esp32: Add SPIRAM test application

Adds application to test SPIRAM

Signed-off-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>

samples/boards/esp32/spiram_test/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.13.1)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(spiram_test)
+
+target_sources(app PRIVATE src/main.c)

samples/boards/esp32/spiram_test/README.rst

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+.. _spiram_test:
+
+Espressif ESP32 SPIRAM test
+###########################
+
+Overview
+********
+
+This sample allocates memory from internal DRAM and SPIRAM by calling `k_malloc`, frees
+allocated memory by calling `k_free` and checks if memory can be allocated again.
+Capability of allocated memory is decided by ESP_HEAP_MIN_EXTRAM_THRESHOLD. If size is less than
+ESP_HEAP_MIN_EXTRAM_THRESHOLD, memory is allocated from internal DRAM. If size is greater than
+ESP_HEAP_MIN_EXTRAM_THRESHOLD, memory is allocated from SPIRAM.
+
+Building and Running
+********************
+
+Make sure you have the ESP32_WROVER_KIT connected over USB port.
+
+.. code-block:: console
+
+   west build -b esp32 samples/boards/esp32/spiram_test
+   west flash --esp-device /dev/ttyUSB0
+
+Sample Output
+=============
+
+To check output of this sample, any serial console program can be used (i.e. on Linux minicom, putty, screen, etc)
+This example uses ``picocom`` on the serial port ``/dev/ttyUS0``:
+
+.. code-block:: console
+
+    mem test ok! 209
+    SPIRAM mem test pass
+    mem test ok! 194
+    Internal mem test pass

samples/boards/esp32/spiram_test/prj.conf

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+CONFIG_ESP_SPIRAM=y
+CONFIG_ESP_HEAP_MIN_EXTRAM_THRESHOLD=2048
+CONFIG_HEAP_MEM_POOL_SIZE=98304
+CONFIG_ESP_HEAP_MEM_POOL_REGION_1_SIZE=100000
+CONFIG_ESP_HEAP_SEARCH_ALL_REGIONS=n

samples/boards/esp32/spiram_test/sample.yaml

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+sample:
+  description: Application to test memory allocation from SPIRAM
+  name: spiram_test
+tests:
+  sample.board.esp32:
+    platform_allow: esp32
+    tags: esp32

samples/boards/esp32/spiram_test/src/main.c

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+/*
+ * Copyright (c) 2021 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <sys/printk.h>
+#include <soc/soc_memory_layout.h>
+
+static int check_allocated_memory(int *m1, size_t size)
+{
+	int ret = 0;
+
+	if (size < CONFIG_ESP_HEAP_MIN_EXTRAM_THRESHOLD) {
+		if (!esp_ptr_internal(m1)) {
+			printk("Memory allocation is not within"
+					" specified bounds\n");
+			ret = -1;
+		}
+	} else {
+		if (!esp_ptr_external_ram(m1)) {
+			printk("Memory allocation is not within"
+					" specified bounds\n");
+			ret = -1;
+		}
+	}
+	return ret;
+}
+
+static int test_heap_caps(size_t size)
+{
+	int *m1, *m2;
+	int cnt = 0, err = 0;
+
+	m2 = NULL;
+	/* Allocated as much as we can, and create linked list */
+	while ((m1 = k_malloc(size))) {
+		if (check_allocated_memory(m1, size) == -1) {
+			err = -1;
+			goto ret;
+		}
+		*(int **) m1 = m2;
+		m2 = m1;
+		cnt++;
+	}
+
+	/* Free all allocated memory */
+	while (m2) {
+		m1 = *(int **) m2;
+		k_free(m2);
+		m2 = m1;
+	}
+	/* Confirm that allocation can succeed now */
+	m1 = k_malloc(size);
+	if (check_allocated_memory(m1, size) == -1) {
+		err = -1;
+		goto ret;
+	}
+	if (!m1) {
+		err = -1;
+	} else {
+		k_free(m1);
+		printk("mem test ok! %d\n", cnt);
+	}
+ret:
+	return err;
+}
+
+void main(void)
+{
+	int err = test_heap_caps(10001);
+
+	if (err == -1) {
+		printk("SPIRAM mem test failed\n");
+	} else {
+		printk("SPIRAM mem test pass\n");
+	}
+
+	err = test_heap_caps(1001);
+	if (err == -1) {
+		printk("Internal mem test failed\n");
+	} else {
+		printk("Internal mem test pass\n");
+	}
+}