Configure TUNA APT Mirrors for Raspberry Pi OS based on Debian 13

Currently, Raspberry Pi OS uses debian repository as its main system package source, while the raspberrypi repository provides Raspberry Pi-specific packages, such as kernel modules, firmware, and related components.

APT source configuration files are located under /etc/apt/sources.list.d, and they use the DEB822 format.

Edit debian.sources to add TUNA mirror:

Types: deb
URIs: https://mirrors.tuna.tsinghua.edu.cn/debian/
Suites: trixie trixie-updates
Components: main contrib non-free non-free-firmware
Signed-By: /usr/share/keyrings/debian-archive-keyring.pgp

And edit raspi.sources to add TUNA mirror:

Types: deb
URIs: https://mirrors.tuna.tsinghua.edu.cn/raspberrypi/
Suites: trixie
Components: main
Signed-By: /usr/share/keyrings/raspberrypi-archive-keyring.pgp

Then, run sudo apt update to refresh the packages indexes.

As for raspbian repository, it is a Debian-derived repository historically used by 32-bit Raspberry Pi OS. It is not needed for current 64-bit Raspberry Pi OS images based on Debian 13 trixie.