Re: [PATCH v2] aspeed: Deprecate the tacoma-bmc machine

[Guenter Roeck]

Hi,

On 8/26/24 02:58, Cédric Le Goater wrote:
> Hello Guenter,
>
> On 8/9/24 00:05, Guenter Roeck wrote:
> > Hi,
> >
> > On Tue, Jun 25, 2024 at 09:08:30AM +0200, Cédric Le Goater wrote:
> > > The tacoma-bmc machine was a board including an AST2600 SoC based BMC
> > > and a witherspoon like OpenPOWER system. It was used for bring up of
> > > the AST2600 SoC in labs. It can be easily replaced by the rainier-bmc
> > > machine which is part of a real product offering.
> > >
> > > Signed-off-by: Cédric Le Goater <clg@redhat.com>
> >
> > I have been using tacoma-bmc to test tcg,tpm-tis-i2c functionality
> > on arm. rainier-bmc doesn't support that, and other IBM BMCs which
> > do support it (bonnell, everest, system1) are not supported in qemu.
> >
> > Do you have a suggested alternative ?
>
> Could you use the ast2600-evb machine instead ? as done in
> machine_aspeed.py, see routine test_arm_ast2600_evb_buildroot_tpm.

Unfortunately, that does not work for me because that requires instantiating
the tpm chip from the CLI by writing into the new_device sysfs attribute,
and I can not do that in my test environment.

> We can't add a "tpm-tis-i2c" device to the tacoma-bmc machine init
> routine because a TPM backend is required.

Not sure I understand; tacoma-bmc instantiates the TPM chip through its
devicetree file which is what I was looking for.

I solved the problem by adding support for IBM Bonnell (which instantiates
the TPM chip through its devicetree file, similar to tacoma-bmc) to my local
copy of qemu. It isn't perfect since I don't know the correct HW pin strapping
and reused the strapping from Rainier, but it works for me.

Thanks,
Guenter