tinyusb.git, branch cdc_persistent

avoid flushing tx buffer on connection

2026-08-04T14:02:10Z

Signed-off-by: Zixun LI

Merge pull request #3787 from hathach/claude/add-etm-trace-skill

2026-07-24T16:11:58Z

Add etm-trace skill: unattended ETM instruction trace + per-board TRACE_ETM support

address #3787 Codex round 3: coverage keys, RA attach limitation

2026-07-24T15:40:52Z

Coverage rows now resolve the de-collided module-qualified key introduced for same-named statics. RA boards: document that --attach requires a debugger-booted target - the C_DEBUGEN gate exists because an unguarded TRCKCR write bricks standalone boots (hardware-proven), so the limitation is documented rather than the guard weakened; a debugger-side TRCKCR hook can lift it later once re-verified on hardware. The stm32n6 board-gating suggestion is not taken: N6 trace pins are AF0-fixed chip-level, the same family-wide pattern as stm32h7.

address #3787 Codex round 2: board-gate PHY resets, session robustness

2026-07-24T14:30:42Z

The board-specific PHY-reset nets move behind a board.h opt-in (TRACE_ETM_QUIET_ENET_PHY on same70_xplained and mimxrt1170_evkb) so other boards of those families cannot inherit a foreign GPIO write; the chip-level trace pin muxes stay family-wide by design (same pattern as stm32h7). same70 reference: width 1 is the validated default until the J403.16 rework, and the hooks now wait (bounded) for PCKRDY3 before Ozone arms trace. ra8m1 reference caches the boot ROM in AfterTargetConnect so --attach sessions decode ROM execution too. etm_capture rejects an unexpanded CMake JLINK_DEVICE with a clear error; PIO-USB + TRACE_ETM on RP2350 is now a compile error (48 MHz trace clock is too slow for PIO-USB and a runtime switch would desync the stream); etm_profile keeps same-named statics from different modules as distinct rows. Build-verified: same70_xplained, mimxrt1170_evkb, raspberry_pi_pico2.

address #3787 reviews: bsp fixes, script hardening, board-note accuracy

2026-07-24T11:38:40Z

Bot findings (Copilot/Codex): no-op board_trace_pinmux stubs for lpcxpresso18s37/43s67 (TRACE_ETM otherwise broke their build), SAME70 ID_PIOD clock enable, capture-script duplicate BeforeTargetConnect on the RA references, profile-script support for --no-timestamps itraces. Deep review (whole branch): same70_xplained board row + caveat restored, stale pico2 72 MHz claim corrected to the shipped 48, explicit SetTracePortWidth(4) in the three references that relied on Ozone's default, coverage-cell guard, median-based SysTick calibration, dead session flag removed, stale RA8M1 divider comment fixed (0x02 = /4 is the validated chip max) and the debugger guard indented. EVKB bench findings: only R1884/D3 remains open (D1/D2 meter-verified); RT1176 trace width is 1 or 4 only - J-Link arms the CSSYS TPIU and its own sampler at 4-bit for any width>=2 request; a powered MCU-Link USB breaks the external probe even with JP4 shorted.

imxrt: hold EVKB Ethernet PHY in reset while tracing, 50 MHz trace pin

2026-07-24T09:20:13Z

Fresh bring-up pass on mimxrt1170_evkb: holding the 100M RTL8201 in reset (ENET_RST_B = GPIO_LPSR_04) stops its RMII lines driving against the shared trace pads and doubles the clean trace-pin rate to 50 MHz (100 MHz CSTRACE root; 133 MHz root is marginal, stock 132 corrupts). Validated 3x 8 s TinyUSB captures at 11.46M fetches. D1-D3 remain silent in every configuration - the welded R1882-R1884 are electrically open; reflow is the remaining step to width 4. Board notes gain JP4 (must be shorted for an external probe on J58).

docs: plan for etm-trace tightening and target-debugger integration

2026-07-24T08:56:14Z

target-debug: list etm-trace as the instruction-level channel

2026-07-24T08:56:14Z

Fifth capture view alongside usbmon/kernel/target/wire: exact execution history via J-Trace, existing only where the trace header is wired - confirm with the user before reaching for it.

agents: target-debugger may escalate to etm-trace, prompt-gated

2026-07-24T08:56:14Z

Instruction-level trace outranks PC-sampling when samples cannot resolve a mechanism, but the J-Trace is exclusive per-board hardware: the agent uses it only when its prompt says the board is trace-wired or the user asked, and otherwise proposes it in notes - mirroring the lock-force consent rule.

etm-trace: post-rename references, per-board hardware-consent gate

2026-07-24T08:56:14Z

target-debug replaced usb-target-debug in the debug-skill overhaul; update the cross-skill table and PC-sampling pointer. Add the consent gate: the J-Trace is a single probe moved between boards, so captures on a board the user did not just ask about need explicit confirmation that it is wired.