Re: Emulation for riscv

[Alistair Francis]

On Fri, Nov 6, 2020 at 2:36 AM Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Palmer Dabbelt <palmer@dabbelt.com> writes:
>
> > On Thu, 22 Oct 2020 17:56:38 PDT (-0700), alistair23@gmail.com wrote:
> >> On Thu, Oct 22, 2020 at 4:58 PM Moises Arreola <moyarrezam@gmail.com> 
> >> wrote:
> >>>
> >>> Hello everyone, my name is Moses and I'm trying to set up a VM for a 
> >>> risc-v processor, I'm using the Risc-V Getting Started Guide and on the 
> >>> final step I'm getting an error while trying to launch the virtual 
> >>> machine using the cmd:
> >>
> >> Hello,
> >>
> >> Please don't use the RISC-V Getting Started Guide. Pretty much all of
> >> the information there is out of date and wrong. Unfortunately we are
> >> unable to correct it.
> >>
> >> The QEMU wiki is a much better place for information:
> >> https://wiki.qemu.org/Documentation/Platforms/RISCV
> >
> > Ya, everything at riscv.org is useless.  It's best to stick to the open 
> > source
> > documentation, as when that gets out of date we can at least fix it.  Using 
> > a
> > distro helps a lot here, the wiki describes how to run a handful of popular
> > ones that were ported to RISC-V early but if your favorite isn't on the list
> > then it may have its own documentation somewhere else.
>
> Even better if you could submit some .rst pages for QEMU's git:
>
>   docs/system/target-riscv.rst
>   docs/system/riscv/virt.rst (and maybe the other models)
>
> then we could improve the user manual where RiscV is currently a little
> under-represented. A number of the systems have simple example command
> lines or explain the kernel support needed for the model.

Thanks for pointing that out Alex. Bin has sent some patches for this
so RISC-V should have a presence soon.

Alistair

>
> >
> >>> sudo qemu-system-riscv64 -nographic -machine virt \
> >>> -kernel linux/arch/riscv/boot/Image -append "root=/dev/vda ro 
> >>> console=ttyS0" \
> >>> -drive file=busybox,format=raw,id=hd0 \
> >>> -device virtio-blk-device,drive=hd0
> >>>
> >>> But what I get in return is a message telling me that the file I gave 
> >>> wasn't the right one, the actual output is:
> >>>
> >>> qemu-system-riscv64: -drive file=busybox,format=raw,id=hd0: A regular 
> >>> file was expected by the 'file' driver, but something else was given
> >>>
> >>> And I checked the file busybox with de cmd "file" and got the following :
> >>> busybox: ELF 64-bit LSB executable, UCB RISC-V, version 1 (SYSV), 
> >>> dynamically linked, interpreter /lib/ld-linux-riscv64-lp64d.so.1, for 
> >>> GNU/Linux 4.15.0, stripped
> >>
> >> That looks like an ELF, which won't work when attached as a drive.
> >>
> >> How are you building this rootFS?
> >>
> >> Alistair
> >>
> >>>
> >>> So I was wondering if the error message was related to qemu.
> >>> Thanks in advance for answering any suggestions are welcome
>
>
> --
> Alex Bennée