[lowrisc-dev] building lowRISC binaries with current riscv-gnu-toolchain?

Dr Jonathan Kimmitt jrrk2 at cam.ac.uk
Wed Oct 17 07:50:25 BST 2018


All our development is constantly publicly accessible. The documentation can be built at any time from the lowrisc-site repo. Therefore the concept of a release consists of branching the repo and getting approval to apply the new documentation to our website www.lowrisc.org, the rest of the time is spent persuading users to upgrade from their previous release:-)

Sent from my iPhone

> On 16 Oct 2018, at 23:33, Bdale Garbee <bdale at gag.com> wrote:
> 
> Is 0.6 accessible now?
> 
> Bdale
> 
>> On October 16, 2018 4:24:34 PM MDT, Dr Jonathan Kimmitt <jrrk2 at cam.ac.uk> wrote:
>> You are correct, release refresh-v0.6 supports priv-1.10, upstream Debian Sid, kernel 4.18, gcc-8, as well as alpha support for freebsd-riscv, and multi operating system Ethernet boot DHCP client, as well as first stage SD-card boot loader, derived from u-boot. And did I mention openocd/gdb bare-metal debugging without any extra hardware. A new quick start procedure makes it easier to get started with binaries, the USB keyboard generates PC compatible up/down events, and the colour screen has downloadable palettes and fonts.
>> The source with small adaptations can also run on the KC705 again and the ArtyA7-A100. Processor speed is doubled to 50MHz, all I/O data path widths are 64-bit, and Ethernet receive has an 8x1536 packet buffer on receive. Security updates can be applied in place just like with a real PC, at about 1/200th of the speed.
>> 
>> It does not have the proprietary tagged memory extensions of previous releases.
>> 
>> Sent from my iPhone
>> 
>>>> On 16 Oct 2018, at 22:11, Karsten Merker <merker at debian.org> wrote:
>>>> 
>>>> On Tue, Oct 16, 2018 at 03:59:29PM -0400, Gabriel L. Somlo wrote:
>>>> 
>>>> I'm trying to bring together a reasonably current hardware+software
>>>> riscv environment, and lowRISC (on nexys4-ddr) appeared to be the most
>>>> likely candidate :)
>>>> 
>>>> So I managed to replicate the entire from-source build process for
>>>> "lowrisc-chip-ethernet-v05", including the bitstream (with Vivado),
>>>> and riscv-tools (riscv-fesvr, riscv-isa-sim, riscv-gnu-toolchain,
>>>> busybox, the kernel, and the bbl bootloader).
>>>> 
>>>> I also managed to build poky, but as it turns out I can leave that
>>>> out, and still get a minimal busybox-in-initramfs working, bootable
>>>> system.
>>>> 
>>>> So far, so good.
>>>> 
>>>> I would, however, like to move toward upgrading this system to more
>>>> modern/recent/upstream components.
>>>> 
>>>> Busybox is easy, I can build 1.28.3 (currently the latest) with the
>>>> included toolchain, and things are still OK.
>>>> 
>>>> This is where I got stuck, though:
>>>> 
>>>> I can't build a more recent kernel (e.g. 4.19-rc8) with the included
>>>> toolchain.
>>>> 
>>>> So I grabbed the sources for https://github.com/riscv/riscv-gnu-toolchain
>>>> and built it for multilib, including "rv64imafd-lp64" which I believe
>>>> "should" work on the lowRISC implementation of the ISA.
>>>> 
>>>> However, if I try building a statically linked busybox binary with the
>>>> new/upstream toolchain, I'm getting either a signal-7 bus error or a
>>>> signal-4 illegal opcode error from the existing (working) lowRISC
>>>> kernel.
>>> 
>>> According to https://www.lowrisc.org/docs/ethernet-v0.5/, LowRISC
>>> v0.5 implements only priv-1.9.1, but the upstream kernel requires
>>> priv 1.10 or newer, so running an upstream kernel on a LowRISC
>>> v0.5 isn't possible.  To make things even worse, upstream glibc
>>> in turn AFAIK requires an upstream kernel (3.15 or newer) and
>>> doesn't build cleanly against older (priv-1.9.1-supporting)
>>> kernels.  AFAIK LowRISC v0.6 is planned to support priv 1.10 and
>>> thereby should work with upstream Linux and glibc.
>>> 
>>> HTH,
>>> 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.
>>> 
>> 
>> 
> 
> -- 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.


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