Re: Emulation for riscv

[Alex Bennée]

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 the information there is out of date and wrong.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 documentation, as when that gets out of date we can at least fix it.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.

>
>>> 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