Re: [PATCH 8/9] ARM: rockchip: pass device tree to TF-A

[Michael Tretter <m.tretter@pengutronix.de>]

On Mon, 26 May 2025 18:37:23 +0200, Marco Felsch wrote:
> On 25-05-26, Michael Tretter wrote:
> > The upstream OP-TEE expects a device tree to be able to initialize the
> > dynamic shared memory. Therefore, barebox should pass a device tree that
> > contains memory nodes through the TF-A to OP-TEE.
> > 
> > Unfortunately, the downstream TF-A fails to start if barebox passes its
> > device tree and it is not possible to detect if the loaded TF-A is able
> > to handle the device tree. Add a config option to pass the device tree
> > if it is possible.
> > 
> > Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
> > ---
> >  arch/arm/mach-rockchip/Kconfig | 13 +++++++++++++
> >  arch/arm/mach-rockchip/atf.c   | 15 ++++-----------
> >  pbl/Kconfig                    |  1 +
> >  3 files changed, 18 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
> > index 98dfd11c182b9fee6e3c958653ad4fa8a7d98d84..257c13bcf4846e805a7803105c71edeff92c534d 100644
> > --- a/arch/arm/mach-rockchip/Kconfig
> > +++ b/arch/arm/mach-rockchip/Kconfig
> > @@ -141,6 +141,19 @@ config ARCH_ROCKCHIP_ATF
> >  	  useful for debugging early startup, but for all other cases,
> >  	  say y here.
> >  
> > +config ARCH_ROCKCHIP_ATF_PASS_FDT
> > +	bool "Pass device tree to TF-A"
> > +	depends on ARCH_ROCKCHIP_ATF
> > +	help
> > +	  Enable this option if you are using an upstream OP-TEE that uses the
> > +	  device tree to initialize dynamic shared memory, which is passed
> > +	  through the upstream TF-A.
> 
> Would be nice to document this within the Documentation/ dir too.

Ack. There are already some notes about the binaries in
Documentation/boards/rockchip.rst. I'll add some documentation about the
device tree size there.

Michael

> 
> Regards,
>   Marco
> 
> > +
> > +	  Disable the option if you are using a downstream TF-A since it
> > +	  doesn't always cope with device trees. Supposedly this happens if the
> > +	  device tree is too large, for example if CONFIG_OF_OVERLAY_LIVE is
> > +	  enabled.
> > +
> >  config ARCH_ROCKCHIP_OPTEE
> >  	bool "Build rockchip OP-TEE binary into barebox"
> >  	depends on ARCH_ROCKCHIP_ATF
> > diff --git a/arch/arm/mach-rockchip/atf.c b/arch/arm/mach-rockchip/atf.c
> > index cfa6df043b34c0f36919048237c7ecf33dfe0724..12cf13717b6972c2eafc5a044ae8d0b4de029c32 100644
> > --- a/arch/arm/mach-rockchip/atf.c
> > +++ b/arch/arm/mach-rockchip/atf.c
> > @@ -186,18 +186,11 @@ void __noreturn rk3588_barebox_entry(void *fdt)
> >  		rk3588_lowlevel_init();
> >  		rockchip_store_bootrom_iram(IOMEM(RK3588_IRAM_BASE));
> >  
> > -		/*
> > -		 * The downstream TF-A doesn't cope with our device tree when
> > -		 * CONFIG_OF_OVERLAY_LIVE is enabled, supposedly because it is
> > -		 * too big for some reason. Otherwise it doesn't have any visible
> > -		 * effect if we pass a device tree or not, except that the TF-A
> > -		 * fills in the ethernet MAC address into the device tree.
> > -		 * The upstream TF-A doesn't use the device tree at all.
> > -		 *
> > -		 * Pass NULL for now until we have a good reason to pass a real
> > -		 * device tree.
> > -		 */
> > +#ifdef CONFIG_ARCH_ROCKCHIP_ATF_PASS_FDT
> > +		rk3588_atf_load_bl31(fdt);
> > +#else
> >  		rk3588_atf_load_bl31(NULL);
> > +#endif
> >  		/* not reached when CONFIG_ARCH_ROCKCHIP_ATF */
> >  	}
> >  
> > diff --git a/pbl/Kconfig b/pbl/Kconfig
> > index 489b2001a855d62e11a2159311332b0e67f3a754..3dfc7de3e80da12a6313e84175275070274b9a5d 100644
> > --- a/pbl/Kconfig
> > +++ b/pbl/Kconfig
> > @@ -63,6 +63,7 @@ config PBL_CLOCKSOURCE
> >  config PBL_FDT_MIN_SIZE
> >  	hex
> >  	default 0x0
> > +	default 0x60000 if ARCH_ROCKCHIP_ATF_PASS_FDT
> >  	prompt "Minimum size of the FDT blob"
> >  	help
> >  	  The TF-A or OP-TEE may modify the FDT or add nodes to the FDT. This
> > 
> > -- 
> > 2.39.5
> > 
> > 
> > 
>