[coreboot] BIOS/CoreBoot/UBOOT

[Simon Glass]

Hi,

On 11 April 2018 at 16:39, Raymond Yeung <rksyeung at hotmail.com> wrote:
>
> I currently have a board that uses Intel Xeon D (previously codenamed Broadwell DE).  It boots up with BIOS/UEFI. I 'm exploring other oot-up options here.
>
>
> I'm not familiar with this early stage of system initialization.  It seems BIOS/UEFI to Linux needs to use PXE, with the need to configure DHCP (and possibly Proxy DHCP), TFTP server PXELINUX, Linux initial RAM disk (initrd) configuration file, and then Linux.  Previously, I'd been using Coreboot/UBOOT environment (as a user, not developer).  Prerequisite seemed much simpler.
>
>
> A few questions -
>
>
> Is there even a coreboot support for this CPU already available and stable that I could download and reflash?  Or are we talking about some serious re-development?
> Is it possible to go from BIOS/UEFI to UBOOT (on-board)?  How?

Yes, this is supported in mainline U-Boot. It builds U-Boot as a
payload for UEFI to load.

Overview here:

https://www.denx.de/wiki/U-Boot/X86

Full details here:

http://git.denx.de/?p=u-boot.git;a=blob;f=doc/README.u-boot_on_efi;h=298b94e342e4cc389df587c45e8b4d067b0feaf3;hb=HEAD

It is also possible to boot EFI applications (e.g. grub) on U-Boot:

http://git.denx.de/?p=u-boot.git;a=blob;f=doc/README.uefi;h=7403be36146d2321b29d82bef306c9d322ab1910;hb=HEAD

> Support for Secure Boot - would one approach be simpler than another?

U-Boot has a secure boot implementation.

> Am I even on the right track thinking this way?
>
>
> Please let me know if this has already been discussed to the death here (or elsewhere), and would appreciate a link/reference.
>
>
> Thanks,
>
> Raymond

Regards,
Simon