Asahi Linux documentation has pretty good writeup. The GPU is described here[1] and the mailbox interface used generally between various components is describe

Asahi Linux documentation has pretty good writeup. The GPU is described here[1] and the mailbox interface used generally between various components is described here [2] [1] https://github.com/AsahiLinux/docs/wiki/HW%3AAGX#overview https://github.com/AsahiLinux/docs/wiki/HW%3AAGX#overview [2] https://github.com/AsahiLinux/docs/wiki/HW%3AASC https://github.com/AsahiLinux/docs/wiki/HW%3AASC