diff --git a/Cargo.lock b/Cargo.lock
index 4ec9784..27a998f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9,20 +9,38 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
 [[package]]
-name = "cobs"
-version = "0.2.3"
+name = "bitflags"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67ba02a97a2bd10f4b59b25c7973101c79642302776489e030cd13cdab09ed15"
+checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+
+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "dev_driver_rpc"
 version = "0.1.0"
 dependencies = [
- "postcard",
+ "parking_lot",
+ "rmp-serde",
  "serde",
- "spin",
 ]
 
+[[package]]
+name = "libc"
+version = "0.2.155"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"
+
 [[package]]
 name = "lock_api"
 version = "0.4.8"
@@ -34,15 +52,43 @@ dependencies = [
 ]
 
 [[package]]
-name = "postcard"
-version = "1.0.2"
+name = "num-traits"
+version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c2b180dc0bade59f03fd005cb967d3f1e5f69b13922dad0cd6e047cb8af2363"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
 dependencies = [
- "cobs",
- "serde",
+ "autocfg",
 ]
 
+[[package]]
+name = "parking_lot"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bf18183cf54e8d6059647fc3063646a1801cf30896933ec2311622cc4b9a27"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e401f977ab385c9e4e3ab30627d6f26d00e2c73eef317493c4ec6d468726cf8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-targets",
+]
+
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.85"
@@ -61,6 +107,37 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "redox_syscall"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "469052894dcb553421e483e4209ee581a45100d31b4018de03e5a7ad86374a7e"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "rmp"
+version = "0.8.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "228ed7c16fa39782c3b3468e974aec2795e9089153cd08ee2e9aefb3613334c4"
+dependencies = [
+ "byteorder",
+ "num-traits",
+ "paste",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52e599a477cf9840e92f2cde9a7189e67b42c57532749bf90aea6ec10facd4db"
+dependencies = [
+ "byteorder",
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
@@ -88,13 +165,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "spin"
-version = "0.9.4"
+name = "smallvec"
+version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f6002a767bff9e83f8eeecf883ecb8011875a21ae8da43bffb817a57e78cc09"
-dependencies = [
- "lock_api",
-]
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 
 [[package]]
 name = "syn"
@@ -112,3 +186,67 @@ name = "unicode-ident"
 version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4f5b37a154999a8f3f98cc23a628d850e154479cd94decf3414696e12e31aaf"
+
+[[package]]
+name = "windows-targets"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88ba073cf16d5372720ec942a8ccbf61626074c6d4dd2e745299726ce8b89670"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bec47e5bfd1bff0eeaf6d8b485cc1074891a197ab4225d504cb7a1ab88b02bf0"
diff --git a/Cargo.toml b/Cargo.toml
index 3809545..7b0dea1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,10 +6,9 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-postcard = { version = "1.0.2", default-features = false, features = ["alloc"] }
-serde = { version = "1.0.144", default-features = false, features = ["alloc", "derive"] }
-spin = "0.9.4"
-# std = { version = "0.1.0", path = "../std" }
+parking_lot = "0.12.3"
+rmp-serde = "1.3.0"
+serde = { version = "1.0.144", features = ["derive"] }
 
 [profile.dev]
 panic="abort"
diff --git a/src/lib.rs b/src/lib.rs
index a91dd8e..7d569c3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,19 +1,17 @@
-// #![no_std]
 #![allow(clippy::result_unit_err)]
 
 use std::{
-    io,
-    os::mikros::ipc::rpc::{self, IncomingCall},
+    os::mikros::ipc::rpc::{self, IncomingCall}, path::Path,
 };
 
-use spin::RwLock;
+use parking_lot::RwLock;
 
 static SERVER: RwLock<Option<Box<dyn Server>>> = RwLock::new(None);
 
 const PROTO: u16 = 0;
 
 pub trait Server: Send + Sync {
-    fn open(&self, path: &str) -> Result<u64, io::Error>;
+    fn open(&self, path: &Path) -> Result<u64, ()>;
 }
 
 #[derive(Copy, Clone)]
@@ -24,9 +22,9 @@ impl Client {
         Self(pid)
     }
 
-    pub fn open(self, path: &str) -> Result<u64, ()> {
-        postcard::from_bytes(
-            &rpc::send_call(self.0, PROTO, 0, &postcard::to_allocvec(path).unwrap()).get_return(),
+    pub fn open(self, path: &Path) -> Result<u64, ()> {
+        rmp_serde::from_slice(
+            &rpc::send_call(self.0, PROTO, 0, &rmp_serde::to_vec(path).unwrap()).get_return(),
         )
         .unwrap()
     }
@@ -46,8 +44,8 @@ fn callback(call: IncomingCall) {
     let server_lock = SERVER.read();
     let server = server_lock.as_ref().unwrap();
     if call.func == 0 {
-        let path = postcard::from_bytes(&call.args).unwrap();
-        let ret = postcard::to_allocvec(&server.open(path).map_err(|e| ())).unwrap();
+        let path = rmp_serde::from_slice(&call.args).unwrap();
+        let ret = rmp_serde::to_vec(&server.open(path)).unwrap();
         call.send_return(&ret);
     }
 }