A bootable image for Raspberry Pi boards based on Debian GNU/Linux and supplied with a set of open firmware from the LibreRPi project is available for testing. The image is generated using the regular Debian 11 repositories for the armhf architecture and is distinguished by the delivery of the librepi-firmware package prepared based on the rpi-open-firmware firmware.
The state of firmware development has been brought to a level suitable for running the Xfce desktop. In its current form, the firmware provides the v3d driver for the VideoCore graphics accelerator, 2D acceleration, DPI video, NTSC video (composite output), Ethernet, USB host, i2c host and SD cards on Raspberry Pi 2 and Raspberry Pi 3 boards. Not yet supported features include video decoding acceleration, CSI, SPI, ISP, PWM audio, DSI and HDMI.
Recall that despite the presence of open drivers, the operation of the VideoCore IV video accelerator is ensured by proprietary firmware loaded into the GPU, which contains quite extensive functionality, for example, support for OpenGL ES is implemented on the firmware side. In fact, on the GPU side, a semblance of an operating system is performed, and the work of open drivers is reduced to broadcasting calls to a closed firmware. To get rid of the need to download blobs, since 2017, the community has been developing a project to develop a free version of the firmware, including components for execution on the VC4 GPU side.
Source: opennet.ru