samples: olimex_stm32_e407: CCM usage example

Add an example program showing the use of the STM32 CCM.

Signed-off-by: Erwin Rol <[email protected]>

samples/boards/olimex_stm32_e407/ccm/CMakeLists.txt

@@ -0,0 +1,4 @@
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(NONE)
+
+target_sources(app PRIVATE src/main.c)

samples/boards/olimex_stm32_e407/ccm/README.rst

@@ -0,0 +1,146 @@
+.. _olimex_stm32_e407_ccm:
+
+Olimex STM32-E407 CCM example
+#############################
+
+Overview
+********
+
+Show usage of the Core Coupled Memory (CCM) that is available
+on several STM32 devices. The very important difference with
+normal RAM is that CCM can not be used for DMA.
+
+By prefixing a variable with __ccm_data_section, __ccm_bss_section,
+or __ccm_noinit_section those variables are placed in the CCM.
+
+The __ccm_data_section prefix should be used for variables that
+are initialized. Like the normal data section the initial
+values take up space in the FLASH image.
+
+The __ccm_bss_section prefix should be used for variables that
+should be initialized to 0. Like the normal bss section they
+do not take up FLASH space.
+
+The __ccm_noinit_section prefix should be used for variables
+that don't need to have a defined initial value (for example
+buffers that will receive data). Compared to bss or data the
+kernel does not need to initialize the noinit section making
+the startup slightly faster.
+
+To add CCM support to a board, add the following line to the
+board's DTS file ``chosen`` section:
+
+.. code-block:: console
+
+   zephyr,ccm = &ccm0;
+
+For example the olimex STM32 E407 DTS file looks like this:
+
+.. literalinclude:: ../../../../boards/arm/olimex_stm32_e407/olimex_stm32_e407.dts
+   :linenos:
+
+Building
+********
+
+.. code-block:: console
+
+   $ cd samples/boards/olimex_stm32_e407/ccm
+   $ mkdir build
+   $ cmake ../ -DBOARD=olimex_stm32_e407
+   $ make
+
+Running
+*******
+
+The first time the example is run after power on, the output will
+look like this:
+
+.. code-block:: console
+
+   ***** BOOTING ZEPHYR OS v1.10.99 - BUILD: Jan 14 2018 09:32:46 *****
+
+   CCM (Core Coupled Memory) usage example
+
+   The total used CCM area   : [0x10000000, 0x10000021)
+   Zero initialized BSS area : [0x10000000, 0x10000007)
+   Unitialized NOINIT area   : [0x10000008, 0x10000013)
+   Initialised DATA area     : [0x10000014, 0x10000021)
+   Start of DATA in FLASH    : 0x08003940
+
+   Checking initial variable values: ... PASSED
+
+   Initial variable values:
+   ccm_data_var_8  addr: 0x10000014 value: 0x12
+   ccm_data_var_16 addr: 0x10000016 value: 0x3456
+   ccm_data_var_32 addr: 0x10000018 value: 0x789abcde
+   ccm_data_array  addr: 0x1000001c size: 5 value:
+           0x11 0x22 0x33 0x44 0x55
+   ccm_bss_array addr: 0x10000000 size: 7 value:
+           0x00 0x00 0x00 0x00 0x00 0x00 0x00
+   ccm_noinit_array addr: 0x10000008 size: 11 value:
+           0xa9 0x99 0xba 0x90 0xe1 0x2a 0xba 0x93 0x4c 0xfe 0x4b
+
+   Variable values after writing:
+   ccm_data_var_8  addr: 0x10000014 value: 0xed
+   ccm_data_var_16 addr: 0x10000016 value: 0xcba9
+   ccm_data_var_32 addr: 0x10000018 value: 0x87654321
+   ccm_data_array  addr: 0x1000001c size: 5 value:
+           0xaa 0xaa 0xaa 0xaa 0xaa
+   ccm_bss_array addr: 0x10000000 size: 7 value:
+           0xbb 0xbb 0xbb 0xbb 0xbb 0xbb 0xbb
+   ccm_noinit_array addr: 0x10000008 size: 11 value:
+           0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc
+
+   Example end
+
+
+First, each CCM section is listed with its address and size. Next, some usage
+examples are shown. Note that the ``noinit`` section holds variables with
+uninitialized data. After writing to the variables, they all should hold the
+values shown above.
+
+When the board is reset (without power-cycling), the output looks like this:
+
+.. code-block:: console
+
+   ***** BOOTING ZEPHYR OS v1.10.99 - BUILD: Jan 14 2018 09:32:46 *****
+
+   CCM (Core Coupled Memory) usage example
+
+   The total used CCM area   : [0x10000000, 0x10000021)
+   Zero initialized BSS area : [0x10000000, 0x10000007)
+   Unitialized NOINIT area   : [0x10000008, 0x10000013)
+   Initialised DATA area     : [0x10000014, 0x10000021)
+   Start of DATA in FLASH    : 0x08003940
+
+   Checking initial variable values: ... PASSED
+
+   Initial variable values:
+   ccm_data_var_8  addr: 0x10000014 value: 0x12
+   ccm_data_var_16 addr: 0x10000016 value: 0x3456
+   ccm_data_var_32 addr: 0x10000018 value: 0x789abcde
+   ccm_data_array  addr: 0x1000001c size: 5 value:
+           0x11 0x22 0x33 0x44 0x55
+   ccm_bss_array addr: 0x10000000 size: 7 value:
+           0x00 0x00 0x00 0x00 0x00 0x00 0x00
+   ccm_noinit_array addr: 0x10000008 size: 11 value:
+           0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc
+
+   Variable values after writing:
+   ccm_data_var_8  addr: 0x10000014 value: 0xed
+   ccm_data_var_16 addr: 0x10000016 value: 0xcba9
+   ccm_data_var_32 addr: 0x10000018 value: 0x87654321
+   ccm_data_array  addr: 0x1000001c size: 5 value:
+           0xaa 0xaa 0xaa 0xaa 0xaa
+   ccm_bss_array addr: 0x10000000 size: 7 value:
+           0xbb 0xbb 0xbb 0xbb 0xbb 0xbb 0xbb
+   ccm_noinit_array addr: 0x10000008 size: 11 value:
+           0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc 0xcc
+
+   Example end
+
+
+The difference with the first run is that the ccm_noinit section still has the
+values from the last write. It is important to notice that this is not guaranteed,
+it still should be considered uninitialized leftover data.
+

samples/boards/olimex_stm32_e407/ccm/prj.conf

@@ -0,0 +1,17 @@
+CONFIG_BOOT_BANNER=y
+CONFIG_CONSOLE=y
+CONFIG_CONSOLE_INPUT_MAX_LINE_LEN=128
+CONFIG_CONSOLE_HAS_DRIVER=y
+CONFIG_CONSOLE_HANDLER=y
+CONFIG_UART_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_UART_STM32=y
+CONFIG_UART_STM32_PORT_1=y
+CONFIG_PRINTK=y
+CONFIG_STDOUT_CONSOLE=y
+CONFIG_EARLY_CONSOLE=y
+CONFIG_SYS_LOG=y
+CONFIG_SYS_LOG_SHOW_TAGS=y
+CONFIG_SYS_LOG_SHOW_COLOR=y
+CONFIG_SYS_LOG_DEFAULT_LEVEL=0
+CONFIG_SYS_LOG_OVERRIDE_LEVEL=0

samples/boards/olimex_stm32_e407/ccm/sample.yaml

@@ -0,0 +1,8 @@
+sample:
+  name: CCM usages example on Olimex STM32-E407
+tests:
+  test:
+    build_only: true
+    platform_whitelist: olimex_stm32_e407
+    tags: samples
+

samples/boards/olimex_stm32_e407/ccm/src/main.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2017 Erwin Rol <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <device.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <linker/linker-defs.h>
+
+#define CCM_DATA_VAR_8_VAL	0x12
+#define CCM_DATA_VAR_16_VAL	0x3456
+#define CCM_DATA_VAR_32_VAL	0x789ABCDE
+
+#define CCM_DATA_ARRAY_SIZE	5
+#define CCM_BSS_ARRAY_SIZE	7
+#define CCM_NOINIT_ARRAY_SIZE	11
+
+#define CCM_DATA_ARRAY_VAL(i)	(((i)+1)*0x11)
+
+u8_t __ccm_data_section ccm_data_var_8 = CCM_DATA_VAR_8_VAL;
+u16_t __ccm_data_section ccm_data_var_16 = CCM_DATA_VAR_16_VAL;
+u32_t __ccm_data_section ccm_data_var_32 = CCM_DATA_VAR_32_VAL;
+
+u8_t __ccm_data_section ccm_data_array[CCM_DATA_ARRAY_SIZE] = {
+	CCM_DATA_ARRAY_VAL(0),
+	CCM_DATA_ARRAY_VAL(1),
+	CCM_DATA_ARRAY_VAL(2),
+	CCM_DATA_ARRAY_VAL(3),
+	CCM_DATA_ARRAY_VAL(4),
+};
+u8_t __ccm_bss_section ccm_bss_array[CCM_BSS_ARRAY_SIZE];
+u8_t __ccm_noinit_section ccm_noinit_array[CCM_NOINIT_ARRAY_SIZE];
+
+void print_array(const void *array, u32_t size)
+{
+	int i;
+
+	for (i = 0; i < size; i++) {
+		printf("0x%02x ", ((const char *)array)[i]);
+	}
+}
+
+void check_initial_var_values(void)
+{
+	int i;
+	int check_failed = 0;
+
+	printf("\nChecking initial variable values: ... ");
+
+	if (ccm_data_var_8 != CCM_DATA_VAR_8_VAL) {
+		check_failed = 1;
+		printf("\nccm_data_var_8 incorrect: 0x%02x should be 0x%02x",
+			ccm_data_var_8, CCM_DATA_VAR_8_VAL);
+	}
+
+	if (ccm_data_var_16 != CCM_DATA_VAR_16_VAL) {
+		check_failed = 1;
+		printf("\nccm_data_var_16 incorrect: 0x%04x should be 0x%04x",
+			ccm_data_var_16, CCM_DATA_VAR_16_VAL);
+	}
+
+	if (ccm_data_var_32 != CCM_DATA_VAR_32_VAL) {
+		check_failed = 1;
+		printf("\nccm_data_var_32 incorrect: 0x%08x should be 0x%08x",
+			ccm_data_var_32, CCM_DATA_VAR_32_VAL);
+	}
+
+	for (i = 0; i < CCM_DATA_ARRAY_SIZE; i++) {
+		if (ccm_data_array[i] != CCM_DATA_ARRAY_VAL(i)) {
+			check_failed = 1;
+			printf("\nccm_data_array[%d] incorrect: "
+				"0x%02x should be 0x%02x",
+				i, ccm_data_array[i], CCM_DATA_ARRAY_VAL(i));
+		}
+	}
+
+	for (i = 0; i < CCM_BSS_ARRAY_SIZE; i++) {
+		if (ccm_bss_array[i] != 0x00) {
+			check_failed = 1;
+			printf("\nccm_bss_array[%d] incorrect: "
+				"0x%02x should be 0x00",
+				i, ccm_bss_array[i]);
+		}
+	}
+
+	if (!check_failed) {
+		printf("PASSED\n");
+	}
+}
+
+void print_var_values(void)
+{
+	printf("ccm_data_var_8  addr: %p value: 0x%02x\n",
+		&ccm_data_var_8, ccm_data_var_8);
+	printf("ccm_data_var_16 addr: %p value: 0x%04x\n",
+		&ccm_data_var_16, ccm_data_var_16);
+	printf("ccm_data_var_32 addr: %p value: 0x%08x\n",
+		&ccm_data_var_32, ccm_data_var_32);
+	printf("ccm_data_array  addr: %p size: %d value:\n\t",
+		ccm_data_array, sizeof(ccm_data_array));
+	print_array(ccm_data_array, sizeof(ccm_data_array));
+	printf("\nccm_bss_array addr: %p size: %d value:\n\t",
+		ccm_bss_array, sizeof(ccm_bss_array));
+	print_array(ccm_bss_array, sizeof(ccm_bss_array));
+	printf("\nccm_noinit_array addr: %p size: %d value:\n\t",
+		ccm_noinit_array, sizeof(ccm_noinit_array));
+	print_array(ccm_noinit_array, sizeof(ccm_noinit_array));
+	printf("\n");
+}
+
+void main(void)
+{
+	printf("\nCCM (Core Coupled Memory) usage example\n\n");
+
+	printf("The total used CCM area   : [%p, %p)\n",
+		&__ccm_start, &__ccm_end);
+	printf("Zero initialized BSS area : [%p, %p)\n",
+		&__ccm_bss_start, &__ccm_bss_end);
+	printf("Unitialized NOINIT area   : [%p, %p)\n",
+		&__ccm_noinit_start, &__ccm_noinit_end);
+	printf("Initialised DATA area     : [%p, %p)\n",
+		&__ccm_data_start, &__ccm_data_end);
+	printf("Start of DATA in FLASH    : %p\n",
+		&__ccm_data_rom_start);
+
+	check_initial_var_values();
+
+	printf("\nInitial variable values:\n");
+	print_var_values();
+
+	ccm_data_var_8  = ~CCM_DATA_VAR_8_VAL;
+	ccm_data_var_16 = ~CCM_DATA_VAR_16_VAL;
+	ccm_data_var_32 = ~CCM_DATA_VAR_32_VAL;
+
+	memset(ccm_data_array, 0xAA, sizeof(ccm_data_array));
+	memset(ccm_bss_array, 0xBB, sizeof(ccm_bss_array));
+	memset(ccm_noinit_array, 0xCC, sizeof(ccm_noinit_array));
+
+	printf("\nVariable values after writing:\n");
+	print_var_values();
+
+	printf("\nExample end\n");
+}
+

samples/boards/olimex_stm32_e407/olimex_stm32_e407.rst

@@ -0,0 +1,10 @@
+.. _olimex_stm32_e407-samples:
+
+Olimex STM32-E407 Samples
+#########################
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   **/*