rpi-open-firmware

> Please correct me if I'm wrong. My memory told me it was the GPU that needed the blobs. So I asked at DDG https://duckduckgo.com/?t=ftsa&q=binary+blobs+and+the+Raspbe... Turned up this: https://wiki.debian.org/RaspberryPi and it says... > All Raspberry Pi models before the 4 (1A, 1B, 1A+, 1B+, Zero, Zero W, 2, 3, Zero 2 W) boot from their GPU (not from the CPU!), so they require a non-free binary blob to boot So the 4 (and I suppose the 5, if it ever actually comes...) Goes on to say: > Since then, Broadcom publicly released some code, licensed as 3-Clause BSD, to aid the making of an open source GPU driver. The "rpi-open-firmware" effort to replace the VPU firmware blob started in 2016. See more at https://news.ycombinator.com/item?id=11703842 . Unfortunately development of rpi-open-firmware is currently (2021-06) stalled. So there yo

https://github.com/librerpi/rpi-open-firmware The paragraph 'Does it boot Linux' should answer your questions

lk-overlay contains many different projects using the vc4-stage1, vc4-stage2, and rpi2-test projects together, you can do the entire boot chain (dram init and loading linux) using open source code other projects act as demo's or tests on how to run custom code at various stages, but not actually boot linux on the arm core many of those demos work on the the entire pi model range pi3 support is only broken due to arm side problems, which could be fixed by just using a different bootloader and the https://github.com/librerpi/rpi-open-firmware codebase can already boot linux headlessly on both pi2 and pi3, it uses a different arm bootloader

Yes, and some folks are reverse engineering their stuff: https://github.com/librerpi/rpi-open-firmware/

There is work being done on the RPi4, for example the SHA1 HMAC protecting the boot on the RPi4 had to be cracked (and was easily), I hear future versions have RSA signing support, so the proprietary firmware might become mandatory at some point. https://github.com/librerpi/rpi-open-firmware/blob/master/do...

There is a project to create an open source version of the proprietary GPU firmware that boots into the ARM processor: https://github.com/librerpi/rpi-open-firmware

I note that even the Raspberry Pi is moving towards locked down devices, the RPi4 has an (easily cracked) HMAC blocking booting into the open source firmware and I hear more recent hardware editions have RSA signing support in the bootrom code. https://github.com/librerpi/rpi-open-firmware/blob/master/do...

There is an open bootloader, sadly it needs a non-upstream toolchain: https://github.com/librerpi/rpi-open-firmware https://github.com/itszor/vc4-toolchain/issues/7

There is libre RPi boot firmware, unfortunately it relies on toolchain support that isn't upstream yet: https://github.com/librerpi/rpi-open-firmware https://github.com/itszor/vc4-toolchain/issues/7

Some links for folks who want to work on fixing the blob situation: https://github.com/librerpi/rpi-open-firmware https://github.com/itszor/vc4-toolchain/issues/7

https://github.com/librerpi/rpi-open-firmware is a pretty serious attempt at the bootloader (incl. VC4 side). As in they can boot an OS, with some limitations but still.

Since the GPU starts before the CPU, you need a blob to boot the GPU before you can start open code on the CPU. There is open GPU boot firmware being worked on but it isn't ready yet and relies on GCC support for the GPU, which isn't mainlined yet and the authors don't intend to mainline. So probably RPi will need blobs to boot for the foreseeable future. https://github.com/librerpi/rpi-open-firmware https://github.com/itszor/vc4-toolchain/issues/7