diff --git a/Cargo.lock b/Cargo.lock
index 6ab71b0..d1373f7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -13,6 +13,12 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "allocator-api2"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56fc6cf8dc8c4158eed8649f9b8b0ea1518eb62b544fe9490d66fa0b349eafe9"
+
 [[package]]
 name = "beef"
 version = "0.5.2"
@@ -70,10 +76,21 @@ dependencies = [
  "ahash",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c6201b9ff9fd90a5a3bac2e56a830d0caa509576f0e503818ee82c181b3437a"
+dependencies = [
+ "ahash",
+ "allocator-api2",
+]
+
 [[package]]
 name = "hbasm"
 version = "0.1.0"
 dependencies = [
+ "hashbrown 0.14.0",
  "hbbytecode",
  "lasso",
  "logos",
@@ -90,7 +107,7 @@ version = "0.1.0"
 dependencies = [
  "delegate",
  "derive_more",
- "hashbrown",
+ "hashbrown 0.13.2",
  "hbbytecode",
  "log",
  "paste",
@@ -103,7 +120,7 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4644821e1c3d7a560fe13d842d13f587c07348a1a05d3a797152d41c90c56df2"
 dependencies = [
- "hashbrown",
+ "hashbrown 0.13.2",
 ]
 
 [[package]]
diff --git a/hbasm/Cargo.toml b/hbasm/Cargo.toml
index 1ab3f41..ff364ad 100644
--- a/hbasm/Cargo.toml
+++ b/hbasm/Cargo.toml
@@ -5,8 +5,9 @@ edition = "2021"
 
 [dependencies]
 hbbytecode = { path = "../hbbytecode" }
-lasso      = "0.7"
-paste      = "1.0"
+lasso = "0.7"
+paste = "1.0"
+hashbrown = "0.14.0"
 
 [dependencies.logos]
 version = "0.13"
diff --git a/hbasm/assets/serial_driver.hbasm b/hbasm/assets/serial_driver.hbasm
index 306bbf7..13bcb3a 100644
--- a/hbasm/assets/serial_driver.hbasm
+++ b/hbasm/assets/serial_driver.hbasm
@@ -5,3 +5,14 @@ start:
 -- Uses r20 to set the port
 init_serial_port:
     add r20, r30, r10
+    li r20, 00
+
+   -- outb(PORT + 1, 0x00);    // Disable all interrupts
+   -- outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
+   -- outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
+   -- outb(PORT + 1, 0x00);    //                  (hi byte)
+   -- outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+   -- outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+   -- outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+   -- outb(PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
+   -- outb(PORT + 0, 0xAE);    // Test serial chip (send byte 0xAE and check if serial returns same byte)
\ No newline at end of file
diff --git a/hbasm/src/lib.rs b/hbasm/src/lib.rs
index 3313693..121927a 100644
--- a/hbasm/src/lib.rs
+++ b/hbasm/src/lib.rs
@@ -1,8 +1,15 @@
-use std::collections::HashMap;
+#![no_std]
+#![feature(error_in_core)]
+
+// use std::collections::HashMap;
+extern crate alloc;
+use alloc::vec::Vec;
+
 use {
+    core::fmt::{Display, Formatter},
+    hashbrown::HashMap,
     lasso::{Rodeo, Spur},
     logos::{Lexer, Logos, Span},
-    std::fmt::{Display, Formatter},
 };
 
 macro_rules! tokendef {
@@ -73,12 +80,12 @@ pub struct Error {
 }
 
 impl Display for Error {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
         write!(f, "Error {:?} at {:?}", self.kind, self.span)
     }
 }
 
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 macro_rules! expect_matches {
     ($self:expr, $($pat:pat),* $(,)?) => {$(
diff --git a/rust-toolchain b/rust-toolchain
index 870bbe4..07ade69 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-stable
\ No newline at end of file
+nightly
\ No newline at end of file