{
  "$schema": "../../../tools/card-layouts/schemas/card-source.schema.json",
  "schema": "esc-card-source.v1",
  "card": {
    "id": "mpabi-freertos-c-14-gpio-timer-deferred",
    "series": "freertos-c",
    "series_title": "FreeRTOS C",
    "number": "14",
    "count": "15",
    "slug": "gpio-timer-deferred",
    "title": "GPIO, hardware timer and deferred work",
    "topic": "mtime tick ISR, pended daemon callback and one bounded GPIO transition",
    "project": "Freestanding C nad FreeRTOS",
    "subject": "Informatyka",
    "level": "Rok 2 · L14 · RV32I/Hazard3",
    "revision_date": "2026-07-19T00:00:00+02:00",
    "status": "Gotowa",
    "version": "v00.01",
    "uuid": "7de92b94-df89-5c00-be47-d85523ad02ac",
    "author": "M. Pabiszczak",
    "year": "2026"
  },
  "generated": {
    "tex": "doc/generated/main.tex",
    "html": "web/index.html",
    "html_css": "web/style.css",
    "html_tree_inspector": false,
    "react_app": true
  },
  "render_dictionary": false,
  "viewpoints": [
    {
      "id": "A1",
      "label": "CONTEXT",
      "subtitle": "hardware/ISR/daemon boundary",
      "status": "enabled",
      "target_label": "fig:a1-context"
    },
    {
      "id": "A2",
      "label": "STRUCTURE",
      "subtitle": "event and register records",
      "status": "enabled",
      "target_label": "fig:a2-structure"
    },
    {
      "id": "A3",
      "label": "DISPATCH",
      "subtitle": "pended callback binding",
      "status": "enabled",
      "target_label": "fig:a3-dispatch"
    },
    {
      "id": "A4",
      "label": "APPLICATION",
      "subtitle": "single event topology",
      "status": "unavailable",
      "reason": "A1 already identifies every application participant and A5 provides the complete concrete topology in time."
    },
    {
      "id": "A5",
      "label": "FLOW",
      "subtitle": "E01-E06 hardware replay",
      "status": "enabled",
      "target_label": "fig:a5-flow"
    },
    {
      "id": "A6",
      "label": "STATE",
      "subtitle": "pending and applied states",
      "status": "enabled",
      "target_label": "fig:a6-state"
    },
    {
      "id": "A7",
      "label": "RUNTIME",
      "subtitle": "mtime, stacks and ELF",
      "status": "enabled",
      "target_label": "fig:a7-runtime"
    },
    {
      "id": "A8",
      "label": "PATTERNS",
      "subtitle": "deferred interrupt processing",
      "status": "unavailable",
      "reason": "Deferred interrupt processing is the mechanism proved in A3 and A6; a separate page would repeat the same decision."
    }
  ],
  "debug_strategies": {
    "code.contract": {
      "id": "code.contract",
      "kind": "code",
      "action": "open",
      "expected_observations": [
        "ISR and callback are separate functions",
        "one GPIO owner"
      ],
      "assertions": [
        "hook never blocks",
        "callback arguments outlive the ISR"
      ],
      "evidence_fields": [
        "code_ref",
        "priority",
        "register",
        "API"
      ],
      "prerequisites": [
        "FC06 and FC07 complete"
      ],
      "layout": [
        "mtime port",
        "tick hook",
        "timer queue",
        "daemon callback",
        "GPIO"
      ],
      "commands": [
        "rg -n 'TickHook|PendFunction|MTIME|gpio' include src Makefile"
      ]
    },
    "run.timer": {
      "id": "run.timer",
      "kind": "run",
      "action": "replay",
      "expected_observations": [
        "E03 at target tick",
        "pend returns pdPASS and wake true"
      ],
      "assertions": [
        "mcause is MTI",
        "compare was reloaded",
        "one command accepted"
      ],
      "evidence_fields": [
        "tick",
        "mtime",
        "mtimecmp",
        "mcause",
        "pend result",
        "ISR SP"
      ],
      "prerequisites": [
        "clean Hazard3 RAM",
        "target tick armed"
      ],
      "layout": [
        "mtime",
        "mtimecmp",
        "mcause",
        "timer command queue"
      ],
      "commands": [
        "make sim",
        "print g_fc14",
        "print g_fc14_events"
      ]
    },
    "run.daemon": {
      "id": "run.daemon",
      "kind": "run",
      "action": "replay",
      "expected_observations": [
        "callback at same tick",
        "GPIO low-to-high once"
      ],
      "assertions": [
        "daemon handle matches",
        "E04 precedes E05",
        "callback stack differs from ISR"
      ],
      "evidence_fields": [
        "TaskHandle_t",
        "SP",
        "tick",
        "GPIO before/after",
        "transition count"
      ],
      "prerequisites": [
        "E03 command queued",
        "daemon priority 3"
      ],
      "layout": [
        "daemon handle",
        "callback arguments",
        "GPIO bank",
        "event order"
      ],
      "commands": [
        "break fc14_checkpoint_committed if $a0 == 4",
        "print g_fc14"
      ]
    },
    "code.identity": {
      "id": "code.identity",
      "kind": "code",
      "action": "open",
      "expected_observations": [
        "all C boundaries are linked",
        "no C++ metadata"
      ],
      "assertions": [
        "timer task implementation is present",
        "pended function API is present"
      ],
      "evidence_fields": [
        "symbol",
        "source blob",
        "ELF SHA256",
        "image SHA256"
      ],
      "prerequisites": [
        "built ELF"
      ],
      "layout": [
        "trap",
        "tick",
        "timer daemon",
        "application symbols"
      ],
      "commands": [
        "make check-abi",
        "riscv64-unknown-elf-nm build/task01_gpio_timer/prog.elf"
      ]
    },
    "run.identity": {
      "id": "run.identity",
      "kind": "run",
      "action": "replay",
      "expected_observations": [
        "one PASS",
        "digest bf66bc48 three times"
      ],
      "assertions": [
        "six ordered events",
        "exactly one GPIO transition"
      ],
      "evidence_fields": [
        "digest",
        "event count",
        "SP values",
        "artifact identity"
      ],
      "prerequisites": [
        "built image"
      ],
      "layout": [
        "six-event trace",
        "three clean processes"
      ],
      "commands": [
        "make check-determinism"
      ]
    }
  },
  "template": "templates/karta-klasyczna.json",
  "title_block": {
    "category": "KARTA PRACY · INFORMATYKA",
    "prepared_by": "M. Pabiszczak",
    "prepared_on": "2026-07-19T00:00:00+02:00",
    "title": "GPIO, hardware timer and deferred work",
    "url": "https://dce7fb9d-7b2f-5d49-96a2-3a30d3070b84.mpabi.pl/0cc561df-bf81-5bba-9df1-c872d5b42eb8",
    "repository_url": "https://zsl-gitea.mpabi.pl/edu-freertos-c/lab-rv32i-freertos-c-gpio-timer",
    "url_host_uuid": "dce7fb9d-7b2f-5d49-96a2-3a30d3070b84",
    "url_domain": "mpabi.pl",
    "doc_uuid": "0cc561df-bf81-5bba-9df1-c872d5b42eb8",
    "revision": "v00.01",
    "issued_on": "2026-07-19T00:00:00+02:00",
    "series": "FREERTOS-C-14",
    "document_type": "karta pracy",
    "tool": "card-layouts",
    "show_qr": true,
    "show_repository_qr": true,
    "height_cm": 2.6,
    "repeat_on_every_page": true,
    "replace_front_matter": true
  },
  "front_page_scope": {
    "title": "Cel karty",
    "content_tex": "Uczeń odróżnia hardware timer interrupt od callbacku software timera: ISR tylko zatwierdza zdarzenie i odkłada pracę, a timer daemon wykonuje ograniczoną zmianę GPIO.",
    "scope_title": "Zakres karty",
    "scope_content_tex": "Stimulus uzbraja tick +3. Machine timer ISR zapisuje mtime, mtimecmp, mcause i stos, po czym wywołuje xTimerPendFunctionCallFromISR. Daemon priority 3 przełącza GPIO przed powrotem do przerwanego taska priority 2.",
    "scope_table": {
      "headers": [
        "Lekcja",
        "Task",
        "Najważniejsza idea",
        "Priorytet",
        "Status",
        "Version"
      ],
      "rows": [
        {
          "chapter": "FC14",
          "task": "Task01",
          "idea_tex": "mtime tick ISR, pended daemon callback and one bounded GPIO transition",
          "priority": "główny",
          "status": "ready",
          "version": "v00.01",
          "key": true
        }
      ]
    }
  },
  "side_margin_tree_layout": {
    "columns": [
      {
        "id": "zawodowe",
        "label": "TECH",
        "side": "left",
        "tree": "WE -> EK -> KW",
        "description": "Dowody runtime."
      },
      {
        "id": "ogolne",
        "label": "OG",
        "side": "right",
        "tree": "WE -> EN -> KW",
        "description": "Model FreeRTOS C."
      }
    ]
  },
  "learning_effects": {
    "FC14.EN01": {
      "bloom_level": "Analiza",
      "label": "Hardware timer versus deferred callback",
      "text": "Uczeń rozdziela machine timer ISR, tick hook, timer command queue, daemon task and GPIO owner.",
      "assessment_criteria": [
        "FC14.KW01"
      ]
    },
    "FC14.EK01": {
      "bloom_level": "Zastosowanie",
      "label": "One-event deferred-work replay",
      "text": "Uczeń odtwarza E01–E06 i dowodzi kolejności ISR → daemon → interrupted task.",
      "assessment_criteria": [
        "FC14.KW01"
      ]
    }
  },
  "assessment_criteria": {
    "FC14.KW01": {
      "text": "PASS; mcause=MTI; mtimecmp>mtime; one successful pend; daemon callback in target tick; one GPIO transition; three distinct stacks; deterministic digest.",
      "learning_effects": [
        "FC14.EN01",
        "FC14.EK01"
      ]
    }
  },
  "educational_requirements": {
    "FC14.WE01": {
      "text": "Projektowanie i badanie deferred interrupt processing dla timera sprzętowego i GPIO w FreeRTOS C.",
      "label": "mtime tick ISR, pended daemon callback and one bounded GPIO transition",
      "learning_effects": [
        "FC14.EN01",
        "FC14.EK01"
      ],
      "learning_tree": {
        "schema": "we-learning-tree.v1",
        "policy": "Każda aktywna kotwica wskazuje kod lub checkpoint.",
        "ogolne": [
          {
            "effect_ref": "FC14.EN01",
            "display": "EN LOCAL RTOS.14",
            "source": "LOCAL",
            "official": "RTOS",
            "local": "14",
            "kind": "EN",
            "tree_id": "FC14.WE01.OG.LOCAL.RTOS.14",
            "text": "Uczeń rozdziela machine timer ISR, tick hook, timer command queue, daemon task and GPIO owner.",
            "kw": [
              {
                "criterion_ref": "FC14.KW01",
                "display": "KW LOCAL RTOS.14",
                "source": "LOCAL",
                "kind": "KW",
                "official": "RTOS",
                "local": "14",
                "text": "Łączy kod, diagram i zweryfikowany dowód."
              }
            ]
          }
        ],
        "zawodowe": [
          {
            "effect_ref": "FC14.EK01",
            "display": "EK LOCAL RTOS.14",
            "source": "LOCAL",
            "official": "RTOS",
            "local": "14",
            "kind": "EK",
            "tree_id": "FC14.WE01.TECH.LOCAL.RTOS.14",
            "text": "Uczeń odtwarza E01–E06 i dowodzi kolejności ISR → daemon → interrupted task.",
            "kw": [
              {
                "criterion_ref": "FC14.KW01",
                "display": "KW LOCAL RTOS.14",
                "source": "LOCAL",
                "kind": "KW",
                "official": "RTOS",
                "local": "14",
                "text": "Łączy kod, diagram i zweryfikowany dowód."
              }
            ]
          }
        ]
      }
    }
  },
  "debug_checkpoints": {
    "schema": "stem-debug-checkpoints.v1",
    "semantics": "deterministic-replay",
    "artifact": {
      "source": "src/tasks/task01_gpio_timer.c",
      "source_git_blob": "ec2e552d61694b31bbe65af1ec361442980de23b",
      "elf": "build/task01_gpio_timer/prog.elf",
      "hazard3_elf_sha256": "dde14e1ccc2ad816883b45a7cd9a1b431f157c1509abe02b9f6559e53365d619",
      "hazard3_image": "build/task01_gpio_timer/prog.bin",
      "hazard3_image_sha256": "3ffeec5e5e362efdd714ef9d354b1e3592a183bda582c6fb21be63736fb7a92d"
    },
    "targets": {
      "hazard3-sim": {
        "adapter": "hazard3-reset-load-replay.v1",
        "baseline": "restart-backend",
        "clean_ram": true
      }
    },
    "items": {
      "task01.configured": {
        "event_id": "E01",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 1"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14_event_count",
              "equals": 1
            },
            {
              "expr": "g_fc14.gpio.direction",
              "equals": 1
            },
            {
              "expr": "g_fc14_events[0].value",
              "equals": 3
            }
          ]
        }
      },
      "task01.armed": {
        "event_id": "E02",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 2"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14.armed",
              "equals": 1
            },
            {
              "expr": "g_fc14.pended",
              "equals": 0
            },
            {
              "expr": "g_fc14.target_tick == g_fc14_events[1].value",
              "equals": 1
            }
          ]
        }
      },
      "task01.tick-isr": {
        "event_id": "E03",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 3"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14.mcause",
              "equals": 2147483655
            },
            {
              "expr": "g_fc14.pend_result",
              "equals": 1
            },
            {
              "expr": "g_fc14.higher_priority_task_woken",
              "equals": 1
            },
            {
              "expr": "g_fc14.mtimecmp_after_reload > g_fc14.mtime_at_isr",
              "equals": 1
            }
          ]
        }
      },
      "task01.callback": {
        "event_id": "E04",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 4"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14.callback_calls",
              "equals": 1
            },
            {
              "expr": "g_fc14.gpio.data",
              "equals": 1
            },
            {
              "expr": "g_fc14.gpio.transitions",
              "equals": 1
            },
            {
              "expr": "g_fc14.callback_saw_stimulus_after",
              "equals": 0
            }
          ]
        }
      },
      "task01.stimulus-resumed": {
        "event_id": "E05",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 5"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14.applied_at_stimulus_resume",
              "equals": 1
            },
            {
              "expr": "g_fc14.stimulus_after",
              "equals": 1
            }
          ]
        }
      },
      "task01.pass": {
        "event_id": "E06",
        "stop": {
          "symbol": "fc14_checkpoint_committed",
          "offset": 0,
          "condition": "$a0 == 6"
        },
        "verify": {
          "expressions": [
            {
              "expr": "g_fc14_pass",
              "equals": 1
            },
            {
              "expr": "g_fc14_event_count",
              "equals": 6
            },
            {
              "expr": "g_fc14.pend_calls",
              "equals": 1
            },
            {
              "expr": "g_fc14.callback_calls",
              "equals": 1
            }
          ]
        }
      }
    }
  },
  "sections": [
    {
      "title": "A1 — Hardware, ISR and daemon boundary",
      "order": 10,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "The hardware interrupt only records and defers. GPIO changes later in task context; this is not a software-timer expiry callback.",
      "assets": [
        {
          "path": "assets/a1-context.png",
          "html_path": "assets/a1-context.svg",
          "source_path": "assets/a1-context.puml",
          "caption": "A1 CONTEXT — mtime, tick ISR, pend queue, daemon and GPIO.",
          "label": "fig:a1-context",
          "alt": "A1 · hardware-to-deferred-work boundary",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "mtime": 1,
              "port": 1,
              "hook": 1,
              "daemon": 1,
              "gpio": 1,
              "pass": 1
            }
          },
          "interactive": {
            "kind": "uml-class",
            "storage_key": "fc14-a1-context",
            "title": "A1 · hardware-to-deferred-work boundary",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a1",
              "label": "A1 CONTEXT",
              "description": "The machine timer, kernel tick path, application hook, timer queue, daemon task and GPIO register bank have separate roles."
            },
            "phases": [
              {
                "id": "boundary",
                "label": "HARDWARE / ISR / DAEMON",
                "steps": [
                  {
                    "id": "mtime",
                    "number": 1,
                    "label": "mtime and mtimecmp generate the kernel tick",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "01",
                    "code_ref": "include/FreeRTOSConfig.h:4",
                    "description": "mtime and mtimecmp generate the kernel tick",
                    "evidence": "10 MHz clock, 1 kHz tick"
                  },
                  {
                    "id": "port",
                    "number": 2,
                    "label": "port reloads compare and increments tick",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "02",
                    "code_ref": "vendor/FreeRTOS-Kernel/portable/GCC/RISC-V/portASM.S:368",
                    "description": "port reloads compare and increments tick",
                    "evidence": "machine timer trap"
                  },
                  {
                    "id": "hook",
                    "number": 3,
                    "label": "tick hook accepts exactly one target event",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "03",
                    "code_ref": "src/tasks/task01_gpio_timer.c:97",
                    "description": "tick hook accepts exactly one target event",
                    "evidence": "minimal ISR path"
                  },
                  {
                    "id": "daemon",
                    "number": 4,
                    "label": "pended function runs on timer daemon",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "04",
                    "code_ref": "src/tasks/task01_gpio_timer.c:127",
                    "description": "pended function runs on timer daemon",
                    "evidence": "task context"
                  },
                  {
                    "id": "gpio",
                    "number": 5,
                    "label": "daemon owns the GPIO transition",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "05",
                    "code_ref": "include/task01_gpio_timer_model.h:32",
                    "description": "daemon owns the GPIO transition",
                    "evidence": "exactly one toggle"
                  },
                  {
                    "id": "pass",
                    "number": 6,
                    "label": "runtime proves every boundary",
                    "mode": "RUN",
                    "event_id": "E06",
                    "strategy_ref": "run.identity",
                    "svg_label": "06",
                    "code_ref": "src/tasks/task01_gpio_timer.c:202",
                    "snapshot_ref": "task01.pass",
                    "description": "runtime proves every boundary",
                    "evidence": "PASS and deterministic digest"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "A2 — Event and register records",
      "order": 20,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "The callback receives a pointer and a 32-bit event value through the timer command queue. It does not capture ISR stack storage.",
      "assets": [
        {
          "path": "assets/a2-structure.png",
          "html_path": "assets/a2-structure.svg",
          "source_path": "assets/a2-structure.puml",
          "caption": "A2 STRUCTURE — experiment, command, GPIO and evidence records.",
          "label": "fig:a2-structure",
          "alt": "A2 · deferred event storage",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "experiment": 1,
              "gpio-record": 1,
              "event-record": 1,
              "command": 1,
              "identity": 1
            }
          },
          "interactive": {
            "kind": "uml-class",
            "storage_key": "fc14-a2-structure",
            "title": "A2 · deferred event storage",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a2",
              "label": "A2 STRUCTURE",
              "description": "One bounded experiment record connects hardware time, trap state, daemon identity, GPIO values and six commit-last events."
            },
            "phases": [
              {
                "id": "storage",
                "label": "RECORDS AND OWNERSHIP",
                "steps": [
                  {
                    "id": "experiment",
                    "number": 1,
                    "label": "experiment stores timing and context proof",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "01",
                    "code_ref": "include/task01_gpio_timer.h:20",
                    "description": "experiment stores timing and context proof",
                    "evidence": "ticks, mtime, SP and result"
                  },
                  {
                    "id": "gpio-record",
                    "number": 2,
                    "label": "volatile GPIO bank stores direction and data",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "02",
                    "code_ref": "include/task01_gpio_timer_model.h:10",
                    "description": "volatile GPIO bank stores direction and data",
                    "evidence": "transition counter"
                  },
                  {
                    "id": "event-record",
                    "number": 3,
                    "label": "six evidence records commit last",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "03",
                    "code_ref": "include/task01_gpio_timer_model.h:17",
                    "description": "six evidence records commit last",
                    "evidence": "sequence, actor and tick"
                  },
                  {
                    "id": "command",
                    "number": 4,
                    "label": "timer queue copies callback and arguments",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "04",
                    "code_ref": "vendor/FreeRTOS-Kernel/timers.c:1233",
                    "description": "timer queue copies callback and arguments",
                    "evidence": "daemon command message"
                  },
                  {
                    "id": "identity",
                    "number": 5,
                    "label": "callback handle equals timer daemon handle",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "05",
                    "code_ref": "src/tasks/task01_gpio_timer.c:135",
                    "snapshot_ref": "task01.callback",
                    "description": "callback handle equals timer daemon handle",
                    "evidence": "same TaskHandle_t"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "A3 — Pended-function dispatch",
      "order": 30,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "The port restores the daemon task before the interrupted stimulus continues. The callback and ISR therefore have different stacks and API permissions.",
      "assets": [
        {
          "path": "assets/a3-dispatch.png",
          "html_path": "assets/a3-dispatch.svg",
          "source_path": "assets/a3-dispatch.puml",
          "caption": "A3 DISPATCH — MTI, tick hook, timer queue and daemon restore.",
          "label": "fig:a3-dispatch",
          "alt": "A3 · timer-to-daemon dispatch",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "trap": 1,
              "reload": 1,
              "pend": 1,
              "yield": 1,
              "callback": 1,
              "resume": 1
            }
          },
          "interactive": {
            "kind": "uml-class",
            "storage_key": "fc14-a3-dispatch",
            "title": "A3 · timer-to-daemon dispatch",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a3",
              "label": "A3 DISPATCH",
              "description": "A real machine timer trap reaches the tick hook, which queues one function and requests a switch to the higher-priority timer daemon."
            },
            "phases": [
              {
                "id": "dispatch",
                "label": "MTI / PEND / RESTORE",
                "steps": [
                  {
                    "id": "trap",
                    "number": 1,
                    "label": "machine timer enters full trap path",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "01",
                    "code_ref": "vendor/FreeRTOS-Kernel/portable/GCC/RISC-V/portASM.S:368",
                    "description": "machine timer enters full trap path",
                    "evidence": "mcause timer interrupt"
                  },
                  {
                    "id": "reload",
                    "number": 2,
                    "label": "port reloads mtimecmp before hook",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "02",
                    "code_ref": "vendor/FreeRTOS-Kernel/portable/GCC/RISC-V/portASM.S:377",
                    "description": "port reloads mtimecmp before hook",
                    "evidence": "next compare is in the future"
                  },
                  {
                    "id": "pend",
                    "number": 3,
                    "label": "hook records and pends one callback",
                    "mode": "RUN",
                    "event_id": "E03",
                    "strategy_ref": "run.timer",
                    "svg_label": "03",
                    "code_ref": "src/tasks/task01_gpio_timer.c:109",
                    "snapshot_ref": "task01.tick-isr",
                    "description": "hook records and pends one callback",
                    "evidence": "pdPASS and wake=true"
                  },
                  {
                    "id": "yield",
                    "number": 4,
                    "label": "FromISR result requests daemon restore",
                    "mode": "CODE",
                    "strategy_ref": "code.contract",
                    "svg_label": "04",
                    "code_ref": "src/tasks/task01_gpio_timer.c:117",
                    "description": "FromISR result requests daemon restore",
                    "evidence": "one port yield"
                  },
                  {
                    "id": "callback",
                    "number": 5,
                    "label": "daemon applies GPIO in the same tick",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "05",
                    "code_ref": "src/tasks/task01_gpio_timer.c:135",
                    "snapshot_ref": "task01.callback",
                    "description": "daemon applies GPIO in the same tick",
                    "evidence": "daemon stack and GPIO=1"
                  },
                  {
                    "id": "resume",
                    "number": 6,
                    "label": "stimulus resumes only after callback",
                    "mode": "RUN",
                    "event_id": "E05",
                    "strategy_ref": "run.daemon",
                    "svg_label": "06",
                    "code_ref": "src/tasks/task01_gpio_timer.c:183",
                    "snapshot_ref": "task01.stimulus-resumed",
                    "description": "stimulus resumes only after callback",
                    "evidence": "applied_at_resume=1"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "A5 — One hardware event replay",
      "order": 50,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "The decisive order is E03 ISR, E04 daemon, E05 interrupted stimulus. Exactly one accepted event produces exactly one GPIO transition.",
      "assets": [
        {
          "path": "assets/a5-flow.png",
          "html_path": "assets/a5-flow.svg",
          "source_path": "assets/a5-flow.puml",
          "caption": "A5 FLOW — E01–E06 from configuration to PASS.",
          "label": "fig:a5-flow",
          "alt": "A5 · deferred GPIO replay",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "config": 1,
              "arm": 1,
              "isr": 1,
              "apply": 1,
              "stimulus": 1,
              "verified": 1
            }
          },
          "interactive": {
            "kind": "uml-sequence",
            "storage_key": "fc14-a5-flow",
            "title": "A5 · deferred GPIO replay",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a5",
              "label": "A5 FLOW",
              "description": "Six events show configuration, arming, timer ISR, daemon callback, interrupted-task resume and final verification."
            },
            "phases": [
              {
                "id": "flow",
                "label": "ARM / INTERRUPT / DEFER / APPLY",
                "steps": [
                  {
                    "id": "config",
                    "number": 1,
                    "label": "configure daemon priority and GPIO output",
                    "mode": "RUN",
                    "event_id": "E01",
                    "strategy_ref": "run.timer",
                    "svg_label": "01",
                    "code_ref": "src/tasks/task01_gpio_timer.c:260",
                    "snapshot_ref": "task01.configured",
                    "description": "configure daemon priority and GPIO output",
                    "evidence": "daemon priority 3"
                  },
                  {
                    "id": "arm",
                    "number": 2,
                    "label": "stimulus arms target tick plus three",
                    "mode": "RUN",
                    "event_id": "E02",
                    "strategy_ref": "run.timer",
                    "svg_label": "02",
                    "code_ref": "src/tasks/task01_gpio_timer.c:163",
                    "snapshot_ref": "task01.armed",
                    "description": "stimulus arms target tick plus three",
                    "evidence": "armed=1"
                  },
                  {
                    "id": "isr",
                    "number": 3,
                    "label": "mtime compare fires at target",
                    "mode": "RUN",
                    "event_id": "E03",
                    "strategy_ref": "run.timer",
                    "svg_label": "03",
                    "code_ref": "src/tasks/task01_gpio_timer.c:112",
                    "snapshot_ref": "task01.tick-isr",
                    "description": "mtime compare fires at target",
                    "evidence": "mcause=MTI; pended once"
                  },
                  {
                    "id": "apply",
                    "number": 4,
                    "label": "daemon toggles GPIO low to high",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "04",
                    "code_ref": "src/tasks/task01_gpio_timer.c:141",
                    "snapshot_ref": "task01.callback",
                    "description": "daemon toggles GPIO low to high",
                    "evidence": "transition count 1"
                  },
                  {
                    "id": "stimulus",
                    "number": 5,
                    "label": "interrupted task resumes after apply",
                    "mode": "RUN",
                    "event_id": "E05",
                    "strategy_ref": "run.daemon",
                    "svg_label": "05",
                    "code_ref": "src/tasks/task01_gpio_timer.c:183",
                    "snapshot_ref": "task01.stimulus-resumed",
                    "description": "interrupted task resumes after apply",
                    "evidence": "applied already true"
                  },
                  {
                    "id": "verified",
                    "number": 6,
                    "label": "verifier commits complete proof",
                    "mode": "RUN",
                    "event_id": "E06",
                    "strategy_ref": "run.identity",
                    "svg_label": "06",
                    "code_ref": "src/tasks/task01_gpio_timer.c:225",
                    "snapshot_ref": "task01.pass",
                    "description": "verifier commits complete proof",
                    "evidence": "digest bf66bc48"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "A6 — Pending and applied states",
      "order": 60,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "Queue acceptance does not mean GPIO has changed. The callback commit is the first point where applied and the output register may be one.",
      "assets": [
        {
          "path": "assets/a6-state.png",
          "html_path": "assets/a6-state.svg",
          "source_path": "assets/a6-state.puml",
          "caption": "A6 STATE — armed, pended, daemon-running, applied and verified.",
          "label": "fig:a6-state",
          "alt": "A6 · deferred-work state machine",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "armed": 1,
              "queued": 1,
              "running": 1,
              "applied": 1,
              "retired": 1,
              "terminal": 1
            }
          },
          "interactive": {
            "kind": "uml-class",
            "storage_key": "fc14-a6-state",
            "title": "A6 · deferred-work state machine",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a6",
              "label": "A6 STATE",
              "description": "The event moves through armed, accepted, queued, executing and applied states; hardware and software ownership change at explicit boundaries."
            },
            "phases": [
              {
                "id": "state",
                "label": "EVENT LIFETIME",
                "steps": [
                  {
                    "id": "armed",
                    "number": 1,
                    "label": "armed until target tick",
                    "mode": "RUN",
                    "event_id": "E02",
                    "strategy_ref": "run.timer",
                    "svg_label": "01",
                    "code_ref": "src/tasks/task01_gpio_timer.c:169",
                    "snapshot_ref": "task01.armed",
                    "description": "armed until target tick",
                    "evidence": "pended=0"
                  },
                  {
                    "id": "queued",
                    "number": 2,
                    "label": "ISR queues one daemon command",
                    "mode": "RUN",
                    "event_id": "E03",
                    "strategy_ref": "run.timer",
                    "svg_label": "02",
                    "code_ref": "src/tasks/task01_gpio_timer.c:117",
                    "snapshot_ref": "task01.tick-isr",
                    "description": "ISR queues one daemon command",
                    "evidence": "pended=1"
                  },
                  {
                    "id": "running",
                    "number": 3,
                    "label": "daemon consumes callback and arguments",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "03",
                    "code_ref": "src/tasks/task01_gpio_timer.c:128",
                    "snapshot_ref": "task01.callback",
                    "description": "daemon consumes callback and arguments",
                    "evidence": "callback_calls=1"
                  },
                  {
                    "id": "applied",
                    "number": 4,
                    "label": "GPIO records one transition",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "04",
                    "code_ref": "src/tasks/task01_gpio_timer.c:142",
                    "snapshot_ref": "task01.callback",
                    "description": "GPIO records one transition",
                    "evidence": "data=1"
                  },
                  {
                    "id": "retired",
                    "number": 5,
                    "label": "stimulus observes completed work",
                    "mode": "RUN",
                    "event_id": "E05",
                    "strategy_ref": "run.daemon",
                    "svg_label": "05",
                    "code_ref": "src/tasks/task01_gpio_timer.c:184",
                    "snapshot_ref": "task01.stimulus-resumed",
                    "description": "stimulus observes completed work",
                    "evidence": "applied=1"
                  },
                  {
                    "id": "terminal",
                    "number": 6,
                    "label": "all counts remain exactly one",
                    "mode": "RUN",
                    "event_id": "E06",
                    "strategy_ref": "run.identity",
                    "svg_label": "06",
                    "code_ref": "src/tasks/task01_gpio_timer.c:203",
                    "snapshot_ref": "task01.pass",
                    "description": "all counts remain exactly one",
                    "evidence": "PASS"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "A7 — Timer, stacks and artifact proof",
      "order": 70,
      "content_kind": "prose",
      "asset_page_mode": "one-per-page",
      "page_orientation": "portrait",
      "content_tex": "The final gate also requires C-only ABI symbols, the exact source and ELF hashes, and three identical simulator processes.",
      "assets": [
        {
          "path": "assets/a7-runtime.png",
          "html_path": "assets/a7-runtime.svg",
          "source_path": "assets/a7-runtime.puml",
          "caption": "A7 RUNTIME — mtime, mtimecmp, cause, three stacks and identity.",
          "label": "fig:a7-runtime",
          "alt": "A7 · hardware and context proof",
          "kind": "diagram",
          "width": 1.0,
          "page_grid": {
            "columns": 1,
            "rows": 1,
            "page_width": 660,
            "page_height": 760,
            "overview": true,
            "step_tiles": {
              "registers": 1,
              "cause": 1,
              "same-tick": 1,
              "stacks": 1,
              "abi": 1,
              "determinism": 1
            }
          },
          "interactive": {
            "kind": "uml-class",
            "storage_key": "fc14-a7-runtime",
            "title": "A7 · hardware and context proof",
            "task": {
              "id": "task01",
              "label": "Task01 · hardware timer to deferred GPIO"
            },
            "block": {
              "id": "a7",
              "label": "A7 RUNTIME",
              "description": "Runtime evidence distinguishes hardware time, RTOS tick, ISR stack, daemon stack and interrupted-task stack."
            },
            "phases": [
              {
                "id": "runtime",
                "label": "RUNTIME PROOF",
                "steps": [
                  {
                    "id": "registers",
                    "number": 1,
                    "label": "mtimecmp is reloaded beyond current mtime",
                    "mode": "RUN",
                    "event_id": "E03",
                    "strategy_ref": "run.timer",
                    "svg_label": "01",
                    "code_ref": "src/tasks/task01_gpio_timer.c:115",
                    "snapshot_ref": "task01.tick-isr",
                    "description": "mtimecmp is reloaded beyond current mtime",
                    "evidence": "compare > counter"
                  },
                  {
                    "id": "cause",
                    "number": 2,
                    "label": "mcause identifies machine timer interrupt",
                    "mode": "RUN",
                    "event_id": "E03",
                    "strategy_ref": "run.timer",
                    "svg_label": "02",
                    "code_ref": "src/tasks/task01_gpio_timer.c:113",
                    "snapshot_ref": "task01.tick-isr",
                    "description": "mcause identifies machine timer interrupt",
                    "evidence": "0x80000007"
                  },
                  {
                    "id": "same-tick",
                    "number": 3,
                    "label": "ISR and callback share target tick",
                    "mode": "RUN",
                    "event_id": "E04",
                    "strategy_ref": "run.daemon",
                    "svg_label": "03",
                    "code_ref": "src/tasks/task01_gpio_timer.c:137",
                    "snapshot_ref": "task01.callback",
                    "description": "ISR and callback share target tick",
                    "evidence": "isr_tick=callback_tick"
                  },
                  {
                    "id": "stacks",
                    "number": 4,
                    "label": "ISR, daemon and stimulus SP differ",
                    "mode": "RUN",
                    "event_id": "E06",
                    "strategy_ref": "run.identity",
                    "svg_label": "04",
                    "code_ref": "src/tasks/task01_gpio_timer.c:222",
                    "snapshot_ref": "task01.pass",
                    "description": "ISR, daemon and stimulus SP differ",
                    "evidence": "three contexts"
                  },
                  {
                    "id": "abi",
                    "number": 5,
                    "label": "ELF exposes tick, pend and daemon symbols",
                    "mode": "CODE",
                    "strategy_ref": "code.identity",
                    "svg_label": "05",
                    "code_ref": "scripts/check_abi.sh:18",
                    "description": "ELF exposes tick, pend and daemon symbols",
                    "evidence": "no C++ runtime"
                  },
                  {
                    "id": "determinism",
                    "number": 6,
                    "label": "three processes agree on digest",
                    "mode": "RUN",
                    "event_id": "E06",
                    "strategy_ref": "run.identity",
                    "svg_label": "06",
                    "code_ref": "scripts/check_determinism.sh:14",
                    "snapshot_ref": "task01.pass",
                    "description": "three processes agree on digest",
                    "evidence": "bf66bc48"
                  }
                ]
              }
            ]
          }
        }
      ]
    },
    {
      "title": "Task01 — hardware timer to deferred GPIO",
      "order": 90,
      "content_kind": "tasks",
      "task_refs": [
        "task01"
      ]
    }
  ],
  "tasks": {
    "task01": {
      "title": "Prove one machine-timer event from ISR to daemon GPIO work",
      "uuid": "0cc561df-bf81-5bba-9df1-c872d5b42eb8",
      "prompt_tex": "Odtwórz E01--E06. Udowodnij, że źródłem jest machine timer interrupt, ISR jedynie odkłada pracę, a GPIO zmienia dopiero callback timer daemon taska.",
      "criterion": "PASS; mcause=MTI; mtimecmp>mtime; one successful pend; daemon callback in target tick; one GPIO transition; three distinct stacks; deterministic digest.",
      "conclusion_tex": "Hardware timer określa moment przerwania; kolejka timer service określa moment wykonania odroczonej funkcji. Są to dwa konteksty, dwa stosy i dwa różne kontrakty API.",
      "flow": [
        {
          "kind": "block",
          "id": "contract",
          "title": "A — kontrakt",
          "content_tex": "Rozdziel hardware, ISR, daemon i rejestr GPIO.",
          "steps": [
            {
              "id": "contexts",
              "title": "Przypisz konteksty i API.",
              "content_tex": "Wskaż, co wolno zrobić w tick hooku, a co dopiero w callbacku."
            },
            {
              "id": "predict",
              "title": "Przewidź kolejność.",
              "content_tex": "Zapisz oczekiwane E03, E04 i E05 dla daemon priority 3."
            }
          ]
        },
        {
          "kind": "block",
          "id": "replay",
          "title": "B — replay",
          "content_tex": "Zbierz dowód hardware i task context.",
          "steps": [
            {
              "id": "timer",
              "title": "Sprawdź E02--E03.",
              "content_tex": "Target tick, mtime, mtimecmp, mcause i pend result."
            },
            {
              "id": "daemon",
              "title": "Sprawdź E04--E05.",
              "content_tex": "Daemon handle, callback SP, GPIO i kolejność restore."
            },
            {
              "id": "pass",
              "title": "Sprawdź E06.",
              "content_tex": "Counts, trzy stosy, ABI i digest."
            }
          ]
        },
        {
          "kind": "exercise",
          "id": "select-mechanism",
          "title": "Ćwiczenie — wybór mechanizmu",
          "prompt_tex": "Dla trzech prac wybierz notification, semaphore albo daemon deferral: inkrementacja licznika, zapis bloku flash i obudzenie konkretnego taska. Uzasadnij właściciela, latency i budżet.",
          "evidence_tex": "Tabela workload → mechanizm → odbiorca → dozwolone operacje → ryzyko blokowania.",
          "criterion": "Wybór wynika z wymaganej własności i kosztu; uczeń nie przeciąża timer daemon taska nieograniczoną pracą.",
          "based_on": [
            "contract",
            "replay"
          ]
        }
      ],
      "educational_requirement_refs": [
        "FC14.WE01"
      ],
      "learning_effect_refs": [
        "FC14.EN01",
        "FC14.EK01"
      ],
      "assessment_criterion_ref": "FC14.KW01"
    }
  },
  "tasks_order": [
    "task01"
  ]
}