Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!ames!killer!dono
From: dono@killer.Dallas.TX.US (Don OConnell)
Newsgroups: comp.os.minix
Subject: Re: Cross compiling under Turbo C
Keywords: turboc->minix general rules
Message-ID: <7632@killer.Dallas.TX.US>
Date: 24 Mar 89 18:10:29 GMT
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 111



This describes the general changes needed to compile MINIX under the Turbo C
1.5 compiler, with the Microsoft assembler. I have used TC15 and Masm to go
from v1.1 to 1.4+, and haven't had many problems in compiling. An added
advantage is 1/2 to 3/4 savings in compilation time.  The executables tend
to be smaller, also.

1.  Make a complete copy of your current Minix system.

2.  Create subdirectory's like these (dos side):

        turboc                      ----    Main TURBO C directory
            minix                   ----    Sources Main directory
                commands            ----    Source directories
                commands\mined      ----
                commands\sh         ----
                fs                  ----
                kernel              ----
                lib                 ----
                mlib                ----
                mm                  ----
                tools               ----

3.  Boot Minix and use the doswrite program to copy the sources to
    DOS-formatted disks (NOTE * below). The compiler-specific modules
    are stored in subdirectories like MINIX, PCIX and C86; use the ones
    for the C86 compiler and modify them appropriately.  After this,
    reboot under DOS and copy the files to your Minix-directory.

    * If you have cpio or a compatible tar and compress/uncompress/zcat
      that runs under Minix and Dos use it, it takes less disks to
      transfer files. *

4.  You're now ready to build the Minix library; when Turbo C does long
    arithmetic, it uses a number of library routines that are unique to
    Turbo C and therefore not included in the Minix library. These
    modules will have to be retrieved from the CS.LIB that came with
    your Turbo C compiler.

    Using a librarian, extract the following modules from CS.LIB;

      ldiv.obj   lrsh.obj   lxmul.obj   spush.obj   scopy.obj

    Next step is compiling the files in the LIB-directory.

    * Use these files:
        prologue.h              --  needed by .asm files
        getutil.asm, catchsig.asm, portio.asm, sendrec.asm, setjmp.asm
      These are executable headers:
        crtso.asm, head.asm     --  See * below
      You won't need these files under TC:
        brksize.asm, end.asm    --  incorporated into crtso/head
        csv.asm                 --  not used
        diskio.asm              --  Turbo has functions to do this

    Using a librarian make the library. The order that I use for my
    v14a lib, along with most of the assembler needed files, have been
    previously posted

    * Head.obj and crtso.obj do not go in the lib. They are linked in
      from the command line. The head/crtso module, that I use are
      modified from the turbo c file - c0.asm. As a result of this, I
      compile in tiny model, but head/crtso are written in such a way,
      that split I/D programs are created automatically. *

5.  Having created the library, you can proceed and compile FS, MM and
    the KERNEL by going to their respective directories and compiling
    the sources. The klib88.s and mpx88.s will have to be converted to
    masm syntax.


6.  Next items are the files in the TOOLS directory; to write a
    boot-disk you'll need to compile DOS2OUT, BUILD, INIT and FSCK.

        FSCK1.s will have to be converted to masm syntax.

        Bootblok.s will also have to be converted to masm syntax. I use
        an ega monitor, and added code to mine to set the pallette
        colors(yellow on blue), and put the monitor in 43 line mode).

    * Dos2out and build are files that have to be compiled with the
      standard turbo c libraries and run as .exe files on the dos
      side.  *

    ** To create a boot disk use a freshly formatted disk

    To create file-systems for Minix from DOS, you'll need MKFS; it's in
    the COMMANDS directory. Just copy it to the TOOLS dir and compile it.

**  BEWARE:  Any program containing setjmp() and longjmp() *MUST* be
    compiled with the -r- option (note: that's "-r-" !) as Turbo C
    doesn't store it's register variables into memory before a
    setjmp()/longjmp(). This is a documented "feature" of the standard
    Turbo C library version of setjmp() so you can use it to implement a
    kind of task-switches (co-routines).

    In the part of the book concerned with using DOS as a development
    system for Minix, AST mentions the routines csv and cret. So far, I
    have used Turbo C with stack-overflow testing OFF so I haven't
    needed them. In case you would like to do this sort of checking, all
    you have to do is write a replacement for the OVERFLOW@ routine that
    is called just after the routine is entered. You cannot use the
    Turbo C version since it does a direct DOS call if my information
    correct. You can however use that version as a basis for further
    development; best thing to do is to compile a short program with
    Stack Overflow Test ON and Map File ON and then use SYMDEB or
    something like that to peek at the code generated.


Don O'Connell       Mar. 23, 1988               killer!dono