implements PLN-0109

crates/console/prometeu-drivers/src/hardware.rs

@@ -11,8 +11,8 @@ use crate::touch::Touch;
 use prometeu_hal::cartridge::AssetsPayloadSource;
 use prometeu_hal::sprite::Sprite;
 use prometeu_hal::{
-    AssetBridge, AudioBridge, GfxBridge, HardwareBridge, InputPlatform, NoopTelemetryPlatform,
-    PadBridge, RenderBackend, RuntimePlatform, TelemetryPlatform, TouchBridge,
+    AssetBridge, AudioBridge, InputPlatform, NoopTelemetryPlatform, PadBridge, RenderBackend,
+    RuntimePlatform, TelemetryPlatform, TouchBridge,
 };
 use prometeu_hal::{
     Game2DFrameComposer, Game2DFramePacket, RenderSubmission, RenderSubmissionPacket,
@@ -53,32 +53,8 @@ impl Default for Hardware {
     }
 }
 
-impl HardwareBridge for Hardware {
-    fn begin_frame(&mut self) {
-        self.frame_composer.begin_frame();
-    }
-
-    fn bind_scene(&mut self, scene_bank_id: usize) -> bool {
-        self.frame_composer.bind_scene(scene_bank_id)
-    }
-
-    fn unbind_scene(&mut self) {
-        self.frame_composer.unbind_scene();
-    }
-
-    fn set_camera(&mut self, x: i32, y: i32) {
-        self.frame_composer.set_camera(x, y);
-    }
-
-    fn emit_sprite(&mut self, sprite: Sprite) -> bool {
-        self.frame_composer.emit_sprite(sprite)
-    }
-
-    fn close_game2d_packet(&self) -> Game2DFramePacket {
-        self.frame_composer.close_game2d_packet()
-    }
-
-    fn publish_render_submission(&mut self, submission: &RenderSubmission) {
+impl Hardware {
+    fn consume_render_submission(&mut self, submission: &RenderSubmission) {
         match &submission.packet {
             RenderSubmissionPacket::Game2D(packet) => {
                 if packet.composer.bound_scene.is_none() {
@@ -94,54 +70,6 @@ impl HardwareBridge for Hardware {
         }
         self.gfx.present();
     }
-
-    fn render_frame(&mut self) {
-        if self.frame_composer.active_scene_id().is_none() {
-            let packet = self.frame_composer.close_game2d_packet();
-            self.gfx.render_game2d_frame_packet(&packet);
-        } else {
-            self.frame_composer.render_frame(&mut self.gfx);
-        }
-    }
-
-    fn has_glyph_bank(&self, bank_id: usize) -> bool {
-        self.gfx.glyph_banks.glyph_bank_slot(bank_id).is_some()
-    }
-
-    fn gfx(&self) -> &dyn GfxBridge {
-        &self.gfx
-    }
-    fn gfx_mut(&mut self) -> &mut dyn GfxBridge {
-        &mut self.gfx
-    }
-
-    fn audio(&self) -> &dyn AudioBridge {
-        &self.audio
-    }
-    fn audio_mut(&mut self) -> &mut dyn AudioBridge {
-        &mut self.audio
-    }
-
-    fn pad(&self) -> &dyn PadBridge {
-        &self.pad
-    }
-    fn pad_mut(&mut self) -> &mut dyn PadBridge {
-        &mut self.pad
-    }
-
-    fn touch(&self) -> &dyn TouchBridge {
-        &self.touch
-    }
-    fn touch_mut(&mut self) -> &mut dyn TouchBridge {
-        &mut self.touch
-    }
-
-    fn assets(&self) -> &dyn AssetBridge {
-        &self.assets
-    }
-    fn assets_mut(&mut self) -> &mut dyn AssetBridge {
-        &mut self.assets
-    }
 }
 
 impl RenderSubmissionSink for Hardware {
@@ -149,14 +77,19 @@ impl RenderSubmissionSink for Hardware {
         &mut self,
         submission: RenderSubmission,
     ) -> Result<(), RenderSubmitError> {
-        self.publish_render_submission(&submission);
+        self.consume_render_submission(&submission);
         Ok(())
     }
 }
 
 impl RenderBackend for Hardware {
     fn render_frame(&mut self) {
-        HardwareBridge::render_frame(self);
+        if self.frame_composer.active_scene_id().is_none() {
+            let packet = self.frame_composer.close_game2d_packet();
+            self.gfx.render_game2d_frame_packet(&packet);
+        } else {
+            self.frame_composer.render_frame(&mut self.gfx);
+        }
     }
 }
 
@@ -183,7 +116,7 @@ impl Game2DFrameComposer for Hardware {
     }
 
     fn emit_sprite(&mut self, sprite: Sprite) -> prometeu_hal::ComposerOpStatus {
-        if !self.has_glyph_bank(sprite.bank_id as usize) {
+        if self.gfx.glyph_banks.glyph_bank_slot(sprite.bank_id as usize).is_none() {
             return prometeu_hal::ComposerOpStatus::BankInvalid;
         }
 
@@ -406,9 +339,12 @@ mod tests {
         let mut glyph_slots = [None; 16];
         glyph_slots[0] = Some(0);
         hardware.assets.glyph_asset_slot_index().rebuild_from_slots(&glyph_slots);
-        assert!(HardwareBridge::bind_scene(&mut hardware, 0));
+        assert_eq!(
+            Game2DFrameComposer::bind_scene(&mut hardware, 0),
+            prometeu_hal::ComposerOpStatus::Ok
+        );
 
-        let mut packet = HardwareBridge::close_game2d_packet(&hardware);
+        let mut packet = Game2DFrameComposer::close_game2d_packet(&hardware);
         packet.gfx2d = vec![Gfx2dCommand::FillRect {
             rect: Rect { x: 0, y: 0, w: 1, h: 1 },
             color: Color::BLUE,
@@ -433,7 +369,10 @@ mod tests {
         let mut glyph_slots = [None; 16];
         glyph_slots[0] = Some(0);
         hardware.assets.glyph_asset_slot_index().rebuild_from_slots(&glyph_slots);
-        assert!(HardwareBridge::bind_scene(&mut hardware, 0));
+        assert_eq!(
+            Game2DFrameComposer::bind_scene(&mut hardware, 0),
+            prometeu_hal::ComposerOpStatus::Ok
+        );
 
         let packet = Game2DFramePacket::new(
             ComposerFramePacket {
@@ -455,7 +394,7 @@ mod tests {
             Vec::new(),
         );
 
-        HardwareBridge::begin_frame(&mut hardware);
+        Game2DFrameComposer::begin_frame(&mut hardware);
         RenderSubmissionSink::submit_render_submission(
             &mut hardware,
             RenderSubmission::game2d(FrameId::ZERO, packet),

crates/console/prometeu-hal/src/hardware_bridge.rs

@@ -1,39 +0,0 @@
-use crate::asset_bridge::AssetBridge;
-use crate::audio_bridge::AudioBridge;
-use crate::gfx_bridge::GfxBridge;
-use crate::pad_bridge::PadBridge;
-use crate::render_submission::{Game2DFramePacket, RenderSubmission};
-use crate::sprite::Sprite;
-use crate::touch_bridge::TouchBridge;
-
-/// Legacy migration scaffold for code that has not moved to `platform` facades yet.
-///
-/// `HardwareBridge` is intentionally not the final runtime-facing contract. New
-/// platform boundaries belong in `crate::platform`, and this trait must be
-/// removed after runtime, firmware, host, and tests finish migrating.
-pub trait HardwareBridge {
-    fn begin_frame(&mut self);
-    fn bind_scene(&mut self, scene_bank_id: usize) -> bool;
-    fn unbind_scene(&mut self);
-    fn set_camera(&mut self, x: i32, y: i32);
-    fn emit_sprite(&mut self, sprite: Sprite) -> bool;
-    fn close_game2d_packet(&self) -> Game2DFramePacket;
-    fn publish_render_submission(&mut self, submission: &RenderSubmission);
-    fn render_frame(&mut self);
-    fn has_glyph_bank(&self, bank_id: usize) -> bool;
-
-    fn gfx(&self) -> &dyn GfxBridge;
-    fn gfx_mut(&mut self) -> &mut dyn GfxBridge;
-
-    fn audio(&self) -> &dyn AudioBridge;
-    fn audio_mut(&mut self) -> &mut dyn AudioBridge;
-
-    fn pad(&self) -> &dyn PadBridge;
-    fn pad_mut(&mut self) -> &mut dyn PadBridge;
-
-    fn touch(&self) -> &dyn TouchBridge;
-    fn touch_mut(&mut self) -> &mut dyn TouchBridge;
-
-    fn assets(&self) -> &dyn AssetBridge;
-    fn assets_mut(&mut self) -> &mut dyn AssetBridge;
-}

crates/console/prometeu-hal/src/host_context.rs

@@ -1,27 +1,17 @@
-use crate::hardware_bridge::HardwareBridge;
 use crate::platform::RuntimePlatform;
 use crate::vm_fault::VmFault;
 
 pub struct HostContext<'a> {
-    pub hw: Option<&'a mut dyn HardwareBridge>,
     pub platform: Option<&'a mut dyn RuntimePlatform>,
 }
 
 impl<'a> HostContext<'a> {
-    pub fn new(hw: Option<&'a mut dyn HardwareBridge>) -> Self {
-        Self { hw, platform: None }
+    pub fn new(platform: Option<&'a mut dyn RuntimePlatform>) -> Self {
+        Self { platform }
     }
 
     pub fn new_platform(platform: Option<&'a mut dyn RuntimePlatform>) -> Self {
-        Self { hw: None, platform }
-    }
-
-    #[inline]
-    pub fn require_hw(&mut self) -> Result<&mut dyn HardwareBridge, VmFault> {
-        match &mut self.hw {
-            Some(hw) => Ok(*hw),
-            None => Err(VmFault::Unavailable),
-        }
+        Self::new(platform)
     }
 
     #[inline]

crates/console/prometeu-hal/src/lib.rs

@@ -11,7 +11,6 @@ pub mod debugger_protocol;
 pub mod gfx_bridge;
 pub mod glyph;
 pub mod glyph_bank;
-pub mod hardware_bridge;
 pub mod host_context;
 pub mod host_return;
 pub mod input_signals;
@@ -40,7 +39,6 @@ pub use asset_bridge::AssetBridge;
 pub use audio_bridge::{AudioBridge, AudioOpStatus, LoopMode};
 pub use composer_status::ComposerOpStatus;
 pub use gfx_bridge::{BlendMode, GfxBridge, GfxOpStatus};
-pub use hardware_bridge::HardwareBridge;
 pub use host_context::{HostContext, HostContextProvider};
 pub use host_return::HostReturn;
 pub use input_signals::InputSignals;
@@ -49,9 +47,8 @@ pub use native_interface::{NativeInterface, SyscallId};
 pub use pad_bridge::PadBridge;
 pub use platform::{
     AssetStoragePlatform, AudioPlatform, ClockPacingPlatform, Game2DFrameComposer, InputPlatform,
-    LegacyHardwareGame2DFrameComposer, LegacyHardwareRenderSubmissionSink,
-    LegacyHardwareRuntimePlatform, NoopTelemetryPlatform, RenderBackend, RenderSubmissionSink,
-    RenderSubmitError, RuntimePlatform, TelemetryPlatform, TestPlatform,
+    NoopTelemetryPlatform, RenderBackend, RenderSubmissionSink, RenderSubmitError, RuntimePlatform,
+    TelemetryPlatform, TestPlatform,
 };
 pub use render_submission::{
     BoundScenePacket, Camera2D, ComposerFramePacket, FrameId, Game2DFramePacket, GameSpritePacket,

crates/console/prometeu-hal/src/platform.rs

@@ -1,7 +1,6 @@
 use crate::asset_bridge::AssetBridge;
 use crate::audio_bridge::AudioBridge;
 use crate::composer_status::ComposerOpStatus;
-use crate::hardware_bridge::HardwareBridge;
 use crate::pad_bridge::PadBridge;
 use crate::render_submission::{Game2DFramePacket, RenderSubmission};
 use crate::sprite::Sprite;
@@ -21,26 +20,6 @@ pub trait RenderSubmissionSink {
     ) -> Result<(), RenderSubmitError>;
 }
 
-pub struct LegacyHardwareRenderSubmissionSink<'a> {
-    hw: &'a mut dyn HardwareBridge,
-}
-
-impl<'a> LegacyHardwareRenderSubmissionSink<'a> {
-    pub fn new(hw: &'a mut dyn HardwareBridge) -> Self {
-        Self { hw }
-    }
-}
-
-impl RenderSubmissionSink for LegacyHardwareRenderSubmissionSink<'_> {
-    fn submit_render_submission(
-        &mut self,
-        submission: RenderSubmission,
-    ) -> Result<(), RenderSubmitError> {
-        self.hw.publish_render_submission(&submission);
-        Ok(())
-    }
-}
-
 pub trait RenderBackend {
     fn render_frame(&mut self);
 }
@@ -54,138 +33,6 @@ pub trait Game2DFrameComposer {
     fn close_game2d_packet(&self) -> Game2DFramePacket;
 }
 
-pub struct LegacyHardwareGame2DFrameComposer<'a> {
-    hw: &'a mut dyn HardwareBridge,
-}
-
-impl<'a> LegacyHardwareGame2DFrameComposer<'a> {
-    pub fn new(hw: &'a mut dyn HardwareBridge) -> Self {
-        Self { hw }
-    }
-}
-
-impl Game2DFrameComposer for LegacyHardwareGame2DFrameComposer<'_> {
-    fn begin_frame(&mut self) {
-        self.hw.begin_frame();
-    }
-
-    fn bind_scene(&mut self, scene_bank_id: usize) -> ComposerOpStatus {
-        if self.hw.bind_scene(scene_bank_id) {
-            ComposerOpStatus::Ok
-        } else {
-            ComposerOpStatus::SceneUnavailable
-        }
-    }
-
-    fn unbind_scene(&mut self) {
-        self.hw.unbind_scene();
-    }
-
-    fn set_camera(&mut self, x: i32, y: i32) -> ComposerOpStatus {
-        self.hw.set_camera(x, y);
-        ComposerOpStatus::Ok
-    }
-
-    fn emit_sprite(&mut self, sprite: Sprite) -> ComposerOpStatus {
-        if !self.hw.has_glyph_bank(sprite.bank_id as usize) {
-            return ComposerOpStatus::BankInvalid;
-        }
-
-        if self.hw.emit_sprite(sprite) {
-            ComposerOpStatus::Ok
-        } else {
-            ComposerOpStatus::SpriteOverflow
-        }
-    }
-
-    fn close_game2d_packet(&self) -> Game2DFramePacket {
-        self.hw.close_game2d_packet()
-    }
-}
-
-pub struct LegacyHardwareRuntimePlatform<'a> {
-    hw: &'a mut dyn HardwareBridge,
-}
-
-impl<'a> LegacyHardwareRuntimePlatform<'a> {
-    pub fn new(hw: &'a mut dyn HardwareBridge) -> Self {
-        Self { hw }
-    }
-}
-
-impl RenderSubmissionSink for LegacyHardwareRuntimePlatform<'_> {
-    fn submit_render_submission(
-        &mut self,
-        submission: RenderSubmission,
-    ) -> Result<(), RenderSubmitError> {
-        self.hw.publish_render_submission(&submission);
-        Ok(())
-    }
-}
-
-impl RenderBackend for LegacyHardwareRuntimePlatform<'_> {
-    fn render_frame(&mut self) {
-        self.hw.render_frame();
-    }
-}
-
-impl Game2DFrameComposer for LegacyHardwareRuntimePlatform<'_> {
-    fn begin_frame(&mut self) {
-        self.hw.begin_frame();
-    }
-
-    fn bind_scene(&mut self, scene_bank_id: usize) -> ComposerOpStatus {
-        if self.hw.bind_scene(scene_bank_id) {
-            ComposerOpStatus::Ok
-        } else {
-            ComposerOpStatus::SceneUnavailable
-        }
-    }
-
-    fn unbind_scene(&mut self) {
-        self.hw.unbind_scene();
-    }
-
-    fn set_camera(&mut self, x: i32, y: i32) -> ComposerOpStatus {
-        self.hw.set_camera(x, y);
-        ComposerOpStatus::Ok
-    }
-
-    fn emit_sprite(&mut self, sprite: Sprite) -> ComposerOpStatus {
-        if !self.hw.has_glyph_bank(sprite.bank_id as usize) {
-            return ComposerOpStatus::BankInvalid;
-        }
-
-        if self.hw.emit_sprite(sprite) {
-            ComposerOpStatus::Ok
-        } else {
-            ComposerOpStatus::SpriteOverflow
-        }
-    }
-
-    fn close_game2d_packet(&self) -> Game2DFramePacket {
-        self.hw.close_game2d_packet()
-    }
-}
-
-impl InputPlatform for LegacyHardwareRuntimePlatform<'_> {
-    fn pad(&self) -> &dyn PadBridge {
-        self.hw.pad()
-    }
-
-    fn pad_mut(&mut self) -> &mut dyn PadBridge {
-        self.hw.pad_mut()
-    }
-
-    fn touch(&self) -> &dyn TouchBridge {
-        self.hw.touch()
-    }
-
-    fn touch_mut(&mut self) -> &mut dyn TouchBridge {
-        self.hw.touch_mut()
-    }
-}
-
 pub trait AudioPlatform: AudioBridge {}
 impl<T: AudioBridge + ?Sized> AudioPlatform for T {}
 
@@ -212,8 +59,6 @@ pub struct NoopTelemetryPlatform;
 
 impl TelemetryPlatform for NoopTelemetryPlatform {}
 
-static LEGACY_NOOP_TELEMETRY: NoopTelemetryPlatform = NoopTelemetryPlatform;
-
 pub trait RuntimePlatform {
     fn display_size(&self) -> (usize, usize) {
         (480, 270)
@@ -231,48 +76,6 @@ pub trait RuntimePlatform {
     fn telemetry(&self) -> &dyn TelemetryPlatform;
 }
 
-impl RuntimePlatform for LegacyHardwareRuntimePlatform<'_> {
-    fn render_submission_sink(&mut self) -> &mut dyn RenderSubmissionSink {
-        self
-    }
-
-    fn render_backend(&mut self) -> &mut dyn RenderBackend {
-        self
-    }
-
-    fn game2d_frame_composer(&mut self) -> &mut dyn Game2DFrameComposer {
-        self
-    }
-
-    fn audio(&self) -> &dyn AudioBridge {
-        self.hw.audio()
-    }
-
-    fn audio_mut(&mut self) -> &mut dyn AudioBridge {
-        self.hw.audio_mut()
-    }
-
-    fn input(&self) -> &dyn InputPlatform {
-        self
-    }
-
-    fn input_mut(&mut self) -> &mut dyn InputPlatform {
-        self
-    }
-
-    fn assets(&self) -> &dyn AssetBridge {
-        self.hw.assets()
-    }
-
-    fn assets_mut(&mut self) -> &mut dyn AssetBridge {
-        self.hw.assets_mut()
-    }
-
-    fn telemetry(&self) -> &dyn TelemetryPlatform {
-        &LEGACY_NOOP_TELEMETRY
-    }
-}
-
 pub trait TestPlatform: RuntimePlatform {}
 impl<T: RuntimePlatform + ?Sized> TestPlatform for T {}
 

crates/console/prometeu-system/src/os/facades/vm.rs

@@ -3,7 +3,7 @@ use crate::os::SystemOS;
 use prometeu_hal::app_mode::AppMode;
 use prometeu_hal::cartridge::Cartridge;
 use prometeu_hal::telemetry::{CertificationConfig, TelemetryFrame};
-use prometeu_hal::{HardwareBridge, InputSignals, RuntimePlatform};
+use prometeu_hal::{InputSignals, RuntimePlatform};
 use prometeu_vm::VirtualMachine;
 use std::sync::atomic::Ordering;
 
@@ -47,9 +47,9 @@ impl<'a> VmFacade<'a> {
     pub fn debug_step_instruction(
         &mut self,
         vm: &mut VirtualMachine,
-        hw: &mut dyn HardwareBridge,
+        platform: &mut dyn RuntimePlatform,
     ) -> Option<CrashReport> {
-        self.os.vm_runtime.debug_step_instruction(&mut self.os.log_service, vm, hw)
+        self.os.vm_runtime.debug_step_instruction(&mut self.os.log_service, vm, platform)
     }
 
     pub fn paused(&self) -> bool {

crates/console/prometeu-system/src/services/vm_runtime/tick.rs

@@ -9,9 +9,8 @@ use crate::services::memcard::MemcardService;
 use prometeu_hal::asset::{BankTelemetry, BankType};
 use prometeu_hal::log::{LogLevel, LogService, LogSource};
 use prometeu_hal::{
-    FrameId, HardwareBridge, HostContext, InputSignals, LegacyHardwareRuntimePlatform,
-    RenderSubmission, RenderSubmissionPacket, RenderSubmissionSink, RuntimePlatform,
-    ShellUiFramePacket,
+    FrameId, HostContext, InputSignals, RenderSubmission, RenderSubmissionPacket,
+    RenderSubmissionSink, RuntimePlatform, ShellUiFramePacket,
 };
 use prometeu_vm::LogicalFrameEndingReason;
 use std::collections::HashMap;
@@ -77,11 +76,10 @@ impl VirtualMachineRuntime {
         &mut self,
         log_service: &mut LogService,
         vm: &mut VirtualMachine,
-        hw: &mut dyn HardwareBridge,
+        platform: &mut dyn RuntimePlatform,
     ) -> Option<CrashReport> {
         let step_result = {
-            let mut platform = LegacyHardwareRuntimePlatform::new(hw);
-            let mut ctx = HostContext::new_platform(Some(&mut platform));
+            let mut ctx = HostContext::new_platform(Some(platform));
             let mut fs = VirtualFS::new();
             let mut fs_state = FsState::Unmounted;
             let mut memcard = MemcardService::new();

crates/host/prometeu-host-desktop-winit/src/debugger.rs

@@ -1,5 +1,5 @@
-use prometeu_drivers::hardware::Hardware;
 use prometeu_firmware::{BootTarget, Firmware};
+use prometeu_hal::RuntimePlatform;
 use prometeu_hal::cartridge_loader::CartridgeLoader;
 use prometeu_hal::debugger_protocol::*;
 use prometeu_hal::telemetry::{CertificationConfig, TelemetryFrame};
@@ -99,7 +99,7 @@ impl HostDebugger {
 
     /// Main maintenance method called by the HostRunner every iteration.
     /// It handles new connections and processes incoming commands.
-    pub fn check_commands(&mut self, firmware: &mut Firmware, hardware: &mut Hardware) {
+    pub fn check_commands(&mut self, firmware: &mut Firmware, platform: &mut dyn RuntimePlatform) {
         // 1. Accept new client connections.
         if let Some(listener) = &self.listener
             && let Ok((stream, _addr)) = listener.accept()
@@ -154,7 +154,7 @@ impl HostDebugger {
                             continue;
                         }
                         if let Ok(cmd) = serde_json::from_str::<DebugCommand>(trimmed) {
-                            self.handle_command(cmd, firmware, hardware);
+                            self.handle_command(cmd, firmware, platform);
                         }
                     }
                 }
@@ -182,7 +182,7 @@ impl HostDebugger {
         &mut self,
         cmd: DebugCommand,
         firmware: &mut Firmware,
-        hardware: &mut Hardware,
+        platform: &mut dyn RuntimePlatform,
     ) {
         match cmd {
             DebugCommand::Ok | DebugCommand::Start => {
@@ -201,7 +201,7 @@ impl HostDebugger {
             DebugCommand::Step => {
                 // Execute exactly one instruction and keep paused.
                 firmware.os.vm().set_paused(true);
-                let _ = firmware.os.vm().debug_step_instruction(&mut firmware.vm, hardware);
+                let _ = firmware.os.vm().debug_step_instruction(&mut firmware.vm, platform);
             }
             DebugCommand::StepFrame => {
                 // Execute until the end of the current logical frame.

docs/specs/runtime/04-gfx-peripheral.md

@@ -31,6 +31,13 @@ MUST contain a frame id, the active app mode, and one typed packet:
 immutable. The runtime backpressure policy is latest-complete-submission-wins;
 it MUST NOT accumulate an unbounded frame queue.
 
+The platform layer is the runtime-facing implementation boundary for render
+handoff. Runtime and firmware code publish completed frames through typed
+platform services such as `RenderSubmissionSink`, and they access Game 2D
+composition through `Game2DFrameComposer`. They MUST NOT depend on a monolithic
+hardware bridge, mutable `Hardware`, mutable `Gfx`, or live `FrameComposer`
+reference as the render handoff contract.
+
 The current 2D graphics model is based on:
 
 - framebuffer
@@ -127,6 +134,10 @@ to the logical/runtime side before handoff, or to an owning service. They MUST
 NOT require the render consumer to hold mutable VM, `Hardware`, `Gfx`, or
 `FrameComposer` references.
 
+Local host implementations may keep a concrete hardware object internally as a
+platform implementation detail. That object is not part of the runtime-facing
+render boundary; the boundary is the typed platform service set.
+
 The runtime does not guarantee visual integrity if a developer or framework
 replaces resources behind an in-flight submission in a way that violates asset
 discipline.

docs/specs/runtime/11-portability-and-cross-platform-execution.md

@@ -123,9 +123,13 @@ The graphics system:
 
 The platform layer:
 
+- exposes typed service facades for render submission, render backend
+  execution, Game 2D composition, input, audio, assets, and telemetry
 - consumes closed render submissions through a render-surface implementation
 - transports published RGBA8888 output into a host presentation surface without
   injecting host-owned debug overlay pixels
+- is the runtime-facing portability boundary; runtime and firmware code must not
+  depend on a monolithic hardware bridge or on a concrete hardware aggregate
 
 The host presentation layer MUST treat RGBA8888 as the canonical logical
 framebuffer format. RGB565 conversion is not part of the normal host

docs/specs/runtime/README.md

@@ -50,6 +50,12 @@ Does not belong in `docs/runtime/specs/` as the primary canonical source:
 
 Here, hardware is not a generic bucket for everything. In the current package, "hardware" means the machine's virtual peripherals: GFX, AUDIO, INPUT, TOUCH, and MEMCARD/save memory. VM, firmware, cartridge, and ABI sit in sibling categories rather than inside hardware.
 
+The implementation boundary for host portability is the platform layer. Runtime,
+firmware, and host integration code use typed platform services for rendering,
+input, audio, assets, and telemetry. A concrete local hardware aggregate may
+exist inside a host or test platform, but it is not the normative runtime-facing
+contract.
+
 ## Document Functions
 
 - `normative`: defines the technical contract, expected behavior, or implementation-facing surface.