Re: RISCV porting effort

[Christopher Lemmer Webber]

Exciting... thanks for this update!  Even if not "usable" quite yet,
it's thrilling to see progress on this. :)


Efraim Flashner writes:

> Last week my HiFive Umatched¹ board came and was quite the object of
> interest at the local computer store as I picked up a case, PSU and
> graphics card.
>
> Couple of observations about the board first:
> It boots very slowly. I think it takes about 5 minutes from power-on to
> being able to sign in at TTY1.
> It has an NVMe slot which I haven't populated yet.
> Ubuntu has an image for the board² which booted up just fine and I'm
> using, since I didn't want to spend too long getting Debian to run on
> the board.
> Upstream u-boot support was merged days ago³ so we should be able to add
> support to our u-boot package soon-ish™.
>
> Porting Guix comes with two parts: building the bootstrap-tarballs and
> adding support for the new architecture in (gnu packages bootstrap).
> Support for riscv was added to GCC with 7.1.0 so I had to bump the
> bootstrap GCC to 7 (and adjust some inputs), and guile-2.0.14 didn't
> known the endianness of riscv64 so instead of patching it I bumped the
> bootstrap guile to 3.0. I uploaded my bootstrap-tarballs to my regular
> spot after signing them and switched over to the riscv machine.
>
> Building Guix from sources is much easier thanks to the work of Vagrant,
> I was able to apt install most of the dependencies on riscv. The
> packaged version of guile-zlib was too old in 21.04 so I built that from
> source (0.1.0 is available in Debian experimental), and I also had to
> build gnutls from source for the guile-3.0 bindings. I added the riscv
> binaries to (gnu packages bootstrap) and temporarily switched the
> raw-build function to look for 3.0 guile libraries instead of 2.0.
>
> Where I'm at right now:
> Downloading using the daemon (builtin:download) fails currently, it says
> it doesn't have permissions to open-file to write downloaded files to
> the store.
> I haven't built anything using the bootstrap binaries to see if they
> actually work yet.
>
>
> (ins)efraim@unmatched:~$ neofetch --off
> efraim@unmatched
> ----------------
> OS: Ubuntu 21.04 riscv64
> Host: SiFive HiFive Unmatched A00
> Kernel: 5.11.0-1007-generic
> Uptime: 3 days, 15 hours, 57 mins
> Packages: 782 (dpkg)
> Shell: bash 5.1.4
> Terminal: /dev/pts/0
> CPU: (4)
> GPU: NVIDIA GeForce GT 730
> Memory: 350MiB / 15995MiB
>
> (ins)efraim@unmatched:~$ lscpu
> Architecture:        riscv64
> Byte Order:          Little Endian
> CPU(s):              4
> On-line CPU(s) list: 0-3
> Thread(s) per core:  4
> Core(s) per socket:  1
> Socket(s):           1
> L1d cache:           32 KiB
> L1i cache:           32 KiB
> L2 cache:            2 MiB
>
>
> ¹https://www.sifive.com/boards/hifive-unmatched
> ²http://cdimage.ubuntu.com/releases/21.04/release/
> ³https://source.denx.de/u-boot/u-boot/-/commit/d8729a114e1e98806cffb87d2dca895f99a0170a