PROCESSOR-SDK-AM62X: How to create a fw-tiboot3.bin that can download a tiboot3.bin via dfu and write to emmc boot0

Here is the FAQ for your reference
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1127618/faq-sk-am62-how-to-flash-emmc-using-usb-dfu-on-am62x-sk-e2
where u-boot binaries need to be signed in order to boot on HS-SE.
Best,
-Hong

We are familiar with the process documented in that FAQ, and have implemented and use it.

But it is not appropriate for our manufacturing environment in which we will be enabling secure boot.  The process involving use of a fw-tiboot3.bin is more appropriate.  That is why I am asking how to build it.

In the factory, we cannot perform the step involving interrupting the u-boot boot flow to manually enable dfu for flashing emmc.

Our devices are configured with emmc as primary boot, and dfu as fallback.  We intend to gang flash emmc such that the tiboot3.bin region of boot0 is is blank, so the device falls back to dfu.

We wish, as approximately described in AM62x_HS_Key_Programming_Flashing_v3.pdf, to:

1) boot a device, and download keywriter (kw-tiboot3.bin), which will enable HS-SE mode.

2) on reset, bootrom enables dfu again, and we download flash writer (fw-tiboot3.bin).

3) device resets and boots into fw-tiboot3.bin, which provides dfu, over which we download main tiboot3.bin, which fw-tiboot3.bin writes to boot0 partition.

Based on AM62x_HS_Key_Programming_Flashing_v3.pdf, this should be possible.

Yes, the flow is doable and described in slide #8 and #9 of the AM62x_HS_Key_Programming_Flashing_v3.pdf.
For your case, the backup boot media is USB-DFU, and the US-DFU u-boot binary needs to be signed as flasher.
Best,
-Hong

I am asking how to create fw-tiboot3.bin.

There is no documentation on how to create it.

One reference is the FAQ in my early reply.
User would need to customize it for production ready flashing tool depending on user's own requirement.
Best,
-Hong