AM2432: Secure boot time

Hi Kuerbis,

1) How long is the boot time of AM2432?

It depends on the size of the AppImage. 

2) How much difference is there in boot time with or without secure boot?

We do not have the benchmark numbers for AM243x secure boot yet

3)  Is there a size constraint for encrypted code deployed on internal SRAM? The external ROM will be a 1MB.

It depends on the way of encrypting/decrypting the SBL uses. If SBL load the whole AppImage into the RAM and then decrypt it, then the external ROM cannot be 1MB or larger. If the SBL load and decrypt AppImage in fixed block (require the encrypting in blocks too), then the AppImage can be larger than 1MB.

I did a very simple normal OSPI boot test on the AM243x EVM. Here is the boot time break down:

[BOOTLOADER PROFILE] System_init                      :      36792us

[BOOTLOADER PROFILE] Drivers_open                   :        272us

[BOOTLOADER PROFILE] Board_driversOpen         :      21792us

[BOOTLOADER PROFILE] CPU load                         :      28120us

[BOOTLOADER_PROFILE] SBL Total Time Taken     :      87912us

The CPU load time is the SBL loading the AppImage (150KB) time. The example application is the IPC notify FreeRTOS example.

With about result, you may get some idea about the normal boot time.

There is not limitation on RAM size for each R5F core. The only limit is the total on-chip memory (2MB + 256KB TCM)

Best regards,

Ming