I've tracked the strtod problem to me not getting lazy fpu right, no
surprise there :-)

On Thu, May 21, 2026 at 1:03 PM ron minnich <[email protected]> wrote:
>
> some news:
> interrupts are working (thanks Shawn Rutledge) and mounting from qemu
> vm to a 9front system works as well (thanks José J. Cabezas Castillo).
>
> We're using listen1 with telnetd atm. We need to test a drawterm in,
> although I need to learn how to invoke drawterm such that it will
> connect. I see services for all the stuff I'm used to, but not 17010.
> But I know 9front improved the situation.
>
> Lazy FPU support is on, which means nested interrupts had to work, and
> they do. Floats seem to work.
>
> And now to the part I don't understand. strtod on this string:
> "2.997925e+8" never returns. This comes up when you run units.
>
> It is calling frnorm and fpcmp and never seems to converge. I put it
> down to something I've fouled up in kernel FPU support, I'm just not
> sure what yet.
>
> strtod does work on several other things ("4.14") but I think the
> exponent is tripping it up, but I'm not sure.
>
> Once this basic stuff is in, we'll want to get bpi-f3 ethernet going.
>
> Thanks to Jacob Moody and other 9front folks for their encouraging
> words. It's meant a lot to us.
>
> On Thu, May 14, 2026 at 11:01 AM Ron Minnich <[email protected]> wrote:
> >
> > We continue to clean up the port, and are to the point that we once
> > again have ethervirtio10 on qemu, and the same kernel boots on bpi-f3
> > and, although the ethervirtio10 is not found, it does not crash :-)
> >
> > We also continue to "narrow down" the set of differences from 9front,
> > and had a great discussion at IWP9 on how to move forward. This time
> > around, changes to virtio are quite minimal, and can be dropped once
> > we get an interrupt controller working -- at the moment, virtio is
> > polled via a clock interrupt (adclock0link ..)
> >
> > DHCP works fine from the guest.
> >
> > I have been able, from qemu, to mount 9p, using my "centre" program as
> > the 9p server.
> >
> > Thanks to everyone at IWP9 (and on the video conference) who took the
> > time to chat!
> >
> > On Sun, Apr 26, 2026 at 9:35 PM ron minnich <[email protected]> wrote:
> > >
> > > one last note: I've cleaned up a lot of the spew that was printing. From 
> > > entering the kexec command on the bpi-f3 to a command prompt is 20s, but 
> > > I think when I get rid of one last bit of mess (trying to get entropy) it 
> > > will be much less time.
> > >
> > > This iteration is about getting it to work at all, getting it faster is 
> > > next.
> > >
> > > One other person has repro'ed the process on qemu, and it works for them.
> > >
> > > ron
> > >
> > > On Sun, Apr 26, 2026 at 8:06 AM ron minnich <[email protected]> wrote:
> > >>
> > >> OK, as of this morning:
> > >>
> > >> Await             1    0:01   0:10       10K 10       bootrc
> > >>
> > >> Idle              3    0:00   0:10       13K 0        pager
> > >>
> > >> Wakeme            5    0:00   0:10       13K 0        alarm
> > >>
> > >> Pread             7    0:02   0:08       10K 0        paqfs
> > >>
> > >> Wakeme            9    0:00   0:07       13K 0        closeproc
> > >>
> > >> Await            12    0:01   0:06       10K 10       rc
> > >>
> > >> Pread            17    0:00   0:00       10K 0        ps
> > >>
> > >> on the bpi-f3
> > >>
> > >>
> > >> So the next step is finding some way to get to network
> > >>
> > >>
> > >> Note that the qemu and bpi-f3 continue to behave the same.
> > >>
> > >>
> > >> The more recent fix was, because the 9front kernel is running as kexec 
> > >> purgatory, to be sure to zero all the memory we intend to use :-)
> > >>
> > >>
> > >>
> > >>
> > >> On Sat, Apr 25, 2026 at 9:12 AM ron minnich <[email protected]> wrote:
> > >>>
> > >>> update:
> > >>> https://github.com/rminnich/9front/tree/lkg-before-ethervirtio-bpi-f3
> > >>> is a bit of a reset. I drove the ron branch off a bridge, I could not 
> > >>> make sense of what it was doing on hardware, so I backed out a bit and 
> > >>> restarted.
> > >>>
> > >>> For every change I make, I test on both the bpi-f3 and qemu, since I've 
> > >>> learned the hard way it's really easy to break one or the other.
> > >>>
> > >>> on qemu you do get to an rc prompt.
> > >>>
> > >>> On bpi-f3, the exec in initcode fails. The second argument is -1, 
> > >>> instead of a proper pointer. Tracking register values, all looks ok. 
> > >>> But ...
> > >>>
> > >>> There seems to be *something* scribbling on the stack page on the 
> > >>> bpi-f3. That's as far as I've gotten.
> > >>>
> > >>> But, I've fixed a few issues that come up when kexec 9qemu, such as the 
> > >>> need in main() to zero bss explicitly, since kexec does not know where 
> > >>> bss is.
> > >>>
> > >>> Getting there. There is one other person testing on qemu, who has 
> > >>> reported some success, so that is a bit of good news.
> > >>>
> > >>> On Tue, Apr 21, 2026 at 9:19 PM ron minnich <[email protected]> wrote:
> > >>>>
> > >>>> yes, bpi-f3 has been a good target for me to work with. Right now, I'm 
> > >>>> hitting a weird problem, but qemu and the bpi-f3 behave identically, 
> > >>>> which is helpful.
> > >>>>
> > >>>> as to stimecmp, it's there and I've no idea what genode is talking 
> > >>>> about.
> > >>>>
> > >>>> On Tue, Apr 21, 2026 at 7:07 PM Frank D. Engel, Jr. 
> > >>>> <[email protected]> wrote:
> > >>>>>
> > >>>>> That article appears to be fairly old; apparently from somewhere 
> > >>>>> around
> > >>>>> 2016 if I am reading it correctly?
> > >>>>>
> > >>>>> Going by the official RISC-V documentation site
> > >>>>> (https://docs.riscv.org/reference/isa/priv/sstc.html) it looks like 
> > >>>>> what
> > >>>>> they did was left MTIMECMP in the core architecture and moved STIMECMP
> > >>>>> to an extension which makes it optional for processors to implement.
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>> On 4/21/26 16:21, Dave Eckhardt wrote:
> > >>>>> >> Things like the STIMECMP were a major improvement and I don't want
> > >>>>> >> to work without them.
> > >>>>> > Given a strong endorsement like that, and knowing very little about
> > >>>>> > RISC-V, I figured maybe it would be good to read up on STIMECMP.
> > >>>>> >
> > >>>>> > One of the first things I found was this:
> > >>>>> >
> > >>>>> > https://genode.org/documentation/articles/riscv#Timer
> > >>>>> >
> > >>>>> > ...which appears to be a claim that STIMECMP is already deprecated,
> > >>>>> > or am I misreading it?
> > >>>>> >
> > >>>>> > Dave Eckhardt
> > >
> > > 9fans / 9fans / see discussions + participants + delivery options 
> > > Permalink

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