Add new OPTEE bootm support to u-boot

Quoted 24 lines · Dr. Philipp Tomsich

Quoted 21 lines · Kever Yang

Hi Bryan,

Quoted 5 lines · Bryan O'Donoghue

This series adds a new OPTEE bootable image type to u-boot, which is directly bootable with the bootm command.

There is already a TEE image type but, in this case the TEE firmware is loaded into RAM, jumped into and then back out of.

This is how OP-TEE upstream designed flow, isn't it?

Quoted 3 lines

This image type is a
directly bootable image as described here :
http://mrvan.github.io/optee-imx6ul

Still not clear about the detail flow you are using :( I don't understand why we need to support OP-TEE in bootm.
Do you make U-Boot working in secure word?

Quoted 3 lines

I would also prefer if we could leave the secure world prior to executing the full U-Boot??? it reduces the attack surface and will be similar to what we do on ARMv8 with ATF.

I forgot to mention that Falcon-mode w/ OPTEE will only be possible if the OPTEE is loaded from SPL.

As I would like to avoid having two different ways to load an OPTEE within U-Boot, this seems to also bias the ???default boot sequence??? towards inserting OPTEE between SPL and the OS-stage (whether this is IH_OS_U_BOOT, IH_OS_LINUX or something else).

Regards,
Philipp.

Quoted 41 lines

Quoted 41 lines

Quoted 16 lines

Instead of reusing the Linux bootable image type instead a new image type is defined, which allows us to perform additional image verification, prior to handing off control via bootm.

OPTEE images get linked to a specific address at compile time and must be loaded to this address too. This series extends out mkimage with a new image type that allows the OPTEE binary link location to be validated against CONFIG_OPTEE_TZDRAM_BASE and CONFIG_OPTEE_TZDRAM_SIZE respectively prior to proceeding through the bootm phase.

Once applied you can generate a bootable OPTEE image like this

mkimage -A arm -T optee -C none -d ./out/arm-plat-imx/core/tee.bin uTee.optee

Quoted 8 lines

That image can then be booted directly by bootm. bootm will verify the header contents of the OPTEE binary against the DRAM area carved out in u-boot. If the defined DRAM area does not match the link address specified we refuse to boot.

Kever - I'd like to suggest that your OPTEE SPL image takes a different image type IH_TYPE_OPTEE_SPL ? to indicate the different behavior your image type has versus a directly bootable bootm image.

Well, I think we can decide after everything is clear.

Thanks,
-Kever

Quoted 12 lines

Bryan O'Donoghue (9):
optee: Add lib entries for sharing OPTEE code across ports
optee: Add CONFIG_OPTEE_TZDRAM_SIZE
optee: Make OPTEE_TZDRAM_BASE a mandatory define
optee: Add optee_image_get_entry_point()
optee: Add optee_image_get_load_addr()
tools: mkimage: add optee image type
optee: Add optee_verify_bootm_image()
optee: Improve error printout
bootm: optee: Add mechanism to validate an OPTEE image before boot

Quoted 14 lines

Quoted 6 lines

Quoted 6 lines

common/bootm.c        | 11 +++++++-
common/image.c        |  1 +
include/image.h       |  1 +
include/tee/optee.h   | 41 ++++++++++++++++++++++++++++++
lib/Kconfig           |  1 +
lib/Makefile          |  1 +

Quoted 8 lines

Quoted 8 lines

lib/optee/Kconfig     | 16 ++++++++++++
lib/optee/Makefile    |  7 ++++++
lib/optee/optee.c     | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++
tools/default_image.c | 25 ++++++++++++++-----
10 files changed, 166 insertions(+), 7 deletions(-)

create mode 100644 lib/optee/Kconfig
create mode 100644 lib/optee/Makefile
create mode 100644 lib/optee/optee.c

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