3.10. DTBO overlays¶

dtbo_a.bin is an Android DTBO image holding three device-tree overlays, one per PCB revision (v10/v20/v30) of the Note Air5 C; how ABL selects one and what actually differs between them is under “Container” and “Difference between the three revisions” below.

3.10.1. Container¶

Android DTBO image (magic 0xd7b7ab1e), header v0, page 4096, total 1,529,557 B (partition is 24 MB; the remainder is zero pad). 3 overlay entries, each ~510 KB, all id=0 rev=0 custom=0:

Entry	File offset	Size	Decompiled	`model`	`onyx,pcbver-id`
0	`0x80`	509,847	`overlay_0.dts` (6888 ln)	Lagoon MTP NoteAir5C v30	`0x02`
1	`0x7c817`	509,735	`overlay_1.dts` (6877 ln)	Lagoon MTP NoteAir5C v10	`0x00`
2	`0xf8f3e`	509,847	`overlay_2.dts` (6888 ln)	Lagoon MTP NoteAir5C v20	`0x01`

All three: compatible = "qcom,lagoon-mtp","qcom,lagoon","qcom,mtp", qcom,msm-id=<0x1b2 0x10000 0x1cb 0x10000> (SoC 434/459), qcom,board-id=<0x08 0x00>. Each is a full board description (109/108/109 fragments, 51 distinct compatibles), not a small patch — ABL picks one whose board-id/pcbver matches the running PCB and applies it over the base SoC DTB (../artifacts/boot_a/board.dts). Fragment targets are unresolved symbolic placeholders (target = <0xffffffff>, fixed up at apply-time via __symbols__/__fixups__), so a raw board.dts diff is not meaningful — the overlays are the board tree.

3.10.2. Difference between the three revisions¶

The v10/v20/v30 blobs are near-identical clones. Stripping phandle noise, the entire substantive delta is the PCB-version tag and the e-ink TCON firmware product-id:

	v10 (pcbver 0)	v20 (pcbver 1)	v30 (pcbver 2)
`onyx,lfcpnx@0 fw-product-id`	`0x9e`	`0x9e` + `0xa5`	`0x9e` + `0xa7`

onyx,lfcpnx@0 = the LFCPNX100 e-ink TCON (timing controller), SPI-attached (spi-cs-gpios, spi-gpios, status="okay"). fw-product-id selects which TCON firmware blob the kernel loads (matches the lfcpnx/lfcpnx100_tcon_fw_* bundle in the kernel config, Boot image: kernel, DTB, ramdisk, config).
v20/v30 add a second lfcpnx@0 fragment carrying a newer product-id (0xa5/0xa7) alongside the base 0x9e — later PCB revisions ship a revised e-ink panel/TCON firmware variant. No panel-technology change, no SoC change, no memory-map change between revisions — this TCON firmware id is the overlay set’s reason to exist.

3.10.3. Onyx-specific hardware the overlays wire up¶

Distinct onyx,* compatibles (identical across all three revisions):

Node	Hardware
`onyx,lfcpnx`	color e-ink TCON (LFCPNX100), SPI
`onyx,lfe5u_i2c`	Lattice ECP5 (LFE5U) FPGA bridge over I²C (e-ink pipeline glue)
`onyx,wacom_i2c`	Wacom EMR stylus digitizer (I²C)
`onyx,backlight` + `onyx,lm3630a_v3`	front-light (TI LM3630A dual LED driver — warm/cold)
`onyx,kb-serial` + `onyx,keyboard-ultra2`	detachable magnetic keyboard (serial)
`onyx,onyx-hall`	Hall sensor (magnetic cover / folio detect)
`onyx,power-manager`	Onyx power-management node

E-ink waveform tunables present in the overlay: onyx,tcon-mode-support, epdc-regal_nm-enable, epdc-gu-regal-enable (Regal grayscale for pen), epdc-a2-enhance-* (A2 fast-refresh mode).

3.10.4. Cross-check¶

This hardware inventory (LFCPNX100 TCON, Lattice ECP5 FPGA bridge, Parade capacitive touch, Wacom EMR digitizer, LM3630A front-light, Hall sensor, serial keyboard — Parade’s compatible/I²C-address/GPIO bindings are also sourced from this overlay, see Capacitive touch (Parade pt_core)) matches the kernel-driver inventory in Boot image: kernel, DTB, ramdisk, config item for item, and refutes the leftover XBL AMOLED panel entry noted there.

3.10.5. Artifacts¶

../artifacts/dtbo_a/overlay_{0,1,2}.dtb (raw) and overlay_{0,1,2}.dts (decompiled: 0=v30, 1=v10, 2=v20).

3.10.6. Provenance¶

Source:: ../_READONLY/lun4/dtbo_a.bin (READ-ONLY). Extracted blobs and decompiled overlays in ../artifacts/dtbo_a/.
Method:: Parse DTBO header (struct big-endian) into 3 entries; carve each blob; dtc -I dtb -O dts. Diff decompiled overlays pairwise, filtering phandle/target/fragment noise to isolate real deltas.
Cross-refs:: Boot image: kernel, DTB, ramdisk, config.