Re: [PATCH v1] Add dummy Aspeed AST2600 Display Port MCU (DPMCU)

[Troy Lee]

On Fri, Dec 10, 2021 at 11:13 PM Cédric Le Goater <clg@kaod.org> wrote:
>
> On 12/10/21 15:33, Troy Lee wrote:
> > On Fri, Dec 10, 2021 at 10:05 PM Cédric Le Goater <clg@kaod.org> wrote:
> >>
> >> On 12/10/21 09:30, Troy Lee wrote:
> >>> AST2600 Display Port MCU introduces 0x18000000~0x1803FFFF as it's memory
> >>> and io address. If guest machine try to access DPMCU memory, it will
> >>> cause a fatal error.
> >>
> >> The Aspeed SoCs have an "aspeed_soc.io" region for unimplemented devices
> >> but it's too small. Anyhow, it is better to have per logic unit. We should
> >> change that one day.
> >>
> > Good idea!
> >
> >> For my information, which FW image are you using ?
> >>
> >
> > We're using Aspeed's SDK image, I tested with ast2600-default machine.
> > Prebuilt image can be download from:
> > https://github.com/AspeedTech-BMC/openbmc/releases/tag/v07.02
>
> Excellent ! Is there one I could try in particular ?
You could use ast2600-default-obmc.tgz, but we will send another patch
for HACE engine.

>
>
> Once correctly supported, we should include one of these SDK images in :
>
>    tests/avocado/boot_linux_console.py
>
> to complete our tests of the device models.
Sure, once the image successfully boots into rootfs, I'll add a test
case for it.

> QEMU is not making much difference between the revision. You might need
> to improve that.
>
> > Without declaring the DPMCU memory, the image will hangs in u-boot.
>
> yeah. You can use -d guest_errors,unimp to catch accesses done on AHB
> windows not covered by the QEMU models. There are plenty of ways to
> move past U-Boot when models are not implemented yet. Don't waste
> too much time, just ask.
>
> eMMC is only on these branches :
>
>    https://github.com/openbmc/qemu/
>    https://github.com/legoater/qemu/
These two branches are very useful!

> Same for SBC and support is primitive.
>
> > We're still working on I3C and SPI issue to be resolved to get into rootfs.
>
> I3C has not much support in Linux and none in QEMU. You will have to
> add dummy models.
Can I submit a dummy model that only responds to the RESET control register?
Or it has to be well implemented like i2c/core.c and i2c/aspeed_i2c.c?


> SPI as a non-SPI flash driver ? The SPI flash controller models should
> be quite well covered today. What's the issue ?
I need some more investigation, because we're using a different spi
driver for fmc-spi.

>
> Thanks,
>
> C.

Thanks,
Troy Lee