Files
bfe-core1106-sdk/docs/decisions/0001-kernel-base.md
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BFE Engineering c756622c96 docs: reposition as the 86 Panel development environment
The repo's documentation framed it as a support repo for one product
(WardenOS). Since going public the real audience is anyone with a Luckfox
Pico 86 Panel: a maintained 6.18 kernel, an off-device development loop,
and a device simulator that exist nowhere else for this board. Reframe the
README and top-level docs board-first, with WardenOS documented as the
downstream consumer it is (ADR-0008).

Also an editorial pass over the whole doc set:
- every H1/H2 is now a short title, not a sentence (ADRs, qemu/, patches/,
  drivers/, architecture, NPU feasibility, config-lint, payload); workflow
  flowchart titles fixed at the source in tools/flowgen.py and regenerated
  with fresh bench numbers
- README Quick Start commands verified against the scripts; requirements
  corrected (curl, bare python, gcc >= 14) and the MC/DC gate added as a
  step (run green locally on gcc 14.2)
- dropped the 'needs python (not python3)' vendor dig: build-kernel.sh
  inherited the same requirement (filed #10 to remove it)
- glossed MC/DC and HPMCU on first use; marked the tests/uboot-ab
  reference as flare-edge; deduplicated the three-simulator list into the
  root README table
2026-08-30 22:19:12 -06:00

1.5 KiB

ADR 0001 — Kernel Forward-Port

Status: Accepted (2026-08-25). Supersedes the README's original plan44/6.6 goal.

Context

The vendor kernel is Rockchip 5.10.160 (via Luckfox). We want the newest stable Linux runnable on our Buildroot LTS (2025.02.x). Two candidate paths existed: (a) baseline on plan44's OpenWrt RV1106 fork (Linux 6.6, 152 RV1106 patches), or (b) forward-port the vendor tree directly onto a chosen upstream stable.

Decision

Forward-port directly to Linux 6.18.46 from vendor 5.10.160, carrying no plan44/OpenWrt code. Reuse the already-upstream rv1126 register data where it matches the RV1106 ("RV-series lite" VOP, clk, pinctrl), and carry the RV1106 deltas as a reviewable patch series in patches/.

Consequences

  • Done and hardware-verified on warden-c8a3: clk, pinctrl, eMMC, GMAC, TRNG, OTP, SARADC/TSADC, RTC, USB host, PWM/backlight, VOP display, GT911 touch, AIC8800 wifi, RGA, I2S audio, HPMCU mailbox, open NPU driver, PVTM.
  • uClibc stays load-bearing — RGA/MPP/ISP/NPU userspace ship as uClibc-only blobs; a glibc swap breaks media (flare-edge #51, wontfix). Any kernel bump inherits this.
  • Kernel bumps risk struct-ABI breaks for out-of-tree modules (the AIC8800/VLAN struct net_device offset saga). Mitigation: ship one matched full boot+oem image, never a partial reflash.
  • Deferred by design: crypto-v3 accelerator (CPU crypto already covers the need), open NPU compute (a person-year register-RE effort, no RV1106 prior art).