[U-Boot] [U-Boot, 06/10] spl: add support to booting with OP-TEE

[Philipp Tomsich]

On Wed, 6 Sep 2017, Kever Yang wrote:

> OP-TEE is an open source trusted OS, in armv7, its loading and
> running are like this:
> loading:
> - SPL load both OP-TEE and U-Boot
> running:
> - SPL run into OP-TEE in secure mode;
> - OP-TEE run into U-Boot in non-secure mode;
>
> More detail:
> https://github.com/OP-TEE/optee_os
> and search for 'boot arguments' for detail entry parameter in:
> core/arch/arm/kernel/generic_entry_a32.S

Adding some documentation to U-Boot that documents the binary interface 
with OPTEE would be helpful.

>
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
>
> common/spl/Kconfig     |  7 +++++++
> common/spl/Makefile    |  1 +
> common/spl/spl.c       |  5 +++++
> common/spl/spl_optee.S | 13 +++++++++++++
> include/spl.h          |  9 +++++++++
> 5 files changed, 35 insertions(+)
> create mode 100644 common/spl/spl_optee.S
>
> diff --git a/common/spl/Kconfig b/common/spl/Kconfig
> index 582b685..85f8d66 100644
> --- a/common/spl/Kconfig
> +++ b/common/spl/Kconfig
> @@ -700,6 +700,13 @@ config SPL_ATF_TEXT_BASE
> 	help
> 	  This is the base address in memory for ATF BL31 text and entry point.
>
> +config SPL_OPTEE_SUPPORT
> +	bool "Support OP-TEE Trusted OS"
> +	depends on ARM
> +	help
> +	  OP-TEE is an open source Trusted OS  which is loaded by SPL.
> +	  More detail at: https://github.com/OP-TEE/optee_os
> +
> config TPL
> 	bool
> 	depends on SUPPORT_TPL
> diff --git a/common/spl/Makefile b/common/spl/Makefile
> index fde0d09..ec37428 100644
> --- a/common/spl/Makefile
> +++ b/common/spl/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_$(SPL_TPL_)UBI) += spl_ubi.o
> obj-$(CONFIG_$(SPL_TPL_)NET_SUPPORT) += spl_net.o
> obj-$(CONFIG_$(SPL_TPL_)MMC_SUPPORT) += spl_mmc.o
> obj-$(CONFIG_$(SPL_TPL_)ATF_SUPPORT) += spl_atf.o
> +obj-$(CONFIG_$(SPL_TPL_)OPTEE_SUPPORT) += spl_optee.o
> obj-$(CONFIG_$(SPL_TPL_)USB_SUPPORT) += spl_usb.o
> obj-$(CONFIG_$(SPL_TPL_)FAT_SUPPORT) += spl_fat.o
> obj-$(CONFIG_$(SPL_TPL_)EXT_SUPPORT) += spl_ext.o
> diff --git a/common/spl/spl.c b/common/spl/spl.c
> index d245cfc..6ff390c 100644
> --- a/common/spl/spl.c
> +++ b/common/spl/spl.c
> @@ -430,6 +430,11 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
> 		bl31_entry();
> 	}
>
> +	if (CONFIG_IS_ENABLED(OPTEE_SUPPORT)) {
> +		debug("loaded - jumping to U-Boot via OP-TEE.\n");
> +		spl_optee_entry(0, 0, 0, (void *)spl_image.entry_point);
> +	}
> +

Shouldn't the fact that we will boot through the OPTEE tracked through 
spl_image->os and shouldn't there be a IH_OS_... constant that indicates 
that we are going to jump to an OPTEE?  This would allow the above switch 
statement to be extended for OPTEE.

> 	debug("loaded - jumping to U-Boot...\n");
> #ifdef CONFIG_BOOTSTAGE_STASH
> 	int ret;
> diff --git a/common/spl/spl_optee.S b/common/spl/spl_optee.S
> new file mode 100644
> index 0000000..4f7f8ba
> --- /dev/null
> +++ b/common/spl/spl_optee.S
> @@ -0,0 +1,13 @@
> +/*
> + * Copyright (C) 2017 Rockchip Electronic Co.,Ltd
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <linux/linkage.h>
> +#include <asm/assembler.h>
> +
> +ENTRY(spl_optee_entry)
> +	ldr lr, =CONFIG_SYS_TEXT_BASE
> +	mov pc, r3
> +ENDPROC(spl_optee_entry)

This looks ARM-specific and shouldn't be in common/spl.

Please note that the next OS image will not always be a CONFIG_SYS_TEXT_BASE.
So the address of the "next image to boot" should be an argument to this
function (we will need to solve this cleanly anyway, as I am currently 
trying to address the same issue with booting through ATF where I have an 
entry address into the ATF and need to keep track of the next image's 
entry address as well).

> diff --git a/include/spl.h b/include/spl.h
> index ce4cf0a..13d46ed 100644
> --- a/include/spl.h
> +++ b/include/spl.h
> @@ -270,6 +270,15 @@ int spl_mmc_load_image(struct spl_image_info *spl_image,
> void bl31_entry(void);
>
> /**
> + * spl_optee_entry - entry function for optee
> + * entry arg0, pagestore
> + * entry arg1, (ARMv7 standard bootarg #1)
> + * entry arg2, device tree address, (ARMv7 standard bootarg #2)
> + * entry arg3, non-secure entry address (ARMv7 bootarg #0)
> + */
> +void spl_optee_entry(void *arg0, void *arg1, void *arg2, void *arg3);
> +
> +/**
>  * board_return_to_bootrom - allow for boards to continue with the boot ROM
>  *
>  * If a board (e.g. the Rockchip RK3368 boards) provide some
>