Console

flowchart TD
    SD[(SD Card\nFAT32)]

    subgraph Core0 ["Core 0 -- Bootloader + Game"]
        Menu["Menu\n- Lists .bin files from SD\n- Selects & launches game"]
        Upload["USB Upload Mode\n- Mounts SD as USB drive\n- Copy .bin files from PC"]
        HAL["HAL\n- drawPixel(), drawText(), drawChar()\n- readInput()\n- sdRead(), sdWrite()\n- getTime()"]
        Game["Game Binary\n- Loaded into RAM @ 0x20010000\n- Owns its own loop\n- Calls HAL only"]
    end

    subgraph Core1 ["Core 1 -- Watchdog"]
        Overlay["Watchdog Loop\n- Monitors A+B+UP\n- Reboots console via watchdog"]
    end

    subgraph Hardware ["Peripherals"]
        OLED["OLED Display\n(mutex-guarded, 128x64)"]
        BTN["Buttons\n(A, B, D-Pad)"]
    end

    SD -->|"Read .bin files"| Menu
    Menu -->|"memcpy to 0x20010000\njump to entry"| Game
    Upload -->|"USB MSC"| SD
    Overlay -->|"watchdog_reboot()\non A+B+UP"| Core0
    Game -->|"calls"| HAL
    HAL -->|"drawPixel()"| OLED
    HAL -->|"readInput()"| BTN