Inline functions offer a trade-off between code size and performance. By default, the compiler decides during optimization whether to inline code or not. The __INLINE attribute gives the compiler an hint to inline this function. Still, the compiler may decide not to inline the function. As the function is global an callable function is also generated.
-Code Example:
+Code Example:
Informs the compiler that the function does not return. The compiler can then perform optimizations by removing code that is never reached.
-Code Example:
+Code Example:
Specifies that a type must have the smallest possible alignment.
-Code Example:
+Code Example:
Specifies that a structure must have the smallest possible alignment.
-Code Example:
+Code Example:
| #define __PROGRAM_START | +
Gives the function to be jumped into right after low level initialization, i.e. SystemInit. This is compiler and library specific. CMSIS specifies common default for supported compilers.
+Code Example:
+The __RESTRICT keyword corresponds to the restrict pointer qualifier that has been introduced in C99. __RESTRICT is a hint to the compiler that enables additional optimizations. It specifies that for the lifetime of the pointer, only the pointer itself or a value directly derived from it (such as pointer + 1) is used to access the object. The compiler may therefore ignore potential pointer aliasing effects and perform additional optimizations.
Code Example:
+Code Example:
| #define __STACK_LIMIT | +
The address of the specified symbol is used to initialize the main stack pointer limit (MSPLIM on Armv8-M) during low level init. This is compiler/linker specific. CMSIS specifies common default for supported compilers.
+Code Example:
+ +Defines a static function that should be always inlined by the compiler.
Code Example:
+Code Example:
Defines a static function that may be inlined by the compiler. If the compiler generates inline code for all calls to this functions, no additional function implementation is generated which may further optimize space.
-Code Example:
+Code Example:
Defines a pointer to a uint16_t from an address that does not need to be aligned. This can then be used in read operations. The compiler will generate the appropriate access (aligned or non-aligned) depending on the underlying Arm processor core and compiler settings.
-Code Example:
+Code Example:
Defines a pointer to a uint16_t from an address that does not need to be aligned. This can then be used in write operations. The compiler will generate the appropriate access (aligned or non-aligned) depending on the underlying Arm processor core and compiler settings.
-Code Example:
+Code Example:
Defines a pointer to a uint32_t from an address that does not need to be aligned. This can then be used in read/write operations. The compiler will generate the appropriate access (aligned or non-aligned) depending on the underlying Arm processor core and compiler settings.
-Code Example:
+Code Example:
Defines a pointer to a uint32_t from an address that does not need to be aligned. This can then be used in read operations. The compiler will generate the appropriate access (aligned or non-aligned) depending on the underlying Arm processor core and compiler settings.
-Code Example:
+Code Example:
Defines a pointer to a uint32_t from an address that does not need to be aligned. This can then be used in write operations. The compiler will generate the appropriate access (aligned or non-aligned) depending on the underlying Arm processor core and compiler settings.
-Code Example:
+Code Example:
Definitions tagged with __USED in the source code should be not removed by the linker when detected as unused.
-Code Example:
+Code Example:
+| #define __VECTOR_TABLE | +
The given name is used for defining the static (compiler time) interrupt vector table. The name must comply with any compiler/linker conventions, e.g. if used for vector table relocation or debugger awareness. CMSIS specifies common default for supported compilers.
+| #define __VECTOR_TABLE_ATTRIBUTE | +
The given decl specs are used for defining the static (compiler time) interrupt vector table, e.g. to mark the table as used and force it into a specific linker section. CMSIS specifies common default for supported compilers.
+Functions defined with __WEAK export their symbols weakly. A weakly defined function behaves like a normally defined function unless a non-weakly defined function of the same name is linked into the same image. If both a non-weakly defined function and a weakly defined function exist in the same image then all calls to the function resolve to call the non-weak function.
Functions declared with __WEAK and then defined without __WEAK behave as non-weak functions.
-Code Example:
+Code Example:
|
+
+ CMSIS-Core (Cortex-M)
+ Version 5.3.0
+
+ CMSIS-Core support for Cortex-M processor-based devices
+ |
+
+
+
+ 
+
+ The Startup File startup_<device>.c contains:
+The file exists for each supported toolchain and is the only tool-chain specific CMSIS file.
+To adapt the file to a new device only the interrupt vector table needs to be extended with the device-specific interrupt handlers. The naming convention for the interrupt handler names are <interrupt_name>_IRQHandler. This table needs to be consistent with IRQn_Type that defines all the IRQ numbers for each interrupt.
+Example:
+The following example shows the extension of the interrupt vector table for the LPC1100 device family.
+A compiler agnostic startup_Device.c Template File for an Armv7-M processor like Cortex-M3 is shown below. The C startup file relys on certain compiler specific preprocessor defines specified in CMSIS compiler headers:
+ +/******************************************************************************
+ * @file startup_Device.c
+ * @brief CMSIS-Core(M) Device Startup File for <Device>
+ * @version V2.0.0
+ * @date 20. May 2019
+ ******************************************************************************/
+/*
+ * Copyright (c) 2009-2019 Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "<Device>.h"
+
+/*----------------------------------------------------------------------------
+ Exception / Interrupt Handler Function Prototype
+ *----------------------------------------------------------------------------*/
+typedef void( *pFunc )( void );
+
+/*----------------------------------------------------------------------------
+ External References
+ *----------------------------------------------------------------------------*/
+extern uint32_t __INITIAL_SP;
+
+extern __NO_RETURN void __PROGRAM_START(void);
+
+/*----------------------------------------------------------------------------
+ Internal References
+ *----------------------------------------------------------------------------*/
+void __NO_RETURN Default_Handler(void);
+void __NO_RETURN Reset_Handler (void);
+
+/*----------------------------------------------------------------------------
+ Exception / Interrupt Handler
+ *----------------------------------------------------------------------------*/
+/* Exceptions */
+void NMI_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void HardFault_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void MemManage_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void BusFault_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void UsageFault_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void SVC_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void DebugMon_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void PendSV_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void SysTick_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+
+void Interrupt0_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt1_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt2_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt3_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt4_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt5_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt6_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt7_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt8_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+void Interrupt9_Handler (void) __attribute__ ((weak, alias("Default_Handler")));
+
+
+/*----------------------------------------------------------------------------
+ Exception / Interrupt Vector table
+ *----------------------------------------------------------------------------*/
+extern const pFunc __VECTOR_TABLE[240];
+ const pFunc __VECTOR_TABLE[240] __VECTOR_TABLE_ATTRIBUTE = {
+ (pFunc)(&__INITIAL_SP), /* Initial Stack Pointer */
+ Reset_Handler, /* Reset Handler */
+ NMI_Handler, /* -14 NMI Handler */
+ HardFault_Handler, /* -13 Hard Fault Handler */
+ MemManage_Handler, /* -12 MPU Fault Handler */
+ BusFault_Handler, /* -11 Bus Fault Handler */
+ UsageFault_Handler, /* -10 Usage Fault Handler */
+ 0, /* Reserved */
+ 0, /* Reserved */
+ 0, /* Reserved */
+ 0, /* Reserved */
+ SVC_Handler, /* -5 SVCall Handler */
+ DebugMon_Handler, /* -4 Debug Monitor Handler */
+ 0, /* Reserved */
+ PendSV_Handler, /* -2 PendSV Handler */
+ SysTick_Handler, /* -1 SysTick Handler */
+
+ /* Interrupts */
+ Interrupt0_Handler, /* 0 Interrupt 0 */
+ Interrupt1_Handler, /* 1 Interrupt 1 */
+ Interrupt2_Handler, /* 2 Interrupt 2 */
+ Interrupt3_Handler, /* 3 Interrupt 3 */
+ Interrupt4_Handler, /* 4 Interrupt 4 */
+ Interrupt5_Handler, /* 5 Interrupt 5 */
+ Interrupt6_Handler, /* 6 Interrupt 6 */
+ Interrupt7_Handler, /* 7 Interrupt 7 */
+ Interrupt8_Handler, /* 8 Interrupt 8 */
+ Interrupt9_Handler /* 9 Interrupt 9 */
+ /* Interrupts 10 .. 223 are left out */
+};
+
+/*----------------------------------------------------------------------------
+ Reset Handler called on controller reset
+ *----------------------------------------------------------------------------*/
+void Reset_Handler(void)
+{
+ SystemInit(); /* CMSIS System Initialization */
+ __PROGRAM_START(); /* Enter PreMain (C library entry point) */
+}
+
+/*----------------------------------------------------------------------------
+ Default Handler for Exceptions / Interrupts
+ *----------------------------------------------------------------------------*/
+void Default_Handler(void)
+{
+ while(1);
+}
+