2. OVERALL SYSTEM ARCHITECTURE
------------------------------

2.1 Layered Architecture
~~~~~~~~~~~~~~~~~~~~~~~~

HyperCP/M employs a layered architecture that separates hardware management,
operating-system personalities, and application software into distinct
responsibilities.

The architectural layers are:

Applications
      |
      v
Operating-System Personality
      |
      v
HyperCP/M Kernel Services
      |
      v
Virtual Resource Manager (VRM)
      |
      v
Physical Hardware

Each layer communicates only with the layer immediately below it through
well-defined interfaces.

The purpose of this separation is to minimize coupling between subsystems
and permit independent evolution of personalities, kernel services, and
hardware implementations.

2.2 Major Components
~~~~~~~~~~~~~~~~~~~~

HyperCP/M consists of the following major architectural components.

HyperCP/M Kernel

The kernel is responsible for:

  * System initialization.
  * Session management.
  * Resource allocation.
  * Session execution control.
  * Hardware abstraction.
  * Kernel service dispatch.

The kernel contains no personality-specific behaviour.

The kernel provides Management Services through defined interfaces.
Management Services expose administrative capabilities without becoming a
personality-specific subsystem.

Session Manager

The Session Manager creates and maintains isolated execution environments.

Responsibilities include:

  * Session creation.
  * Session destruction.
  * Session switching.
  * Session isolation.
  * Association of personalities with sessions.

Each session represents an independent virtual machine. HyperCP/M shall
ensure that each session maintains independent CPU state, memory state, and
console state. Shared resources, including storage devices, shall have
explicitly defined sharing semantics.

Personality Framework

The personality framework allows multiple operating-system environments to
execute under HyperCP/M.

Responsibilities include:

  * Personality registration.
  * Personality loading.
  * Personality lifecycle management.
  * Personality interface definition.

Each personality defines the operating environment observed by applications
executing within that session.

Console Manager

The Console Manager provides console infrastructure used by both session
consoles and the Management Services Console.

Responsibilities include:

  * Console creation.
  * Console switching.
  * Keyboard routing.
  * Display routing.
  * System hotkey processing.

The Console Manager provides the mechanism by which consoles operate; it
does not define the management interface itself.

Storage Manager

The Storage Manager provides access to storage resources.

Responsibilities include:

  * System volume management.
  * Personality package loading.
  * Virtual drive presentation.
  * Storage mapping.

Storage implementation details are defined by the Storage Specification.

Virtual Resource Manager (VRM)

The Virtual Resource Manager presents a consistent virtual hardware
environment to the kernel regardless of the underlying implementation.

Responsibilities include:

  * Memory management.
  * Bank switching.
  * Device abstraction.
  * Interrupt routing.
  * Timer services.
  * Storage abstraction.

The VRM Specification defines these interfaces.

Management Services

Management Services provide kernel-level capabilities for managing and
controlling HyperCP/M resources.

Responsibilities include:

  * Session creation.
  * Session destruction.
  * Session switching.
  * Personality management.
  * System status queries.
  * Resource management operations.

Management Services do not define a user interface. They are accessed
through the Management Services Interface by authorized software components,
including the Management Services Shell and HyperCP/M utilities.

Debug Services

Debug Services provide kernel-level facilities for observing, diagnosing,
and debugging HyperCP/M during development and system maintenance.

Responsibilities include:

  * Diagnostic logging.
  * Assertions.
  * Event tracing.
  * Panic reporting.
  * Runtime inspection of kernel state.

Debug Services provide common diagnostic capabilities for kernel subsystems
and authorized management software. They are intended to support system
development, testing, maintenance, and fault diagnosis while remaining
independent of personality-specific behavior.

2.3 Boot Overview
~~~~~~~~~~~~~~~~~

System startup proceeds through the following stages.

Power On
    |
    v
Boot Loader
    |
    v
HyperCP/M Kernel
    |
    v
Initialize Kernel Services
    |
    v
Create Initial Session
    |
    v
Load Default Personality
    |
    v
Transfer Control to Personality

The initial implementation shall load the CP/M 2.2 personality as the
default operating environment.

The Management Services Console shall remain available through the
designated system hotkey.

2.4 Component Relationships
~~~~~~~~~~~~~~~~~~~~~~~~~~~

The relationships between the major architectural components are illustrated
below. Arrows indicate architectural relationships and service dependencies;
they do not necessarily represent execution order.

                                HyperCP/M Kernel
                                      |
   +---------+-----------+--------+---+----+-----------+-----------+
   v         v           v        v        v           v           v
Session  Personality  Console  Storage    VRM      Management    Debug
Manager  Framework    Manager  Manager     |       Services      Services
   |     +---+           |                 |           |
   |     |        +------+------+          v           |
   v     |        v             v       Physical       v
Sessions |      Session    Management   Hardware   Management
   |     |      Consoles   Services                Services
   v     v                 Console                 Interface
Operating-System                                       |
Personality                                            v
   |                                        Management Services Shell
   v
Applications

The kernel is the only component that directly interacts with the VRM.

Applications execute entirely within the context of a personality.

Personalities communicate with the kernel exclusively through the defined
HyperCP/M service interface.

Management Services provide administrative capabilities through the
Management Services Interface. Management Services do not directly implement
resource management operations; requests are dispatched to the appropriate
kernel subsystems.

No personality shall directly access kernel internals, VRM implementation
details, or resources belonging to another session except through explicitly
defined kernel services.

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