[PATCH] binman: add CST backend selection for i.MX8M signing

[Simon Glass]

Hi Marek,

On Fri, 13 Feb 2026 at 12:27, Marek Vasut <marex at nabladev.com> wrote:
>
> On 2/13/26 6:53 PM, Simon Glass wrote:
>
> Hello Simon,
>
> >> @@ -161,8 +165,14 @@ class Entry_nxp_imx8mcst(Entry_mkimage):
> >>           with open(cfg_fname, 'w') as cfgf:
> >>               config.write(cfgf)
> >>
> >> +        # SSL is the default backend, PKCS11 backend is optional
> >> +        if self.backend == "pkcs11":
> >> +            cst_backend = "pkcs11"
> >> +        else:
> >> +            cst_backend = "ssl"
> >> +
> >>           output_fname = tools.get_output_filename(f'nxp.csf-output-blob.{uniq}')
> >> -        args = ['-i', cfg_fname, '-o', output_fname]
> >> +        args = ['-i', cfg_fname, '-o', output_fname, '-b', cst_backend]
> >>           if self.cst.run_cmd(*args) is not None:
> >>               outdata = tools.read_file(output_fname)
> >>               # fixme: 0x2000 should be CONFIG_CSF_SIZE
> >> --
> >> 2.51.0
> >>
> >
> > This should be documented somewhere, likely in the comment for this
> > entry type, so it ends up visible in the docs.
>
> I will send a V2 with documentation.
>
> > Also, this code path will need a test, please.
> How do you propose to test this ?

Extend or copy one of the existing imx8 tests, perhaps with a new .dts
- and I suppose set the env var and see that it works too?

Note that imx8 has basic test coverage but there is quite a bit missing:

tools/binman/btool/cst.py                                  18      4    78%
tools/binman/etype/nxp_imx8mcst.py                         89     69    22%
tools/binman/etype/nxp_imx8mimage.py                       38      6    84%

I shed a small tear whenever I see that :-)

Regards,
Simon