[0/2] scripts/make_fit fix and disabled compression for DTBs

Message

Chen-Yu Tsai May 21, 2024, 6:51 a.m. UTC

Hi folks,

Here are a couple changes for the FIT image packing script. While
unreleated, they are sent together because the change context overlaps.

The first patch drops the compatible string property from the fdt image
nodes. According to the FIT image spec, the compatible string in the
(fdt/kernel) image node is used to specify special loading mechanisms,
and is _not_ for identifying the DTB.

The second patch adds an option that disables compression for _just_ the
included DTBs. This is needed for RK3399 and MT8173 based Chromebooks,
whose firmware does not support decompressing DTBs, but does need kernel
image compression to fit the image within their relatively small image
size of 32 MiB.

Please take a look.


Thanks
ChenYu


Chen-Yu Tsai (2):
  scripts/make_fit: Drop fdt image entry compatible string
  scripts/make_fit: Add option to disable compression for DTBs

 scripts/Makefile.lib |  1 +
 scripts/make_fit.py  | 14 +++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

Comments

Masahiro Yamada May 22, 2024, 1:08 p.m. UTC | #1

On Tue, May 21, 2024 at 3:51 PM Chen-Yu Tsai <[e-mail]> wrote:
>
> Hi folks,
>
> Here are a couple changes for the FIT image packing script. While
> unreleated, they are sent together because the change context overlaps.
>
> The first patch drops the compatible string property from the fdt image
> nodes. According to the FIT image spec, the compatible string in the
> (fdt/kernel) image node is used to specify special loading mechanisms,
> and is _not_ for identifying the DTB.

This makes sense.


> The second patch adds an option that disables compression for _just_ the
> included DTBs. This is needed for RK3399 and MT8173 based Chromebooks,
> whose firmware does not support decompressing DTBs, but does need kernel
> image compression to fit the image within their relatively small image
> size of 32 MiB.


Any platform that wants to use scripts/make_fit.py
must implement decompression of DTBs.
(or does not compress anything)

Otherwise, RK3399 and MT8173 cannot use this script.

I will not add any weird knob to it.






>
> Please take a look.
>
>
> Thanks
> ChenYu
>
>
> Chen-Yu Tsai (2):
>   scripts/make_fit: Drop fdt image entry compatible string
>   scripts/make_fit: Add option to disable compression for DTBs
>
>  scripts/Makefile.lib |  1 +
>  scripts/make_fit.py  | 14 +++++++++++---
>  2 files changed, 12 insertions(+), 3 deletions(-)
>
> --
> 2.45.0.215.g3402c0e53f-goog
>
>