[U-Boot] Next for x86?

[Bin Meng]

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.
>
> 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limitations exist as there are still lots of unpublished chipset docs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).

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)
- TPM support, and Intel TXT/TXE
- xHCI support on Intel chipset (looks the U-Boot xHCI driver is not
working for Intel)
- Audio support (maybe just providing audio codec's verb table in U-Boot)

Regards,
Bin