zephyr: improve shimming for unit tests

* Move the Ztest-related definitions out of test_util and into a
shim version of that header.
* Add definitions for EC unit tests declaring additional tasks so
the task shim will pick them up correctly.
* Copy the prng functions into the shimmed test_util.

BUG=None
BRANCH=None
TEST=`make clobber ; make buildall -j ; make runhosttests`
Then build the unit tests that have been ported to Ztest,
e.g. `zmake configure --test -B build/base32 zephyr/test/base32`
for `base32`, `crc`, `hooks`, `i2c`,and  `tasks`

Signed-off-by: Paul Fagerburg <pfagerburg@google.com>
Change-Id: Ia2873a4c2028fcb6960e80f683189def2f3a228d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2605231
Tested-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Commit-Queue: Paul Fagerburg <pfagerburg@chromium.org>
Auto-Submit: Paul Fagerburg <pfagerburg@chromium.org>

5 files changed, 81 insertions, 24 deletions

diff --git a/include/test_util.h b/include/test_util.h
index d33691a626..ef2ec0a48a 100644
--- a/include/test_util.h
+++ b/include/test_util.h
@@ -8,24 +8,6 @@
 #ifndef __CROS_EC_TEST_UTIL_H
 #define __CROS_EC_TEST_UTIL_H
 
-#ifdef CONFIG_ZTEST
-
-#include <ztest.h>
-
-/*
- * We need these macros so that a test can be built for either Ztest or the
- * EC test framework.
- *
- * Ztest unit tests are void and do not return a value. In the EC framework,
- * if none of the assertions fail, the test is supposed to return EC_SUCCESS,
- * so just define that as empty and `return EC_SUCCESS;` will get pre-processed
- * into `return ;`
- */
-#define EC_TEST_RETURN void
-#define EC_SUCCESS
-
-#else /* CONFIG_ZTEST */
-
 #include "common.h"
 #include "console.h"
 #include "stack_trace.h"
@@ -329,6 +311,9 @@ int test_attach_i2c(const int port, const uint16_t addr_flags);
  */
 #define EC_TEST_RETURN int
 
+/* An EC task only has one void parameter */
+#define TASK_PARAMS void *p1
+
 /*
  * Map the Ztest assertions onto EC assertions. There are two significant
  * issues here.
@@ -354,6 +339,4 @@ int test_attach_i2c(const int port, const uint16_t addr_flags);
 #define zassert_mem_equal(buf, exp, size, msg, ...) \
 	TEST_ASSERT_ARRAY_EQ(buf, exp, size)
 
-#endif /* CONFIG_ZTEST */
-
 #endif /* __CROS_EC_TEST_UTIL_H */
diff --git a/zephyr/shim/include/shimmed_task_id.h b/zephyr/shim/include/shimmed_task_id.h
index fd23ad47de..29b6d675b6 100644
--- a/zephyr/shim/include/shimmed_task_id.h
+++ b/zephyr/shim/include/shimmed_task_id.h
@@ -39,17 +39,29 @@ typedef uint8_t task_id_t;
 				   CONFIG_TASK_KEYSCAN_STACK_SIZE)), ())
 #elif defined(CONFIG_HAS_TEST_TASKS)
 #include "shimmed_test_tasks.h"
-#ifndef CROS_EC_TASK_LIST
-#error "shimmed_test_tasks.h should define CROS_EC_TASK_LIST"
-#endif /* !CROS_EC_TASK_LIST */
+/*
+ * There are two different ways to define a task list (because historical
+ * reasons). Applications use CROS_EC_TASK_LIST to define their tasks, while
+ * unit tests that need additional tasks use CONFIG_TEST_TASK_LIST. For
+ * shimming a unit test, define CROS_EC_TASk_LIST as whatever
+ * CONFIG_TEST_TASK_LIST expands to.
+ */
+#if defined(CONFIG_TEST_TASK_LIST) && !defined(CROS_EC_TASK_LIST)
+#define CROS_EC_TASK_LIST CONFIG_TEST_TASK_LIST
+#endif /* CONFIG_TEST_TASK_LIST && !CROS_EC_TASK_LIST */
 #endif /* !CONFIG_ZTEST */
 
 #ifndef CROS_EC_TASK_LIST
 #define CROS_EC_TASK_LIST
 #endif /* CROS_EC_TASK_LIST */
 
-/* Define the task_ids globally for all shimmed platform/ec code to use */
+/*
+ * Define the task_ids globally for all shimmed platform/ec code to use.
+ * Note that unit test task lists use TASK_TEST, which we can just alias
+ * into a regular CROS_EC_TASK.
+ */
 #define CROS_EC_TASK(name, ...) TASK_ID_##name,
+#define TASK_TEST(name, ...) CROS_EC_TASK(name)
 enum {
 	TASK_ID_IDLE = -1, /* We don't shim the idle task */
 	CROS_EC_TASK_LIST
@@ -57,5 +69,6 @@ enum {
 	TASK_ID_INVALID = 0xff, /* Unable to find the task */
 };
 #undef CROS_EC_TASK
+#undef TASK_TEST
 
 #endif /* __CROS_EC_SHIMMED_TASK_ID_H */
diff --git a/zephyr/shim/include/test_util.h b/zephyr/shim/include/test_util.h
new file mode 100644
index 0000000000..cc28bcf697
--- /dev/null
+++ b/zephyr/shim/include/test_util.h
@@ -0,0 +1,34 @@
+/* Copyright 2020 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.
+ */
+
+/* Various utility for unit testing */
+
+#ifndef __CROS_EC_TEST_UTIL_H
+#define __CROS_EC_TEST_UTIL_H
+
+#include <ztest.h>
+#include "ec_tasks.h"
+
+/*
+ * We need these macros so that a test can be built for either Ztest or the
+ * EC test framework.
+ *
+ * Ztest unit tests are void and do not return a value. In the EC framework,
+ * if none of the assertions fail, the test is supposed to return EC_SUCCESS,
+ * so just define that as empty and `return EC_SUCCESS;` will get pre-processed
+ * into `return ;`
+ */
+#define EC_TEST_RETURN void
+#define EC_SUCCESS
+#define test_pass ztest_test_pass
+
+/* Zephyr threads have three void pointers as parameters */
+#define TASK_PARAMS void *p1, void *p2, void *p3
+
+uint32_t prng(uint32_t seed);
+
+uint32_t prng_no_seed(void);
+
+#endif /* __CROS_EC_TEST_UTIL_H */
diff --git a/zephyr/shim/src/tasks.c b/zephyr/shim/src/tasks.c
index 45450076ee..8ce84adce6 100644
--- a/zephyr/shim/src/tasks.c
+++ b/zephyr/shim/src/tasks.c
@@ -17,13 +17,17 @@ BUILD_ASSERT(CONFIG_NUM_PREEMPT_PRIORITIES + 1 >= TASK_ID_COUNT,
 /* Declare all task stacks here */
 #define CROS_EC_TASK(name, e, p, size) \
 	K_THREAD_STACK_DEFINE(name##_STACK, size);
+#define TASK_TEST(name, e, p, size) CROS_EC_TASK(name, e, p, size)
 CROS_EC_TASK_LIST
 #undef CROS_EC_TASK
+#undef TASK_TEST
 
 /* Forward declare all task entry point functions */
 #define CROS_EC_TASK(name, entry, ...) void entry(void *p);
+#define TASK_TEST(name, entry, ...) CROS_EC_TASK(name, entry)
 CROS_EC_TASK_LIST
 #undef CROS_EC_TASK
+#undef TASK_TEST
 
 /** Context for each CROS EC task that is run in its own zephyr thread */
 struct task_ctx {
@@ -55,8 +59,11 @@ struct task_ctx {
 		.stack_size = _size,                   \
 		.name = #_name,                        \
 	},
+#define TASK_TEST(_name, _entry, _parameter, _size) \
+	CROS_EC_TASK(_name, _entry, _parameter, _size)
 static struct task_ctx shimmed_tasks[] = { CROS_EC_TASK_LIST };
 #undef CROS_EC_TASK
+#undef TASK_TEST
 
 task_id_t task_get_current(void)
 {
diff --git a/zephyr/shim/src/test_util.c b/zephyr/shim/src/test_util.c
new file mode 100644
index 0000000000..28be596043
--- /dev/null
+++ b/zephyr/shim/src/test_util.c
@@ -0,0 +1,20 @@
+/* Copyright 2020 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.
+ *
+ * Test utilities.
+ */
+
+#include "test_util.h"
+
+/* Linear congruential pseudo random number generator */
+uint32_t prng(uint32_t seed)
+{
+	return 22695477 * seed + 1;
+}
+
+uint32_t prng_no_seed(void)
+{
+	static uint32_t seed = 0x1234abcd;
+	return seed = prng(seed);
+}