As much as I like the Raspberry Pi (no, I really do!), the graphical chip on this can only be better than the NDA nightmare of the RPi. It hasn't impacted me personally, but a few friends who are using it for specific use cases have had the problem when designing their own bootloader. Interested in getting my hands on one, but now all I need is time...
I've dug a little bit, and it looks like I'm a bit late. Broadcom did indeed give the keys to developers for the VideoCore IV, and a while ago. Yes, I haven't worked on RPi for some time. Previous to this, we had no idea how the chip worked, and we relied solely on a blob. So I stand corrected, things have indeed changed since my time. Thankfully! My bad.
The Raspberry Pi is the ONLY ARM based SOC that has fully documented the "graphical chip", there is no NDA ! I have no idea why you think there is.
The RPI GPU has a disassembler that can be used to on the "proprietary" boot loader (not very proprietary when you can disassemble it) to see exactly
what is needed to build your own.
Are people allowed to do that? I'm wondering it that gets classed as reverse engineering (which is not legal in some countries).
Furthermore, even if one did have the right to disassemble, they couldn't publish the disassembed code or share it with anyone, since I don't recall raspberry pi. org extending any license to allow that.
That could certainly make development of a custom bootloader awkward if you can't share with your team what you've found in the proprietary bootloader.
While we're on the subject of things that make development awkward on the Pi, I recall the information to make use of the CSI/DSI ports is still not available, making life difficult for anyone who
wishes to use their own hardware over those interfaces..
And of course the lack of full schematics, which causes issues.
In my ARM book, I talked about the RPi (version 1) and the bootloader, with an example of how to write boot code. I had multiple exchanges with ARM because it was a very delicate subject. I ended up publishing about 20% of what I had originally written, no-one wanted to go close to that subject.
In my ARM book, I talked about the RPi (version 1) and the bootloader, with an example of how to write boot code. I had multiple exchanges with ARM because it was a very delicate subject. I ended up publishing about 20% of what I had originally written, no-one wanted to go close to that subject.
