svn commit: r366542 - in head/sys: amd64/amd64 arm/arm arm64/arm64 kern riscv/riscv sys

[Kyle Evans]

On Thu, Oct 8, 2020 at 1:02 PM Mitchell Horne <mhorne at freebsd.org> wrote:
>
> Author: mhorne
> Date: Thu Oct  8 18:02:05 2020
> New Revision: 366542
> URL: https://svnweb.freebsd.org/changeset/base/366542
>
> Log:
>   Add a routine to dump boot metadata
>
>   The boot metadata (also referred to as modinfo, or preload metadata)
>   provides information about the size and location of the kernel,
>   pre-loaded modules, and other metadata (e.g. the EFI framebuffer) to be
>   consumed during by the kernel during early boot. It is encoded as a
>   series of type-length-value entries and is usually constructed by
>   loader(8) and passed to the kernel. It is also faked on some
>   architectures when booted by other means.
>
>   Although much of the module information is available via kldstat(8),
>   there is no easy way to debug the metadata in its entirety. Add some
>   routines to parse this data and allow it to be printed to the console
>   during early boot or output via a sysctl.
>
>   Since the output can be lengthly, printing to the console is gated
>   behind the debug.dump_modinfo_at_boot kenv variable as well as the
>   BOOTVERBOSE flag. The sysctl to print the metadata is named
>   debug.dump_modinfo.
>

Hi,

Why both a tunable and boot -v? The tunable is already specifically
scoped to just this operation, it seems a little odd to double-gate
it.

Thanks,

Kyle Evans