I have written a small 16-bit assembly program that writes some values in some memory locations.Is there a way I can test it in 32-bit protected mode on Linux?
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Ciro Santilli Путлер Капут 六四事
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vjain27
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2what instruction set architecture? avr? msp430? 8088? 8086? thumb? 16 bit mips?... – old_timer Oct 20 '11 at 00:52
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8086. I was trying to write real mode code.It contains only some movw statements. – vjain27 Oct 20 '11 at 16:48
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ad pcemu to the list that Yahn provided. – old_timer Oct 20 '11 at 17:17
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Yann Ramin
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Concrete examples: https://stackoverflow.com/questions/22054578/how-to-run-a-program-without-an-operating-system/32483545#32483545 – Ciro Santilli Путлер Капут 六四事 May 07 '18 at 09:29
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Yes, 16-bit code is supported in user processes in Linux. The system call to do it is called vm86() (there's a man page, but there's not much in it). It is, naturally, only works on x86 platforms (and 32-bit only).
If you want an example, the ELKS project has a complete tool for running ELKS 8086 binaries on Linux, which uses it:
https://github.com/lkundrak/dev86/tree/master/elksemu
Look for the run_elks() function. It's pretty straightforward.
David Given
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3@CiroSantilli包子露宪六四事件法轮功 v86 mode isn't supported inside x86-64 native mode. To implement this syscall, Linux would have to switch to 32-bit mode, only then to v86, which would be too much of an overhead for small benefit. But then, there's a [V86-64](http://v86-64.sourceforge.net/) patch (last updated in 2008). – Ruslan May 08 '18 at 13:40