diff --git a/bitfield/Cargo.toml b/bitfield/Cargo.toml
new file mode 100644
index 000000000..1b60685c0
--- /dev/null
+++ b/bitfield/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "bitfield"
+version = "0.0.0"
+edition = "2018"
+autotests = false
+publish = false
+
+[[test]]
+name = "tests"
+path = "tests/progress.rs"
+
+[dev-dependencies]
+workshop-test-runner = { path = "../test-runner" }
+
+[dependencies]
+bitfield-impl = { path = "impl" }
diff --git a/bitfield/impl/Cargo.toml b/bitfield/impl/Cargo.toml
new file mode 100644
index 000000000..4cc1bc943
--- /dev/null
+++ b/bitfield/impl/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "bitfield-impl"
+version = "0.0.0"
+edition = "2018"
+publish = false
+
+[lib]
+proc-macro = true
+
+[dependencies]
+# TODO
diff --git a/bitfield/impl/src/lib.rs b/bitfield/impl/src/lib.rs
new file mode 100644
index 000000000..65a22e14b
--- /dev/null
+++ b/bitfield/impl/src/lib.rs
@@ -0,0 +1,11 @@
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+
+#[proc_macro_attribute]
+pub fn bitfield(args: TokenStream, input: TokenStream) -> TokenStream {
+    let _ = args;
+    let _ = input;
+
+    unimplemented!()
+}
diff --git a/bitfield/src/lib.rs b/bitfield/src/lib.rs
new file mode 100644
index 000000000..406e10347
--- /dev/null
+++ b/bitfield/src/lib.rs
@@ -0,0 +1,15 @@
+// Crates that have the "proc-macro" crate type are only allowed to export
+// procedural macros. So we cannot have one crate that defines procedural macros
+// alongside other types of public APIs like traits and structs.
+//
+// For this project we are going to need a #[bitfield] macro but also a trait
+// and some structs. We solve this by defining the trait and structs in this
+// crate, defining the attribute macro in a separate bitfield-impl crate, and
+// then re-exporting the macro from this crate so that users only have one crate
+// that they need to import.
+//
+// From the perspective of a user of this crate, they get all the necessary APIs
+// (macro, trait, struct) through the one bitfield crate.
+pub use bitfield_impl::bitfield;
+
+// TODO other things
diff --git a/bitfield/tests/00-INCOMPLETE b/bitfield/tests/00-INCOMPLETE
new file mode 100644
index 000000000..bab8fbadf
--- /dev/null
+++ b/bitfield/tests/00-INCOMPLETE
@@ -0,0 +1 @@
+This test suite needs more work and explanations...
diff --git a/bitfield/tests/01-parse.rs b/bitfield/tests/01-parse.rs
new file mode 100644
index 000000000..585bbd8e2
--- /dev/null
+++ b/bitfield/tests/01-parse.rs
@@ -0,0 +1,11 @@
+use bitfield::*;
+
+#[bitfield]
+pub struct MyFourBytes {
+    a: B1,
+    b: B3,
+    c: B4,
+    d: B24,
+}
+
+fn main() {}
diff --git a/bitfield/tests/progress.rs b/bitfield/tests/progress.rs
new file mode 100644
index 000000000..5044d9f93
--- /dev/null
+++ b/bitfield/tests/progress.rs
@@ -0,0 +1,5 @@
+#[test]
+fn tests() {
+    let t = workshop::TestCases::new();
+    //t.pass("tests/01-parse.rs");
+}