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

From	"Rod Pemberton" <boo@fasdfrewar.cdm>
Newsgroups	alt.os.development
Subject	Re: What form of executable or load module for your OS?
Date	2015-07-03 16:54 -0400
Organization	Aioe.org NNTP Server
Message-ID	<op.x07tovymyfako5@localhost> (permalink)
References	(4 earlier) <mn3749$3nl$1@dont-email.me> <75acded2-9f64-4d9f-81c2-7ec73fd72e01@googlegroups.com> <mn5dto$q6c$1@dont-email.me> <1687b850-3c16-44ec-9bd9-4eb0dc2a201b@googlegroups.com> <mn5o0b$uv1$1@dont-email.me>

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On Fri, 03 Jul 2015 06:27:42 -0400, James Harris  
<james.harris.1@gmail.com> wrote:
> "Alexei A. Frounze" <alexfrunews@gmail.com> wrote in message  
> news:1687b850-3c16-44ec-9bd9-4eb0dc2a201b@googlegroups.com...
>> On Friday, July 3, 2015 at 12:35:41 AM UTC-7, James Harris wrote:
>>> "Alexei A. Frounze" <...@gmail.com> wrote in message
>>> news:75acded2-9f64-4d9f-81c2-7ec73fd72e01@googlegroups.com...
>>> > On Thursday, July 2, 2015 at 4:27:25 AM UTC-7, James Harris wrote:

>>> I wish. AIUI yours won't generate 8086 code but assumes a later CPU.
>>
>> True. But how much code do you need to be 8086-only? I bet, for anything
>> practical you too would need at least a 80386. So, is it then only the
>> part that ensures that the CPU is at least a 80386 and prints an error
>> message if it's not?
>
> No, far from it. I wouldn't expect to do video editing(!) with 8086 code
> but I found that it can do a lot more than people think: multitasking
> OS, device drivers, hardware control/interaction, memory management etc.
> An 8086 OS would be very suitable for interacting with hardware such as
> in a lab environment. And if I ever write a boot manager (which I have
> been thinking of for a while) I would choose to use 8086 code simply
> because it is so portable. Nothing more is needed. The areas where 8086
> code falls down are those that require protection or lots of memory but
> 600k can be quite a lot for an OS and many apps.
>
> Much of the OS C code I have written so far can compile both to 8086
> code and to 80386 code, and run just as well in real mode as in
> protected mode, so it's not as if the time spent producing 8086 code
> will only work in that environment.

IIRC, Alexei said SmallerC can emit NASM.  If so, you only need add
a NASM directive to the assembly, i.e., CPU 8086, to have NASM tell
you which instructions are incorrect for 8086.  If the C code is
minimal, e.g., bootloader or bootsector, then it's not really that
much assembly to rework by hand.  Or, you could do like Ben and
customize SmallerC.  I.e., you could adjust the assembly selection
code of SmallerC to not use 386 or later instructions.  Just how
many more advanced x86 instructions could Alexei really use? ...
The basic x86 instructions were set before the 386.


Rod Pemberton

-- 
Tolerance and socialism attracts intolerance and terrorism.  See:
France, United Kingdom, Germany, Denmark, Belgium, Netherlands, ...

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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