openwrt/docs/barebones-image-research.md

Barebones OpenWrt Image Research (GL-AX1800)

Objectives

• Create a stripped-down image for GL-AX1800 (Flint 1).
• Accessible via SSH.
• No LuCI or GL.iNet UI.
• Use gl-infra-builder for hardware-specific optimizations.
• Ensure U-Boot compatible image output.

Tool Selection

• Builder: FUjr/gl-infra-builder.
• Base Config: config-wlan-ap.yml (Qualcomm SDK based).
• Target Profile: target_wlan_ap-gl-ax1800.

Findings

1. Reorganization

• Workspace reorganized into firmware/, sdk/, docs/, scripts/, packages/, repo/.
• Created PROJECT_INDEX.md as a master reference.

2. gl-infra-builder Logic

• The builder uses YAML profiles in the profiles/ directory.
• gen_config.py merges multiple profiles.
• Standard GL.iNet profiles (glinet_ax1800.yml) include a heavy set of proprietary services.
• A "Barebones" profile can be created by overriding these with -package or CONFIG_PACKAGE_xxx=n in the diffconfig section.

3. OpenWrt Snapshots & Upgrade Path

• V21.02 (GL 4.x): Current base for most GL firmware.
• V23.05: Transitional, used ipq40xx target.
• Master/V24/V25: Native qualcommax/ipq60xx target (merged March 2025).
• Upgrade Path:
  • From GL Stock -> Vanilla: Flash factory.ubi via U-Boot recovery (192.168.1.1).
  • From Vanilla -> Newer Vanilla: Use sysupgrade.bin.
  • Note: Partition layouts might change between 21.02 and 24.x. Using the factory.ubi is safest for major transitions.

4. Barebones Configuration Plan

• Include dropbear (SSH), opkg (Package management).
• Include essential HW drivers: kmod-gl-sdk4-hw-info, gl-sdk4-led.
• Explicitly disable luci, nginx, and all gl-sdk4-ui-* packages.
• Ensure ath11k drivers are included for Wi-Fi (if using OpenWrt master) or the proprietary QSDK drivers (if using the builder).