diff --git a/Cargo.lock b/Cargo.lock
index 9ed5941..ef0a2d9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -69,6 +69,22 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "arm7tdmi"
+version = "0.1.0"
+dependencies = [
+ "ansi_term 0.12.1",
+ "bit",
+ "byteorder",
+ "cfg-if 1.0.0",
+ "colored",
+ "enum-primitive-derive",
+ "num 0.2.1",
+ "num-traits 0.2.12",
+ "rustboyadvance-utils",
+ "serde",
+]
+
 [[package]]
 name = "arrayref"
 version = "0.3.6"
@@ -1351,6 +1367,7 @@ name = "rustboyadvance-core"
 version = "0.1.0"
 dependencies = [
  "ansi_term 0.12.1",
+ "arm7tdmi",
  "arrayvec 0.5.2",
  "bincode",
  "bit",
@@ -1371,14 +1388,13 @@ dependencies = [
  "goblin",
  "hex-literal",
  "hexdump",
- "instant",
  "lazy_static 1.4.0",
  "log 0.4.11",
  "memmem",
  "nom",
  "num 0.2.1",
  "num-traits 0.2.12",
- "ringbuf",
+ "rustboyadvance-utils",
  "rustyline",
  "serde",
  "sha2",
@@ -1433,11 +1449,20 @@ dependencies = [
  "log 0.4.11",
  "ringbuf",
  "rustboyadvance-core",
+ "rustboyadvance-utils",
  "sdl2 0.33.0",
  "spin_sleep",
  "winres",
 ]
 
+[[package]]
+name = "rustboyadvance-utils"
+version = "0.1.0"
+dependencies = [
+ "instant",
+ "ringbuf",
+]
+
 [[package]]
 name = "rustboyadvance-wasm"
 version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index a9fe5ef..3319548 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,8 @@
 [workspace]
 members = [
     "core",
+    "arm7tdmi",
+    "utils",
     "platform/rustboyadvance-sdl2",
     "platform/rustboyadvance-libretro",
     "platform/rustboyadvance-minifb",
diff --git a/arm7tdmi/Cargo.toml b/arm7tdmi/Cargo.toml
new file mode 100644
index 0000000..5304536
--- /dev/null
+++ b/arm7tdmi/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "arm7tdmi"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rustboyadvance-utils = {"path" = "../utils" }
+bit = "^0.1"
+cfg-if = "1.0.0"
+serde = { version = "1.0.104", features = ["derive", "rc"] }
+ansi_term = "0.12.1"
+colored = "1.9"
+byteorder = "1"
+num = "0.2.1"
+num-traits = "0.2"
+enum-primitive-derive = "^0.1"
+
+[build-dependencies]
+bit = "^0.1"
\ No newline at end of file
diff --git a/core/build.rs b/arm7tdmi/build.rs
similarity index 97%
rename from core/build.rs
rename to arm7tdmi/build.rs
index 3deefd8..d02b75c 100644
--- a/core/build.rs
+++ b/arm7tdmi/build.rs
@@ -1,3 +1,4 @@
+/// This build script creates ARM_LUT and THUMB_LUT opcode lookup table used cpu.rs
 use std::env;
 use std::fs;
 use std::io::Write;
@@ -6,7 +7,7 @@ use std::path::Path;
 extern crate bit;
 use bit::BitIndex;
 
-// copied and slightly adjusted from src/core/arm7tdmi/thumb/mod.rs
+// copied and slightly adjusted from arm7tdmi/thumb/mod.rs
 fn thumb_decode(i: u16) -> (&'static str, String) {
     let offset5 = i.bit_range(6..11) as u8;
     let load = i.bit(11);
@@ -180,7 +181,7 @@ trait BitAsInt<T: From<bool>>: BitIndex {
 
 impl BitAsInt<u32> for u32 {}
 
-/// Returns a string representation of rustboyadvance_ng::core::arm7tdmi::arm::ArmFormat enum member
+/// Returns a string representation of arm7tdmi::arm::ArmFormat enum member
 /// # Arguments
 /// * `i` - A 32bit ARM instruction
 ///
@@ -368,7 +369,7 @@ fn arm_decode(i: u32) -> (&'static str, String) {
 }
 
 fn generate_thumb_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
-    writeln!(file, "impl<I: MemoryInterface> Core<I> {{")?;
+    writeln!(file, "impl<I: MemoryInterface> Arm7tdmiCore<I> {{")?;
     writeln!(
         file,
         "   pub const THUMB_LUT: [ThumbInstructionInfo<I>; 1024] = ["
@@ -380,7 +381,7 @@ fn generate_thumb_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
             file,
             "       /* {:#x} */
         ThumbInstructionInfo {{
-            handler_fn: Core::{},
+            handler_fn: Arm7tdmiCore::{},
             #[cfg(feature = \"debugger\")]
             fmt: ThumbFormat::{},
         }},",
@@ -395,7 +396,7 @@ fn generate_thumb_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
 }
 
 fn generate_arm_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
-    writeln!(file, "impl<I: MemoryInterface> Core<I> {{")?;
+    writeln!(file, "impl<I: MemoryInterface> Arm7tdmiCore<I> {{")?;
     writeln!(
         file,
         "    pub const ARM_LUT: [ArmInstructionInfo<I>; 4096] = ["
@@ -406,7 +407,7 @@ fn generate_arm_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
             file,
             "       /* {:#x} */
         ArmInstructionInfo {{
-            handler_fn: Core::{},
+            handler_fn: Arm7tdmiCore::{},
             #[cfg(feature = \"debugger\")]
             fmt: ArmFormat::{},
         }} ,",
diff --git a/core/src/arm7tdmi/alu.rs b/arm7tdmi/src/alu.rs
similarity index 98%
rename from core/src/arm7tdmi/alu.rs
rename to arm7tdmi/src/alu.rs
index 52c124d..06c8e5d 100644
--- a/core/src/arm7tdmi/alu.rs
+++ b/arm7tdmi/src/alu.rs
@@ -1,7 +1,6 @@
 use bit::BitIndex;
 
-use super::memory::MemoryInterface;
-use super::{Core, REG_PC};
+use crate::{memory::MemoryInterface, registers_consts::REG_PC, Arm7tdmiCore};
 
 #[derive(Debug, Primitive, Eq, PartialEq)]
 pub enum AluOpCode {
@@ -110,7 +109,7 @@ impl BarrelShifterValue {
     }
 }
 
-impl<I: MemoryInterface> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
     pub fn lsl(&mut self, val: u32, amount: u32, carry: &mut bool) -> u32 {
         match amount {
             0 => val,
diff --git a/core/src/arm7tdmi/arm/disass.rs b/arm7tdmi/src/arm/disass.rs
similarity index 100%
rename from core/src/arm7tdmi/arm/disass.rs
rename to arm7tdmi/src/arm/disass.rs
diff --git a/core/src/arm7tdmi/arm/exec.rs b/arm7tdmi/src/arm/exec.rs
similarity index 98%
rename from core/src/arm7tdmi/arm/exec.rs
rename to arm7tdmi/src/arm/exec.rs
index 885b55b..adf9d9f 100644
--- a/core/src/arm7tdmi/arm/exec.rs
+++ b/arm7tdmi/src/arm/exec.rs
@@ -1,17 +1,19 @@
 use crate::bit::BitIndex;
 
-use super::super::alu::*;
-use crate::arm7tdmi::psr::RegPSR;
-use crate::arm7tdmi::CpuAction;
-use crate::arm7tdmi::{Addr, Core, CpuMode, CpuState, REG_LR, REG_PC};
+use crate::{
+    alu::*,
+    memory::{MemoryAccess, MemoryInterface},
+    psr::RegPSR,
+    registers_consts::{REG_LR, REG_PC},
+    Arm7tdmiCore, CpuAction, CpuMode, CpuState,
+};
 
-use super::super::memory::{MemoryAccess, MemoryInterface};
 use MemoryAccess::*;
 
 use super::ArmDecodeHelper;
 use super::*;
 
-impl<I: MemoryInterface> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
     pub fn arm_undefined(&mut self, insn: u32) -> CpuAction {
         panic!(
             "executing undefined arm instruction {:08x} at @{:08x}",
diff --git a/core/src/arm7tdmi/arm/mod.rs b/arm7tdmi/src/arm/mod.rs
similarity index 99%
rename from core/src/arm7tdmi/arm/mod.rs
rename to arm7tdmi/src/arm/mod.rs
index 745dc8d..f64540b 100644
--- a/core/src/arm7tdmi/arm/mod.rs
+++ b/arm7tdmi/src/arm/mod.rs
@@ -5,11 +5,12 @@ pub mod exec;
 use serde::{Deserialize, Serialize};
 
 use super::alu::*;
-use crate::arm7tdmi::{Addr, InstructionDecoder};
+use super::memory::Addr;
+use super::InstructionDecoder;
 
-use crate::bit::BitIndex;
-use crate::byteorder::{LittleEndian, ReadBytesExt};
-use crate::num::FromPrimitive;
+use bit::BitIndex;
+use byteorder::{LittleEndian, ReadBytesExt};
+use num::FromPrimitive;
 
 use std::io;
 
diff --git a/core/src/arm7tdmi/cpu.rs b/arm7tdmi/src/cpu.rs
similarity index 96%
rename from core/src/arm7tdmi/cpu.rs
rename to arm7tdmi/src/cpu.rs
index 8c8bcb3..d3a4eb7 100644
--- a/core/src/arm7tdmi/cpu.rs
+++ b/arm7tdmi/src/cpu.rs
@@ -4,7 +4,7 @@ pub use super::exception::Exception;
 
 use super::{arm::ArmCond, psr::RegPSR, Addr, CpuMode, CpuState};
 
-use crate::util::{Shared, WeakPointer};
+use rustboyadvance_utils::{Shared, WeakPointer};
 
 use super::memory::{MemoryAccess, MemoryInterface};
 use MemoryAccess::*;
@@ -19,14 +19,14 @@ use super::arm::ArmFormat;
 
 #[cfg_attr(not(feature = "debugger"), repr(transparent))]
 pub struct ThumbInstructionInfo<I: MemoryInterface> {
-    pub handler_fn: fn(&mut Core<I>, insn: u16) -> CpuAction,
+    pub handler_fn: fn(&mut Arm7tdmiCore<I>, insn: u16) -> CpuAction,
     #[cfg(feature = "debugger")]
     pub fmt: ThumbFormat,
 }
 
 #[cfg_attr(not(feature = "debugger"), repr(transparent))]
 pub struct ArmInstructionInfo<I: MemoryInterface> {
-    pub handler_fn: fn(&mut Core<I>, insn: u32) -> CpuAction,
+    pub handler_fn: fn(&mut Arm7tdmiCore<I>, insn: u32) -> CpuAction,
     #[cfg(feature = "debugger")]
     pub fmt: ArmFormat,
 }
@@ -104,7 +104,7 @@ impl Default for DebuggerState {
 }
 
 #[derive(Clone, Debug)]
-pub struct Core<I: MemoryInterface> {
+pub struct Arm7tdmiCore<I: MemoryInterface> {
     pub pc: u32,
     pub(super) bus: Shared<I>,
 
@@ -121,10 +121,10 @@ pub struct Core<I: MemoryInterface> {
     pub dbg: DebuggerState,
 }
 
-impl<I: MemoryInterface> Core<I> {
-    pub fn new(bus: Shared<I>) -> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
+    pub fn new(bus: Shared<I>) -> Arm7tdmiCore<I> {
         let cpsr = RegPSR::new(0x0000_00D3);
-        Core {
+        Arm7tdmiCore {
             bus,
             pc: 0,
             gpr: [0; 15],
@@ -139,12 +139,12 @@ impl<I: MemoryInterface> Core<I> {
         }
     }
 
-    pub fn weak_ptr(&mut self) -> WeakPointer<Core<I>> {
-        WeakPointer::new(self as *mut Core<I>)
+    pub fn weak_ptr(&mut self) -> WeakPointer<Arm7tdmiCore<I>> {
+        WeakPointer::new(self as *mut Arm7tdmiCore<I>)
     }
 
-    pub fn from_saved_state(bus: Shared<I>, state: SavedCpuState) -> Core<I> {
-        Core {
+    pub fn from_saved_state(bus: Shared<I>, state: SavedCpuState) -> Arm7tdmiCore<I> {
+        Arm7tdmiCore {
             bus,
 
             pc: state.pc,
diff --git a/core/src/arm7tdmi/disass.rs b/arm7tdmi/src/disass.rs
similarity index 100%
rename from core/src/arm7tdmi/disass.rs
rename to arm7tdmi/src/disass.rs
diff --git a/core/src/arm7tdmi/exception.rs b/arm7tdmi/src/exception.rs
similarity index 96%
rename from core/src/arm7tdmi/exception.rs
rename to arm7tdmi/src/exception.rs
index 90d835c..2b2322a 100644
--- a/core/src/arm7tdmi/exception.rs
+++ b/arm7tdmi/src/exception.rs
@@ -1,5 +1,5 @@
-use super::cpu::Core;
 use super::memory::MemoryInterface;
+use super::Arm7tdmiCore;
 use super::{CpuMode, CpuState};
 
 #[derive(Debug, Clone, Copy, PartialEq)]
@@ -16,7 +16,7 @@ pub enum Exception {
     Fiq = 0x1c,
 }
 
-impl<I: MemoryInterface> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
     pub fn exception(&mut self, e: Exception, lr: u32) {
         use Exception::*;
         let (new_mode, irq_disable, fiq_disable) = match e {
diff --git a/core/src/arm7tdmi/mod.rs b/arm7tdmi/src/lib.rs
similarity index 92%
rename from core/src/arm7tdmi/mod.rs
rename to arm7tdmi/src/lib.rs
index 81d3297..90952fa 100644
--- a/core/src/arm7tdmi/mod.rs
+++ b/arm7tdmi/src/lib.rs
@@ -1,3 +1,12 @@
+#[macro_use]
+extern crate serde;
+
+#[macro_use]
+extern crate enum_primitive_derive;
+use bit;
+use num;
+use num_traits;
+
 use std::fmt;
 
 use num::Num;
@@ -14,16 +23,17 @@ pub use cpu::*;
 pub mod alu;
 pub mod memory;
 pub use alu::*;
+use memory::Addr;
 pub mod exception;
 pub mod psr;
 pub use psr::*;
 pub mod disass;
 
-pub const REG_PC: usize = 15;
-pub const REG_LR: usize = 14;
-pub const REG_SP: usize = 13;
-
-pub(self) use crate::Addr;
+pub mod registers_consts {
+    pub const REG_PC: usize = 15;
+    pub const REG_LR: usize = 14;
+    pub const REG_SP: usize = 13;
+}
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
 pub enum DecodedInstruction {
diff --git a/core/src/arm7tdmi/memory.rs b/arm7tdmi/src/memory.rs
similarity index 94%
rename from core/src/arm7tdmi/memory.rs
rename to arm7tdmi/src/memory.rs
index cd14079..bcf9cc9 100644
--- a/core/src/arm7tdmi/memory.rs
+++ b/arm7tdmi/src/memory.rs
@@ -1,7 +1,8 @@
-use super::cpu::Core;
-use super::Addr;
+use super::Arm7tdmiCore;
 use std::fmt;
 
+pub type Addr = u32;
+
 #[derive(Serialize, Deserialize, Debug, Copy, Clone)]
 pub enum MemoryAccess {
     NonSeq = 0,
@@ -35,7 +36,7 @@ pub enum MemoryAccessWidth {
     MemoryAccess32,
 }
 
-/// A trait meant to abstract memory accesses and report the access type back to the user of the arm7tdmi::Core
+/// A trait meant to abstract memory accesses and report the access type back to the user of the arm7tdmi::Arm7tdmiCore
 ///
 /// struct Memory {
 ///     data: [u8; 0x4000]
@@ -60,7 +61,7 @@ pub enum MemoryAccessWidth {
 /// }
 ///
 /// let mem = Shared::new(Memory { ... });
-/// let cpu = arm7tdmi::Core::new(mem.clone())
+/// let cpu = arm7tdmi::Arm7tdmiCore::new(mem.clone())
 ///
 pub trait MemoryInterface {
     /// Read a byte
@@ -80,7 +81,7 @@ pub trait MemoryInterface {
     fn idle_cycle(&mut self);
 }
 
-impl<I: MemoryInterface> MemoryInterface for Core<I> {
+impl<I: MemoryInterface> MemoryInterface for Arm7tdmiCore<I> {
     #[inline]
     fn load_8(&mut self, addr: u32, access: MemoryAccess) -> u8 {
         self.bus.load_8(addr, access)
@@ -117,7 +118,7 @@ impl<I: MemoryInterface> MemoryInterface for Core<I> {
 }
 
 /// Implementation of memory access helpers
-impl<I: MemoryInterface> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
     #[inline]
     pub(super) fn store_aligned_32(&mut self, addr: Addr, value: u32, access: MemoryAccess) {
         self.store_32(addr & !0x3, value, access);
diff --git a/core/src/arm7tdmi/psr.rs b/arm7tdmi/src/psr.rs
similarity index 100%
rename from core/src/arm7tdmi/psr.rs
rename to arm7tdmi/src/psr.rs
diff --git a/core/src/arm7tdmi/thumb/disass.rs b/arm7tdmi/src/thumb/disass.rs
similarity index 100%
rename from core/src/arm7tdmi/thumb/disass.rs
rename to arm7tdmi/src/thumb/disass.rs
diff --git a/core/src/arm7tdmi/thumb/exec.rs b/arm7tdmi/src/thumb/exec.rs
similarity index 98%
rename from core/src/arm7tdmi/thumb/exec.rs
rename to arm7tdmi/src/thumb/exec.rs
index d36f90a..33e8fca 100644
--- a/core/src/arm7tdmi/thumb/exec.rs
+++ b/arm7tdmi/src/thumb/exec.rs
@@ -1,13 +1,17 @@
-use crate::arm7tdmi::*;
+use crate::{
+    exception::Exception,
+    memory::{MemoryAccess, MemoryInterface},
+    registers_consts::*,
+    Arm7tdmiCore, CpuAction,
+};
 
-use crate::bit::BitIndex;
+use bit::BitIndex;
 
-use super::super::memory::{MemoryAccess, MemoryInterface};
 use super::ThumbDecodeHelper;
 use super::*;
 use MemoryAccess::*;
 
-impl<I: MemoryInterface> Core<I> {
+impl<I: MemoryInterface> Arm7tdmiCore<I> {
     /// Format 1
     /// Execution Time: 1S
     pub(in super::super) fn exec_thumb_move_shifted_reg<const BS_OP: u8, const IMM: u8>(
diff --git a/core/src/arm7tdmi/thumb/mod.rs b/arm7tdmi/src/thumb/mod.rs
similarity index 98%
rename from core/src/arm7tdmi/thumb/mod.rs
rename to arm7tdmi/src/thumb/mod.rs
index 7ace8c8..35bfc29 100644
--- a/core/src/arm7tdmi/thumb/mod.rs
+++ b/arm7tdmi/src/thumb/mod.rs
@@ -1,9 +1,10 @@
 use super::alu::*;
 use super::arm::*;
-use super::{Addr, InstructionDecoder};
-use crate::bit::BitIndex;
-use crate::byteorder::{LittleEndian, ReadBytesExt};
-use crate::num::FromPrimitive;
+use super::memory::Addr;
+use super::InstructionDecoder;
+use bit::BitIndex;
+use byteorder::{LittleEndian, ReadBytesExt};
+use num::FromPrimitive;
 
 #[cfg(feature = "debugger")]
 pub mod disass;
diff --git a/core/Cargo.toml b/core/Cargo.toml
index 2c23504..6e4fe36 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -5,6 +5,8 @@ authors = ["Michel Heily <michelheily@gmail.com>"]
 edition = "2018"
 
 [dependencies]
+arm7tdmi = { "path" = "../arm7tdmi" }
+rustboyadvance-utils = { "path" = "../utils" }
 cfg-if = "1.0.0"
 serde = { version = "1.0.104", features = ["derive", "rc"] }
 bincode = "1.2.1"
@@ -35,7 +37,6 @@ hex-literal = "0.2.1"
 rustyline = { version = "6.0.0", optional = true }
 nom = { version = "5.0.0", optional = true }
 gdbstub = { version = "0.1.2", optional = true, features = ["std"] }
-ringbuf = "0.2.2"
 goblin = { version = "0.2", optional = true }
 fuzzy-matcher = { version = "0.3.4", optional = true }
 bit_reverse = "0.1.8"
@@ -43,12 +44,6 @@ yaml-rust = "0.4"
 lazy_static = "1.4.0"
 smart-default = "0.6.0"
 
-[target.'cfg(target_arch="wasm32")'.dependencies]
-instant = { version = "0.1.2", features = ["wasm-bindgen"] }
-
-[build-dependencies]
-bit = "^0.1"
-
 [dev-dependencies]
 criterion = "0.3"
 
diff --git a/core/src/bios.rs b/core/src/bios.rs
index 022cfff..6fca0ff 100644
--- a/core/src/bios.rs
+++ b/core/src/bios.rs
@@ -1,7 +1,8 @@
-use super::arm7tdmi;
-use super::bus::{Addr, Bus, DebugRead};
-use super::util::WeakPointer;
+use super::bus::{Bus, DebugRead};
 use super::SysBus;
+use arm7tdmi::{memory::Addr, Arm7tdmiCore};
+
+use rustboyadvance_utils::WeakPointer;
 
 /// Struct representing the sytem ROM
 #[derive(Clone)]
@@ -11,7 +12,7 @@ pub struct Bios {
     /// Last read value
     last_opcode: u32,
     /// Arm pointer - used only to read the PC register
-    arm_core: WeakPointer<arm7tdmi::Core<SysBus>>,
+    arm_core: WeakPointer<Arm7tdmiCore<SysBus>>,
 }
 
 impl Bios {
@@ -23,7 +24,7 @@ impl Bios {
         }
     }
 
-    pub(super) fn connect_arm_core(&mut self, arm_ptr: WeakPointer<arm7tdmi::Core<SysBus>>) {
+    pub(super) fn connect_arm_core(&mut self, arm_ptr: WeakPointer<Arm7tdmiCore<SysBus>>) {
         self.arm_core = arm_ptr;
     }
 
diff --git a/core/src/bus.rs b/core/src/bus.rs
index fd7ba7d..172dbcf 100644
--- a/core/src/bus.rs
+++ b/core/src/bus.rs
@@ -1,4 +1,4 @@
-pub type Addr = u32;
+pub use arm7tdmi::memory::Addr; // re-export
 
 pub trait Bus {
     fn read_32(&mut self, addr: Addr) -> u32 {
diff --git a/core/src/cartridge/backup/backup_file.rs b/core/src/cartridge/backup/backup_file.rs
index 08c9a33..adfb320 100644
--- a/core/src/cartridge/backup/backup_file.rs
+++ b/core/src/cartridge/backup/backup_file.rs
@@ -8,7 +8,7 @@ use serde::de::{self, Deserialize, Deserializer, SeqAccess, Visitor};
 use serde::ser::{Serialize, SerializeStruct, Serializer};
 
 use super::BackupMemoryInterface;
-use crate::util::write_bin_file;
+use rustboyadvance_utils::write_bin_file;
 
 #[derive(Debug)]
 pub struct BackupFile {
diff --git a/core/src/cartridge/loader.rs b/core/src/cartridge/loader.rs
index 474bde5..69d3df5 100644
--- a/core/src/cartridge/loader.rs
+++ b/core/src/cartridge/loader.rs
@@ -6,7 +6,7 @@ use std::io::prelude::*;
 use std::io::Cursor;
 use std::path::Path;
 
-use crate::util::read_bin_file;
+use rustboyadvance_utils::read_bin_file;
 use zip::ZipArchive;
 
 #[cfg(feature = "elf_support")]
diff --git a/core/src/debugger/command.rs b/core/src/debugger/command.rs
index f53824c..be7fb97 100644
--- a/core/src/debugger/command.rs
+++ b/core/src/debugger/command.rs
@@ -7,7 +7,7 @@ use crate::arm7tdmi::thumb::ThumbInstruction;
 use crate::arm7tdmi::CpuState;
 use crate::bus::{Addr, Bus, DebugRead};
 use crate::disass::Disassembler;
-use crate::util::{read_bin_file, write_bin_file};
+use rustboyadvance_utils::{read_bin_file, write_bin_file};
 
 // use super::palette_view::create_palette_view;
 // use super::tile_view::create_tile_view;
diff --git a/core/src/gba.rs b/core/src/gba.rs
index d46291c..f1fbdf3 100644
--- a/core/src/gba.rs
+++ b/core/src/gba.rs
@@ -5,7 +5,6 @@ use std::rc::Rc;
 use bincode;
 use serde::{Deserialize, Serialize};
 
-use super::arm7tdmi;
 use super::cartridge::Cartridge;
 use super::dma::DmaController;
 use super::gpu::*;
@@ -15,14 +14,16 @@ use super::sched::{EventType, Scheduler, SchedulerConnect, SharedScheduler};
 use super::sound::SoundController;
 use super::sysbus::SysBus;
 use super::timer::Timers;
-use super::util::Shared;
 
 #[cfg(not(feature = "no_video_interface"))]
 use super::VideoInterface;
 use super::{AudioInterface, InputInterface};
 
+use arm7tdmi::{self, Arm7tdmiCore};
+use rustboyadvance_utils::Shared;
+
 pub struct GameBoyAdvance {
-    pub cpu: Box<arm7tdmi::Core<SysBus>>,
+    pub cpu: Box<Arm7tdmiCore<SysBus>>,
     pub sysbus: Shared<SysBus>,
     pub io_devs: Shared<IoDevices>,
     pub scheduler: SharedScheduler,
@@ -103,7 +104,7 @@ impl GameBoyAdvance {
             gamepak,
         ));
 
-        let cpu = Box::new(arm7tdmi::Core::new(sysbus.clone()));
+        let cpu = Box::new(Arm7tdmiCore::new(sysbus.clone()));
 
         let mut gba = GameBoyAdvance {
             cpu,
@@ -150,7 +151,7 @@ impl GameBoyAdvance {
             decoded.ewram,
             decoded.iwram,
         ));
-        let mut arm7tdmi = Box::new(arm7tdmi::Core::from_saved_state(
+        let mut arm7tdmi = Box::new(Arm7tdmiCore::from_saved_state(
             sysbus.clone(),
             decoded.cpu_state,
         ));
diff --git a/core/src/gdb.rs b/core/src/gdb.rs
index 4274d40..f0a1fd2 100644
--- a/core/src/gdb.rs
+++ b/core/src/gdb.rs
@@ -10,6 +10,44 @@ use gdbstub::{Access, Target, TargetState};
 
 use std::io::Cursor;
 
+use gdbstub;
+use gdbstub::GdbStub;
+use std::fmt;
+use std::net::TcpListener;
+use std::net::ToSocketAddrs;
+
+pub fn spawn_and_run_gdb_server<A: ToSocketAddrs + fmt::Display>(
+    #[allow(unused)] target: &mut GameBoyAdvance,
+    #[allow(unused)] addr: A,
+) -> Result<(), Box<dyn std::error::Error>> {
+    #[cfg(feature = "gdb")]
+    {
+        info!("spawning gdbserver, listening on {}", addr);
+
+        let sock = TcpListener::bind(addr)?;
+        let (stream, addr) = sock.accept()?;
+
+        info!("got connection from {}", addr);
+
+        let mut gdb = GdbStub::new(stream);
+        let result = match gdb.run(target) {
+            Ok(state) => {
+                info!("Disconnected from GDB. Target state: {:?}", state);
+                Ok(())
+            }
+            Err(gdbstub::Error::TargetError(e)) => Err(e),
+            Err(e) => return Err(e.into()),
+        };
+
+        info!("Debugger session ended, result={:?}", result);
+    }
+    #[cfg(not(feature = "gdb"))]
+    {
+        error!("failed. please compile me with 'gdb' feature")
+    }
+
+    Ok(())
+}
 impl Target for GameBoyAdvance {
     type Usize = u32;
     type Error = ();
diff --git a/core/src/gpu/mod.rs b/core/src/gpu/mod.rs
index 1110695..36989cc 100644
--- a/core/src/gpu/mod.rs
+++ b/core/src/gpu/mod.rs
@@ -3,8 +3,11 @@ use std::cell::RefCell;
 #[cfg(not(feature = "no_video_interface"))]
 use std::rc::Rc;
 
+use num::FromPrimitive;
 use serde::{Deserialize, Serialize};
 
+use rustboyadvance_utils::index2d;
+
 use super::bus::*;
 use super::dma::{DmaNotifer, TIMING_HBLANK, TIMING_VBLANK};
 use super::interrupt::{self, Interrupt, InterruptConnect, SharedInterruptFlags};
@@ -13,8 +16,6 @@ pub use super::sysbus::consts::*;
 #[cfg(not(feature = "no_video_interface"))]
 use super::VideoInterface;
 
-use crate::num::FromPrimitive;
-
 mod render;
 
 use render::Point;
diff --git a/core/src/gpu/render/bitmap.rs b/core/src/gpu/render/bitmap.rs
index 8b953b9..3ffc81e 100644
--- a/core/src/gpu/render/bitmap.rs
+++ b/core/src/gpu/render/bitmap.rs
@@ -7,6 +7,7 @@ use super::super::Rgb15;
 use super::{utils, MODE5_VIEWPORT, SCREEN_VIEWPORT};
 
 use crate::Bus;
+use rustboyadvance_utils::index2d;
 
 impl Gpu {
     pub(in super::super) fn render_mode3(&mut self, bg: usize) {
diff --git a/core/src/gpu/render/obj.rs b/core/src/gpu/render/obj.rs
index fe0595f..b76b6b7 100644
--- a/core/src/gpu/render/obj.rs
+++ b/core/src/gpu/render/obj.rs
@@ -1,6 +1,8 @@
 use super::super::regs::*;
 use super::super::*;
 
+use rustboyadvance_utils::index2d;
+
 const OVRAM: u32 = 0x0601_0000;
 const PALRAM_OFS_FG: u32 = 0x200;
 const ATTRS_SIZE: u32 = 2 * 3 + 2;
diff --git a/core/src/gpu/render/text.rs b/core/src/gpu/render/text.rs
index a7e62a6..b90a6b0 100644
--- a/core/src/gpu/render/text.rs
+++ b/core/src/gpu/render/text.rs
@@ -7,6 +7,8 @@ use super::{utils, ViewPort};
 
 use crate::Bus;
 
+use rustboyadvance_utils::index2d;
+
 impl Gpu {
     pub(in super::super) fn render_reg_bg(&mut self, bg: usize) {
         let (h_ofs, v_ofs) = (self.bg_hofs[bg] as u32, self.bg_vofs[bg] as u32);
diff --git a/core/src/lib.rs b/core/src/lib.rs
index d67b621..5f687f8 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -9,17 +9,13 @@ extern crate debug_stub_derive;
 
 #[macro_use]
 extern crate enum_primitive_derive;
-use num;
 use num_traits;
 
-use bit;
 #[macro_use]
 extern crate bitfield;
 #[macro_use]
 extern crate bitflags;
 
-use byteorder;
-
 #[macro_use]
 extern crate log;
 
@@ -36,9 +32,7 @@ use zip;
 use std::error::Error;
 use std::fmt;
 
-#[macro_use]
-pub mod util;
-pub mod arm7tdmi;
+pub use arm7tdmi;
 pub use arm7tdmi::disass;
 mod bios;
 pub mod cartridge;
@@ -140,10 +134,10 @@ pub mod prelude {
     #[cfg(feature = "debugger")]
     pub use super::debugger::Debugger;
     pub use super::gpu::{DISPLAY_HEIGHT, DISPLAY_WIDTH};
-    pub use super::util::{read_bin_file, write_bin_file};
     pub use super::Bus;
     #[cfg(not(feature = "no_video_interface"))]
     pub use super::VideoInterface;
     pub use super::{AudioInterface, InputInterface, StereoSample};
     pub use super::{GBAError, GBAResult, GameBoyAdvance};
+    pub use rustboyadvance_utils::{read_bin_file, write_bin_file};
 }
diff --git a/core/src/sched.rs b/core/src/sched.rs
index 3464a3e..4ef031c 100644
--- a/core/src/sched.rs
+++ b/core/src/sched.rs
@@ -1,7 +1,7 @@
 use std::cmp::Ordering;
 use std::collections::BinaryHeap;
 
-use super::util::Shared;
+use rustboyadvance_utils::Shared;
 
 use serde::{Deserialize, Serialize};
 
@@ -271,17 +271,19 @@ mod test {
         let mut sched = holder.sched.clone();
         holder
             .sched
-            .push(EventType::Gpu(GpuEvent::VBlankHDraw), 240);
+            .schedule((EventType::Gpu(GpuEvent::VBlankHDraw), 240));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg1Generate), 60);
-        holder.sched.push(EventType::Apu(ApuEvent::Sample), 512);
+            .schedule((EventType::Apu(ApuEvent::Psg1Generate), 60));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg2Generate), 13);
+            .schedule((EventType::Apu(ApuEvent::Sample), 512));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg4Generate), 72);
+            .schedule((EventType::Apu(ApuEvent::Psg2Generate), 13));
+        holder
+            .sched
+            .schedule((EventType::Apu(ApuEvent::Psg4Generate), 72));
 
         assert_eq!(
             sched.events.pop(),
@@ -300,17 +302,19 @@ mod test {
         let mut sched = holder.sched.clone();
         holder
             .sched
-            .push(EventType::Gpu(GpuEvent::VBlankHDraw), 240);
+            .schedule((EventType::Gpu(GpuEvent::VBlankHDraw), 240));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg1Generate), 60);
-        holder.sched.push(EventType::Apu(ApuEvent::Sample), 512);
+            .schedule((EventType::Apu(ApuEvent::Psg1Generate), 60));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg2Generate), 13);
+            .schedule((EventType::Apu(ApuEvent::Sample), 512));
         holder
             .sched
-            .push(EventType::Apu(ApuEvent::Psg4Generate), 72);
+            .schedule((EventType::Apu(ApuEvent::Psg2Generate), 13));
+        holder
+            .sched
+            .schedule((EventType::Apu(ApuEvent::Psg4Generate), 72));
 
         println!("all events");
         for e in sched.events.iter() {
diff --git a/core/src/sysbus.rs b/core/src/sysbus.rs
index f0c3b6b..b4227f9 100644
--- a/core/src/sysbus.rs
+++ b/core/src/sysbus.rs
@@ -1,6 +1,5 @@
 use serde::{Deserialize, Serialize};
 
-use super::arm7tdmi;
 use super::arm7tdmi::memory::*;
 use super::bios::Bios;
 use super::bus::*;
@@ -8,7 +7,8 @@ use super::cartridge::Cartridge;
 use super::dma::DmaNotifer;
 use super::iodev::{IoDevices, WaitControl};
 use super::sched::*;
-use super::util::{Shared, WeakPointer};
+use arm7tdmi::{self, Arm7tdmiCore};
+use rustboyadvance_utils::{Shared, WeakPointer};
 
 pub mod consts {
     pub const WORK_RAM_SIZE: usize = 256 * 1024;
@@ -145,7 +145,7 @@ impl CycleLookupTables {
 pub struct SysBus {
     pub io: Shared<IoDevices>,
     scheduler: Shared<Scheduler>,
-    arm_core: WeakPointer<arm7tdmi::Core<SysBus>>,
+    arm_core: WeakPointer<Arm7tdmiCore<SysBus>>,
 
     bios: Bios,
     ewram: Box<[u8]>,
@@ -225,7 +225,7 @@ impl SysBus {
     }
 
     /// must be called whenever this object is instanciated
-    pub fn init(&mut self, arm_core: WeakPointer<arm7tdmi::Core<SysBus>>) {
+    pub fn init(&mut self, arm_core: WeakPointer<Arm7tdmiCore<SysBus>>) {
         self.arm_core = arm_core.clone();
         self.bios.connect_arm_core(arm_core.clone());
         let ptr = SysBusPtr::new(self as *mut SysBus);
@@ -268,10 +268,9 @@ impl SysBus {
     /// `addr` is considered to be an address of
     fn read_invalid(&mut self, addr: Addr) -> u32 {
         warn!("invalid read @{:08x}", addr);
-        use super::arm7tdmi::CpuState;
         let value = match self.arm_core.cpsr.state() {
-            CpuState::ARM => self.arm_core.get_prefetched_opcode(),
-            CpuState::THUMB => {
+            arm7tdmi::CpuState::ARM => self.arm_core.get_prefetched_opcode(),
+            arm7tdmi::CpuState::THUMB => {
                 // For THUMB code the result consists of two 16bit fragments and depends on the address area
                 // and alignment where the opcode was stored.
 
diff --git a/platform/rustboyadvance-sdl2/Cargo.toml b/platform/rustboyadvance-sdl2/Cargo.toml
index fe106e2..e3e6180 100644
--- a/platform/rustboyadvance-sdl2/Cargo.toml
+++ b/platform/rustboyadvance-sdl2/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 
 [dependencies]
 rustboyadvance-core = { path = "../../core/", features = ["elf_support"] }
+rustboyadvance-utils = { path = "../../utils/" }
 sdl2 = { version = "0.33.0", features = ["image"] }
 ringbuf = "0.2.2"
 bytesize = "1.0.0"
diff --git a/platform/rustboyadvance-sdl2/src/main.rs b/platform/rustboyadvance-sdl2/src/main.rs
index 3e19041..df17136 100644
--- a/platform/rustboyadvance-sdl2/src/main.rs
+++ b/platform/rustboyadvance-sdl2/src/main.rs
@@ -41,9 +41,11 @@ use input::create_input;
 use video::{create_video_interface, SCREEN_HEIGHT, SCREEN_WIDTH};
 
 use rustboyadvance_core::cartridge::BackupType;
+#[cfg(feature = "gdb")]
+use rustboyadvance_core::gdb::spawn_and_run_gdb_server;
 use rustboyadvance_core::prelude::*;
-use rustboyadvance_core::util::spawn_and_run_gdb_server;
-use rustboyadvance_core::util::FpsCounter;
+
+use rustboyadvance_utils::FpsCounter;
 
 const LOG_DIR: &str = ".logs";
 const DEFAULT_GDB_SERVER_ADDR: &'static str = "localhost:1337";
@@ -237,6 +239,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     }
 
+    #[cfg(feature = "gdb")]
     if with_gdbserver {
         spawn_and_run_gdb_server(&mut gba, DEFAULT_GDB_SERVER_ADDR)?;
     }
diff --git a/utils/Cargo.toml b/utils/Cargo.toml
new file mode 100644
index 0000000..e046852
--- /dev/null
+++ b/utils/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "rustboyadvance-utils"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ringbuf = "0.2.2"
+
+[target.'cfg(target_arch="wasm32")'.dependencies]
+instant = { version = "0.1.2", features = ["wasm-bindgen"] }
diff --git a/core/src/util.rs b/utils/src/lib.rs
similarity index 79%
rename from core/src/util.rs
rename to utils/src/lib.rs
index 9f15b93..ab1747e 100644
--- a/core/src/util.rs
+++ b/utils/src/lib.rs
@@ -22,49 +22,6 @@ fn now() -> Instant {
     instant::Instant::now()
 }
 
-use crate::GameBoyAdvance;
-#[cfg(feature = "gdb")]
-use gdbstub;
-#[cfg(feature = "gdb")]
-use gdbstub::GdbStub;
-use std::fmt;
-#[cfg(feature = "gdb")]
-use std::net::TcpListener;
-use std::net::ToSocketAddrs;
-
-pub fn spawn_and_run_gdb_server<A: ToSocketAddrs + fmt::Display>(
-    #[allow(unused)] target: &mut GameBoyAdvance,
-    #[allow(unused)] addr: A,
-) -> Result<(), Box<dyn std::error::Error>> {
-    #[cfg(feature = "gdb")]
-    {
-        info!("spawning gdbserver, listening on {}", addr);
-
-        let sock = TcpListener::bind(addr)?;
-        let (stream, addr) = sock.accept()?;
-
-        info!("got connection from {}", addr);
-
-        let mut gdb = GdbStub::new(stream);
-        let result = match gdb.run(target) {
-            Ok(state) => {
-                info!("Disconnected from GDB. Target state: {:?}", state);
-                Ok(())
-            }
-            Err(gdbstub::Error::TargetError(e)) => Err(e),
-            Err(e) => return Err(e.into()),
-        };
-
-        info!("Debugger session ended, result={:?}", result);
-    }
-    #[cfg(not(feature = "gdb"))]
-    {
-        error!("failed. please compile me with 'gdb' feature")
-    }
-
-    Ok(())
-}
-
 pub fn read_bin_file(filename: &Path) -> io::Result<Vec<u8>> {
     let mut buf = Vec::new();
     let mut file = File::open(filename)?;