diff --git a/RELEASE_NOTES.rst b/RELEASE_NOTES.rst
index cc540f779..e6fc5e4e1 100644
--- a/RELEASE_NOTES.rst
+++ b/RELEASE_NOTES.rst
@@ -36,6 +36,8 @@ Release notes
   identifiers (``true``, ``null``, ...) with their Python equivalents
   (``True``, ``None` ...).
 * Controllers are now named ``aqctl_XXX`` instead of ``XXX_controller``.
+* In the device database, the "comm" device has been folded into the "core" device.
+  Move the "host" argument into the "core" device, and remove the "comm" device.
 
 
 2.3
diff --git a/artiq/coredevice/comm_kernel.py b/artiq/coredevice/comm_kernel.py
index eba2a9dbd..ff92b72ce 100644
--- a/artiq/coredevice/comm_kernel.py
+++ b/artiq/coredevice/comm_kernel.py
@@ -109,8 +109,34 @@ def initialize_connection(host, port):
     return sock
 
 
+class CommKernelDummy:
+    def __init__(self):
+        pass
+
+    def switch_clock(self, external):
+        pass
+
+    def load(self, kernel_library):
+        pass
+
+    def run(self):
+        pass
+
+    def serve(self, embedding_map, symbolizer, demangler):
+        pass
+
+    def check_system_info(self):
+        pass
+
+    def get_log(self):
+        return ""
+
+    def clear_log(self):
+        pass
+
+
 class CommKernel:
-    def __init__(self, dmgr, host, port=1381):
+    def __init__(self, host, port=1381):
         self._read_type = None
         self.host = host
         self.port = port
diff --git a/artiq/coredevice/comm_kernel_dummy.py b/artiq/coredevice/comm_kernel_dummy.py
deleted file mode 100644
index c9dae5200..000000000
--- a/artiq/coredevice/comm_kernel_dummy.py
+++ /dev/null
@@ -1,27 +0,0 @@
-from operator import itemgetter
-
-
-class CommKernel:
-    def __init__(self, dmgr):
-        super().__init__()
-
-    def switch_clock(self, external):
-        pass
-
-    def load(self, kernel_library):
-        pass
-
-    def run(self):
-        pass
-
-    def serve(self, embedding_map, symbolizer, demangler):
-        pass
-
-    def check_system_info(self):
-        pass
-
-    def get_log(self):
-        return ""
-
-    def clear_log(self):
-        pass
diff --git a/artiq/coredevice/comm_mgmt.py b/artiq/coredevice/comm_mgmt.py
index d4a787622..e50a3167e 100644
--- a/artiq/coredevice/comm_mgmt.py
+++ b/artiq/coredevice/comm_mgmt.py
@@ -42,7 +42,7 @@ def initialize_connection(host, port):
 
 
 class CommMgmt:
-    def __init__(self, dmgr, host, port=1380):
+    def __init__(self, host, port=1380):
         self.host = host
         self.port = port
 
diff --git a/artiq/coredevice/core.py b/artiq/coredevice/core.py
index 78858d849..1cce9ad7d 100644
--- a/artiq/coredevice/core.py
+++ b/artiq/coredevice/core.py
@@ -13,6 +13,7 @@ from artiq.compiler.module import Module
 from artiq.compiler.embedding import Stitcher
 from artiq.compiler.targets import OR1KTarget
 
+from artiq.coredevice.comm_kernel import CommKernel, CommKernelDummy
 # Import for side effects (creating the exception classes).
 from artiq.coredevice import exceptions
 
@@ -50,6 +51,7 @@ def rtio_get_counter() -> TInt64:
 class Core:
     """Core device driver.
 
+    :param host: hostname or IP address of the core device.
     :param ref_period: period of the reference clock for the RTIO subsystem.
         On platforms that use clock multiplication and SERDES-based PHYs,
         this is the period after multiplication. For example, with a RTIO core
@@ -61,7 +63,6 @@ class Core:
     :param ref_multiplier: ratio between the RTIO fine timestamp frequency
         and the RTIO coarse timestamp frequency (e.g. SERDES multiplication
         factor).
-    :param comm_device: name of the device used for communications.
     """
 
     kernel_invariants = {
@@ -69,13 +70,16 @@ class Core:
         "external_clock",
     }
 
-    def __init__(self, dmgr, ref_period, external_clock=False,
-                 ref_multiplier=8, comm_device="comm"):
+    def __init__(self, dmgr, host, ref_period, external_clock=False,
+                 ref_multiplier=8):
         self.ref_period = ref_period
         self.external_clock = external_clock
         self.ref_multiplier = ref_multiplier
         self.coarse_ref_period = ref_period*ref_multiplier
-        self.comm = dmgr.get(comm_device)
+        if host is None:
+            self.comm = CommKernelDummy()
+        else:
+            self.comm = CommKernel(host)
 
         self.first_run = True
         self.dmgr = dmgr
diff --git a/artiq/dashboard/moninj.py b/artiq/dashboard/moninj.py
index 42150e5e0..716c3ac1b 100644
--- a/artiq/dashboard/moninj.py
+++ b/artiq/dashboard/moninj.py
@@ -197,7 +197,7 @@ class _DeviceManager:
         try:
             if v["type"] == "local":
                 widget = None
-                if k == "comm":
+                if k == "core":
                     self.core_addr = v["arguments"]["host"]
                     self.new_core_addr.set()
                 elif v["module"] == "artiq.coredevice.ttl":
diff --git a/artiq/examples/drtio/device_db.py b/artiq/examples/drtio/device_db.py
index 8171fda1b..2de6862c8 100644
--- a/artiq/examples/drtio/device_db.py
+++ b/artiq/examples/drtio/device_db.py
@@ -3,17 +3,11 @@
 # The list of devices here is not exhaustive.
 
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel",
-        "class": "CommKernel",
-        "arguments": {"host": "kc705.lab.m-labs.hk"}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 2e-9}
+        "arguments": {"host": "kc705.lab.m-labs.hk", "ref_period": 2e-9}
     },
     "core_cache": {
         "type": "local",
diff --git a/artiq/examples/master/device_db.py b/artiq/examples/master/device_db.py
index 513984d6d..b53f53734 100644
--- a/artiq/examples/master/device_db.py
+++ b/artiq/examples/master/device_db.py
@@ -3,17 +3,11 @@
 # The list of devices here is not exhaustive.
 
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel",
-        "class": "CommKernel",
-        "arguments": {"host": "kc705.lab.m-labs.hk"}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 1e-9}
+        "arguments": {"host": "kc705.lab.m-labs.hk", "ref_period": 1e-9}
     },
     "core_cache": {
         "type": "local",
diff --git a/artiq/examples/phaser/device_db.py b/artiq/examples/phaser/device_db.py
index 0f740fae9..d1397efb9 100644
--- a/artiq/examples/phaser/device_db.py
+++ b/artiq/examples/phaser/device_db.py
@@ -1,17 +1,12 @@
 # The RTIO channel numbers here are for Phaser on KC705.
 
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel",
-        "class": "CommKernel",
-        "arguments": {"host": "kc705aux.lab.m-labs.hk"}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
         "arguments": {
+            "host": "kc705aux.lab.m-labs.hk",
             "ref_period": 5e-9/6
         }
     },
diff --git a/artiq/frontend/artiq_coreanalyzer.py b/artiq/frontend/artiq_coreanalyzer.py
index 22cafc5b7..0a5fad21b 100755
--- a/artiq/frontend/artiq_coreanalyzer.py
+++ b/artiq/frontend/artiq_coreanalyzer.py
@@ -43,7 +43,7 @@ def main():
         with open(args.read_dump, "rb") as f:
             dump = f.read()
     else:
-        core_addr = device_mgr.get_desc("comm")["arguments"]["host"]
+        core_addr = device_mgr.get_desc("core")["arguments"]["host"]
         dump = get_analyzer_dump(core_addr)
     decoded_dump = decode_dump(dump)
     if args.print_decoded:
diff --git a/artiq/frontend/artiq_coreboot.py b/artiq/frontend/artiq_coreboot.py
index e619bc69a..c39c267e8 100755
--- a/artiq/frontend/artiq_coreboot.py
+++ b/artiq/frontend/artiq_coreboot.py
@@ -36,7 +36,7 @@ def main():
     init_logger(args)
     device_mgr = DeviceManager(DeviceDB(args.device_db))
     try:
-        core_addr = device_mgr.get_desc("comm")["arguments"]["host"]
+        core_addr = device_mgr.get_desc("core")["arguments"]["host"]
         mgmt = CommMgmt(device_mgr, core_addr)
         if args.action == "reboot":
             mgmt.reboot()
diff --git a/artiq/frontend/artiq_coreconfig.py b/artiq/frontend/artiq_coreconfig.py
index 43aa02739..6f1ff2e42 100755
--- a/artiq/frontend/artiq_coreconfig.py
+++ b/artiq/frontend/artiq_coreconfig.py
@@ -52,7 +52,7 @@ def main():
     init_logger(args)
     device_mgr = DeviceManager(DeviceDB(args.device_db))
     try:
-        comm = device_mgr.get("comm")
+        comm = device_mgr.get("core").comm
         comm.check_system_info()
 
         if args.action == "read":
diff --git a/artiq/frontend/artiq_corelog.py b/artiq/frontend/artiq_corelog.py
index 5ba31ac32..475386fa7 100755
--- a/artiq/frontend/artiq_corelog.py
+++ b/artiq/frontend/artiq_corelog.py
@@ -37,7 +37,7 @@ def main():
     args = get_argparser().parse_args()
     init_logger(args)
 
-    core_addr = DeviceDB(args.device_db).get("comm")["arguments"]["host"]
+    core_addr = DeviceDB(args.device_db).get("core")["arguments"]["host"]
     mgmt = CommMgmt(None, core_addr)
     try:
         if args.action == "set_level":
diff --git a/artiq/test/coredevice/test_analyzer.py b/artiq/test/coredevice/test_analyzer.py
index fb7b35ec8..0f3b57495 100644
--- a/artiq/test/coredevice/test_analyzer.py
+++ b/artiq/test/coredevice/test_analyzer.py
@@ -40,7 +40,7 @@ class WriteLog(EnvExperiment):
 
 class AnalyzerTest(ExperimentCase):
     def test_ttl_pulse(self):
-        core_host = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_host = self.device_mgr.get_desc("core")["arguments"]["host"]
 
         exp = self.create(CreateTTLPulse)
         exp.initialize_io()
@@ -64,7 +64,7 @@ class AnalyzerTest(ExperimentCase):
             1000, delta=1)
 
     def test_rtio_log(self):
-        core_host = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_host = self.device_mgr.get_desc("core")["arguments"]["host"]
 
         exp = self.create(WriteLog)
         get_analyzer_dump(core_host)  # clear analyzer buffer
diff --git a/artiq/test/coredevice/test_moninj.py b/artiq/test/coredevice/test_moninj.py
index b69ccd302..2d95e4f8e 100644
--- a/artiq/test/coredevice/test_moninj.py
+++ b/artiq/test/coredevice/test_moninj.py
@@ -6,7 +6,7 @@ from artiq.test.hardware_testbench import ExperimentCase
 
 class MonInjTest(ExperimentCase):
     def test_moninj(self):
-        core_host = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_host = self.device_mgr.get_desc("core")["arguments"]["host"]
         loop_out_channel = self.device_mgr.get_desc("loop_out")["arguments"]["channel"]
         loop_in_channel = self.device_mgr.get_desc("loop_in")["arguments"]["channel"]
 
diff --git a/artiq/test/coredevice/test_rtio.py b/artiq/test/coredevice/test_rtio.py
index 3c8fb0131..1c75ab7ee 100644
--- a/artiq/test/coredevice/test_rtio.py
+++ b/artiq/test/coredevice/test_rtio.py
@@ -402,7 +402,7 @@ class CoredeviceTest(ExperimentCase):
             self.execute(SequenceError)
 
     def test_collision(self):
-        core_addr = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_addr = self.device_mgr.get_desc("core")["arguments"]["host"]
         mgmt = CommMgmt(self.device_mgr, core_addr)
         mgmt.clear_log()
         self.execute(Collision)
@@ -411,7 +411,7 @@ class CoredeviceTest(ExperimentCase):
         mgmt.close()
 
     def test_address_collision(self):
-        core_addr = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_addr = self.device_mgr.get_desc("core")["arguments"]["host"]
         mgmt = CommMgmt(self.device_mgr, core_addr)
         mgmt.clear_log()
         self.execute(AddressCollision)
@@ -576,7 +576,7 @@ class DMATest(ExperimentCase):
             exp.nested()
 
     def test_dma_trace(self):
-        core_host = self.device_mgr.get_desc("comm")["arguments"]["host"]
+        core_host = self.device_mgr.get_desc("core")["arguments"]["host"]
 
         exp = self.create(_DMA)
         exp.record()
diff --git a/artiq/test/lit/devirtualization/device_db.py b/artiq/test/lit/devirtualization/device_db.py
index 99fa148fd..e39c83c09 100644
--- a/artiq/test/lit/devirtualization/device_db.py
+++ b/artiq/test/lit/devirtualization/device_db.py
@@ -1,14 +1,8 @@
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel_dummy",
-        "class": "CommKernel",
-        "arguments": {}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 1e-9}
+        "arguments": {"host": None, "ref_period": 1e-9}
     }
 }
diff --git a/artiq/test/lit/embedding/device_db.py b/artiq/test/lit/embedding/device_db.py
index 99fa148fd..e39c83c09 100644
--- a/artiq/test/lit/embedding/device_db.py
+++ b/artiq/test/lit/embedding/device_db.py
@@ -1,14 +1,8 @@
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel_dummy",
-        "class": "CommKernel",
-        "arguments": {}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 1e-9}
+        "arguments": {"host": None, "ref_period": 1e-9}
     }
 }
diff --git a/artiq/test/lit/escape/device_db.py b/artiq/test/lit/escape/device_db.py
index 99fa148fd..e39c83c09 100644
--- a/artiq/test/lit/escape/device_db.py
+++ b/artiq/test/lit/escape/device_db.py
@@ -1,14 +1,8 @@
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel_dummy",
-        "class": "CommKernel",
-        "arguments": {}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 1e-9}
+        "arguments": {"host": None, "ref_period": 1e-9}
     }
 }
diff --git a/artiq/test/lit/regression/device_db.py b/artiq/test/lit/regression/device_db.py
index 99fa148fd..e39c83c09 100644
--- a/artiq/test/lit/regression/device_db.py
+++ b/artiq/test/lit/regression/device_db.py
@@ -1,14 +1,8 @@
 device_db = {
-    "comm": {
-        "type": "local",
-        "module": "artiq.coredevice.comm_kernel_dummy",
-        "class": "CommKernel",
-        "arguments": {}
-    },
     "core": {
         "type": "local",
         "module": "artiq.coredevice.core",
         "class": "Core",
-        "arguments": {"ref_period": 1e-9}
+        "arguments": {"host": None, "ref_period": 1e-9}
     }
 }