FIT table contains microcode update files with size 0

[Paul Menzel]

Dear coreboot folks,

Making a Kaby Lake-U variant port [1], building an image, I notice the 
log say the microcode update files sizes in the FIT table are 0.
> Platform is: sklkbl
> File build/coreboot.pre is 16777216 bytes
>     IFDTOOL    me.bin -> coreboot.pre
> Platform is: sklkbl
> File build/coreboot.pre is 16777216 bytes
> File me.bin is 3141632 bytes
> Adding me.bin as the Intel ME section of build/coreboot.pre
> Writing new image to build/coreboot.pre  
>     IFDTOOL    Unlocking Management Engine
> Platform is: sklkbl
> File build/coreboot.pre is 16777216 bytes
> Writing new image to build/coreboot.pre  
>     IFDTOOL    Setting EM100 mode
> Platform is: sklkbl
> File build/coreboot.pre is 16777216 bytes
> Writing new image to build/coreboot.pre  
>     CBFS       coreboot.rom
>     UPDATE-FIT
> FIT table:
> Index  Type                 Addr             Size
>      0 Microcode            0xffb5b710      0x00000000
>      1 Microcode            0xffb73f10      0x00000000
>      2 Microcode            0xffb8c710      0x00000000
>
> CBFSLAYOUT  coreboot.rom

Kind regards,

Paul

[1]: https://review.coreboot.org/c/coreboot/+/43760
      "mb/clevo/kbl-u: Add Clevo N240BU as variant"

[Nico Huber]

Hi Paul,

On 27.07.20 09:20, Paul Menzel wrote:
> Making a Kaby Lake-U variant port [1], building an image, I notice the
> log say the microcode update files sizes in the FIT table are 0.

IIRC, this is intentional, because the update itself already has a
header that specifies its length. If the length were stored redundantly
in the FIT, it would just be one more thing that could be wrong.

Nico