diff --git a/pci.h b/pci.h
new file mode 100644
index 0000000..95beb21
--- /dev/null
+++ b/pci.h
@@ -0,0 +1,52 @@
+#ifndef UAPI_PCI_VERSION
+#define UAPI_PCI_VERSION 1
+#endif
+
+#if UAPI_PCI_VERSION != 1
+#error pci.h API version mismatch, make sure all uDrivers are using the same base
+#endif
+
+#ifndef UAPI_PCI_INCLUDED
+#define UAPI_PCI_INCLUDED
+
+#ifndef UAPI_KERNEL_API
+#error this header should not be included directly, use kernel_api.h
+#endif
+
+#ifndef UAPI_WANTS_PCI
+#error pci.h is not used by any of the included uDrivers and should not be included
+#endif
+
+#include "platform/types.h"
+#include "platform/compiler.h"
+#include "types.h"
+
+UAPI_BEGIN_DECLS
+
+/*
+ * Open a PCI device at 'address'. The returned 'out_handle' may be used for
+ * all compiled-in uAPI PCI functions.
+ */
+uapi_status uapi_pci_device_open(
+    uapi_pci_address *address, uapi_handle *out_handle
+);
+
+/*
+ * Read & write PCI configuration space for a previously open PCI device handle.
+ *
+ * NOTE:
+ * 'byte_width' is ALWAYS one of 1, 2, 4. Since PCI registers are 32 bits wide
+ * this must be able to handle e.g. a 1-byte access by reading at the nearest
+ * 4-byte aligned offset below, then masking the value to select the target
+ * byte.
+ */
+uapi_status uapi_kernel_pci_cfg_read(
+    uapi_handle, uapi_size offset, uapi_u8 byte_width, uapi_u64 *value
+);
+uapi_status uapi_kernel_pci_cfg_write(
+    uapi_handle, uapi_size offset, uapi_u8 byte_width, uapi_u64 value
+);
+
+UAPI_END_DECLS
+
+#endif
diff --git a/status.h b/status.h
new file mode 100644
index 0000000..ebb524c
--- /dev/null
+++ b/status.h
@@ -0,0 +1,36 @@
+#ifndef UAPI_STATUS_VERSION
+#define UAPI_STATUS_VERSION 1
+#endif
+
+#if UAPI_STATUS_VERSION != 1
+#error status.h API version mismatch, make sure all uDrivers are using the same base
+#endif
+
+#ifndef UAPI_STATUS_INCLUDED
+#define UAPI_STATUS_INCLUDED
+
+#include "platform/types.h"
+#include "platform/compiler.h"
+
+UAPI_BEGIN_DECLS
+
+#ifndef UAPI_STATUS_BASE
+#define UAPI_STATUS_BASE 0
+#endif
+
+typedef enum uapi_status {
+    UAPI_STATUS_OK = UAPI_STATUS_BASE,
+    UAPI_STATUS_MAPPING_FAILED,
+    UAPI_STATUS_OUT_OF_MEMORY,
+    UAPI_STATUS_BAD_CHECKSUM,
+    UAPI_STATUS_NOT_FOUND,
+    UAPI_STATUS_INVALID_ARGUMENT,
+    UAPI_STATUS_UNIMPLEMENTED,
+    UAPI_STATUS_ALREADY_EXISTS,
+    UAPI_STATUS_INTERNAL_ERROR,
+    UAPI_STATUS_TIMEOUT,
+} uapi_status;
+
+UAPI_END_DECLS
+
+#endif
diff --git a/types.h b/types.h
new file mode 100644
index 0000000..3724883
--- /dev/null
+++ b/types.h
@@ -0,0 +1,28 @@
+#ifndef UAPI_TYPES_VERSION
+#define UAPI_TYPES_VERSION 1
+#endif
+
+#if UAPI_TYPES_VERSION != 1
+#error types.h API version mismatch, make sure all uDrivers are using the same base
+#endif
+
+#ifndef UAPI_TYPES_INCLUDED
+#define UAPI_TYPES_INCLUDED
+
+#include "platform/types.h"
+#include "platform/compiler.h"
+
+UAPI_BEGIN_DECLS
+
+typedef void *uapi_handle;
+
+typedef struct uapi_pci_address {
+    uapi_u16 segment;
+    uapi_u8 bus;
+    uapi_u8 device;
+    uapi_u8 function;
+} uapi_pci_address;
+
+UAPI_END_DECLS
+
+#endif