Files
bfe-core1106-sdk/kernel/docs/bringup.md
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BFE Engineering 42fb386f60 docs: ASCII typography and style normalization across all repo text
Replace every em dash with real punctuation (rewrites, not hyphen swaps)
in docs, code comments, scripts, configs, and the port records; convert
en dashes, curly quotes, ellipsis glyphs, arrows, and section signs to
ASCII; drop machine-writing tell phrases from living docs. ADR titles
now use a colon. The M2 bring-up DTS model string carried an em dash
into the patch series and its record echoes; fixed at both, and the full
series re-verified to apply cleanly onto pristine 6.18.46. One comment
in freshness.h deliberately names the em dash glyph the UI renders as
the unknown mark; that is data, kept as prose naming it.

Verified: cargo tests (sim, config-lint, rs485-bridge), shellcheck,
both driver MC/DC harnesses, patches-apply.
2026-08-31 12:31:27 -06:00

3.9 KiB

RV1106 -> Linux 6.18 forward-port (self-built, from vendor 5.10)

Decision (2026-08-23): forward-port the RV1106 SoC enablement from the Rockchip vendor 5.10 tree straight to Linux 6.18 LTS, ourselves, using no plan44 code, built on our Buildroot 2025.02 LTS + uClibc. We own the tree.

The reality this rests on (verified, not assumed)

Vanilla mainline (6.6.93 and 6.18) has zero RV1106 support: no devicetree, no clock driver, no pinctrl data, not one rv1106 reference in arch/arm or drivers/. So "the newest kernel" is a generic ARM kernel that cannot boot this SoC. What we forward-port is the entire RV1106 BSP: ~120 files in the vendor 5.10 tree touch rv1106 (DT, clk, pinctrl, mach/PM, VOP display, mmc, and the out-of-tree AIC8800/RGA/MPP). This is a large, multi-milestone kernel effort; it is delivered incrementally, console-first.

Method (how each piece is ported)

  • Framework drivers -> sibling-delta. clk and pinctrl are driven by the shared rockchip framework (drivers/clk/rockchip/clk.c, pinctrl-rockchip.c). RV1106's siblings rv1126 and rv1108 exist in BOTH vendor-5.10 and mainline-6.18, so their 5.10->6.18 delta is the exact recipe for how the framework API changed. We apply that recipe to rv1106's data (clk-rv1106.c = 1284 lines; rv1106-cru.h clock IDs; the rv1106 pinctrl table). This turns "adapt to APIs we have to guess" into "copy a diff a sibling already proves."
  • SoC-unique code -> forward-port + build-fix-build. mach-rockchip (machine, rockchip_hptimer, rv1106_pm/rv1106_sleep.S), the CRU/GRF glue, and the board DT have no sibling; port directly and iterate on the 6.18 build.
  • Mainline-present drivers -> just wire DT + clocks. 8250-dw UART, dw_mmc (SDIO/eMMC), dw-apb i2c, rockchip gpio/pinctrl core, pwm, dw-wdt watchdog are all in mainline 6.18. We do not port them, we supply the DT nodes + clock/reset phandles and let the mainline drivers bind.
  • Out-of-tree drivers -> port the driver. AIC8800 wifi (plan44 has none; ours), RGA/MPP kernel bits (assess vs need: the 86-Panel has no camera), carrying our Tier-1 SDIO-wakeup fix forward.
  • Our 4 kernel patches (panel-mcu-reset/logo, watchdog-enable, usb-otg dual-role, recovery-splash) -> re-apply against 6.18 (line offsets + some DT bindings changed).

Bring-up milestones (console-first order)

  • M0: buildable base. 6.18.46 tree + our Buildroot/uClibc toolchain builds a generic ARM kernel; a rv1106_defconfig forward-ported from vendor 5.10.
  • M1: SoC compiles. mach-rockchip RV1106 select + clk-rv1106 + rv1106 pinctrl data + rv1106-cru.h compile clean against 6.18 (no boot yet).
  • M2: earlycon boot. DT (rv1106.dtsi core) + clk + pinctrl + 8250-dw -> kernel prints to the RV1106 UART. The first "it's alive."
  • M3: rootfs boot. dw_mmc + DT -> eMMC/SD rootfs, userspace up on our Buildroot.
  • M4: display. VOP2 + the RGB666 720x720 panel + GT911 touch + PWM backlight -> the LVGL UI renders.
  • M5: wifi + our patches. AIC8800 SDIO driver ported (+ Tier-1 fix); the 4 custom kernel patches re-applied.
  • M6: the rest. RGA (UI accel), watchdog, HPMCU coprocessor, USB-OTG dual role.

Regression (so a 6.18 port doesn't reintroduce the struct-ABI bug class)

The warden-sdk simulator + MC/DC harness are how we hold the line: HpmcuSim and the register/MemBus seam test the supervisor/reset logic off the ported kernel; the relays-mcdc pattern extends to each ported driver we own; and a config-lint CI gate (the class that bricked c8a3: a load address in unreserved kernel RAM) checks the DT reservations against the drivers on every build.

Layout (this repo)

kernel/
  rv1106-enablement/   the ported RV1106 BSP as it lands (patches/files on 6.18)
  docs/bringup.md      this plan

The 6.18.46 source + the vendor 5.10 tree stay in flare-edge/research/ and flare-edge/.../sdk/ respectively (references, not committed here).