diff --git a/Makefile b/Makefile
index b14e8ef..6129697 100644
--- a/Makefile
+++ b/Makefile
@@ -411,6 +411,7 @@
 	sha_benchmark \
 	sha_tests \
 	stateful_util_tests \
+	tlcl_tests \
 	tpm_bootmode_tests \
 	utility_string_tests \
 	utility_tests \
@@ -838,6 +839,11 @@
 ${BUILD}/tests/rollback_index2_tests: \
 	${BUILD}/firmware/lib/rollback_index_for_test.o
 
+${BUILD}/tests/tlcl_tests: OBJS += \
+	${BUILD}/firmware/lib/tpm_lite/tlcl_for_test.o
+${BUILD}/tests/tlcl_tests: \
+	${BUILD}/firmware/lib/tpm_lite/tlcl_for_test.o
+
 ${BUILD}/tests/vboot_audio_tests: OBJS += \
 	${BUILD}/firmware/lib/vboot_audio_for_test.o
 ${BUILD}/tests/vboot_audio_tests: \
@@ -933,6 +939,7 @@
 	${RUNTEST} ${BUILD_RUN}/tests/rsa_utility_tests
 	${RUNTEST} ${BUILD_RUN}/tests/sha_tests
 	${RUNTEST} ${BUILD_RUN}/tests/stateful_util_tests
+	${RUNTEST} ${BUILD_RUN}/tests/tlcl_tests
 	${RUNTEST} ${BUILD_RUN}/tests/tpm_bootmode_tests
 	${RUNTEST} ${BUILD_RUN}/tests/utility_string_tests
 	${RUNTEST} ${BUILD_RUN}/tests/utility_tests
diff --git a/firmware/include/tlcl.h b/firmware/include/tlcl.h
index ca4e47f..5ce0563 100644
--- a/firmware/include/tlcl.h
+++ b/firmware/include/tlcl.h
@@ -134,6 +134,8 @@
  */
 uint32_t TlclFinalizePhysicalPresence(void);
 
+uint32_t TlclAssertPhysicalPresenceResult(void);
+
 /**
  * Turn off physical presence and locks it off until next reboot.  The TPM
  * error code is returned.
diff --git a/firmware/lib/tpm_lite/tlcl.c b/firmware/lib/tpm_lite/tlcl.c
index ce5614e..7acca9a 100644
--- a/firmware/lib/tpm_lite/tlcl.c
+++ b/firmware/lib/tpm_lite/tlcl.c
@@ -21,6 +21,11 @@
 #include "utility.h"
 #include "vboot_api.h"
 
+#ifdef FOR_TEST
+/* Allow unit testing implementation of TlclSendReceive() */
+#undef CHROMEOS_ENVIRONMENT
+#endif
+
 /* Sets the size field of a TPM command. */
 static INLINE void SetTpmCommandSize(uint8_t* buffer, uint32_t size) {
   ToTpmUint32(buffer + sizeof(uint16_t), size);
diff --git a/tests/tlcl_tests.c b/tests/tlcl_tests.c
new file mode 100644
index 0000000..4765cff
--- /dev/null
+++ b/tests/tlcl_tests.c
@@ -0,0 +1,351 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Tests for TPM lite library
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <tss/tcs.h>
+/* Don't use the vboot constants, since they conflict with the TCS lib */
+#define VBOOT_REFERENCE_TSS_CONSTANTS_H_
+
+#include "host_common.h"
+#include "test_common.h"
+#include "tlcl.h"
+#include "tlcl_internal.h"
+#include "vboot_common.h"
+
+/* Mock data */
+static char debug_info[4096];
+static VbError_t mock_retval;
+
+/* Call to mocked VbExTpmSendReceive() */
+struct srcall
+{
+	const uint8_t *req;  /* Request */
+	uint8_t *rsp;  /* Response */
+	uint8_t rsp_buf[32];  /* Default response buffer, if not overridden */
+	int req_size;  /* Request size */
+	uint32_t req_cmd;  /* Request command code */
+	int rsp_size;  /* Response size */
+	VbError_t retval;  /* Value to return */
+};
+
+#define MAXCALLS 8
+static struct srcall calls[MAXCALLS];
+static int ncalls;
+
+/**
+ * Reset mock data (for use before each test)
+ */
+static void ResetMocks(void)
+{
+	int i;
+
+	*debug_info = 0;
+	mock_retval = VBERROR_SUCCESS;
+
+	memset(calls, 0, sizeof(calls));
+	for (i = 0; i < MAXCALLS; i++)
+		calls[i].rsp = calls[i].rsp_buf;
+	ncalls = 0;
+}
+
+/**
+ * Set response code and length for call <call_idx>.
+ */
+static void SetResponse(int call_idx, uint32_t response_code, int rsp_size)
+{
+	struct srcall *c = calls + call_idx;
+
+	c->rsp_size = rsp_size;
+	ToTpmUint32(c->rsp_buf + 6, response_code);
+}
+
+/* Mocks */
+
+VbError_t VbExTpmInit(void)
+{
+	return mock_retval;
+}
+
+
+VbError_t VbExTpmClose(void)
+{
+	return mock_retval;
+}
+
+VbError_t VbExTpmSendReceive(const uint8_t *request, uint32_t request_length,
+                             uint8_t *response, uint32_t *response_length)
+{
+	struct srcall *c = calls + ncalls++;
+
+	c->req = request;
+	c->req_size = request_length;
+
+	/* Parse out the command code */
+	FromTpmUint32(request + 6, &c->req_cmd);
+
+	// KLUDGE - remove
+	printf("TSR [%d] 0x%x\n", ncalls-1, c->req_cmd);
+
+	memset(response, 0, *response_length);
+	if (c->rsp_size)
+		memcpy(response, c->rsp, c->rsp_size);
+	*response_length = c->rsp_size;
+
+	return c->retval;
+}
+
+/**
+ * Test assorted tlcl functions
+ */
+static void TlclTest(void)
+{
+	uint8_t buf[32], buf2[32];
+
+	ResetMocks();
+	TEST_EQ(TlclLibInit(), VBERROR_SUCCESS, "Init");
+
+	ResetMocks();
+	mock_retval = VBERROR_SIMULATED;
+	TEST_EQ(TlclLibInit(), mock_retval, "Init bad");
+
+	ResetMocks();
+	TEST_EQ(TlclLibClose(), VBERROR_SUCCESS, "Close");
+
+	ResetMocks();
+	mock_retval = VBERROR_SIMULATED;
+	TEST_EQ(TlclLibClose(), mock_retval, "Close bad");
+
+	ResetMocks();
+	ToTpmUint32(buf + 2, 123);
+	TEST_EQ(TlclPacketSize(buf), 123, "TlclPacketSize");
+
+	ResetMocks();
+	ToTpmUint32(buf + 2, 10);
+	TEST_EQ(TlclSendReceive(buf, buf2, sizeof(buf2)), 0, "SendReceive");
+	TEST_PTR_EQ(calls[0].req, buf, "SendReceive req ptr");
+	TEST_EQ(calls[0].req_size, 10, "SendReceive size");
+
+	ResetMocks();
+	calls[0].retval = VBERROR_SIMULATED;
+	ToTpmUint32(buf + 2, 10);
+	TEST_EQ(TlclSendReceive(buf, buf2, sizeof(buf2)), VBERROR_SIMULATED,
+		"SendReceive fail");
+
+	ResetMocks();
+	SetResponse(0, 123, 10);
+	ToTpmUint32(buf + 2, 10);
+	TEST_EQ(TlclSendReceive(buf, buf2, sizeof(buf2)), 123,
+		"SendReceive error response");
+
+	// TODO: continue self test (if needed or doing)
+	// TODO: then retry doing self test
+
+}
+
+
+/**
+ * Test send-command functions
+ */
+static void SendCommandTest(void)
+{
+	ResetMocks();
+	TEST_EQ(TlclStartup(), 0, "SaveState");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_Startup, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSaveState(), 0, "SaveState");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_SaveState, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclResume(), 0, "Resume");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_Startup, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSelfTestFull(), 0, "SelfTestFull");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_SelfTestFull, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclContinueSelfTest(), 0, "ContinueSelfTest");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_ContinueSelfTest, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclAssertPhysicalPresence(), 0,
+		"AssertPhysicalPresence");
+	TEST_EQ(calls[0].req_cmd, TSC_ORD_PhysicalPresence, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclPhysicalPresenceCMDEnable(), 0,
+		"PhysicalPresenceCMDEnable");
+	TEST_EQ(calls[0].req_cmd, TSC_ORD_PhysicalPresence, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclFinalizePhysicalPresence(), 0,
+		"FinalizePhysicalPresence");
+	TEST_EQ(calls[0].req_cmd, TSC_ORD_PhysicalPresence, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclAssertPhysicalPresenceResult(), 0,
+		"AssertPhysicalPresenceResult");
+	TEST_EQ(calls[0].req_cmd, TSC_ORD_PhysicalPresence, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclLockPhysicalPresence(), 0,
+		"LockPhysicalPresence");
+	TEST_EQ(calls[0].req_cmd, TSC_ORD_PhysicalPresence, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclIsOwned(), 0, "IsOwned");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_ReadPubek, "  cmd");
+	ResetMocks();
+	calls[0].retval = VBERROR_SIMULATED;
+	TEST_NEQ(TlclIsOwned(), 0, "IsOwned");
+
+	ResetMocks();
+	TEST_EQ(TlclForceClear(), 0, "ForceClear");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_ForceClear, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSetEnable(), 0, "SetEnable");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_PhysicalEnable, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclClearEnable(), 0, "ClearEnable");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_PhysicalDisable, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSetDeactivated(0), 0, "SetDeactivated");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_PhysicalSetDeactivated, "  cmd");
+}
+
+/**
+ * NV spaces test
+ *
+ * TODO: check params/data read/written.
+ */
+static void ReadWriteTest(void)
+{
+	uint8_t buf[32];
+
+	ResetMocks();
+	TEST_EQ(TlclDefineSpace(1, 2, 3), 0, "DefineSpace");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_DefineSpace, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSetNvLocked(), 0, "SetNvLocked");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_DefineSpace, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclWrite(1, buf, 3), 0, "Write");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_WriteValue, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclRead(1, buf, 3), 0, "Read");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_ReadValue, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclWriteLock(1), 0, "WriteLock");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_WriteValue, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclReadLock(1), 0, "ReadLock");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_ReadValue, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclSetGlobalLock(), 0, "SetGlobalLock");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_NV_WriteValue, "  cmd");
+}
+
+/**
+ * Test PCR funcs
+ *
+ * TODO: check params/data read/written.
+ */
+static void PcrTest(void)
+{
+	uint8_t buf[kPcrDigestLength], buf2[kPcrDigestLength];
+
+	ResetMocks();
+	TEST_EQ(TlclPCRRead(1, buf, kPcrDigestLength), 0, "PCRRead");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_PcrRead, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclPCRRead(1, buf, kPcrDigestLength - 1), TPM_E_IOERROR,
+		"PCRRead too small");
+
+	ResetMocks();
+	TEST_EQ(TlclExtend(1, buf, buf2), 0, "Extend");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_Extend, "  cmd");
+}
+
+/**
+ * Test flags / capabilities
+ *
+ * TODO: check params/data read/written.
+ */
+static void FlagsTest(void)
+{
+	TPM_PERMANENT_FLAGS pflags;
+	TPM_STCLEAR_FLAGS vflags;
+	uint8_t disable = 0, deactivated = 0, nvlocked = 0;
+	uint32_t u;
+	uint8_t buf[32];
+
+	ResetMocks();
+	TEST_EQ(TlclGetPermanentFlags(&pflags), 0, "GetPermanentFlags");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetCapability, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclGetSTClearFlags(&vflags), 0, "GetSTClearFlags");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetCapability, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclGetFlags(NULL, NULL, NULL), 0, "GetFlags NULL");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetCapability, "  cmd");
+	ResetMocks();
+	TEST_EQ(TlclGetFlags(&disable, &deactivated, &nvlocked), 0, "GetFlags");
+
+	ResetMocks();
+	TEST_EQ(TlclGetPermissions(1, &u), 0, "GetPermissions");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetCapability, "  cmd");
+
+	ResetMocks();
+	TEST_EQ(TlclGetOwnership(buf), 0, "GetOwnership");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetCapability, "  cmd");
+}
+
+/**
+ * Test random
+ *
+ * TODO: check params/data read/written.
+ * TODO: check overflow tests.
+ */
+static void RandomTest(void)
+{
+	uint8_t buf[32];
+	uint32_t size;
+
+	ResetMocks();
+	size = sizeof(buf);
+	TEST_EQ(TlclGetRandom(buf, sizeof(buf), &size), 0, "GetRandom");
+	TEST_EQ(calls[0].req_cmd, TPM_ORD_GetRandom, "  cmd");
+	TEST_EQ(size, 0, "  size 0");
+}
+
+int main(void)
+{
+	TlclTest();
+	SendCommandTest();
+	ReadWriteTest();
+	PcrTest();
+	FlagsTest();
+	RandomTest();
+
+	return gTestSuccess ? 0 : 255;
+}