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Re: What form of executable or load module for your OS?

Newsgroups alt.os.development
Date 2015-07-05 02:58 -0700
References (13 earlier) <op.x08ojxp5yfako5@localhost> <853c70d5-5652-42e9-ac0f-e4b832b56ca3@googlegroups.com> <op.x1ad7uijyfako5@localhost> <a4f7d2ad-2109-4cf9-ac92-fc660efbdeed@googlegroups.com> <op.x1am9mo9yfako5@localhost>
Message-ID <1399541c-e62d-4a64-9f68-011365509d53@googlegroups.com> (permalink)
Subject Re: What form of executable or load module for your OS?
From "Alexei A. Frounze" <alexfrunews@gmail.com>

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On Sunday, July 5, 2015 at 2:28:21 AM UTC-7, Rod Pemberton wrote:
> On Sun, 05 Jul 2015 03:47:12 -0400, Alexei A. Frounze
> <...@gmail.com> wrote:
...
> > ----8<----
> > ; file: br.asm
> > ; compile (with nasm 2.10): nasm -f bin br.asm -o br.com
> > ; decompile: ndisasm -b 16 -o 0x100 br.com
> > CPU 8086
> > org 0x100
> > bits 16
> >
> > jz lab
> > times 256 nop
> > lab:
> > ret
> > ----8<----
> > Assembles without errors.
> >
> > Disassembly:
> > ----8<----
> > 00000100  7503              jnz 0x105
> > 00000102  E90001            jmp word 0x205
> > 00000105  90                nop
> > 00000106  90                nop
> > 00000107  90                nop
> > 00000108  90                nop
> > ...
> > 00000200  90                nop
> > 00000201  90                nop
> > 00000202  90                nop
> > 00000203  90                nop
> > 00000204  90                nop
> > 00000205  C3                ret
> > ----8<----
> >
> > So, NASM 2.10 (or maybe all the way back to 2.03) is doing just fine.
> 
> Are you saying NASM actually compiles that for the 8086 source?

Yes, as you can see. :)

> It clearly  DID NOT  do what it was told to do ...  Bad assembler!

GOOD assembler! Here, have a treat! :)

> So, that's rather surprising to me, since NASM is so "pedantic".
> 
> Let's check:
> 
> yes 2.09.04 64-bit Linux
> yes 2.06rc8 to 2.10.01 32-bit DOS (5 versions)
> no  0.98.39 32-bit DOS
> 
> The classic 0.98.39 version of NASM reports an error on line 5:
> "... error short jump is out of range"
> 
> James was concerned with Jcc with an offset greater than 8-bits
> for 8086 code.  The 8086 only supported the 8-bit offset for Jcc
> instruction.  So, as long as James doesn't need compatibility
> with NASM 0.98.39 or some other older intermediate version, he's
> all set.  NASM does what I suggested as a fix for short branches,
> for the more recent versions.

We just learned a new thing. Made a discovery. In something we use
often. :) I guess, the fireworks were quite appropriate. :)

Alex

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Thread

Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-06-25 21:20 -0700
  Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-01 10:36 +0100
    Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-01 21:07 -0700
      Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-02 23:35 -0700
        Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-03 08:35 +0100
          Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-03 02:49 -0700
            Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-03 11:27 +0100
              Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-03 16:54 -0400
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-03 22:45 +0100
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-03 17:56 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-03 15:28 -0700
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-03 23:48 +0100
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-03 21:52 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-04 04:00 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-04 04:42 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-05 02:12 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-05 00:47 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-05 05:28 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-05 02:58 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-06 06:21 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-07 01:44 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-07 05:40 -0400
                Re: What form of executable or load module for your OS? "Kerr Mudd-John" <admin@127.0.0.1> - 2015-07-07 14:02 +0100
                Re: What form of executable or load module for your OS? "wolfgang kern" <nowhere@never.at> - 2015-07-07 18:13 +0200
                Re: What form of executable or load module for your OS? "Kerr Mudd-John" <notsaying@invalid.org> - 2015-07-08 12:54 -0100
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-09 13:19 +0100
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-07 22:10 -0700
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-08 08:48 +0100
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-08 23:53 -0700
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-09 17:29 +0100
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-10 01:01 -0700
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-10 13:46 +0100
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-10 00:59 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-08 03:52 -0400
                Re: What form of executable or load module for your OS? "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-08 06:46 -0700
                Re: What form of executable or load module for your OS? "James Harris" <james.harris.1@gmail.com> - 2015-07-09 13:16 +0100
                Re: What form of executable or load module for your OS? "s_dubrovich@yahoo.com" <s_dubrovich@yahoo.com> - 2015-07-11 09:57 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-13 02:47 -0400
                Re: What form of executable or load module for your OS? "s_dubrovich@yahoo.com" <s_dubrovich@yahoo.com> - 2015-07-14 07:39 -0700
                Re: What form of executable or load module for your OS? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-15 02:37 -0400
        Code insanity "Mike Gonta" <mikegonta@gmail.com> - 2015-07-03 03:47 -0400
          Re: Code insanity "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-07-03 02:57 -0700
          Re: Code insanity (was: What form of executable or load module for your OS?) "James Harris" <james.harris.1@gmail.com> - 2015-07-03 11:35 +0100

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