Date: Mon, 1 Dec 2025 10:57:25 -0600 (CST) From: Timothy Pearson <tpearson@raptorengineering.com> To: Piotr Kubaj <pkubaj@freebsd.org> Cc: Al <al@datazap.net>, Poul-Henning Kamp <phk@phk.freebsd.dk>, Minsoo Choo <minsoochoo0122@proton.me>, Warner Losh <imp@bsdimp.com>, "freebsd-arch@freebsd.org" <arch@freebsd.org>, freebsd-ppc <freebsd-ppc@freebsd.org> Subject: Re: What's the plan for powerpc64 in FreeBSD 16 Message-ID: <526620325.132622.1764608245446.JavaMail.zimbra@raptorengineeringinc.com> In-Reply-To: <aSrV3LKupuDGBtEk@talos-powerpc64le> References: <CANCZdfrQthqYeGYD_9LRcH94JJZuF2%2BUxAqf7Lcoe6p5VzJf9g@mail.gmail.com> <NqfDArT7jTPoIyfcShDccomNhLR9YUp1_S6kjK_NKIaiQVy2QK4n2KdbZIKm9gqda9fLP62MYQA-N5KOkECydNd1ktiUUuepzOVwCX8thgY=@proton.me> <202511261707.5AQH7N1u016543@critter.freebsd.dk> <Pine.NEB.4.64.2511261539520.27486@agnus.datazap.net> <aSdqppYvg5bWwuy6@talos-powerpc64le> <529626383.127814.1764191318804.JavaMail.zimbra@raptorengineeringinc.com> <aSrV3LKupuDGBtEk@talos-powerpc64le>
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----- Original Message ----- > From: "Piotr Kubaj" <pkubaj@freebsd.org> > To: "Timothy Pearson" <tpearson@raptorengineering.com> > Cc: "Al" <al@datazap.net>, "Poul-Henning Kamp" <phk@phk.freebsd.dk>, "Minsoo Choo" <minsoochoo0122@proton.me>, "Warner > Losh" <imp@bsdimp.com>, "freebsd-arch@freebsd.org" <arch@freebsd.org>, "freebsd-ppc" <freebsd-ppc@freebsd.org> > Sent: Saturday, November 29, 2025 5:15:40 AM > Subject: Re: What's the plan for powerpc64 in FreeBSD 16 > On 25-11-26 15:08:38, Timothy Pearson wrote: >> >> >> ----- Original Message ----- >> > From: "Piotr Kubaj" <pkubaj@freebsd.org> >> > To: "Al" <al@datazap.net> >> > Cc: "Poul-Henning Kamp" <phk@phk.freebsd.dk>, "Minsoo Choo" >> > <minsoochoo0122@proton.me>, "Warner Losh" <imp@bsdimp.com>, >> > "freebsd-arch@freebsd.org" <arch@freebsd.org>, "freebsd-ppc" >> > <freebsd-ppc@freebsd.org> >> > Sent: Wednesday, November 26, 2025 3:01:26 PM >> > Subject: Re: What's the plan for powerpc64 in FreeBSD 16 >> >> > On 25-11-26 15:47:38, Al wrote: >> >> >> >> On Wed, 26 Nov 2025, Poul-Henning Kamp wrote: >> >> >> >> > Date: Wed, 26 Nov 2025 17:07:23 +0000 >> >> > From: Poul-Henning Kamp <phk@phk.freebsd.dk> >> >> > To: Minsoo Choo <minsoochoo0122@proton.me> >> >> > Cc: Warner Losh <imp@bsdimp.com>, >> >> > "freebsd-arch@freebsd.org" <arch@freebsd.org> >> >> > Subject: Re: What's the plan for powerpc64 in FreeBSD 16 >> >> > >> >> > Minsoo Choo writes: >> >> > >> >> >> After reading replies, I still have questions why we should keep powerpc64be. >> >> > >> >> >> Second, regarding arguments about keeping big-endian support in codebase even >> >> >> if no one actually physically runs the code: >> >> >> This also applies to leaving 32-bit code (armv7) in tree for future >> >> >> compatibility. >> >> > >> >> > I think that is a bit of a leap, although in principle I agree. >> >> > >> >> > However, I am much less convinced that a relevant new 32 bit platform >> >> > will appear, than that somebody comes out with a 64 BE platform. >> >> > >> >> > Bit-rot is a thing, and unless we are willing to say "Screw anybody >> >> > silly enough to create BE platform now or in the future" we should >> >> > still guard against it. >> >> >> >> There is a number of new PowerPC 64 BE systems: >> >> A1222 >> > BE, but not 64-bit. It's supported via powerpcspe port on FreeBSD, which >> > is already deprecated along with powerpc. >> >> Sam460 several versions >> > I'm not sure about that, I think it's also 32-bit. >> >> Mirari (New PPC hardware) >> > This one will be ugly, similarly to e5500. e5500 is 64-bit, but without >> > Altivec, so it's below the usual baseline. Mirari will use e6500. e6500 >> > supports BE with Altivec. It also supports LE, but without VSX. The >> > current baseline for LE is POWER8, which supports VSX. >> > e5500 works on FreeBSD, but requires building everything on your own, >> > along with the OS itself, by using CPUTYPE?=e5500 in make.conf, >> > otherwise Altivec instructions will be issued by clang. If we ever get >> > binary packages on powerpc64, e5500 users will still need to build their >> > own because of that. >> >> If that's correct, then ABIv2 would be broken in LE mode, making LE mode even >> less useful on that hardware. I really don't want to be forced to keep the >> early ABI support around just for quite old, fairly quirky cores. > > Why? ELFv2 itself works fine without VSX, e.g. on G5 and e5500, on BE. > Why would running on LE specifically require VSX if the binaries are > built without VSX? ABIv2 requires the use of VSX registers for argument passing. It's possible this still works at a hardware level on these devices, or that we simply haven't hit the spill level where they are needed for most (all?) function calls in practice. Regardless, it's a point of concern for legacy, non-OpenPOWER compliant hardware.help
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