New RISCV board (cartesi-machine)

[Ahmad Fatoum]

Hello Marcelo,

On 15.09.21 23:43, Marcelo Politzer wrote:
> On Wed, Sep 15, 2021 at 6:17 PM Ahmad Fatoum <a.fatoum at pengutronix.de> wrote:
>>
>> Hello Marcelo,
>>
>> On 15.09.21 22:30, Marcelo Politzer wrote:
>>> Hi, I'm new to barebox
>>>
>>> I'm currently porting barebox to a riscv board (cartesi-machine).
>>
>> Oh, looks interesting! What SoC does it use?
> 
> It uses SOC_VIRT. It is an emulator to be precise, we use it for
> verifiable computations.
> It is pretty easy to try it out (there is a docker image for it):
> https://www.cartesi.io/en/docs/machine/host/overview/

Thanks, will check it out.

>>> I got it mostly working:
>>> - new serial: serial_sbi.c and
>>
>> Keep in mind that newer SBI versions deprecate
>> sbi_console_getchar() and sbi_console_putchar() with no replacement.
>>
>> But if your board's firmware provides it, there is no issue with
>> adding a driver for it.
> 
> That is what the emulator implements for now.
> I have to admit that a virtio system would be cool, maybe in the future.

Like this? :-)

https://www.barebox.org/jsbarebox/

>>> - ext4 filesystem with mtdram
>>>
>>> 1) What I am still trying to figure out is how to customize `env` correctly.
>>> I got it to build and appear based on the docs [1], [2],
>>
>> Those look ok. I assume you have
>>
>> defaultenv_append_directory(defaultenv_cartesi); in your board code?
> 
> yes
> 
>>
>>> however the only way I found around [3] was to replace `bin/init` with
>>> this[4] layout.
>>
>> After drivers probe, barebox invokes init to source init scripts and
>> do the countdown and such. This is written in C, but you can override
>> it with an /env/bin/init shell script, which is what you did here.
>>
>> I would not recommend this. Drop /env/bin/init and use the same C init
>> nearly everyone else does. You can still customize it via the
>> /env/init/ scripts
>>
>>> Is there a recommended way to go about this?
>>
>> You need to set boot.default, e.g.
>>
>> echo 'cartesi net' > defaultenv-cartesi/nv/boot.default
>>
>> Which would try cartesi first and then net if the first one failed.
> 
> That worked great.
> Looks a lot cleaner now.
> 
>>
>>> 2) I also would like clarification on the upstreaming process, is it
>>> PR based, patches on this list?
>>
>> Patches to the mailing list are the usual way of contributing.
> 
> OK, I'll clean this up and send it as two patches:
> - serial_sbi
> - cartesi (board)

Sounds good.

Cheers,
Ahmad

> 
>>
>> Cheers,
>> Ahmad
>>
>>>
>>> best,
>>> Marcelo
>>>
>>>
>>> [1] Makefile:
>>> ```
>>> bbenv-$(CONFIG_BOARD_CARTESI) += defaultenv-cartesi
>>> ```
>>>
>>> [2] arch/riscv/boards/cartesi:
>>> ```
>>> defaultenv-cartesi
>>> ├── boot
>>> │   └── cartesi
>>> ├── init
>>> │   ├── automount
>>> │   └── ps1
>>> └── nv
>>>     ├── allow_color
>>>     ├── autoboot_timeout
>>>     └── user
>>> ```
>>>
>>> [3]
>>> ```
>>> Hit m for menu or any to stop autoboot:    0
>>> Booting entry 'net'
>>> ```
>>>
>>> [4]
>>> ```
>>> defaultenv-cartesi
>>> ├── bin
>>> │   └── init
>>> └── boot
>>>     └── cartesi
>>> ```
>>>
>>> _______________________________________________
>>> barebox mailing list
>>> barebox at lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/barebox
>>>
>>
>>
>> --
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> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |