samples: code_relocation: An example for code relocation feature.

This sample provides an example for using the code relocation
feature. This example will place text,data,bss from 3 files to
various parts in the SRAM. For this a custom linker file is used
which is derived from include/arch/arm/cortex_m/scripts/linker.ld.

Signed-off-by: Varun Sharma <[email protected]>
Signed-off-by: Adithya Baglody <[email protected]>

samples/application_development/code_relocation/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.8.2)
+
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(test_relocation)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})
+
+# Code relocation feature
+zephyr_code_relocate(src/test_file1.c SRAM2)
+
+zephyr_code_relocate(src/test_file2.c SRAM)
+
+zephyr_code_relocate(src/test_file3.c SRAM2_TEXT)
+zephyr_code_relocate(src/test_file3.c SRAM_DATA)
+zephyr_code_relocate(src/test_file3.c SRAM2_BSS)
+
+zephyr_code_relocate(../../../kernel/sem.c SRAM)

samples/application_development/code_relocation/custom-sections.ld

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+    SECTION_DATA_PROLOGUE(_CUSTOM_SECTION_NAME2,,)
+        {
+		KEEP(*(".custom_section.*"));
+	} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)

samples/application_development/code_relocation/linker_arm_sram2.ld

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+/*
+ * Copyright (c) 2013-2014 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief Linker command/script file
+ *
+ * Linker script for the Cortex-M platforms.
+ */
+
+#define _LINKER
+#define _ASMLANGUAGE
+
+#include <autoconf.h>
+#include <linker/sections.h>
+#include <generated_dts_board.h>
+
+#include <linker/linker-defs.h>
+#include <linker/linker-tool.h>
+
+/** enable CONFIG_SRAM2 or any other partition in soc Kconfig,
+ * this is just an example to show relocation of code/data/bss script
+ */
+#if defined CONFIG_ARM
+  #define CONFIG_SRAM2 1
+  #define _SRAM2_DATA_SECTION_NAME  .sram2_data
+  #define _SRAM2_BSS_SECTION_NAME   .sram2_bss
+  #define _SRAM2_TEXT_SECTION_NAME  .sram2_text
+#endif
+
+#define RAM_SIZE2 (CONFIG_SRAM_SIZE * 512)
+MEMORY
+    {
+#ifdef CONFIG_SRAM2
+    SRAM2                  (wx) : ORIGIN = (CONFIG_SRAM_BASE_ADDRESS + RAM_SIZE2), LENGTH = RAM_SIZE2
+#endif
+    }
+
+#include <arch/arm/cortex_m/scripts/linker.ld>

samples/application_development/code_relocation/prj.conf

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+CONFIG_CODE_DATA_RELOCATION=y
+CONFIG_HAVE_CUSTOM_LINKER_SCRIPT=y
+CONFIG_CUSTOM_LINKER_SCRIPT="linker_arm_sram2.ld"
+CONFIG_CUSTOM_SECTIONS_LD=y

samples/application_development/code_relocation/sample.yaml

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+sample:
+  description: Code data relocation Sample
+  name: code relocation
+tests:
+  test:
+    harness: console
+    harness_config:
+      type: one_line
+      regex:
+      - "Hello World! (.*)"
+    platform_whitelist: qemu_cortex_m3 mps2_an385 sam_e70_xplained
+    tags: linker

samples/application_development/code_relocation/src/main.c

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+/*
+ * Copyright (c) 2018 Intel Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <kernel.h>
+#include <misc/printk.h>
+
+
+/* This function will allow execute from sram region.
+ * This is needed only for this sample because by default all soc will
+ * disable the execute from SRAM.
+ * An application that requires that the code be executed from SRAM will
+ *  have to configure the region appropriately in arm_mpu_regions.c.
+ */
+
+#ifdef CONFIG_ARM_MPU
+#include <arch/arm/cortex_m/cmsis.h>
+void disable_mpu_rasr_xn(void)
+{
+	u32_t index;
+	/* Kept the max index as 8(irrespective of soc) because the sram
+	 * would most likely be set at index 2.
+	 */
+	for (index = 0; index < 8; index++) {
+		MPU->RNR = index;
+		if (MPU->RASR & MPU_RASR_XN_Msk) {
+			MPU->RASR ^= MPU_RASR_XN_Msk;
+		}
+	}
+
+}
+#endif	/* CONFIG_ARM_MPU */
+
+
+extern void function_in_sram2(void);
+extern void function_in_split_multiple(void);
+
+void main(void)
+{
+#ifdef CONFIG_ARM_MPU
+	disable_mpu_rasr_xn();
+#endif	/* CONFIG_ARM_MPU */
+
+	printk("Address of main function %p\n\n", &main);
+	function_in_sram2();
+	function_in_split_multiple();
+}

samples/application_development/code_relocation/src/test_file1.c

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+/*
+ * Copyright (c) 2012-2014 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <misc/printk.h>
+
+u32_t var_sram2_data = 10U;
+u32_t var_sram2_bss;
+K_SEM_DEFINE(test, 0, 1);
+const u32_t var_sram2_rodata = 100U;
+
+__in_section(custom_section, static, var) u32_t var_custom_data = 1U;
+
+extern void function_in_sram(s32_t value);
+void function_in_custom_section(void);
+void function_in_sram2(void)
+{
+	/* Print values from sram2 */
+	printk("Address of function_in_sram2 %p\n", &function_in_sram2);
+	printk("Address of var_sram2_data %p\n", &var_sram2_data);
+	printk("Address of k_sem_give %p\n", &k_sem_give);
+	printk("Address of var_sram2_rodata %p\n", &var_sram2_rodata);
+	printk("Address of var_sram2_bss %p\n\n", &var_sram2_bss);
+
+	/* Print values from sram */
+	function_in_sram(var_sram2_data);
+
+	/* Print values which were placed using attributes */
+	printk("Address of custom_section, func placed using attributes %p\n",
+	       &function_in_custom_section);
+	printk("Address of custom_section data placed using attributes %p\n\n",
+	       &var_custom_data);
+
+	k_sem_give(&test);
+}
+
+__in_section(custom_section, static, fun) void function_in_custom_section(void)
+{
+	return;
+
+}

samples/application_development/code_relocation/src/test_file2.c

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+/*
+ * Copyright (c) 2012-2014 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <misc/printk.h>
+
+void function_in_sram(s32_t value)
+{
+	printk("Address of function_in_sram %p\n", &function_in_sram);
+	printk("Hello World! %s\n", CONFIG_BOARD);
+}

samples/application_development/code_relocation/src/test_file3.c

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+/*
+ * Copyright (c) 2012-2014 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <misc/printk.h>
+
+u32_t var_file3_sram_data = 10U;
+u32_t var_file3_sram2_bss;
+
+void function_in_split_multiple(void)
+{
+	printk("Address of function_in_split_multiple %p\n",
+	       &function_in_split_multiple);
+	printk("Address of var_file3_sram_data %p\n", &var_file3_sram_data);
+	printk("Address of var_file3_sram2_bss %p\n\n", &var_file3_sram2_bss);
+}