[PATCH 1/5] efi_loader: increase eventlog buffer size

[Simon Glass]

Hi Heinrich,

On Thu, 15 Jul 2021 at 08:38, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 7/15/21 2:57 PM, Simon Glass wrote:
> > Hi Ilias,
> >
> > On Thu, 15 Jul 2021 at 00:20, Ilias Apalodimas
> > <ilias.apalodimas at linaro.org> wrote:
> >>
> >> On Wed, Jul 14, 2021 at 08:52:07AM -0600, Simon Glass wrote:
> >>> Hi Ilias,
> >>>
> >>> On Mon, 12 Jul 2021 at 03:28, Ilias Apalodimas
> >>> <ilias.apalodimas at linaro.org> wrote:
> >>>>
> >>>> On Mon, 12 Jul 2021 at 11:40, Masahisa Kojima
> >>>> <masahisa.kojima at linaro.org> wrote:
> >>>>>
> >>>>> Hi Simon,
> >>>>>
> >>>>> On Sun, 11 Jul 2021 at 09:01, Simon Glass <sjg at chromium.org> wrote:
> >>>>>>
> >>>>>> Hi Masahisa,
> >>>>>>
> >>>>>> On Wed, 7 Jul 2021 at 20:21, Masahisa Kojima <masahisa.kojima at linaro.org> wrote:
> >>>>>>>
> >>>>>>> On Wed, 7 Jul 2021 at 22:47, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On 7/7/21 3:36 PM, Masahisa Kojima wrote:
> >>>>>>>>> This is a preperation to add eventlog support
> >>>>>>>>> described in TCG PC Client PFP spec.
> >>>>>>>>>
> >>>>>>>>> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> >>>>>>>>> ---
> >>>>>>>>>    lib/efi_loader/Kconfig | 2 +-
> >>>>>>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>>>>>>
> >>>>>>>>> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> >>>>>>>>> index b2ab48a048..a87bf3cc98 100644
> >>>>>>>>> --- a/lib/efi_loader/Kconfig
> >>>>>>>>> +++ b/lib/efi_loader/Kconfig
> >>>>>>>>> @@ -327,7 +327,7 @@ config EFI_TCG2_PROTOCOL
> >>>>>>>>>    config EFI_TCG2_PROTOCOL_EVENTLOG_SIZE
> >>>>>>>>>        int "EFI_TCG2_PROTOCOL EventLog size"
> >>>>>>>>>        depends on EFI_TCG2_PROTOCOL
> >>>>>>>>> -     default 4096
> >>>>>>>>> +     default 16384
> >>>>>>>>
> >>>>>>>> I found this text in EDK II:
> >>>>>>>>
> >>>>>>>> Minimum length(in bytes) of the system preboot TCG event log area(LAML)
> >>>>>>>> -----------------------------------------------------------------------
> >>>>>>>>
> >>>>>>>> For PC Client Implementation spec up to and including 1.2 the minimum
> >>>>>>>> log size is 64KB. (SecurityPkg/SecurityPkg.dec)
> >>>>>>>
> >>>>>>> Thank you for your feedback.
> >>>>>>> I have not checked this.
> >>>>>>> TCG spec also says "The Log Area Minimum Length for the TCG event log
> >>>>>>> MUST be at least 64KB." in ACPI chapter.
> >>>>>>> I will update to set 64KB as default.
> >>>>>>>
> >>>>>>
> >>>>>> Is this the same as the BLOBLISTT_TPM2_TCG_LOG thing? If so, can we
> >>>>>> put this in the bloblist? We want to avoid adding code in EFI which is
> >>>>>> in U-Boot.
> >>>>>
> >>>>> I think bloblist is used for data passing from SPL/TPL to u-boot.
> >>>>> Is your comment saying that the eventlog generated
> >>>>> in u-boot(done in efi_tcg2.c with this patch series) should be appended
> >>>>> into the buffer pointed by BLOBLISTT_TPM2_TCG_LOG blob?
> >>>>>
> >>>>
> >>>> Even in that case the eventlog can't be appended.  The TCG eventlog
> >>>> hould be copied into EFI memory, since the kernel expects to find it
> >>>> there.
> >>>
> >>> Typically bloblist is relocated by U-Boot. There are lots of tables
> >>> that must be passed to linux, including ACPI and SMBIOS. With bloblist
> >>> they can all be in one place.
> >>
> >>
> >> The eventlog must be allocated in EFI memory though.
> >
> > There is really only one memory in U-Boot. I feel that all stuff that
> > EFI passes on to linux should be in a single bloblist.
>
> We have should follow existing standards and not invent our own. LInux
> is not the only OS booted via U-Boot.

Perhaps we can talk about it in the next call. My point is not about
avoiding standards!

What I am saying is that if we put things in a bloblist, and make that
available to Linux (or other OS) via EFI, things should work, but
non-EFI people are happy too. See the ACPI stuff for example - we put
all of those bits in a bloblist, which is really just a contiguous
area of memory. It is more convenient for U-Boot than allocating
memory willy nilly. Plus the 'bloblist' command lets you see what is
there.

Anyway I really don't understand all of this well enough to say what
we should do. I am just passing on hints. There is way too much
'separate' EFI code in U-Boot at present and we need to work to reduce
that and hopefully not add more.

[..]

Regards,
Simon