diff --git a/CMakeLists.txt b/CMakeLists.txt
index fe51f1c..cabcb47 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -69,7 +69,19 @@ add_custom_command(
 	COMMAND ${CMAKE_STRIP} -g $<TARGET_FILE:${kernel_exe_name}>)
 
 target_link_libraries(${kernel_exe_name} -nostdlib -ffreestanding -lgcc)
-target_compile_definitions(${kernel_exe_name} PRIVATE KERNEL_VERSION="${kernel_version}")
+target_compile_definitions(${kernel_exe_name} PRIVATE
+	KERNEL_NAME="${kernel_name}"
+	KERNEL_VERSION="${kernel_version}"
+	KERNEL_ARCH="${kernel_arch}")
 
 include(arch/${kernel_arch}/config.cmake)
 include(arch/${kernel_arch}/targets.cmake)
+
+add_subdirectory(debug)
+target_link_libraries(${kernel_exe_name} magenta_debug)
+target_compile_definitions(magenta_debug PRIVATE KERNEL_VERSION="${kernel_version}")
+target_include_directories(magenta_debug PRIVATE
+	include
+	libc/include
+	libmagenta/include
+	arch/${kernel_arch}/include)
diff --git a/debug/CMakeLists.txt b/debug/CMakeLists.txt
new file mode 100644
index 0000000..03a2e96
--- /dev/null
+++ b/debug/CMakeLists.txt
@@ -0,0 +1,4 @@
+file(GLOB sources *.c *.h include/magenta/debug/*.h)
+
+add_library(magenta_debug STATIC ${sources})
+target_include_directories(magenta_debug PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
diff --git a/debug/event.c b/debug/event.c
new file mode 100644
index 0000000..f4a58d7
--- /dev/null
+++ b/debug/event.c
@@ -0,0 +1,29 @@
+#include <magenta/debug/event.h>
+
+const char *mxdbg_event_type_get_description(enum mxdbg_event_type type)
+{
+	switch (type) {
+	case MXDBG_EVENT_TASK_CREATED:
+		return "task-create";
+	case MXDBG_EVENT_TASK_STARTED:
+		return "task-start";
+	case MXDBG_EVENT_TASK_STOPPED:
+		return "task-stop";
+	case MXDBG_EVENT_TASK_DESTROYED:
+		return "task-destroy";
+	case MXDBG_EVENT_THREAD_CREATED:
+		return "thread-create";
+	case MXDBG_EVENT_THREAD_STARTED:
+		return "thread-start";
+	case MXDBG_EVENT_THREAD_STOPPED:
+		return "thread-stop";
+	case MXDBG_EVENT_THREAD_DESTROYED:
+		return "thread-destroy";
+	case MXDBG_EVENT_THREAD_FAULT:
+		return "thread-fault";
+	case MXDBG_EVENT_PANIC:
+		return "panic";
+	default:
+		return "<unknown>";
+	}
+}
diff --git a/debug/host.c b/debug/host.c
new file mode 100644
index 0000000..f3cbbf5
--- /dev/null
+++ b/debug/host.c
@@ -0,0 +1,110 @@
+#include "magenta/debug/util.h"
+
+#include <magenta/debug/host.h>
+#include <magenta/debug/packet.h>
+#include <magenta/debug/request.h>
+
+enum mxdbg_status mxdbg_host_handle_request(struct mxdbg_host *host)
+{
+	struct mxdbg_packet packet = {0};
+	enum mxdbg_status status = mxdbg_host_recv(host, &packet);
+	if (status != MXDBG_SUCCESS) {
+		debug_printf("debug: failed to read packet");
+		return status;
+	}
+
+	if (packet.pkt_magic != MXDBG_PACKET_MAGIC) {
+		debug_printf(
+			"debug: packet is malformed (magic=%08x)",
+			packet.pkt_magic);
+		return MXDBG_ERR_BAD_FORMAT;
+	}
+
+	return mxdbg_handle_request(host, &packet);
+}
+
+enum mxdbg_status mxdbg_host_recv(
+	struct mxdbg_host *host,
+	struct mxdbg_packet *packet)
+{
+	size_t r;
+
+	if (host->read_remote) {
+		return host->read_remote(host, packet, sizeof *packet, &r);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
+
+enum mxdbg_status mxdbg_host_recv_packet_data(
+	struct mxdbg_host *host,
+	struct mxdbg_packet *packet)
+{
+	if (packet->pkt_magic != MXDBG_PACKET_MAGIC) {
+		return MXDBG_ERR_INVALID_ARGUMENT;
+	}
+
+	if (!packet->pkt_length) {
+		return MXDBG_SUCCESS;
+	}
+
+	size_t r;
+	void *dest = packet + 1;
+	if (host->read_remote) {
+		return host->read_remote(
+			host,
+			dest,
+			packet->pkt_length - sizeof *packet,
+			&r);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
+
+enum mxdbg_status mxdbg_host_send(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *packet)
+{
+	size_t w;
+	if (host->write_remote) {
+		return host->write_remote(host, packet, packet->pkt_length, &w);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
+
+enum mxdbg_status mxdbg_host_identify(
+	struct mxdbg_host *host,
+	enum mxdbg_identity_key key,
+	void *out,
+	size_t max)
+{
+	if (host->identify) {
+		return host->identify(host, key, out, max);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
+
+enum mxdbg_status mxdbg_host_identify_task(
+	struct mxdbg_host *host,
+	unsigned int tid,
+	enum mxdbg_identity_key key,
+	void *out,
+	size_t max)
+{
+	if (host->identify_task) {
+		return host->identify_task(host, tid, key, out, max);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
+
+enum mxdbg_status mxdbg_host_resume(struct mxdbg_host *host)
+{
+	if (host->resume) {
+		return host->resume(host);
+	}
+
+	return MXDBG_ERR_NOT_SUPPORTED;
+}
diff --git a/debug/include/magenta/debug/event.h b/debug/include/magenta/debug/event.h
new file mode 100644
index 0000000..a9a2210
--- /dev/null
+++ b/debug/include/magenta/debug/event.h
@@ -0,0 +1,23 @@
+#ifndef MAGENTA_DEBUG_EVENT_H_
+#define MAGENTA_DEBUG_EVENT_H_
+
+enum mxdbg_event_type {
+	MXDBG_EVENT_NONE = 0,
+
+	MXDBG_EVENT_TASK_CREATED,
+	MXDBG_EVENT_TASK_STARTED,
+	MXDBG_EVENT_TASK_STOPPED,
+	MXDBG_EVENT_TASK_DESTROYED,
+
+	MXDBG_EVENT_THREAD_CREATED,
+	MXDBG_EVENT_THREAD_STARTED,
+	MXDBG_EVENT_THREAD_STOPPED,
+	MXDBG_EVENT_THREAD_DESTROYED,
+	MXDBG_EVENT_THREAD_FAULT,
+
+	MXDBG_EVENT_PANIC,
+};
+
+extern const char *mxdbg_event_type_get_description(enum mxdbg_event_type type);
+
+#endif
diff --git a/debug/include/magenta/debug/host.h b/debug/include/magenta/debug/host.h
new file mode 100644
index 0000000..a3b3488
--- /dev/null
+++ b/debug/include/magenta/debug/host.h
@@ -0,0 +1,61 @@
+#ifndef MAGENTA_DEBUG_HOST_H_
+#define MAGENTA_DEBUG_HOST_H_
+
+#include <magenta/debug/identity.h>
+#include <magenta/debug/status.h>
+#include <stddef.h>
+#include <stdint.h>
+
+struct mxdbg_packet;
+struct mxdbg_packet_event;
+
+struct mxdbg_host {
+	enum mxdbg_status (
+		*read_remote)(struct mxdbg_host *, void *, size_t, size_t *);
+	enum mxdbg_status (*write_remote)(
+		struct mxdbg_host *,
+		const void *,
+		size_t,
+		size_t *);
+	enum mxdbg_status (*identify)(
+		struct mxdbg_host *,
+		enum mxdbg_identity_key,
+		void *,
+		size_t);
+	enum mxdbg_status (*identify_task)(
+		struct mxdbg_host *,
+		unsigned int,
+		enum mxdbg_identity_key,
+		void *,
+		size_t);
+	enum mxdbg_status (*resume)(struct mxdbg_host *);
+};
+
+extern enum mxdbg_status mxdbg_host_handle_request(struct mxdbg_host *host);
+
+extern enum mxdbg_status mxdbg_host_recv(
+	struct mxdbg_host *host,
+	struct mxdbg_packet *packet);
+extern enum mxdbg_status mxdbg_host_recv_packet_data(
+	struct mxdbg_host *host,
+	struct mxdbg_packet *packet);
+extern enum mxdbg_status mxdbg_host_send(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *packet);
+extern enum mxdbg_status mxdbg_host_identify(
+	struct mxdbg_host *host,
+	enum mxdbg_identity_key key,
+	void *out,
+	size_t max);
+extern enum mxdbg_status mxdbg_host_identify_task(
+	struct mxdbg_host *host,
+	unsigned int task,
+	enum mxdbg_identity_key key,
+	void *out,
+	size_t max);
+extern enum mxdbg_status mxdbg_host_resume(struct mxdbg_host *host);
+extern enum mxdbg_status mxdbg_host_send_event(
+	struct mxdbg_host *host,
+	struct mxdbg_packet_event *ev);
+
+#endif
diff --git a/debug/include/magenta/debug/identity.h b/debug/include/magenta/debug/identity.h
new file mode 100644
index 0000000..89d66e7
--- /dev/null
+++ b/debug/include/magenta/debug/identity.h
@@ -0,0 +1,16 @@
+#ifndef MAGENTA_DEBUG_IDENTITY_H_
+#define MAGENTA_DEBUG_IDENTITY_H_
+
+enum mxdbg_identity_key {
+	MXDBG_IDENTITY_NONE = 0,
+	MXDBG_IDENTITY_KERNEL_NAME,
+	MXDBG_IDENTITY_KERNEL_VERSION,
+	MXDBG_IDENTITY_KERNEL_ARCH,
+
+	/* identify_task keys */
+	MXDBG_IDENTITY_TASK_NAME,
+	MXDBG_IDENTITY_TASK_PARENT,
+	MXDBG_IDENTITY_TASK_NR_THREADS,
+};
+
+#endif
diff --git a/debug/include/magenta/debug/packet.h b/debug/include/magenta/debug/packet.h
new file mode 100644
index 0000000..3f850fa
--- /dev/null
+++ b/debug/include/magenta/debug/packet.h
@@ -0,0 +1,66 @@
+#ifndef MAGENTA_DEBUG_PACKET_H_
+#define MAGENTA_DEBUG_PACKET_H_
+
+#include <magenta/debug/event.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define MXDBG_PACKET_MAGIC 0xdecafbaf
+
+enum mxdbg_packet_type {
+	MXDBG_PACKET_NONE = 0,
+	MXDBG_PACKET_IDENTIFY_KERNEL,
+	MXDBG_PACKET_IDENTIFY_TASK,
+	MXDBG_PACKET_LIST_TASK,
+	MXDBG_PACKET_RESUME,
+	MXDBG_PACKET_STOP,
+	MXDBG_PACKET_EVENT,
+};
+
+enum mxdbg_packet_flags {
+	MXDBG_PACKET_F_NONE = 0,
+	MXDBG_PACKET_F_RESPONSE = 0x01u,
+};
+
+struct mxdbg_packet {
+	uint32_t pkt_magic;
+	uint16_t pkt_length;
+	uint8_t pkt_type;
+	uint8_t pkt_flags;
+};
+
+struct mxdbg_packet_identify_kernel {
+	struct mxdbg_packet id_base;
+	char id_kernel_name[32];
+	char id_kernel_version[32];
+	char id_kernel_arch[16];
+};
+
+struct mxdbg_packet_list_task {
+	struct mxdbg_packet l_base;
+	uint16_t l_task_count;
+};
+
+struct mxdbg_packet_identify_task {
+	struct mxdbg_packet id_base;
+	uint16_t id_task, id_parent;
+	uint16_t id_thread_count;
+	char id_task_name[64];
+};
+
+struct mxdbg_packet_event {
+	struct mxdbg_packet ev_base;
+	uint16_t ev_type;
+	uint16_t ev_task, ev_thread;
+	uint32_t ev_code;
+};
+
+extern void mxdbg_packet_init(
+	struct mxdbg_packet *packet,
+	size_t size,
+	enum mxdbg_packet_type type,
+	enum mxdbg_packet_flags flags);
+extern bool mxdbg_packet_validate(const struct mxdbg_packet *packet);
+
+#endif
diff --git a/debug/include/magenta/debug/request.h b/debug/include/magenta/debug/request.h
new file mode 100644
index 0000000..86326ef
--- /dev/null
+++ b/debug/include/magenta/debug/request.h
@@ -0,0 +1,11 @@
+#ifndef MAGENTA_DEBUG_REQUEST_H_
+#define MAGENTA_DEBUG_REQUEST_H_
+
+struct mxdbg_host;
+struct mxdbg_packet;
+
+extern enum mxdbg_status mxdbg_handle_request(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *req);
+
+#endif
diff --git a/debug/include/magenta/debug/status.h b/debug/include/magenta/debug/status.h
new file mode 100644
index 0000000..731ef81
--- /dev/null
+++ b/debug/include/magenta/debug/status.h
@@ -0,0 +1,12 @@
+#ifndef MAGENTA_DEBUG_STATUS_H_
+#define MAGENTA_DEBUG_STATUS_H_
+
+enum mxdbg_status {
+	MXDBG_SUCCESS = 0,
+	MXDBG_ERR_INVALID_ARGUMENT,
+	MXDBG_ERR_NOT_SUPPORTED,
+	MXDBG_ERR_BAD_FORMAT,
+	MXDBG_ERR_IO_FAILURE,
+};
+
+#endif
diff --git a/debug/include/magenta/debug/util.h b/debug/include/magenta/debug/util.h
new file mode 100644
index 0000000..3a5267d
--- /dev/null
+++ b/debug/include/magenta/debug/util.h
@@ -0,0 +1,14 @@
+#ifndef MAGENTA_DEBUG_UTIL_H_
+#define MAGENTA_DEBUG_UTIL_H_
+
+#if defined(KERNEL_VERSION)
+#include <kernel/libc/string.h>
+#include <kernel/printk.h>
+#define debug_printf(...) printk(__VA_ARGS__)
+#else
+#include <stdio.h>
+#include <string.h>
+#define debug_printf(...) printf(__VA_ARGS__)
+#endif
+
+#endif
diff --git a/debug/packet.c b/debug/packet.c
new file mode 100644
index 0000000..a06800c
--- /dev/null
+++ b/debug/packet.c
@@ -0,0 +1,20 @@
+#include <magenta/debug/packet.h>
+#include <magenta/debug/util.h>
+
+void mxdbg_packet_init(
+	struct mxdbg_packet *packet,
+	size_t size,
+	enum mxdbg_packet_type type,
+	enum mxdbg_packet_flags flags)
+{
+	memset(packet, 0x0, sizeof *packet);
+	packet->pkt_magic = MXDBG_PACKET_MAGIC;
+	packet->pkt_length = size;
+	packet->pkt_type = type;
+	packet->pkt_flags = flags;
+}
+
+bool mxdbg_packet_validate(const struct mxdbg_packet *packet)
+{
+	return packet->pkt_magic == MXDBG_PACKET_MAGIC;
+}
diff --git a/debug/request.c b/debug/request.c
new file mode 100644
index 0000000..bc7e0f2
--- /dev/null
+++ b/debug/request.c
@@ -0,0 +1,106 @@
+#include <magenta/debug/host.h>
+#include <magenta/debug/packet.h>
+#include <magenta/debug/util.h>
+
+static enum mxdbg_status identify_kernel(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *req)
+{
+	struct mxdbg_packet_identify_kernel id = {0};
+	mxdbg_packet_init(
+		&id.id_base,
+		sizeof id,
+		MXDBG_PACKET_IDENTIFY_KERNEL,
+		MXDBG_PACKET_F_RESPONSE);
+
+	mxdbg_host_identify(
+		host,
+		MXDBG_IDENTITY_KERNEL_NAME,
+		id.id_kernel_name,
+		sizeof id.id_kernel_name);
+	mxdbg_host_identify(
+		host,
+		MXDBG_IDENTITY_KERNEL_VERSION,
+		id.id_kernel_version,
+		sizeof id.id_kernel_version);
+	mxdbg_host_identify(
+		host,
+		MXDBG_IDENTITY_KERNEL_ARCH,
+		id.id_kernel_arch,
+		sizeof id.id_kernel_arch);
+
+	mxdbg_host_send(host, &id.id_base);
+
+	return MXDBG_SUCCESS;
+}
+
+static enum mxdbg_status identify_task(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *packet)
+{
+	struct mxdbg_packet_identify_task *req
+		= (struct mxdbg_packet_identify_task *)packet;
+	struct mxdbg_packet_identify_task id = {0};
+	id.id_base = *packet;
+	mxdbg_host_recv_packet_data(host, &id.id_base);
+	unsigned int tid = id.id_task;
+
+	mxdbg_packet_init(
+		&id.id_base,
+		sizeof id,
+		MXDBG_PACKET_IDENTIFY_TASK,
+		MXDBG_PACKET_F_RESPONSE);
+
+	mxdbg_host_identify_task(
+		host,
+		tid,
+		MXDBG_IDENTITY_TASK_NAME,
+		id.id_task_name,
+		sizeof id.id_task_name);
+	mxdbg_host_identify_task(
+		host,
+		tid,
+		MXDBG_IDENTITY_TASK_PARENT,
+		&id.id_parent,
+		sizeof id.id_parent);
+	mxdbg_host_identify_task(
+		host,
+		tid,
+		MXDBG_IDENTITY_TASK_NR_THREADS,
+		&id.id_thread_count,
+		sizeof id.id_thread_count);
+
+	size_t w;
+	mxdbg_host_send(host, &id.id_base);
+	debug_printf("debug: identify_task response sent");
+
+	return MXDBG_SUCCESS;
+}
+
+static enum mxdbg_status resume(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *req)
+{
+	return mxdbg_host_resume(host);
+}
+
+enum mxdbg_status mxdbg_handle_request(
+	struct mxdbg_host *host,
+	const struct mxdbg_packet *req)
+{
+	switch (req->pkt_type) {
+	case MXDBG_PACKET_IDENTIFY_KERNEL:
+		return identify_kernel(host, req);
+	case MXDBG_PACKET_IDENTIFY_TASK:
+		return identify_task(host, req);
+	case MXDBG_PACKET_RESUME:
+		return resume(host, req);
+	default:
+		debug_printf(
+			"debug: unrecognised packet 0x%02x",
+			req->pkt_type);
+		return MXDBG_ERR_NOT_SUPPORTED;
+	}
+
+	return MXDBG_SUCCESS;
+}