diff --git a/Cargo.toml b/Cargo.toml
index b3cb1ae..b4434a9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,7 @@
 [workspace]
 members = [
     "nucleus",
+    "machine",
     "bin/chainboot",
     "bin/chainofcommand"
 ]
diff --git a/bin/chainboot/Cargo.toml b/bin/chainboot/Cargo.toml
index 4355cf7..38d0c39 100644
--- a/bin/chainboot/Cargo.toml
+++ b/bin/chainboot/Cargo.toml
@@ -34,3 +34,7 @@ bitflags = "1.3"
 cfg-if = "1.0"
 snafu = { version = "0.7", default-features = false }
 seahash = "4.1"
+
+[[bin]]
+name = "chainboot"
+test = false
diff --git a/bin/chainboot/src/main.rs b/bin/chainboot/src/main.rs
index e794654..a1a6865 100644
--- a/bin/chainboot/src/main.rs
+++ b/bin/chainboot/src/main.rs
@@ -8,7 +8,7 @@
 #![no_builtins]
 
 use {
-    core::{hash::Hasher, panic::PanicInfo},
+    core::hash::Hasher,
     cortex_a::asm::barrier,
     machine::{
         devices::SerialOps,
@@ -147,12 +147,20 @@ fn kernel_main(max_kernel_size: u64) -> ! {
 
 #[cfg(not(test))]
 #[panic_handler]
-fn panicked(info: &PanicInfo) -> ! {
+fn panicked(info: &core::panic::PanicInfo) -> ! {
     machine::panic::handler(info)
 }
 
-#[cfg(test)]
 #[panic_handler]
-fn panicked(info: &PanicInfo) -> ! {
+#[cfg(test)]
+fn panicked(info: &core::panic::PanicInfo) -> ! {
     machine::panic::handler_for_tests(info)
 }
+
+#[cfg(test)]
+mod chainboot_tests {
+    #[test_case]
+    fn nothing() {
+        assert_eq!(2 + 2, 4);
+    }
+}
diff --git a/machine/Cargo.toml b/machine/Cargo.toml
index 22e5d23..9f9a3b2 100644
--- a/machine/Cargo.toml
+++ b/machine/Cargo.toml
@@ -39,3 +39,9 @@ cfg-if = "1.0"
 snafu = { version = "0.7", default-features = false }
 buddy-alloc = { git = "https://github.com/metta-systems/buddy-alloc", version = "0.6.0", branch = "feature/allocator-api" }
 once_cell = { version = "1.14", default-features = false, features = ["unstable"] }
+
+[lib]
+name = "machine"
+test = true
+
+# For proper testing in libmachine, we build it as a test_runner binary!
diff --git a/machine/build.rs b/machine/build.rs
new file mode 100644
index 0000000..75c61c1
--- /dev/null
+++ b/machine/build.rs
@@ -0,0 +1,8 @@
+const LINKER_SCRIPT: &str = "linker/aarch64.ld";
+const LINKER_SCRIPT_AUX: &str = "linker/aarch64-exceptions.ld";
+
+fn main() {
+    println!("cargo:rerun-if-changed={}", LINKER_SCRIPT);
+    println!("cargo:rerun-if-changed={}", LINKER_SCRIPT_AUX);
+    println!("cargo:rustc-link-arg=--script={}", LINKER_SCRIPT);
+}
diff --git a/machine/src/lib.rs b/machine/src/lib.rs
index 46f54e0..41c2b16 100644
--- a/machine/src/lib.rs
+++ b/machine/src/lib.rs
@@ -66,3 +66,18 @@ static DMA_ALLOCATOR: sync::NullLock<Lazy<BuddyAlloc>> =
 
 // 0x00600000 as usize,
 // 0x007FFFFF as usize,
+
+#[cfg(test)]
+mod lib_tests {
+    #[panic_handler]
+    fn panicked(info: &core::panic::PanicInfo) -> ! {
+        crate::panic::handler_for_tests(info)
+    }
+
+    /// Main for running tests.
+    #[no_mangle]
+    pub unsafe fn main() -> ! {
+        crate::test_main();
+        crate::qemu::semihosting::exit_success()
+    }
+}
diff --git a/machine/src/platform/rpi3/mailbox.rs b/machine/src/platform/rpi3/mailbox.rs
index 1e09660..53c1aa0 100644
--- a/machine/src/platform/rpi3/mailbox.rs
+++ b/machine/src/platform/rpi3/mailbox.rs
@@ -669,7 +669,7 @@ mod tests {
     // by the end() fn.
     #[test_case]
     fn test_prepare_mailbox() {
-        let mut mailbox = Mailbox::default();
+        let mut mailbox = Mailbox::<8>::default();
         let index = mailbox.request();
         let index = mailbox.set_led_on(index, true);
         let mailbox = mailbox.end(index);
diff --git a/machine/src/platform/rpi3/pl011_uart.rs b/machine/src/platform/rpi3/pl011_uart.rs
index 5bce434..e67d8aa 100644
--- a/machine/src/platform/rpi3/pl011_uart.rs
+++ b/machine/src/platform/rpi3/pl011_uart.rs
@@ -442,6 +442,8 @@ mod tests {
         const BAUD_RATE: u32 = 115_200;
 
         let divisors = RateDivisors::from_clock_and_rate(CLOCK, BAUD_RATE);
+        assert!(divisors.is_ok());
+        let divisors = divisors.unwrap();
         assert_eq!(divisors.integer_baud_rate_divisor, 1);
         assert_eq!(divisors.fractional_baud_rate_divisor, 40);
     }
diff --git a/nucleus/Cargo.toml b/nucleus/Cargo.toml
index bc738f7..fefb9b4 100644
--- a/nucleus/Cargo.toml
+++ b/nucleus/Cargo.toml
@@ -36,3 +36,7 @@ bit_field = "0.10"
 bitflags = "1.3"
 cfg-if = "1.0"
 snafu = { version = "0.7", default-features = false }
+
+[[bin]]
+name = "nucleus"
+test = false