canbus support (QEMU-209)

[maedoc]

Checklist

• Checked the issue tracker for similar issues to ensure this is not a duplicate.
• Described the feature in detail and justified the reason for the request.
• Provided specific use cases and examples.

Feature description

Support the canbus object per https://www.qemu.org/docs/master/system/devices/can.html

Use cases

I would like to debug my esp32 app using the twai (or similar) with a virtual can interface on linux

Alternatives

The linux target, but it doesn't compile with my app.

Additional context

No response

[igrr]

@maedoc I've looked into the possibility of CAN support, and it seems very doable. QEMU already has an implementation of SJA1000 controller, we just need to implement a small wrapper device to attach SJA1000 as an MMIO peripheral (similar to hw/net/can/can_pcm3680_pci.c, just without PCI...)

This will only work on Linux hosts, though, since the only CAN host in QEMU is socketcan, which is only supported on Linux. I would just like to confirm whether you are okay with using Linux as host OS?

[maedoc]

okay with using Linux as host OS?

yes only been using esp idf on Linux, or Docker on macOS, so that would be fine.

thanks for considering implementing!