Re: [PATCH v5 0/3] x86/boot: Introduce the kernel_info et consortes

From: Daniel Kiper
Date: Thu Nov 07 2019 - 06:34:00 EST


On Wed, Nov 06, 2019 at 09:56:48AM -0800, hpa@xxxxxxxxx wrote:
> On November 6, 2019 9:03:33 AM PST, Borislav Petkov <bp@xxxxxxxxx> wrote:
> >On Mon, Nov 04, 2019 at 04:13:51PM +0100, Daniel Kiper wrote:
> >> Hi,
> >>
> >> Due to very limited space in the setup_header this patch series introduces new
> >> kernel_info struct which will be used to convey information from the kernel to
> >> the bootloader. This way the boot protocol can be extended regardless of the
> >> setup_header limitations. Additionally, the patch series introduces some
> >> convenience features like the setup_indirect struct and the
> >> kernel_info.setup_type_max field.
> >
> >That's all fine and dandy but I'm missing an example about what that'll
> >be used for, in practice.
> >
> >Thx.
>
> For one thing, we already have people asking for more than 4 GiB worth
> of initramfs, and especially with initramfs that huge it would make a
> *lot* of sense to allow loading it in chunks without having to
> concatenate them. I have been asking for a long time for initramfs
> creators to split the kernel-dependent and kernel independent parts
> into separate initramfs modules.

Another user of this patchset is the TrenchBoot project on which we are
working on. We have to introduce separate entry point for Intel TXT MLE
startup code. That is why we need the kernel_info struct.

Daniel