AM6442: Secure boot with encrypted appimage is failed

Koji Hirohashi

Intellectual 430 points

Part Number: AM6442

I would like to test secure boot from eMMC on AM6442 HS-SE.

Incase of "ENC_SBL_ENABLED?=yes", secure booting is succeeded.

However, secure booting in case of "ENC_ENABLED?=yes" is failed:

DMSC Firmware Version 9.1.6--v09.01.06 (Kool Koala)
DMSC Firmware revision 0x9
DMSC ABI revision 3.1

Some tests have failed!!

This log is shown if any of the using appimage are encrypted:

linux.appimage(bl31.bin, bl32.bin, u-boot-spl.bin)

hello_world.release.appimage

I referenced following question but I couldn't resolved the issue.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1307606/sk-am62a-lp-rpmsg_char_zerocopy-sample-code-boot-fail-dmsc-abi-revision-3-1-some-tests-have-failed?tisearch=e2e-sitesearch&keymatch=Some%20tests%20have%20failed%20sbl#

What else should I check to this boot issue?

my sdk:

mcu_plus_sdk_am64x_09_01_00_41

ti-processor-sdk-linux-am64xx-evm-09.01.00.08

over 1 year ago

0 Prashant Shivhare over 1 year ago

TI__Guru* 78261 points

Hi Koji,

Thank you for reporting the issue.

I have reproduced the issue. And on looking into the code, I understand that due to the way the authentication procedure is implemented in the SDK, it is not possible to have a successful boot with encrypted appimage.

Root Cause

For eMMC, the authentication procedure involves reading the image into DDR and requesting the authentication. This passes successfully and the decrypted image resides in the DDR. However, the current implementation again reads the appimage from eMMC for booting. Since, the appimage is encrypted in the eMMC, the boot fails.

After successful authentication, the decrypted appimage resides in the DDR and so the driver should read and parse the decrypted appimage from DDR instead of eMMC.

Action: I will file a bug ticket internally for this issue.

Regards,

Prashant

0 Koji Hirohashi over 1 year ago in reply to Prashant Shivhare

Intellectual 430 points

Hi Prashant

Thank you for your swift response.

I would like to use the SoC for our new product.

Could you inform me when the bug will be fixed?

Best Regards,

Koji

0 Prashant Shivhare over 1 year ago in reply to Koji Hirohashi

TI__Guru* 78261 points

Hi Koji,

Koji Hirohashi said:
Could you inform me when the bug will be fixed?

I have already created the ticket internally. It may take some time for the team to evaluate the issue. I will let you know if there is any update.

For now, the best I can do is to give you a workaround to boot encrypted appimages successfully.

Regards,

Prashant

0 Prashant Shivhare over 1 year ago in reply to Prashant Shivhare

TI__Guru* 78261 points

Closing the issue as it is further followed here

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1383716/am6442-secure-boot-with-encrypted-appimage-is-failed-part2

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AM6442: Secure boot with encrypted appimage is failed