| RISC-V Port Merged to Linux | Palmer Dabbelt | 15/11/17 11:51 | The RISC-V port was just merged to Linux a few minutes ago. This means we will
be in the 4.15 release, which should be out about 10 weeks from last Sunday. As soon as the tarballs are created, the RISC-V Linux ABI will be stable, and since we'll ideally be in a glibc release that comes out soon after that we'll be fully ABI stable by early in February. While this is a big accomplishment, it does mean we now have a clock on sorting out the user-visible ABI issues. The current problems I know of are: * Signal registers are mismatched, these just need to be sanitized. * We're going to add some VDSO entries. * We need an i-cache fence system call. I'll be fixing these up ASAP, along with a handful of other comments and fallout from the merge. If anyone else knows about any ABI weirdness in RISC-V Linux land then speak up soon -- if you don't, then we'll be stuck with it forever :). If distribution people are interested in starting preliminary work, I've got backports of Linux and glibc tagged in freedom-u-sdk, which will build and boot a working kernel and userspace via "make sim". We won't be ready to actually commit to a stable ABI for a bit, so it's not quite time to start releasing binaries yet... Thanks to everyone who has helped out. I'd specifically like to thank Albert Ou, who is co-maintaining Linux with me, and Arnd Bergmann, who helped review the port. To anyone who is going to try out the port in its current state: good luck :). The backports should be pretty solid! |
| Re: [sw-dev] RISC-V Port Merged to Linux | john.leidel | 15/11/17 11:53 | Palmer, congrats!! Thanks very much for helping to support the community with your diligent efforts.
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| RE: [sw-dev] RISC-V Port Merged to Linux | Ted Speers | 15/11/17 11:57 | Nice!
Congrats to Palmer, Albert and Arnd on achieving the merge. -----Original Message----- From: Palmer Dabbelt [mailto:pal...@sifive.com] Sent: Wednesday, November 15, 2017 11:52 AM To: sw-...@groups.riscv.org Cc: alb...@sifive.com; Arnd Bergmann <ar...@arndb.de> Subject: [sw-dev] RISC-V Port Merged to Linux EXTERNAL EMAIL |
| Re: [sw-dev] RISC-V Port Merged to Linux | Michael Clark | 15/11/17 12:00 | This is excellent news!
I think we will need some documentation on the riscv device tree eventually. Your --enable-print-device-tree patch to riscv-pk gets us most of the way there but it would be nice to have this documented somewhere. I’m going to see if I can get latest linux running in qemu… :-D > To view this discussion on the web visit https://groups.google.com/a/groups.riscv.org/d/msgid/sw-dev/CAC6GRO8LhXKwYk%3DwTAnhYKvvsRJQZ5VNgbK1RkqpyfKQ1YMsUg%40mail.gmail.com. |
| Re: [sw-dev] RISC-V Port Merged to Linux | waterman | 15/11/17 12:07 | Awesome!
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| Re: [sw-dev] RISC-V Port Merged to Linux | krste | 15/11/17 12:10 | Wonderful news, a major RISC-V milestone! Krste
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| Re: [sw-dev] RISC-V Port Merged to Linux | Jeppe Johansen | 15/11/17 12:44 | Great work!
Would the current state of the port support RV32I, or does it need the A extension and/or 64 bit instructions? |
| Re: [sw-dev] RISC-V Port Merged to Linux | Karsten Merker | 15/11/17 13:07 | On Wed, Nov 15, 2017 at 09:44:10PM +0100, Jeppe Johansen wrote:
[RISC-V Linux port merged upstream] > Would the current state of the port support RV32I, or does itThe kernel code originally contained a syscall for emulating atomic operations on systems without the A extension, but that part has been rejected by upstream during the review phase, so for the time being, the A extension is effectively mandatory. Regards, Karsten -- Gem. Par. 28 Abs. 4 Bundesdatenschutzgesetz widerspreche ich der Nutzung sowie der Weitergabe meiner personenbezogenen Daten für Zwecke der Werbung sowie der Markt- oder Meinungsforschung. |
| Re: [sw-dev] RISC-V Port Merged to Linux | Bruce Hoult | 15/11/17 13:26 | On Wed, Nov 15, 2017 at 10:51 PM, Palmer Dabbelt <pal...@sifive.com> wrote:The RISC-V port was just merged to Linux a few minutes ago. This means we will be in the 4.15 release, which should be out about 10 weeks from last Sunday. As soon as the tarballs are created, the RISC-V Linux ABI will be stable, and since we'll ideally be in a glibc release that comes out soon after that we'll be fully ABI stable by early in February. Fantastic!! Well done to all concerned. |
| Re: [sw-dev] RISC-V Port Merged to Linux | Palmer Dabbelt | 15/11/17 15:53 | On Wed, 15 Nov 2017 13:07:38 PST (-0800), mer...@debian.org wrote:Yep, it's mandatory. If you're considering building a Linux-capable RISC-V system right now, it'd probably be best to go with at least RV64IMAC (ideally RV64GC), as that's going to get the most testing -- we expect non-multilib distros will start with RV64GC. When we upstream glibc, the plan is to have RV32IMAC, RV32GC, RV64IMAC, and RV64GC as the default multilib set. We also expect that distros will also follow suit here, as those are the only glibc targets we currently test regularly. We're open to expanding the number of ISAs we support in Linux land, but it won't happen until we at least get the current set upstream. There's just too many moving parts right now, we need some time to shake out issues with what we've already got working. If there's a compelling reason to start supporting more ISAs (ie, there's interesting hardware out there) then we can always add them later. It's much harder to remove things. |
| Re: [sw-dev] RISC-V Port Merged to Linux | peter.ashenden | 15/11/17 15:56 | Hi Palmer,
How much of the A-extension is used? Just LR/SC, or the AMO operations also? Thanks. PA -- Peter Ashenden, CTO IC Design, ASTC |
| RE: [sw-dev] RISC-V Port Merged to Linux | Daniel Lustig | 15/11/17 16:04 | +1, congratulations! From: Krste Asanovic [mailto:kr...@berkeley.edu]
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| Re: [sw-dev] RISC-V Port Merged to Linux | Palmer Dabbelt | 15/11/17 16:16 | We make pretty much everything available to Linux
https://github.com/riscv/riscv-linux/blob/riscv-next/arch/riscv/include/asm/atomic.h https://github.com/riscv/riscv-linux/blob/riscv-next/arch/riscv/include/asm/cmpxchg.h though you might be able to get away with setting a bunch of Kconfig options that remove most of those files. It's a bad idea (because we don't test it), and it'll only work on single-hart systems, but it might be possible. We also make all of them available glibc https://github.com/riscv/riscv-glibc/blob/2f626de717a86be3a1fe39e779f0b179e13ccfbb/sysdeps/unix/sysv/linux/riscv/atomic-machine.h and there's no way to build-time disable those because there's system call any more. Of course, if you're on a single-hart system then you could always just trap and emulate everything in M mode, then nobody would notice. It'd probably be easier to get this right if you just implement A, though :). Note that we'll only ever support non-A Linux systems with one hart, as there's just no way to write sane multi-hart software without the A extension. > --> To view this discussion on the web visit https://groups.google.com/a/groups.riscv.org/d/msgid/sw-dev/e5cf0ed1-5635-ccf9-ea6a-90b02830323b%40astc-design.com. |
| Re: [sw-dev] RISC-V Port Merged to Linux | mgi...@antmicro.com | 15/11/17 18:43 | Congrats Palmer, Albert, Arnd & co, this is really huge news, definitely something we need to do a lot of marketing around! And right in time, a fantastic announcement for the upcoming Workshop. |
| Re: RISC-V Port Merged to Linux | Albert Ou | 15/11/17 19:34 | Special thanks to Palmer for spearheading the upstreaming effort and to
Quan Nguyen, who started the port with me at Berkeley in 2012. -- Albert Ou |
| Re: [sw-dev] RISC-V Port Merged to Linux | Richard W.M. Jones | 16/11/17 03:38 | Great stuff.
From a Fedora point of view we're just waiting for glibc to go upstream to start building things, so we should be able to start in January or February (around FOSDEM time). Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v |
| Re: RISC-V Port Merged to Linux | Jeshwanth Kumar N K | 16/11/17 08:04 | Congratulations. If anybody wants to contribute for porting linux to RISC-V, is there any board available to test ? or do we have qemu for RISC-V already? How are you testing? |
| Re: [sw-dev] Re: RISC-V Port Merged to Linux | Palmer Dabbelt | 16/11/17 08:14 | There are currently no ASIC-based dev boards available, but SiFive has
announced availability in Q1 2018. We do have FPGA-based development boards. There are instructions on SiFive's website as to how to purchase one, currently you'll need the VC707 to run Linux https://dev.sifive.com/freedom-soc/evaluate/fpga/ Internally we have a handful of those boards that we test things on. The port is reasonably solid: we can boot, mount disks via PCIe SATA controllers, and run a handful of benchmarks/test suites, etc. The QEMU port is out of date, but there's an active effort going on to update it right now https://github.com/riscv/riscv-qemu/pull/70 There's a handful of other ISA simulators available for RISC-V, you can build and boot a kernel on Spike (our ISA golden model) by running "make sim" here: https://github.com/sifive/freedom-u-sdk It's the same kernel image that runs on the FPGA and will run on the ASIC based boards. |
| Re: [sw-dev] RISC-V Port Merged to Linux | Quan Minh Nguyen | 16/11/17 11:46 | Congratulations to all for a job very well done! Hats off to Albert, co-conspirator extraordinaire, and to Arnd and Palmer for turning two undergrads' whimsical little project into something we couldn't have ever imagined when we started.
Here's Albert's first commit to riscv-linux from five years ago: commit 786f6e84fac8736e255a1be1191e4ef10e012898 Author: Albert Ou Date: Fri Jun 29 16:33:57 2012 -0700 Adding minimal subtree for the Linux/RISC-V port The journey of a thousand lines of C begins with a single commit. We instead ended up with 5,012 lines of C and 839 lines of assembly, according to David Wheeler's SLOCCount. Not bad. Quan M. Nguyen <q...@mit.edu> |
| Re: RISC-V Port Merged to Linux | Alan (Quey-Liang) Kao | 23/11/17 23:22 | Hi Palmer, Congradulations to you all for the accomplishment! Our software team in Andes Technology will start to contribute the RISC-V Linux port recenlty, but we are still wondering which branch to be based on when formatting patch sets. So the question is, which is the best branch that can ease the reviewing process? Would it be __archive__? 4.14-rc8? or others? Thanks! Palmer Dabbelt於 2017年11月16日星期四 UTC+8上午3時51分55秒寫道： |
| Re: [sw-dev] Re: RISC-V Port Merged to Linux | john.leidel | 29/11/17 16:34 | Palmer (et al.), which riscv-tools branch/tag is suitable to build/test the Linux 4.15 rc1 tree? cheers john
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| Re: [sw-dev] Re: RISC-V Port Merged to Linux | Jim Wilson | 29/11/17 17:14 | On Wed, Nov 29, 2017 at 4:34 PM, John Leidel <john....@gmail.com> wrote:The default branches you get from a riscv/riscv-gnu-toolchain checkout on github should work. And if not, that is a bug that will have to be quickly fixed. Jim |
| Re: [sw-dev] Re: RISC-V Port Merged to Linux | john.leidel | 29/11/17 17:24 | Jim/Palmer, I had an issue in my cross compilation. I believe I've shaken it out at this point. The build appears to be rolling. cheers john |