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[OpenWatcom] building a COM file without pulling in the Watcom standard library

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Hello all,

I am experimenting with OpenWatcom, trying to compile a simple C
file into a COM executable. The tricky part is that I'd like to avoid
pulling in watcom's standard library and startup code in the process.

I have such TEST.C file:

void main(void) {
  static char *hello = "Hello$";
  _asm {
    mov ah, 9
    mov dx, hello
    int 0x21
  }
}

I compile it into an object and pass to wlink using these commands:

wcc -0 -ms -od -s -d0 -zl -zls test.c
wlink @TEST.LNK

I filled TEST.LNK with the following directives:

FORMAT DOS COM
FILE test.obj
OPTION NODEFAULTLIBS
NAME TEST.COM
OPTION START=main_

I do get "something" out of this, but the binary file does not work
properly. The disassembled COM looks like that:

00000000  53                push bx
00000001  51                push cx
00000002  52                push dx
00000003  56                push si
00000004  57                push di
00000005  B409              mov ah,0x9
00000007  8B160C00          mov dx,[0xc]    <-- this should be 0x11C
0000000B  CD21              int 0x21
0000000D  5F                pop di
0000000E  5E                pop si
0000000F  5A                pop dx
00000010  59                pop cx
00000011  5B                pop bx
00000012  C3                ret
00000013  004865            add [bx+si+0x65],cl
00000016  6C                insb
00000017  6C                insb
00000018  6F                outsw
00000019  2400              and al,0x0
0000001B  0004              add [si],al   <-- this should be 0x114
0000001D  00                db 0x00

It appears that the COM file is not being originated at offset 0x100,
despite the "FORMAT DOS COM" wlink directive. It's also not
0-originated, so I am not sure how the offsets are calculated exactly.
Once I fix them with a hex editor, the executable works.

What am I missing here?

Mateusz

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[OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-07-31 17:28 +0200
  Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library JJ <jj4public@outlook.com> - 2023-08-01 18:38 +0700
    Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-01 14:50 +0200
      Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library T. Ment <t.ment@protocol.invalid> - 2023-08-01 15:23 +0100
  Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "Alexei A. Frounze" <alexfrunews@gmail.com> - 2023-08-02 20:28 -0700
    Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-03 10:21 +0200
      Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "Alexei A. Frounze" <alexfrunews@gmail.com> - 2023-08-03 19:41 -0700
        Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-04 14:03 +0200
  Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "R.Wieser" <address@is.invalid> - 2023-08-03 10:39 +0200
    Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-03 12:07 +0200
      Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "R.Wieser" <address@is.invalid> - 2023-08-03 14:35 +0200
      Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "R.Wieser" <address@is.invalid> - 2023-08-04 08:31 +0200
        Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-04 14:03 +0200
          Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "R.Wieser" <address@is.invalid> - 2023-08-04 16:29 +0200
            Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-04 16:56 +0200
              Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library "R.Wieser" <address@is.invalid> - 2023-08-04 19:02 +0200
                Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-08-04 21:18 +0200
  Re: [OpenWatcom] building a COM file without pulling in the Watcom standard library Mateusz Viste <mateusz@x.invalid> - 2023-11-10 00:19 +0100

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