Customize Clocks

Purpose

Customize CPU, GPU, and EMC clock behavior on a Jetson target by editing files under Linux_for_Tegra/ before flashing the image. Two layers are in scope:

• The BPMP DTB at Linux_for_Tegra/bootloader/<BPFDTB_FILE> — per-clock max-rate-custom ceilings, plus the EMC DVFS gate (bwmgr + cactmon on all SoCs; osp-controller on T26x only).
• nvpower.sh at Linux_for_Tegra/rootfs/etc/systemd/nvpower.sh — cpufreq / devfreq governors and (optionally) per-device min / max / static rates written to sysfs at boot.

Common triggers: "lock CPU/GPU/EMC frequency", "pin GPU to Fmax", "pin EMC to MAXN", "disable/enable EMC DVFS", "disable/enable CPU DVFS", "set CPU/GPU max rate", "change cpufreq governor".

Out of scope: runtime clock tuning on a live target (no flash step), nvpmodel power-mode edits (use the sibling skill /jetson-customize-nvpmodel), and silicon-ceiling overrides (max-rate-maxn is read-only).

Prerequisites

Resolve the active profile per ../../context/target-platform-contract.md. Refuse and route in these cases: