[PATCH 07/11] board: stm32mp1: use FDT address provided by TF-A at boot time

[Patrice CHOTARD]

Hi

On 3/18/20 9:22 AM, Patrick Delaunay wrote:
> Save and use the FDT address provided by TF-A in r2 at boot time
> (it is NT_FW_CONFIG = Non Trusted Firmware configuration file)
>
> Address is saved in save_boot_params(), called by start.S
> and the used DTB is gd->fdt_blob = board_fdt_blob_setup().
>
> If dtb is not provided or invalid, U-Boot use as fallback
> the builtin DTB.
>
> Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> ---
>
>  arch/arm/mach-stm32mp/Makefile      |  1 +
>  arch/arm/mach-stm32mp/boot_params.c | 45 +++++++++++++++++++++++++++++
>  2 files changed, 46 insertions(+)
>  create mode 100644 arch/arm/mach-stm32mp/boot_params.c
>
> diff --git a/arch/arm/mach-stm32mp/Makefile b/arch/arm/mach-stm32mp/Makefile
> index eee39c27c3..19ca3b08a5 100644
> --- a/arch/arm/mach-stm32mp/Makefile
> +++ b/arch/arm/mach-stm32mp/Makefile
> @@ -13,6 +13,7 @@ else
>  obj-y += bsec.o
>  obj-$(CONFIG_CMD_STM32KEY) += cmd_stm32key.o
>  obj-$(CONFIG_ARMV7_PSCI) += psci.o
> +obj-$(CONFIG_STM32MP1_TRUSTED) += boot_params.o
>  endif
>  
>  obj-$(CONFIG_$(SPL_)DM_REGULATOR) += pwr_regulator.o
> diff --git a/arch/arm/mach-stm32mp/boot_params.c b/arch/arm/mach-stm32mp/boot_params.c
> new file mode 100644
> index 0000000000..e4351de939
> --- /dev/null
> +++ b/arch/arm/mach-stm32mp/boot_params.c
> @@ -0,0 +1,45 @@
> +// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
> +/*
> + * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
> + */
> +
> +#include <common.h>
> +#include <asm/sections.h>
> +#include <asm/system.h>
> +
> +/*
> + * Force data-section, as .bss will not be valid
> + * when save_boot_params is invoked.
> + */
> +static unsigned long nt_fw_dtb __section(".data");
> +
> +/*
> + * Save the FDT address provided by TF-A in r2 at boot time
> + * This function is called from start.S
> + */
> +void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
> +		      unsigned long r3)
> +{
> +	nt_fw_dtb = r2;
> +
> +	save_boot_params_ret();
> +}
> +
> +/*
> + * Use the saved FDT address provided by TF-A at boot time (NT_FW_CONFIG =
> + * Non Trusted Firmware configuration file) when the pointer is valid
> + */
> +void *board_fdt_blob_setup(void)
> +{
> +	debug("%s: nt_fw_dtb=%lx\n", __func__, nt_fw_dtb);
> +
> +	/* use external device tree only if address is valid */
> +	if (nt_fw_dtb >= STM32_DDR_BASE) {
> +		if (fdt_magic(nt_fw_dtb) == FDT_MAGIC)
> +			return (void *)nt_fw_dtb;
> +		debug("%s: DTB not found.\n", __func__);
> +	}
> +	debug("%s: fall back to builtin DTB, %p\n", __func__, &_end);
> +
> +	return (void *)&_end;
> +}

Reviewed-by: Patrice Chotard <patrice.chotard at st.com>

Patrice