reframe

Reframe Skill — Embedded Challenge Protocol

5-phase 21-question problem validation. Run BEFORE /pdca plan for complex features.

Arguments

Argument	Description	Example
{feature}	Feature name to reframe	/reframe uart-dma
{feature} --mode full	Full mode: all 21 questions	/reframe uart-dma --mode full
{feature} --mode standard	Standard mode: Q1-Q15 (default)	/reframe uart-dma --mode standard
{feature} --mode quick	Quick mode: 7 core questions	/reframe uart-dma --mode quick

Mode Selection

Mode	Questions	When to Use
Full (21)	Q1-Q21	New features, architecture changes, high-risk work
Standard (15)	Q1-Q15	Medium-scale tasks, code quality covered in review
Quick (7)	Q1,Q3,Q5,Q7,Q11,Q13,Q18	Bug fixes, small improvements

Methodology

Six validated frameworks integrated into 5 phases:

Framework	Source	Phase
Problem Reframing	Wedell-Wedellsborg (HBR 2017)	Phase 1
Demand Reality + Narrowest Wedge	Garry Tan (gstack /office-hours)	Phase 1, 3
Pre-Mortem	Gary Klein (HBR 2007)	Phase 2
Assumption Mapping	David Bland (Strategyzer)	Phase 2
Five Whys	Toyota Production System	Phase 3
MECE Decomposition	McKinsey	Phase 3

Execution Flow

Step 1: Mode Selection

If --mode not specified, use AskUserQuestion:

"Which reframe mode? Feature complexity determines depth."

• Full (21 questions) — new features, architecture changes
• Standard (15 questions) — medium tasks (default)
• Quick (7 questions) — bug fixes, small improvements

Step 2: Domain Detection

Auto-detect project domain (MCU/MPU/WPF) from project files. Domain determines reframing guides, MECE checklists, and assumption examples.

Step 3: Interactive Questions

Execute questions sequentially using AskUserQuestion for each. Provide domain-specific hints and examples with each question.

Phase 1: Problem Validation (Q1-Q4)

Questions probe problem definition, demand reality, status quo cost, and alternative framing.

Q4 Domain-Specific Reframing Guide:

Instead of asking...	Reframe to...
MCU: "How to make this ISR faster?"	"Should this work be in the ISR at all, or deferred?"
MCU: "How to fit in Flash?"	"What are we storing that's actually unnecessary?"
MPU: "How to add ioctl?"	"Is sysfs/configfs sufficient? Why is ioctl really needed?"
MPU: "Why does probe fail?"	"Does DT compatible string match? Are dependencies (clk, gpio, regulator) ready?"
WPF: "How to make WPF UI responsive?"	"Should this processing be in ViewModel or a background service?"
WPF: "Why is DataGrid slow?"	"Is virtualization enabled? Are 10,000 rows really needed?"

Phase 2: Assumption Surfacing (Q5-Q8)

Surfaces hidden assumptions, identifies Leap of Faith risks, runs pre-mortem analysis.

Domain-Specific Leap of Faith Examples:

Domain	Common Unverified Assumptions
MCU	DMA handles this transfer rate without CPU, RTOS scheduler won't starve low-priority tasks, silicon errata doesn't affect this peripheral
MPU	Kernel API stable at this version, DMA buffer allocation guarantees contiguous physical memory, ioctl interface works as expected from user space, shared library ABI compatible
WPF	DataGrid handles 10K rows without UI lag, SerialPort behaves identically across all Windows versions, .NET 8 runtime exists on customer PCs

Domain-Specific Pre-Mortem Scenarios:

Domain	Representative Failures
MCU	Flash at 92% overflows during integration, eval board vs production board differences undetected, watchdog reset from unserviced timer
MPU	Kernel API change breaks driver build, probe failure leaves device unrecognized, user app/driver ioctl mismatch, shared library symbol collision
WPF	Customer PC .NET version mismatch, DPI scaling breaks layout, event subscription memory leak

Phase 3: Solution Challenge (Q9-Q12)

Traces root cause via Five Whys, checks MECE alternatives, defines narrowest wedge MVP.

Q10 Domain-Specific MECE Checklist:

Domain	Alternative Categories to Consider
MCU	Existing HAL/SDK function? HW capability (HW CRC, DMA, Comparator)? Standard protocol (Modbus, CANopen)? Polling vs interrupt vs DMA?
MPU	Kernel built-in driver? sysfs/ioctl/netlink — which interface? Existing library (libgpiod, libi2c)? User space vs kernel space?
WPF	CommunityToolkit feature? NuGet package? .NET built-in API? Existing ResourceDictionary?

Phase 4: Measurement Contract (Q13-Q15)

Establishes numeric pass/fail criteria and measurement tools before any code is written.

Phase 5: Code Quality Challenge (Q16-Q21) — Full Mode Only

Examines codebase consistency, dependency direction, error handling, concurrency, testability, API contracts.

Q16-Q21 Domain-Specific Details:

Question	MCU	MPU	WPF
Q16 Consistency	HAL callback pattern? HAL_*_MspInit placement?	checkpatch.pl pass? platform_driver pattern? App directory structure?	MVVM pattern? [ObservableProperty] usage?
Q17 Dependencies	Application→Driver→HAL one-way? No ISR→App direct call?	User space→Kernel interface clear? ioctl/sysfs choice?	View→ViewModel→Model one-way? ViewModel doesn't reference View?
Q18 Error handling	Peripheral timeout recovery? HAL_StatusTypeDef check?	Syscall errno check? Driver probe failure handling?	try-catch scope? Serial communication timeout?
Q19 Concurrency	ISR↔main shared vars volatile? RTOS mutex/semaphore?	Kernel spinlock/mutex? User space thread sync?	UI thread↔background Dispatcher.Invoke? Serial rx thread?
Q20 Testability	HAL mockable? Register access isolated?	Driver logic testable without DT?	ViewModel unit testable? Commands executable without View?
Q21 API contract	Parameter range specified? Null pointer guard?	ioctl commands documented? Return value contract?	Public method XML comments? Event contracts?

Step 4: Document Generation

1. Read templates/reframe.template.md
2. Fill template with collected answers
3. Write to docs/00-pm/{feature}.reframe.md
4. Create Task: [Reframe] {feature}

Step 5: Summary & Next Step

Output summary comparison table (before/after reframe) and guide:

"Reframe complete. Run /pdca plan {feature} — the plan will auto-reference this reframe document."

Domain Quick Reference Cards

MCU Firmware — Top 10 Challenge Questions

1. Does HAL/SDK already provide this driver/function?
2. Flash/RAM impact? Can we stay under 85%/75%?
3. Have you read the silicon errata for this peripheral on this part number?
4. Is too much work happening inside this ISR?
5. What happens at timing margins (max bus load, min voltage, max temperature)?
6. Should DMA be used here, or would it add unnecessary complexity?
7. Is the clock source and clock tree verified for this peripheral speed?
8. Any race conditions between ISR context and main/task context?
9. Can this be tested without target hardware (HAL mocking)?
10. If this peripheral fails at runtime, what is the recovery path?

Embedded Linux (Kernel/Driver/App) — Top 10 Challenge Questions

1. Does a kernel built-in driver already provide this? (check mainline)
2. User space (sysfs/libgpiod) vs kernel space (driver) — which is appropriate?
3. Does the Device Tree compatible string exactly match the driver?
4. ioctl/sysfs/netlink/configfs — which interface fits this use case?
5. Does it pass checkpatch.pl? Does it follow kernel coding style?
6. On probe failure, does the error path release all resources (clk, gpio, irq, memory)?
7. DMA buffer: is contiguous physical memory guaranteed? (dma_alloc_coherent vs kmalloc)
8. User space ↔ driver data size/struct alignment match? (32/64-bit compatible)
9. Shared library versioning: soname and ABI compatibility maintained?
10. Will kernel API changes (deprecated functions, struct changes) affect this driver?

WPF Desktop — Top 10 Challenge Questions

1. Does ViewModel reference System.Windows.Controls types? (it should NOT)
2. Using {Binding} (WPF) not {x:Bind} (UWP/WinUI only)?
3. Using CommunityToolkit.Mvvm ObservableObject/RelayCommand?
4. Is long-running work on a background thread, not blocking the UI thread?
5. Does it work at all target DPI settings (100%, 125%, 150%, 200%)?
6. Is DataGrid/ListView virtualized for large datasets?
7. Are IDisposable resources (SerialPort, sockets) properly Disposed?
8. Does the published app include required .NET 8 runtime dependencies?
9. Any memory leaks from unsubscribed event handlers?
10. Tested with net8.0-windows TFM and <UseWPF>true</UseWPF>?

Output

Output Path: docs/00-pm/{feature}.reframe.md

PDCA Connection

• Runs as Phase -1, before /pdca plan
• Plan document's rationale section auto-references reframe results
• /pdca plan checks for {feature}.reframe.md and loads it as context

Usage Examples

# Standard reframe (15 questions)
/reframe uart-dma

# Full reframe for architecture change
/reframe kernel-spi-driver --mode full

# Quick reframe for bug fix
/reframe serialport-timeout --mode quick