diff --git a/.gitignore b/.gitignore
index 088ba6b..f2e972d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,9 +2,5 @@
 # will have compiled files and executables
 /target/
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk
diff --git a/Cargo.toml b/Cargo.toml
index 0db13d4..d93dbf1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,8 +1,24 @@
 [package]
 name = "va108xx-hal"
 version = "0.1.0"
+authors = ["Robin Mueller <robin.mueller.m@gmail.com>"]
 edition = "2018"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+description = "HAL for the Vorago VA108xx family of microcontrollers"
+homepage = "https://github.com/robamu/va108xx-hal-rs"
+repository = "https://github.com/robamu/va108xx-hal-rs"
+license = "MIT OR Apache-2.0"
+keywords = ["no-std", "hal", "cortex-m", "vorago", "va108xx"]
+categories = ["embedded", "no-std", "hardware-support"]
 
 [dependencies]
+
+cortex-m = "0.7.3"
+cortex-m-rt = "0.7.0"
+nb = "1"
+embedded-hal = { features = ["unproven"], version = "0.2.6" }
+
+[dependencies.va108xx]
+version = "0.1.0"
+
+[features]
+rt = ["va108xx/rt"]
\ No newline at end of file
diff --git a/src/gpio.rs b/src/gpio.rs
new file mode 100644
index 0000000..7174f53
--- /dev/null
+++ b/src/gpio.rs
@@ -0,0 +1,505 @@
+use crate::pac::SYSCONFIG;
+use core::convert::Infallible;
+use core::marker::PhantomData;
+use embedded_hal::digital::v2::{toggleable, InputPin, OutputPin, StatefulOutputPin};
+
+/// Extension trait to split a GPIO peripheral in independent pins and registers
+pub trait GpioExt {
+    /// The parts to split the GPIO into.
+    type Parts;
+
+    /// Splits the GPIO block into independent pins and registers.
+    fn split(self, syscfg: &mut SYSCONFIG) -> Self::Parts;
+}
+
+trait GpioRegExt {
+    fn is_low(&self, pos: u8) -> bool;
+    fn is_set_low(&self, pos: u8) -> bool;
+    fn set_high(&self, pos: u8);
+    fn set_low(&self, pos: u8);
+}
+
+/// Input mode (type state)
+pub struct Input<MODE> {
+    _mode: PhantomData<MODE>,
+}
+
+/// Output mode (type state)
+pub struct Output<MODE> {
+    _mode: PhantomData<MODE>,
+}
+
+/// Floating input (type state)
+pub struct Floating;
+/// Pulled down input (type state)
+pub struct PullDown;
+/// Pulled up input (type state)
+pub struct PullUp;
+/// Open drain output (type state)
+pub struct OpenDrain;
+// Push-pull output (type state)
+pub struct PushPull;
+
+pub struct OutputInverted;
+
+pub struct InputInverted;
+
+// FUNSEL0 is the regular GPIO port configuration
+pub struct FUNSEL1;
+pub struct FUNSEL2;
+pub struct FUNSEL3;
+
+/// Function select (type state)
+pub struct Funsel<FUN> {
+    _mode: PhantomData<FUN>,
+}
+
+pub enum FilterType {
+    SystemClock = 0,
+    DirectInputWithSynchronization = 1,
+    FilterOneClockCycle = 2,
+    FilterTwoClockCycles = 3,
+    FilterThreeClockCycles = 4,
+    FilterFourClockCycles = 5,
+}
+
+pub enum FilterClkSel {
+    SysClk = 0,
+    Clk1 = 1,
+    Clk2 = 2,
+    Clk3 = 3,
+    Clk4 = 4,
+    Clk5 = 5,
+    Clk6 = 6,
+    Clk7 = 7,
+}
+
+/// Fully erased pin
+pub struct Pin<MODE> {
+    i: u8,
+    port: *const dyn GpioRegExt,
+    _mode: PhantomData<MODE>,
+}
+unsafe impl<MODE> Sync for Pin<MODE> {}
+// NOTE(unsafe) this only enables read access to the same pin from multiple threads
+unsafe impl<MODE> Send for Pin<MODE> {}
+impl<MODE> StatefulOutputPin for Pin<Output<MODE>> {
+    #[inline(always)]
+    fn is_set_high(&self) -> Result<bool, Self::Error> {
+        self.is_set_low().map(|v| !v)
+    }
+    #[inline(always)]
+    fn is_set_low(&self) -> Result<bool, Self::Error> {
+        Ok(unsafe { (*self.port).is_set_low(self.i) })
+    }
+}
+impl<MODE> OutputPin for Pin<Output<MODE>> {
+    type Error = Infallible;
+    #[inline(always)]
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        unsafe { (*self.port).set_high(self.i) };
+        Ok(())
+    }
+    #[inline(always)]
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        unsafe { (*self.port).set_low(self.i) }
+        Ok(())
+    }
+}
+impl<MODE> toggleable::Default for Pin<Output<MODE>> {}
+impl InputPin for Pin<Output<OpenDrain>> {
+    type Error = Infallible;
+    #[inline(always)]
+    fn is_high(&self) -> Result<bool, Self::Error> {
+        self.is_low().map(|v| !v)
+    }
+    #[inline(always)]
+    fn is_low(&self) -> Result<bool, Self::Error> {
+        Ok(unsafe { (*self.port).is_low(self.i) })
+    }
+}
+impl<MODE> InputPin for Pin<Input<MODE>> {
+    type Error = Infallible;
+    #[inline(always)]
+    fn is_high(&self) -> Result<bool, Self::Error> {
+        self.is_low().map(|v| !v)
+    }
+    #[inline(always)]
+    fn is_low(&self) -> Result<bool, Self::Error> {
+        Ok(unsafe { (*self.port).is_low(self.i) })
+    }
+}
+
+// This is only needs to be implemented for PORTA because PORTB is derived
+// from PORTA
+impl GpioRegExt for crate::pac::porta::RegisterBlock {
+    fn is_low(&self, pos: u8) -> bool {
+        self.datainraw().read().bits() & (1 << pos) == 0
+    }
+    fn is_set_low(&self, pos: u8) -> bool {
+        // Note that this only works if the IENWO bit is enabled in IOCONFIG
+        // This is done by default for output pins for now
+        self.datainraw().read().bits() & (1 << pos) == 0
+    }
+    fn set_high(&self, pos: u8) {
+        unsafe { self.setout().write(|w| w.bits(1 << pos)) }
+    }
+    fn set_low(&self, pos: u8) {
+        unsafe { self.clrout().write(|w| w.bits(1 << pos)) }
+    }
+}
+
+macro_rules! gpio {
+    ($PORTX:ident, $portx:ident, [
+        $($PXi:ident: ($pxi:ident, $i:expr),)+
+    ]) => {
+        pub mod $portx {
+            use core::marker::PhantomData;
+            use core::convert::Infallible;
+            use cortex_m::interrupt::CriticalSection;
+            use super::{
+                FUNSEL1, FUNSEL2, FUNSEL3, Floating, Funsel, GpioExt, Input, OpenDrain,
+                PullUp, Output, FilterType, FilterClkSel, Pin, GpioRegExt, PushPull
+            };
+            use crate::{pac::$PORTX, pac::SYSCONFIG, pac::IOCONFIG};
+            use embedded_hal::digital::v2::{InputPin, OutputPin, StatefulOutputPin, toggleable};
+            pub struct Parts {
+                $(
+                    pub $pxi: $PXi<Input<Floating>>,
+                )+
+            }
+
+            impl GpioExt for $PORTX {
+                type Parts = Parts;
+                fn split(self, syscfg: &mut SYSCONFIG) -> Parts {
+                    syscfg.peripheral_clk_enable.modify(|_, w| {
+                        w.$portx().set_bit();
+                        w.gpio().set_bit();
+                        w.ioconfig().set_bit();
+                        w
+                    });
+                    Parts {
+                        $(
+                            $pxi: $PXi { _mode : PhantomData },
+                        )+
+                    }
+                }
+            }
+
+            fn _set_alternate_mode(index: usize, mode: u8) {
+                unsafe {
+                    let reg = &(*IOCONFIG::ptr());
+                    reg.$portx[index].modify(|_, w| {
+                        w.funsel().bits(mode)
+                    })
+                }
+            }
+
+            $(
+                pub struct $PXi<MODE> {
+                    _mode: PhantomData<MODE>,
+                }
+
+                impl<MODE> $PXi<MODE> {
+                    pub fn into_funsel_1(self, _cs: &CriticalSection) -> $PXi<Funsel<FUNSEL1>> {
+                        _set_alternate_mode(0, 1);
+                        $PXi { _mode: PhantomData }
+                    }
+                    pub fn into_funsel_2(self, _cs: &CriticalSection) -> $PXi<Funsel<FUNSEL2>> {
+                        _set_alternate_mode(0, 2);
+                        $PXi { _mode: PhantomData }
+                    }
+                    pub fn into_funsel_3(self, _cs: &CriticalSection) -> $PXi<Funsel<FUNSEL3>> {
+                        _set_alternate_mode(0, 3);
+                        $PXi { _mode: PhantomData }
+                    }
+                    pub fn into_floating_input(self, _cs: &CriticalSection) -> $PXi<Input<Floating>> {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[0].modify(|_, w| {
+                                w.funsel().bits(0);
+                                w.pen().clear_bit();
+                                w.opendrn().clear_bit()
+                            });
+                            let port_reg = &(*$PORTX::ptr());
+                            port_reg.dir().modify(|r,w| w.bits(r.bits() & !(1 << 0)));
+                        }
+                        $PXi { _mode: PhantomData }
+                    }
+
+                    pub fn into_pull_up_input(self, _cs: &CriticalSection) -> $PXi<Input<PullUp>> {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[0].modify(|_, w| {
+                                w.funsel().bits(0);
+                                w.pen().set_bit();
+                                w.plevel().set_bit();
+                                w.opendrn().clear_bit()
+                            });
+                            let port_reg = &(*$PORTX::ptr());
+                            port_reg.dir().modify(|r,w| w.bits(r.bits() & !(1 << 0)));
+                        }
+                        $PXi { _mode: PhantomData }
+                    }
+
+                    pub fn into_pull_down_input(self, _cs: &CriticalSection) -> $PXi<Input<PullUp>> {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[0].modify(|_, w| {
+                                w.funsel().bits(0);
+                                w.pen().set_bit();
+                                w.plevel().clear_bit();
+                                w.opendrn().clear_bit()
+                            });
+                            let port_reg = &(*$PORTX::ptr());
+                            port_reg.dir().modify(|r,w| w.bits(r.bits() & !(1 << 0)));
+                        }
+                        $PXi { _mode: PhantomData }
+                    }
+
+                    pub fn into_open_drain_output(self, _cs: &CriticalSection) -> $PXi<Output<OpenDrain>> {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[$i].modify(|_, w| {
+                                w.funsel().bits(0);
+                                w.pen().clear_bit();
+                                w.opendrn().set_bit()
+                            });
+                            let port_reg = &(*$PORTX::ptr());
+                            port_reg.dir().modify(|r,w| w.bits(r.bits() | (1 << 0)));
+                        }
+                        let $pxi: $PXi<Output<OpenDrain>> = $PXi { _mode: PhantomData };
+                        // Enable input functionality by default to ensure this is a stateful output pin
+                        let $pxi = $pxi.enable_input(_cs, true);
+                        $pxi
+                    }
+
+                    pub fn into_push_pull_output(self, _cs: &CriticalSection) -> $PXi<Output<PushPull>> {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[$i].modify(|_, w| {
+                                w.funsel().bits(0);
+                                w.opendrn().clear_bit()
+                            });
+                            let port_reg = &(*$PORTX::ptr());
+                            port_reg.dir().modify(|r,w| w.bits(r.bits() | (1 << 0)));
+                        }
+                        let $pxi: $PXi<Output<PushPull>> = $PXi { _mode: PhantomData };
+                        // Enable input functionality by default to ensure this is a stateful output pin
+                        let $pxi = $pxi.enable_input(_cs, true);
+                        $pxi
+                    }
+
+                    pub fn filter_type(self,  _cs: &CriticalSection, filter: FilterType, clksel: FilterClkSel) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[$i].modify(|_, w| {
+                                w.flttype().bits(filter as u8);
+                                w.fltclk().bits(clksel as u8)
+                            })
+                        }
+                        self
+                    }
+                }
+
+                impl<MODE> $PXi<Input<MODE>> {
+                    pub fn input_inversion(self, _cs: &CriticalSection, enable: bool) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            if enable {
+                                reg.$portx[$i].modify(|_, w| w.invinp().set_bit());
+                            } else {
+                                reg.$portx[$i].modify(|_, w| w.invinp().clear_bit());
+                            }
+                        }
+                        self
+                    }
+                }
+
+                impl<MODE> $PXi<Output<MODE>> {
+                    pub fn output_inversion(self, _cs: &CriticalSection, enable: bool) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            if enable {
+                                reg.$portx[$i].modify(|_, w| w.invout().set_bit());
+                            } else {
+                                reg.$portx[$i].modify(|_, w| w.invout().clear_bit());
+                            }
+                        }
+                        self
+                    }
+
+                    /// Enable Input even when in output mode. In
+                    /// this mode the input receiver is enabled even
+                    /// if the direction is configured as an output.
+                    /// This allows monitoring of output values
+                    pub fn enable_input(self, _cs: &CriticalSection, enable: bool) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            if enable {
+                                reg.$portx[$i].modify(|_, w| w.iewo().set_bit());
+                            } else {
+                                reg.$portx[$i].modify(|_, w| w.iewo().clear_bit());
+                            }
+                        }
+                        self
+                    }
+
+                    /// Enable Pull up/down even when output is active. The Default is to disable pull
+                    /// up/down when output is actively driven. This bit enables the pull up/down all the time.
+                    ///
+                    /// # Arguments
+                    ///
+                    /// `enable` - Enable the peripheral functionality
+                    /// `enable_pullup` - Enable the pullup itself
+                    pub fn enable_pull_up(self, _cs: &CriticalSection, enable: bool, enable_pullup: bool) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[$i].modify(|_, w| {
+                                if enable { w.pwoa().set_bit(); } else { w.pwoa().clear_bit(); }
+                                if enable_pullup { w.pen().set_bit(); } else { w.pen().clear_bit(); }
+                                w.plevel().set_bit()
+                            });
+                        }
+                        self
+                    }
+                    /// Enable Pull up/down even when output is active. The Default is to disable pull
+                    /// up/down when output is actively driven. This bit enables the pull up/down all the time.
+                    ///
+                    /// # Arguments
+                    ///
+                    /// `enable` - Enable the peripheral functionality
+                    /// `enable_pullup` - Enable the pulldown itself
+                    pub fn enable_pull_down(self, _cs: &CriticalSection, enable: bool, enable_pulldown: bool) -> Self {
+                        unsafe {
+                            let reg = &(*IOCONFIG::ptr());
+                            reg.$portx[$i].modify(|_, w| {
+                                if enable { w.pwoa().set_bit(); } else { w.pwoa().clear_bit(); }
+                                if enable_pulldown { w.pen().set_bit(); } else { w.pen().clear_bit(); }
+                                w.plevel().clear_bit()
+                            });
+                        }
+                        self
+                    }
+                }
+
+                impl<MODE> $PXi<Output<MODE>> {
+                    /// Erases the pin number from the type
+                    ///
+                    /// This is useful when you want to collect the pins into an array where you
+                    /// need all the elements to have the same type
+                    pub fn downgrade(self) -> Pin<Output<MODE>> {
+                        Pin {
+                            i: $i,
+                            port: $PORTX::ptr() as *const dyn GpioRegExt,
+                            _mode: self._mode,
+                        }
+                    }
+                }
+
+                impl<MODE> StatefulOutputPin for $PXi<Output<MODE>> {
+                    fn is_set_high(&self) -> Result<bool, Self::Error> {
+                        self.is_set_low().map(|v| !v)
+                    }
+                    fn is_set_low(&self) -> Result<bool, Self::Error> {
+                        Ok(unsafe { (*$PORTX::ptr()).is_set_low(0) })
+                    }
+                }
+                impl<MODE> OutputPin for $PXi<Output<MODE>> {
+                    type Error = Infallible;
+                    fn set_high(&mut self) -> Result<(), Self::Error> {
+                        Ok(unsafe { (*$PORTX::ptr()).set_high(0) })
+                    }
+                    fn set_low(&mut self) -> Result<(), Self::Error> {
+                        Ok(unsafe { (*$PORTX::ptr()).set_low(0) })
+                    }
+                }
+                impl<MODE> toggleable::Default for $PXi<Output<MODE>> {}
+                impl<MODE> $PXi<Input<MODE>> {
+                    /// Erases the pin number from the type
+                    ///
+                    /// This is useful when you want to collect the pins into an array where you
+                    /// need all the elements to have the same type
+                    pub fn downgrade(self) -> Pin<Input<MODE>> {
+                        Pin {
+                            i: $i,
+                            port: $PORTX::ptr() as *const dyn GpioRegExt,
+                            _mode: self._mode,
+                        }
+                    }
+                }
+                impl<MODE> InputPin for $PXi<Input<MODE>> {
+                    type Error = Infallible;
+                    fn is_high(&self) -> Result<bool, Self::Error> {
+                        self.is_low().map(|v| !v)
+                    }
+                    fn is_low(&self) -> Result<bool, Self::Error> {
+                        Ok(unsafe { (*$PORTX::ptr()).is_low(0) })
+                    }
+                }
+            )+
+        }
+    }
+}
+
+gpio!(PORTA, porta, [
+    PA0: (pa0, 0),
+    PA1: (pa1, 1),
+    PA2: (pa2, 2),
+    PA3: (pa3, 3),
+    PA4: (pa4, 4),
+    PA5: (pa5, 5),
+    PA6: (pa6, 6),
+    PA7: (pa7, 7),
+    PA8: (pa8, 8),
+    PA9: (pa9, 9),
+    PA10: (pa10, 10),
+    PA11: (pa11, 11),
+    PA12: (pa12, 12),
+    PA13: (pa13, 13),
+    PA14: (pa14, 14),
+    PA15: (pa15, 15),
+    PA16: (pa16, 16),
+    PA17: (pa17, 17),
+    PA18: (pa18, 18),
+    PA19: (pa19, 19),
+    PA20: (pa20, 20),
+    PA21: (pa21, 21),
+    PA22: (pa22, 22),
+    PA23: (pa23, 23),
+    PA24: (pa24, 24),
+    PA25: (pa25, 25),
+    PA26: (pa26, 26),
+    PA27: (pa27, 27),
+    PA28: (pa28, 28),
+    PA29: (pa29, 29),
+    PA30: (pa30, 30),
+    PA31: (pa31, 31),
+]);
+
+gpio!(PORTB, portb, [
+    PB0: (pb0, 0),
+    PB1: (pb1, 1),
+    PB2: (pb2, 2),
+    PB3: (pb3, 3),
+    PB4: (pb4, 4),
+    PB5: (pb5, 5),
+    PB6: (pb6, 6),
+    PB7: (pb7, 7),
+    PB8: (pb8, 8),
+    PB9: (pb9, 9),
+    PB10: (pb10, 10),
+    PB11: (pb11, 11),
+    PB12: (pb12, 12),
+    PB13: (pb13, 13),
+    PB14: (pb14, 14),
+    PB15: (pb15, 15),
+    PB16: (pb16, 16),
+    PB17: (pb17, 17),
+    PB18: (pb18, 18),
+    PB19: (pb19, 19),
+    PB20: (pb20, 20),
+    PB21: (pb21, 21),
+    PB22: (pb22, 22),
+    PB23: (pb23, 23),
+]);
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..a8c2307
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,7 @@
+#![no_std]
+
+pub use va108xx;
+
+pub mod gpio;
+
+pub use va108xx as pac;
diff --git a/src/main.rs b/src/main.rs
deleted file mode 100644
index e7a11a9..0000000
--- a/src/main.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn main() {
-    println!("Hello, world!");
-}