[U-Boot] Next for x86?

[Simon Glass]

Hi Bin,

On 19 November 2015 at 20:38, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Fri, Nov 20, 2015 at 11:09 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi,
>>
>> I'm wondering what might come next for U-Boot x86 support.
>>
>> The PCI conversion to driver model is coming along nicely. The ACPI
>> support is only partially there but it is a good start.

I have another series of PCI patches in the works and hope to get
these out in a few weeks. The intent is to fully move x86 to use the
driver model API.

>>
>> What else? More platforms? Other features? Better support for existing
>> platforms?
>>
>
> Two biggest feature gaps so far are complete ACPI support, and SMM
> support. ACPI is pretty much a must-have if we want power management
> feature in the OS. For SMM, I am not convinced that we have to do that
> in U-Boot, for example those BIOS guys invented USB legacy support
> (I/O port emulation of PS/2 keyboard) via SMM but today we have native
> USB support and we should not do such with SMM in U-Boot. One corner
> case is that some ACPI AML codes on some commercial BIOS trap the ACPI
> calls into SMM where SMM is a must-have. Unfortunately such
> limitations exist as there are still lots of unpublished chipset docs
> from various vendors who want to protect their IP (so-called).
>
> ACPI support seems to be a must if we want to support booting Windows,
> also we may need help from SeaBIOS (chain-loaded from U-Boot).

Yes we should try to get that finished. It seems pretty close at least
on qemu and minnowboard max.

>
> For other features, what I can think of now are:
> - New platform support which relies on FSP. With FSP it is quite easy
> to add a new platform support for Intel processors.
> - FSP spec 1.1 support, however Intel has not released any FSP package
> based on FSP spec 1.1. I believe their next gen Atom/Core processors'
> FSP will support FSP 1.1 (like Braswell, Skylake)

Yes it seems like this will happen when we get the first board that supports it.

> - TPM support, and Intel TXT/TXE

There is LPC TPM support at present so perhaps that is a start.

> - xHCI support on Intel chipset (looks the U-Boot xHCI driver is not
> working for Intel)

Agreed, this shouldn't be too tricky as it is a standard.

> - Audio support (maybe just providing audio codec's verb table in U-Boot)

There is basic speaker support, and on a few ARM boards there is basic
audio support (playing a waveform, and code to generate a waveform).
This is pretty platform-specific as each codec is different. Do you
have a board with a built-in audio codec?

Regards,
Simon