AM62A7-Q1: Why is there so many Authentications during the boot process, and can I reduce the number of Authentications to improve the boot time?

Hi，Prashant

Authentication checks are causing the boot time to take too long. So  can I turn off some authentication checks? What should I do?

Or is there another way to reduce the time to authentication checks?

Regards,

gangqiang

The boot log is as follows：

·······[0.000000 0.000000] 
[0.000276 0.000276] U-Boot SPL 2023.04-g4ad0bf40-dirty (Mar 28 2024 - 19:17:33 -0700)
[0.004827 0.004550] SYSFW ABI: 3.1 (firmware rev 0x0009 '9.1.8--v09.01.08 (Kool Koala)')
[0.056899 0.052073] am62a_init: board_init_f done
[0.059284 0.002385] SPL initial stack usage: 17040 bytes
[0.063100 0.003816] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.069575 0.006475] Trying to boot from MMC1
[0.576587 0.507012] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.582406 0.005819] Authentication passed
[0.593301 0.010895] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.599524 0.006223] Authentication passed
[0.607265 0.007741] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.613235 0.005970] Authentication passed
[0.659851 0.046616] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.667841 0.007990] Authentication passed
[0.671415 0.003574] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.677467 0.006052] Authentication passed
[0.693923 0.016456] Starting ATF on ARM64 core...
[0.697912 0.003989] 
[0.698015 0.000104] NOTICE:  BL31: v2.9(release):v2.9.0-614-gd7a7135d32-dirty
[0.703209 0.005193] NOTICE:  BL31: Built : 09:34:15, Aug 24 2023
[0.855398 0.152189] 
[0.855814 0.000417] U-Boot SPL 2023.04-dirty (Mar 29 2024 - 10:23:57 +0800)
[0.859951 0.004136] SYSFW ABI: 3.1 (firmware rev 0x0009 '9.1.8--v09.01.08 (Kool Koala)')
[0.866963 0.007012] am62a_init: board_init_f done
[0.869651 0.002688] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[0.876128 0.006477] Trying to boot from MMC1
[1.008748 0.132620] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[1.014214 0.005466] Authentication passed
[1.639498 0.625283] am62a_init: spl_boot_device: devstat = 0x4b bootmedia = 0x9 bootindex = 0
[1.646000 0.006503] Authentication passed
[2.353033 0.707032] 
[2.353522 0.000490] 
[2.353603 0.000080] U-Boot 2023.04-g4ad0bf40-dirty (Mar 28 2024 - 19:17:28 -0700)
[2.359774 0.006171] 
[2.359885 0.000110] SoC:   AM62AX SR1.0 HS-FS
[2.363874 0.003990] Model: Texas Instruments AM62A7 SK
[2.364471 0.000597] DRAM:  2 GiB (effective 4 GiB)
[2.641799 0.277328] Core:  58 devices, 28 uclasses, devicetree: separate
[2.646383 0.004584] MMC:   mmc@fa10000: 0, mmc@fa00000: 1
[2.655421 0.009039] Loading Environment from MMC... OK
[2.750122 0.094700] In:    serial@2800000
[2.751599 0.001477] Out:   serial@2800000
[2.753502 0.001903] Err:   serial@2800000
[2.758575 0.005073] Net:   eth0: ethernet@8000000port@1
[2.766715 0.008140] Hit any key to stop autoboot:  0 
[2.903259 0.136544] 19974656 bytes read in 131 ms (145.4 MiB/s)
[2.930170 0.026911] 51387 bytes read in 21 ms (2.3 MiB/s)
[2.933882 0.003712] Working FDT set to 88000000
[2.936420 0.002539] ## Flattened Device Tree blob at 88000000
[2.940394 0.003974]    Booting using the fdt blob at 0x88000000
[2.947414 0.007020] Working FDT set to 88000000
[2.973331 0.025917]    Loading Device Tree to 000000008fef0000, end 000000008fffffff ... OK
[2.982185 0.008854] Working FDT set to 8fef0000
[2.988991 0.006806] 
[2.989515 0.000524] Starting kernel ...
[2.989939 0.000423] 
[3.006347 0.016408] [    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034]

Hi Prashant,

We tried Falcon mode, but it didn't meet our requirements. First of all, there are OTA requirements in our project. In Falcon mode, whether OTA can be realized still needs to be verified. Second, in our tests, Falcon mode did not improve the startup time significantly.

So we tried to optimize in normal startup mode. In the normal mode, could you please give me a little more advice to achieve my purpose?

Regards,

Gangqiang

Hi,

He Gangqiang said:

In Falcon mode, whether OTA can be realized still needs to be verified.

The Falcon boot doesn't change anything. The primary purpose of Falcon boot is to remove the A53 SPL and A53 U-Boot from the boot flow. You can still use Falcon boot to boot your already existing rootfs supposedly with OTA capabilities.

In the normal boot flow, the authentication time will be there. You will have to look at other aspects to achieve improved boot time.

Regards,

Prashant

You can evaluate these threads if it helps

- e2e.ti.com/.../sk-am62a-lp-booting-to-linux-kernel-directly-from-r5f-spl

- e2e.ti.com/.../processor-sdk-am62a-reducing-linux-boot-time

Hi Prashant,

We also have a requirement that we will start the MCU first, and then start the SOC, and using falcon mode will not affect it? If it does not affect, we will try to use falcon to fulfill our requirements.

Regards,

Gangqiang

Hi,

He Gangqiang said:

We also have a requirement that we will start the MCU first, and then start the SOC, and using falcon mode will not affect it?

In the normal boot flow, the MCU firmware is only booted by the Linux Remoteproc driver. How are you achieving the early booting of MCU with the existing boot flow?

Hi Prashant,

I follow this document:

https://software-dl.ti.com/mcu-plus-sdk/esd/AM62AX/09_01_00_39/exports/docs/api_guide_am62ax/GETTING_STARTED_FLASH.html

To enable the MCU to start first. Is that right?

Regards,

Gangqiang

Hi,

He Gangqiang said:

To enable the MCU to start first. Is that right?

But, this is when you use the MCU+ SDK boot flow which I believe you are not using at the moment. If you happen to use MCU+ SDK boot flow then yes the MCU is first started before booting Linux.

Regards,

Prashant

Hi Prashant,

We will later boot flow based on MCU+SDK. On this basis, there is also a problem that authentication checks cause a long time. Is there a way to improve boot time in this mode? This need is very important to us.

Regards,

Gangqiang

Hi,

If you are okay with booting unauthenticated images, then you can simply disable the authentication.

Regards,

Prashant 

Hi Prashant,

How to simply disable the authentication?

Regards,

Gangqiang

Hi Prashant,

Thanks for your support, I tried to disable the authentication successfully.

Regards,

Gangqiang