Date: Tue, 13 Jan 2026 22:33:35 +0000 From: Javi Hotmail <volkovdablo@hotmail.com> To: ppc@freebsd.org, Timothy Pearson <tpearson@raptorengineering.com>, Lexi Winter <ivy@freebsd.org> Cc: freebsd-ppc <freebsd-ppc@freebsd.org> Subject: Re: 2026 TODO list! Message-ID: <PA4P191MB1663103CA24D73BBED475BC6AC8EA@PA4P191MB1663.EURP191.PROD.OUTLOOK.COM> In-Reply-To: <347736550.201698.1768339625331.JavaMail.zimbra@raptorengineeringinc.com> References: <CAJ-VmonYHdVhdPiaLHUqzPv33_iAGiTY=_hGrhg4rXF5%2BYZPQQ@mail.gmail.com> <aWYThFQ8ODI9P0ml@amaryllis.le-fay.org> <347736550.201698.1768339625331.JavaMail.zimbra@raptorengineeringinc.com>
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[-- Attachment #1 --] Nice to meet you all!, I would like to join the team to maintain PPC/PPC64 for development and testing. The good: I have a G5 Quad, an XServe G5, and a Dual G4 @ 500, so I think I have a "decent" coverage surface. The bad: Aside from the G4, both G5s need maintenance before I can keep them running for hours, I'm on top of that, but it's gonna take a while. The ugly: I have development (kernel / userspace) experience on Linux, but on FBSD I'm mostly relegated to userspace at the moment. I want to change that; I'd like to have robust knowledge for kernel and driver development on FBSD for PPC/x86. That's why I am here. Questions: - What is the best technique for kernel debugging on FBSD? (please don't say printf :D). Does remote GDB over serial work? I've read about KDBG but I'm not sure which approach is better. - Has anybody tested on QEmu some sort of paravirtualization running on G4/G5, so we don't need to go baremetal all the time when doing kernel development? Sorry for the long email! Kind Regards, Javi. On January 13, 2026 9:27:05 PM UTC, Timothy Pearson <tpearson@raptorengineering.com> wrote: > > >----- Original Message ----- >> From: "Lexi Winter" <ivy@freebsd.org> >> To: "freebsd-ppc" <freebsd-ppc@freebsd.org> >> Sent: Tuesday, January 13, 2026 3:42:28 AM >> Subject: Re: 2026 TODO list! > >> Adrian Chadd wrote in >> <CAJ-VmonYHdVhdPiaLHUqzPv33_iAGiTY=_hGrhg4rXF5+YZPQQ@mail.gmail.com>: >>> I'd like to assemble a 2026 TODO list for PPC64 work. Justin, Ivy, >>> Warner, I and and others have been poking at the sharp edges and >>> trying to use/abuse various PPC64 hardware and VMs. >>> >>> I'd appreciate some brainstorming from y'all about what you'd like to >>> see fixed, implemented and working. >> >> i've been meaning to look at making lldb work on powerpc64le for both >> kernel and userland debugging. this looks like it should be pretty >> simple, since it already supports FreeBSD/ppc64 and Linux/ppc64le, >> so it's just a matter of combining the two. >> >> i've been busy with non-FreeBSD stuff recently but i'm hoping i can >> look at this soon. >> >> Raptor has kindly given me access to a Talos II so i can do dev work >> and also test patches there if needed. >> >> a couple of other things i think are important: >> >> - non-OpenFirmware ppc64le loader - i see a couple of people have >> already mentioned this. >> >> - SMP performance is quite bad; this 44-core SMT4 Talos II runs >> buildworld at the same speed as my 8-core 2.6GHz Xeon system. >> i mentioned this to Justin and he suspects this could be from >> locking issues in vm/pmap. > >After digging around in the PCI driver for the past month, I think we're also not getting DMA enabled on potentially *any* PCI devices. It looks like the DMA tag was removed for PHB4 (POWER9) support, but it might have worked on PHB3 (POWER8). Once I finish fixing the rest of the PE 1:1 mapping mess I'll start looking at that and see if we can't get DMA reenabled -- no DMA would definitely explain poor performance on disk intensive activity... > [-- Attachment #2 --] <html><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body><div dir="auto">Nice to meet you all!,<br>I would like to join the team to maintain PPC/PPC64 for development and testing.<br><br>The good:<br>I have a G5 Quad, an XServe G5, and a Dual G4 @ 500, so I think I have a "decent" coverage surface.<br><br>The bad:<br>Aside from the G4, both G5s need maintenance before I can keep them running for hours, I'm on top of that, but it's gonna take a while.<br><br>The ugly:<br>I have development (kernel / userspace) experience on Linux, but on FBSD I'm mostly relegated to userspace at the moment.<br><br>I want to change that; I'd like to have robust knowledge for kernel and driver development on FBSD for PPC/x86. That's why I am here.<br><br>Questions:<br>- What is the best technique for kernel debugging on FBSD? (please don't say printf :D). Does remote GDB over serial work? I've read about KDBG but I'm not sure which approach is better.<br><br>- Has anybody tested on QEmu some sort of paravirtualization running on G4/G5, so we don't need to go baremetal all the time when doing kernel development?<br><br>Sorry for the long email!<br><br>Kind Regards,<br>Javi.<br><br><br><br></div><br><br><div class="gmail_quote"><div dir="auto">On January 13, 2026 9:27:05 PM UTC, Timothy Pearson <tpearson@raptorengineering.com> wrote:</div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <pre class="k9mail"><div dir="auto"><br><br>----- Original Message -----<br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"><div dir="auto">From: "Lexi Winter" <ivy@freebsd.org><br>To: "freebsd-ppc" <freebsd-ppc@freebsd.org><br>Sent: Tuesday, January 13, 2026 3:42:28 AM<br>Subject: Re: 2026 TODO list!<br></div></blockquote><div dir="auto"><br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"><div dir="auto">Adrian Chadd wrote in<br><CAJ-VmonYHdVhdPiaLHUqzPv33_iAGiTY=_hGrhg4rXF5+YZPQQ@mail.gmail.com>:<br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ad7fa8; padding-left: 1ex;"><div dir="auto">I'd like to assemble a 2026 TODO list for PPC64 work. Justin, Ivy,<br>Warner, I and and others have been poking at the sharp edges and<br>trying to use/abuse various PPC64 hardware and VMs.<br><br>I'd appreciate some brainstorming from y'all about what you'd like to<br>see fixed, implemented and working.<br></div></blockquote><div dir="auto"><br>i've been meaning to look at making lldb work on powerpc64le for both<br>kernel and userland debugging. this looks like it should be pretty<br>simple, since it already supports FreeBSD/ppc64 and Linux/ppc64le,<br>so it's just a matter of combining the two.<br><br>i've been busy with non-FreeBSD stuff recently but i'm hoping i can<br>look at this soon.<br><br>Raptor has kindly given me access to a Talos II so i can do dev work<br>and also test patches there if needed.<br><br>a couple of other things i think are important:<br><br>- non-OpenFirmware ppc64le loader - i see a couple of people have<br> already mentioned this.<br><br>- SMP performance is quite bad; this 44-core SMT4 Talos II runs<br> buildworld at the same speed as my 8-core 2.6GHz Xeon system.<br> i mentioned this to Justin and he suspects this could be from<br> locking issues in vm/pmap.<br></div></blockquote><div dir="auto"><br>After digging around in the PCI driver for the past month, I think we're also not getting DMA enabled on potentially *any* PCI devices. It looks like the DMA tag was removed for PHB4 (POWER9) support, but it might have worked on PHB3 (POWER8). Once I finish fixing the rest of the PE 1:1 mapping mess I'll start looking at that and see if we can't get DMA reenabled -- no DMA would definitely explain poor performance on disk intensive activity...<br><br></div></pre></blockquote></div></body></html>home | help
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