Re: Emulating sd card with hifive_u risc-v machine

[Alistair Francis]

On Mon, Feb 8, 2021 at 12:00 PM Pascal Scholz
<s6899329@msx.tu-dresden.de> wrote:
>
> Hi all,
>
> I'm hoping that I addressed the right mailing lists.

Hello Pascal,

Yep, this is the right place :)

>
> I'm working a bit with qemu's risc-v emulation. My current goal is to
> simulate a complete boot process for the SiFive Unleashed Board (SU 540
> SoC)[1]. I've created the correspondig OpenSBI and U-Boot images, being
> the -bios and the -kernel images. It's possible for me to boot up to the
> U-Boot prompt. From this prompt I now want to boot an system image
> located on an emulated sd card.
>
> However I now fail to get a working sd card within qemu for the device
> sifive_u. For example i tried the following command:
>
> qemu-system-riscv64 -M sifive_u -m 8G -serial stdio -bios
> build/platform/sifive/fu540/firmware/fw_jump.bin -kernel
> ../../u-boot/u-boot.bin -device sdhci-pci -device sd-card,drive=sdX
> -drive id=sdX,if=none,format=raw,file=path/to/image.elf
>
> This results in Qemu telling me: -device sdhci-pci: No 'PCI' bus found
> for device 'sdhci-pci'.
>
> Using the machine "virt" the command above works.
>
> The thing i tried was:
>
> qemu-system-riscv64 -M sifive_u -m 8G -serial stdio -bios
> opensbi/build/platform/sifive/fu540/firmware/fw_jump.bin -kernel
> ../u-boot/u-boot.bin -sd path/to/image.elf
>
> Resulting in: machine type does not support if=sd,bus=0,unit=0
>
>
> Even if the machine gets stuck at some point when booting, Qemu has no
> problem starting the VM if I use "-M virt" instead of "-M sifive_u". At
> this point i think, that the machine "sifive_u" doesn't support sd
> cards? Is this guess right or is there anything left I can try? After

Correct. There is no SD card support for the SiFive U in QEMU.

You actually just reminded me though that someone has sent patches to
add support and I need to review them.

You can find the patches here:
https://patchew.org/QEMU/20210126060007.12904-1-bmeng.cn@gmail.com/
which should work when applied to QEMU.

If you do get a chance to test the patches it would be great if you
can let me know what works/doesn't work for you.

Alistair

> all I'm a bit confused, because there seems to be a block device "sd0"
> when I try to start the machine "sifive_u" without any additional
> device/drive arguments. I would really appreciate if someone would tell
> me, what I'm doing wrong.
>
> Thanks in advance and stay healthy!
>
> Best regards
>
> Pascal
>
>
> [1] https://www.sifive.com/boards/hifive-unleashed
>
>