Trusty, a Trusted Execution Environment

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

Hi there I want to Implement Trusty on Jetson AGX Xavier.
So far
I have gone through Secureboot and Disk Encryption. I have L4T Driver Package (BSP) Sources on my host. I am not sure what to do next kindly guide me what will be the next step from here.
Thanks

3

hello AbdulWasey,

are you saying developing TAs/CAs that run with Trusty’s Trusted Execution Environment (TEE)?
please access to developer guide, Trusted Application Development for reference,
thanks

4

Hi @JerryChang

Yes, But this <trusty_top> directory of source package is available on the host. I am trying to understand how trusty will be available on Xavier where I can build and run my code in TEE on the Xavier not on the host.

5

Hi @JerryChang
I am trying to understand the trusty and how it can be implemented?
I can see a file atf_and_trusty_README.txt in /source/public which shows how to create tos_t194.img and replacing with the old tos.img. Now what will happen when board is flashed with new tos_t194.img? Did this creates some secure directory where I can put my data and code?
Thanks

6

please check this thread as see-also. [TRUSTY] Trusted Application Testing

7

Hi @JerryChang
Where can I get more details about CAs and TAs implementation? I don’t have much idea about that. I can see in . [TRUSTY] Trusted Application Testing that I have to go through the atf_and_trusty.README to implement SecureOS. Will this all to enable TEE on the Xavier.

8

hello AbdulWasey,

there’s NO specific rules for the implementation of CA.
please refer to this for the steps or guides to implement or extend more functions into it.
thanks

9

Hi @JerryChang
The bootloader allocates a dedicated carveout, TZ-DRAM, to run a secure OS
What is the allocated size of TZ-DRAM in case of Xavier AGX can you specify please
thanks

10

hello AbdulWasey,

please refer to cboot sources for the carveout index.
for example, $L4T_Sources/r32.5.1/Linux_for_Tegra/source/public/cboot$ vim ./bootloader/partner/t19x/mb1-headers/tegrabl_carveout_id.h
it’s #define CARVEOUT_TZDRAM 34U for the TZ-DRAM.

then, you’re able to check the CBoot logs for allocated base address and also the size.
for example,

��[0001.089] I> Welcome to Cboot
��fmon_post initialized
��[0001.090] I> Cboot Version: t194-9efcbc4f
...
[0001.367] I> 34) Base:0xf3c00000 Size:0x01000000

note,
there’s erroneous in the makefile, please check Physical address range in the secure world - #5 by JerryChang.
we’ve also done the update, please expect next public release (i.e. JetPack-4.6) will include the fixes.
thanks

11

Hi @JerryChang
I have gone through the atf_and_trusty.README and successfully created the tos_t194.img, and will flash that after enabling the scureboot. but I am bit confused regarding the TAs/CAs. The thing I want to do with trusty is to save some keys, some important data and certificates and access them and change them whenever I need. How can be this possible kindly guide me.
Thanks

12

hello AbdulWasey,

please check the TA/CA sample in the developer guide, it’s hwkey-agent and hwkey-app to use the key for data encryption and decryption.
thanks

13

Hi @JerryChang
I have gone through hwkey-agent and hwkey-app. To enable the hwkey-agent and other TAs on Xavier I have to do ?

  1. newly generated tos_t194.img placed in /linux_for-tegra/bootloader/ directory by following the instruction in atf_and_trusty.README
  2. Secureboot enabled with <pkc.pem> and <SBK.key> keys
  3. <eks_image_file> genrated by gen_ekb.py and placed in /linux_for-tegra/bootloader/ directory
    or there is anything else that I am missing kindly guide me.
    Thanks
14

hello AbdulWasey,

you’ll need to have secure-os partition flashed with your customize image,
for example,

[ 214.3226 ] Writing partition secure-os with tos-trusty_t194_sigheader.img.encrypt
[ 214.4007 ] [................................................] 100%

those others looks correct, please have a try,
thanks

15

Hi @JerryChang

Does the

Means that the 0x01000000 in hex equals to 16,777,216 in decimal so is this size in bytes? So it will be then 16MB of TZ-DRAM allocated to secure OS?
Thanks

16

that’s correct.

18

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