[PATCH] ARM: imx: Enable kaslrseed command on DH i.MX8M Plus DHCOM

[Tim Harvey]

On Thu, Apr 18, 2024 at 11:42 AM Marek Vasut <marex at denx.de> wrote:
>
> On 4/18/24 8:02 PM, Fabio Estevam wrote:
> > Hi Tim,
> >
> > On Thu, Apr 18, 2024 at 2:54 PM Tim Harvey <tharvey at gateworks.com> wrote:
> >
> >> Fabio, if you enable CONFIG_DM_RNG on an imx8m{m,p}_evk do you get the
> >> following in the SPL?
> >> Couldn't bind rng driver (-96)
> >> SEC0:  RNG instantiated
> >>
> >> sec_init failed!
> >
> > Yes, if I add CONFIG_DM_RNG=y to imx8mm_evk_defconfig I get:
> >
> > U-Boot SPL 2024.04-00793-g3434b88d2c2f-dirty (Apr 18 2024 - 14:58:57 -0300)
> > No pmic
> > Couldn't bind rng driver (-96)
> > SEC0:  RNG instantiated
> >
> > sec_init failed!
>
> Interesting. Which TFA blob version do you use ? I used the mainline
> 2.10 for my tests.

Marek,

Were you able to reproduce this as well with the board you enabled
DM_RNG for? If it does work fine what dtb were you using... perhaps
there is something in its u-boot.dtsi that we need?

The error -EPFNOSUPPORT is interesting and helps point to the only
place it can be where the comment says the strange errno is to make
this easier to find:
https://elixir.bootlin.com/u-boot/latest/source/drivers/core/uclass.c#L70:
        if (!uc_drv) {
                debug("Cannot find uclass for id %d: please add the
UCLASS_DRIVER() declaration for this UCLASS_... id\n",
                      id);
                /*
                 * Use a strange error to make this case easier to find. When
                 * a uclass is not available it can prevent driver model from
                 * starting up and this failure is otherwise hard to debug.
                 */
                return -EPFNOSUPPORT;
        }

I'm not very familiar with the dm driver binding - does the
U-BOOT_DRIVER usage in drivers/crypto/fsl/rng.c need to be refactored
to use UCLASS_DRIVER for it to be usable in both SPL and U-Boot?

Honestly I don't know why we need DM_RNG in SPL anyway and we could
just add support for disabling it there to avoid unwanted bloat.

Tim