $70a0 00 00 .. $70a2 and#$3f $70a4 = $$70d2 ldb> d { continue disassembling } $70a6 cmp#$20 $70a8 bcs$$70ac $70aa ora#$40 $70ac jsr$$9069 $70af bcc$$70d2 $70b1 jsr$$70b7 $70b4 jmp$$901b $70b7 bit$$7071 $70ba bpl$$70d2 $70bc lda$$7075 ---------------------------------------- ldb> f @:prim { load file 'prim' } ldb> r 10000,10 { exec 'prim 10000,10' } ldb> i { info } pc=2d:0046 sr=00 a=00 x=00 y=00 stack 17 90 zp 57 38 a9 20 20 ac 38 a6 57 e8 86 ldb> t { let prim run for one tick } ldb> i { print info agin } pc=2d:0170 sr=23 a=00 x=00 y=04 stack 3d 2f 17 90 zp 57 0a 00 d0 01 00 00 01 01 00 00 ldb> t ldb> i pc=2d:0154 sr=23 a=00 x=00 y=07 stack 3d 2f 17 90 zp 57 0a 00 80 03 00 00 13 04 00 00 ldb> t ldb> i pc=2d:0158 sr=23 a=00 x=00 y=02 stack 3d 2f 17 90 zp 57 0a 00 e4 00 00 00 af 01 00 00 ldb> t ldb> i pc=2d:014b sr=22 a=ff x=00 y=0e stack 3d 2f 17 90 zp 57 0a 00 00 40 1c 00 17 27 00 00 ldb> t 10007 { a prime number calculated by prim after 5 ticks } ldb> i pc=2d:017b sr=21 a=00 x=09 y=04 stack 3d 2f 17 90 zp 57 09 00 60 02 00 00 79 01 00 00 ldb> s s #signum (1..16) sends signal to process ldb> s 7 { send signal 7 'killed parent' } process doesn't support this signal ldb> s 6 { send signal 6 'user break' } ldb> t { another tick.. } Process died { process caught the signal and ended } ldb> i No file loaded ldb> x { exit from ldb .. back to shell } @> disassembler notes: ------------------- The assemblersytax may look strange to you, because it is based on an old assembler i wrote (it was easier to use it's disass-tables as writing some new, wich i may do somewhen in future). lda#$12 --- parameter #12 is decimal, $12 hex, "a ascii, <label a label the parameter may be preceeded by a l (low byte) or h (high byte) eg. lda#l$1234 is the same as lda#$34 and lda#h$1234 like lda#$12. --- the first 3 chars define the command (like lda,sta,inc,and,...) - the fourth char defines the addess-mode # immediate $ adr x adr,x y adr,y ii (adr),y (third and fourth char 'i') ix (adr,x) some examples: lda#$23 is lda #$23 lda$$23 is lda $23 lda$$1234 is lda $1234 ldii$a2 is lda ($a2),y ldax$c000 is lda $c000,x adcx$c080 is adc $c080,x + ii$bf is adc ($bf),y = $$1234 is beq $1234 <> $$1234 is bne $1234 pjp$$1234 is byte $0c; word $1234 jsr$$9012 is jsr $9012 4. Where can i get the lastest version of LUnix and/or updates, patches ? ========================================================================= WWW: LUnix-homepage http://wwwcip.rus.uni-stuttgart.de/~etk10217/c64.html or http://wwwcip.rus.uni-stuttgart.de/~etk10217/lunix.html There also is additional information about the kernel-structure. FTP: ftp://ftp.uni-hildesheim.de/pub/... ftp://ftp.giga.or.at/pub/c64/... If you need support, or have some questions/remarks/suggestions write an email to me. eMail: Daniel.Dallmann(a)studbox.uni-stuttgart.de 5. Can i write my own applications ? ==================================== Of course you can ! But you have to take care of some simple rules. A LUnix-application must have a special header, must be relocatable by the system and mustn't access memory/hardware that may be used by other applications or by the system. (Applications may access hardware-directly because the kernel doesn't provide the neccesary routines yet) Details on how to write applications can be found on my WWW-page. If you want to use an other machine (linux/UNIX/amiga) for development, you can use some tools i've written to help writing LUnix-applications. there is luna: a 6502/10 cross-assembler lupo: a preprocessor for assembler sources lld: a linker for objectfiles created by luna All you need is a C-compiler (i used the GNU-C-Compiler "gcc") to built the executables. (Thanks to Stefan Haubenthal there is a compiled version for AMIGA). Everyone, who wants to do something for LUnix is welcomned and will get all information needed (just contact me). If you already played around with LUnix and wrote some little applications *please* send them to me, i'll include them into the patchlevel 3c release. In fact LUnix0.1 is quite limited, thats why i'm working on a new version. But it won't be released before 1997 (i'm not that far). If someone likes to have more information on the next release, or better has some suggestions, look at my WWW-page or write an (e)Mail. ...and, don't forget: HAVE FUN !! --- snip from README ---