diff --git a/Cargo.lock b/Cargo.lock
index 53fda81..605c158 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7889,6 +7889,7 @@ version = "0.1.0"
 name = "mirada-layout"
 version = "0.1.0"
 dependencies = [
+ "libm",
  "serde",
 ]
 
diff --git a/crates/modules/mirada/mirada-brain/Cargo.toml b/crates/modules/mirada/mirada-brain/Cargo.toml
index bc9315b..f55109a 100644
--- a/crates/modules/mirada/mirada-brain/Cargo.toml
+++ b/crates/modules/mirada/mirada-brain/Cargo.toml
@@ -8,7 +8,9 @@ publish.workspace = true
 description = "mirada — orquestador de escritorio del compositor: mantiene salidas, escritorios virtuales, ventanas y foco; consume BodyEvent y produce BrainCommand. Agnóstico de GPUI y de smithay."
 
 [dependencies]
-mirada-layout = { path = "../mirada-layout" }
+# `serde` activa los `derive` de los tipos de layout (este crate
+# serializa el estado del escritorio a RON).
+mirada-layout = { path = "../mirada-layout", features = ["serde"] }
 mirada-protocol = { path = "../mirada-protocol" }
 serde = { workspace = true }
 ron = { workspace = true }
diff --git a/crates/modules/mirada/mirada-layout/Cargo.toml b/crates/modules/mirada/mirada-layout/Cargo.toml
index e8df6d8..e448a26 100644
--- a/crates/modules/mirada/mirada-layout/Cargo.toml
+++ b/crates/modules/mirada/mirada-layout/Cargo.toml
@@ -8,4 +8,18 @@ publish.workspace = true
 description = "mirada — motor de teselado del compositor Wayland: reparte la pantalla entre ventanas según el modo de layout. Agnóstico de Wayland y de smithay."
 
 [dependencies]
-serde = { workspace = true }
+# Deps declaradas directas (no `workspace = true`): mirada-layout es un
+# crate-núcleo compartido entre dos workspaces de Cargo —brahman y
+# renaser— así que mantiene sus dependencias autocontenidas.
+#
+# `libm`: `sqrt`/`ceil`/`round` viven en `std`, no en `core`; este crate
+# es `no_std`, así que la matemática de punto flotante pasa por `libm`.
+libm = "0.2"
+# `serde` es opcional: el motor de teselado no necesita (de)serializar
+# para funcionar. Los consumidores Linux (mirada-protocol/brain) activan
+# la feature; el kernel bare-metal de renaser no. `default-features =
+# false` evita arrastrar `std` aun con la feature activa.
+serde = { version = "1", optional = true, default-features = false, features = ["derive", "alloc"] }
+
+[features]
+serde = ["dep:serde"]
diff --git a/crates/modules/mirada/mirada-layout/src/geometry.rs b/crates/modules/mirada/mirada-layout/src/geometry.rs
index aa3a306..ceb12d3 100644
--- a/crates/modules/mirada/mirada-layout/src/geometry.rs
+++ b/crates/modules/mirada/mirada-layout/src/geometry.rs
@@ -1,10 +1,14 @@
 //! Geometría — el rectángulo en coordenadas de pantalla.
 
+use alloc::vec::Vec;
+
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 /// Un rectángulo en píxeles de pantalla. El origen `(0,0)` es la
 /// esquina superior-izquierda; `x` crece a la derecha, `y` hacia abajo.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Rect {
     pub x: i32,
     pub y: i32,
diff --git a/crates/modules/mirada/mirada-layout/src/layout.rs b/crates/modules/mirada/mirada-layout/src/layout.rs
index 629631e..bcc1277 100644
--- a/crates/modules/mirada/mirada-layout/src/layout.rs
+++ b/crates/modules/mirada/mirada-layout/src/layout.rs
@@ -1,5 +1,8 @@
 //! Modos de teselado — cómo se reparte la pantalla entre ventanas.
 
+use alloc::{vec, vec::Vec};
+
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 use crate::geometry::{split, Rect};
@@ -8,8 +11,9 @@ use crate::geometry::{split, Rect};
 ///
 /// Las variantes nuevas se añaden **al final** para no mover los índices
 /// con que `postcard` las serializa en el API de control.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-#[serde(rename_all = "kebab-case")]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "serde", serde(rename_all = "kebab-case"))]
 pub enum LayoutMode {
     /// Una ventana maestra a la izquierda; el resto apiladas a la derecha.
     MasterStack,
@@ -49,7 +53,8 @@ impl LayoutMode {
 }
 
 /// Parámetros del teselado.
-#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct LayoutParams {
     pub mode: LayoutMode,
     /// Fracción del ancho para la ventana maestra en `MasterStack` y
@@ -108,7 +113,9 @@ fn columns(screen: Rect, count: usize) -> Vec<Rect> {
 
 /// Rejilla `cols × rows` lo más cuadrada posible.
 fn grid(screen: Rect, count: usize) -> Vec<Rect> {
-    let cols = (count as f64).sqrt().ceil() as usize;
+    // `libm` en vez de los métodos de `f64`: `sqrt`/`ceil` viven en
+    // `std`, no en `core` — y este crate es `no_std`.
+    let cols = libm::ceil(libm::sqrt(count as f64)) as usize;
     let rows = count.div_ceil(cols);
     let col_parts = split(screen.w, cols);
     let row_parts = split(screen.h, rows);
@@ -162,7 +169,7 @@ fn centered_master(screen: Rect, count: usize, ratio: f32, master_count: usize)
         return master_stack(screen, count, ratio, master_count);
     }
     let ratio = ratio.clamp(0.05, 0.95);
-    let master_w = (screen.w as f32 * ratio).round() as i32;
+    let master_w = libm::roundf(screen.w as f32 * ratio) as i32;
     let sides = split(screen.w - master_w, 2);
     let (left_w, right_w) = (sides[0].1, sides[1].1);
     let left_n = stack / 2;
@@ -194,7 +201,7 @@ fn master_stack(screen: Rect, count: usize, ratio: f32, master_count: usize) ->
             .collect();
     }
     let ratio = ratio.clamp(0.05, 0.95);
-    let master_w = (screen.w as f32 * ratio).round() as i32;
+    let master_w = libm::roundf(screen.w as f32 * ratio) as i32;
     let stack_x = screen.x + master_w;
     let stack_w = screen.w - master_w;
 
diff --git a/crates/modules/mirada/mirada-layout/src/lib.rs b/crates/modules/mirada/mirada-layout/src/lib.rs
index 7f2936f..3fe0db2 100644
--- a/crates/modules/mirada/mirada-layout/src/lib.rs
+++ b/crates/modules/mirada/mirada-layout/src/lib.rs
@@ -12,8 +12,14 @@
 //! Todo es determinista y testeable sin un servidor gráfico: la misma
 //! pantalla y las mismas ventanas dan siempre la misma distribución.
 
+#![cfg_attr(not(test), no_std)]
 #![forbid(unsafe_code)]
 
+// Lógica pura sobre `core` + `alloc`: sin `std`. Así el mismo motor de
+// teselado compila para Linux y para el kernel bare-metal de renaser
+// (`x86_64-unknown-none`); el allocator lo aporta el consumidor.
+extern crate alloc;
+
 pub mod geometry;
 pub mod layout;
 pub mod workspace;
diff --git a/crates/modules/mirada/mirada-layout/src/workspace.rs b/crates/modules/mirada/mirada-layout/src/workspace.rs
index dbead27..56e4f11 100644
--- a/crates/modules/mirada/mirada-layout/src/workspace.rs
+++ b/crates/modules/mirada/mirada-layout/src/workspace.rs
@@ -1,7 +1,12 @@
 //! `Workspace` — un conjunto de ventanas, su foco y su modo de teselado.
 
-use std::collections::BTreeMap;
+use alloc::collections::BTreeMap;
+use alloc::vec::Vec;
+// El macro `vec!` sólo lo usan los tests de este módulo.
+#[cfg(test)]
+use alloc::vec;
 
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 use crate::geometry::Rect;
@@ -11,7 +16,8 @@ use crate::layout::{tile, LayoutMode, LayoutParams};
 pub type WindowId = u64;
 
 /// Un escritorio: ventanas en orden de teselado + la enfocada + el modo.
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Workspace {
     /// Ventanas en orden de teselado (la 0 es la maestra en `MasterStack`).
     windows: Vec<WindowId>,
diff --git a/crates/modules/mirada/mirada-protocol/Cargo.toml b/crates/modules/mirada/mirada-protocol/Cargo.toml
index 73200ea..2983428 100644
--- a/crates/modules/mirada/mirada-protocol/Cargo.toml
+++ b/crates/modules/mirada/mirada-protocol/Cargo.toml
@@ -8,6 +8,8 @@ publish.workspace = true
 description = "mirada — contrato Cerebro↔Cuerpo del compositor: comandos de geometría que el Cerebro (GPUI) envía y eventos de hardware/superficies que el Cuerpo (smithay) reporta. Marco postcard con prefijo de longitud."
 
 [dependencies]
-mirada-layout = { path = "../mirada-layout" }
+# `serde` activa los `derive` de los tipos de layout — este crate los
+# (de)serializa con postcard.
+mirada-layout = { path = "../mirada-layout", features = ["serde"] }
 serde = { workspace = true }
 postcard = { workspace = true }