Hi Ahmad,
On 26-01-15, Ahmad Fatoum wrote:
> Hi,
>
> On 11/10/25 9:34 PM, Marco Felsch wrote:
> > Add support to handover the BL32 and BL33 entrypoints via the TF-A
> > struct::bl_params in arg0. This eliminates the requirement to share the
> > different load addresses between multiple binaries to lower the BSP
> > integration effort.
> >
> > In addition to the entriespoints, this commit also adds the support to
> > pass the builtin barebox DTB to OP-TEE if enabled.
> >
> > Signed-off-by: Marco Felsch <[email protected]>
> > ---
>
>
> > +config ARCH_IMX_ATF_PASS_BL_PARAMS
> > + bool "Pass BL3x bl_params as arg0 to TF-A"
> > + depends on ARCH_IMX_ATF
> > + select ARM_ATF
> > + select ARCH_HAS_EARLY_FDT_SUPPORT
> > + help
> > + Enable this option if you are using an upstream TF-A that uses
> > + the struct::bl_params to handover all required BL32 and BL33
> > + information required to start the BL32 and BL33 image.
> > +
> > + Since upstream TF-A v2.12 all i.MX8M support this feature except for
> > + the i.MX8MQ.
> I think the help text is misleading, because you still need to enable
> the PBL_EARLY_FDT_LOAD option for this to actually work.
>
> What you want instead is for the SoC symbols for i.MX8M[MNQ] to select
> ARCH_HAS_EARLY_FDT_SUPPORT and then this symbol here would select
> PBL_EARLY_FDT_LOAD.
I agree with the ARCH_HAS_EARLY_FDT_SUPPORT selection. For actual making
use of the "BL3x bl_params" we should make it a runtime selectable
variable. Since there may be boards with an old OP-TEE not supporting
this and newer ones. To honor multiconfig board builds, I would rather
make it a runtime-variable, like I said PBL_EARLY_FDT_LOAD.
> PBL_EARLY_FDT_LOAD itself would lose its prompt, but you probably will
> want to keep a
>
> prompt "Include Early FDT loading support" if COMPILE_TEST
>
> So it has coverage from the static analyzers running for sandbox.
>
> > + if (!IS_ENABLED(CONFIG_ARCH_IMX_ATF_PASS_BL_PARAMS) || cpu_is_mx8mq()) {
>
> Ok, good thing this is guarded, so I think that answers my questions
> regarding the LIBFDT dependency.
>
> > + ret = pbl_load_fdt(fdt, buf, bufsz);
>
> Did you consider replacing the uncompressed DT in the handoff data if we
> already spent the time to decompress it here?
I saw the duplicated decompress step too :/ But I dedicded to skip this
part for further improvements. It's woth a comment for sure!
> > + if (!ret) {
> > + unsigned long mem_base = MX8M_DDR_CSD1_BASE_ADDR;
> > + unsigned long mem_sz;
> > +
> > + if (cpu_is_mx8mn())
> > + mem_sz = imx8m_ddrc_sdram_size(16);
> > + else
> > + mem_sz = imx8m_ddrc_sdram_size(32);
> > +
> > + fdt = buf;
> > + ret = fdt_fixup_mem(fdt, &mem_base, &mem_sz, 1);
> > + if (ret) {
> > + pr_warn("Failed to fixup FDT memory node,
> > continue without\n");
> > + fdt = NULL;
> > + }
>
> Ok, that answers my question about the memory being inaccurate.
>
> Keep in mind that all this runs without MMU enabled, so it will be
> slower. A FIXME comment may be apt to alert to this fact.
Sure! It's worth a comment that these ops are slower :/
Regards,
Marco
>
> Thanks,
> Ahmad
>
>
> --
> Pengutronix e.K. | |
> Steuerwalder Str. 21 | http://www.pengutronix.de/ |
> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
>
>
--
#gernperDu
#CallMeByMyFirstName
Pengutronix e.K. | |
Steuerwalder Str. 21 | https://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
