GPU memory split behavior change on 64-bit Raspberry Pi OS
Documented behavior shift The Raspberry Pi 4's gpu_mem parameter in /boot/config.txt has historically controlled the GPU/CPU memory split on 32-bit Raspberry Pi OS, with values such as 256 MB being honored directly. Starting with the 64-bit Raspberry Pi OS (Bullseye and later) and bootloader firmware 2022.02, a new gpu_mem_256 flag was introduced that appear
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