_BOOT_DATA is different from C BootData

[Xaymar]

In the Teensyduino library, the start entry of .bootdata is set to 0x6000_0000, but in your version of .bootdata it is set to 0x0. While I think both adresses alias the same memory, is accessing the flash through the ITCM On-Chip RAM faster than reading from the "FlexSPI ciphertext" Flash memory?

[branan]

Mine should be 0x6000_0000.

The ROM bootloader doesn't care about that number in the teensy case where the flash is memory mapped, since there's a direct entry point. But in theory a future ROM revision might care.

I'm not working on this repo anymore - I'm moving towards a unified runtime for multiple generations of Teensy, which is not yet public. I'll make sure to address this there.

[Xaymar]

Mine should be 0x6000_0000.

Alright, I'll change that locally then. I have the basic boot process working, just wanted to make sure that i wasn't doing something wrong. Still have to figure out how to move the heap into RAM2, since it isn't by default mapped to anywhere. Probably will run into it soon enough if i convert the Teensyduino 4.0 library over far enough.

I'm not working on this repo anymore - I'm moving towards a unified runtime for multiple generations of Teensy, which is not yet public. I'll make sure to address this there.

That sounds great. I've been trying to get rust to boot on a Teensy 4.0 and have run into a few difficulties with the initial state not matching what it should be - so it's been an inconsistent boot process for now.

[Xaymar]

I've managed to fully boot the Teensy 4.0 now, including all hardware security features and devices. It's a lot of messy code right now, but this repo helped out a lot to get things started. Thanks @branan