Messages in this thread | | | From | Ondrej Zary <> | Subject | Re: [PATCH v3] x86: add NOPL and CMOV emulation | Date | Sun, 27 Jun 2021 21:20:06 +0200 |
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On Saturday 26 June 2021 15:03:14 Marcos Del Sol Vives wrote: > NOPL and CMOV are a set of instructions that were introduced to the > x86 architecture with the i686 ISA in 1995, first implemented in the > Intel Pentium Pro and Pentium II processors. > > While virtually all desktop and server systems are modern enough to > support these instructions, in the embedded market things are a little > bit different: DM&P is still manufacturing their i586-only Vortex86 > SoCs, and many embedded devices still in use are stuck on legacy SoCs > that either are i586-only (AMD Elan, AMD Geode GX1) or implement i686 > but lack the NOPL instructions (Transmeta devices, AMD Geode LX). > > This is a problem because most modern Linux distributions, such as > Debian and all its derivatives, have started compiling targeting i686, > leaving old embedded devices using binary distributions without an > easy upgrade path. > > This ultimately results in most of these embedded devices running > years old, insecure and obsolete installations, and this itself can be > seen on the DM&P's own supported OS page where the newest supported > desktop Linux distro is Ubuntu 18.04, already three years old. > > The emulation of these instructions thus allow upgrading to newer > distributions just by replacing the kernel, keeping all precompiled > binaries intact.
Great, this would allow me to update my old Pentium 133 box from unsupported Debian 8 to 9, 10 and even the upcoming 11.
-- Ondrej Zary
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