[U-Boot] [PATCH 0/9] Add new OPTEE bootm support to u-boot

[Dr. Philipp Tomsich]

> On 15 Jan 2018, at 05:39, Kever Yang <kever.yang at rock-chips.com> wrote:
> 
> Hi Bryan,
> 
> On 01/12/2018 10:52 PM, Bryan O'Donoghue wrote:
>> 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?
>> 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?

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.

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