“periph_blinky”を読む(cr_startup_lpc175x_6x.c編)

最後にcr_startup_lpc175x_6x.c

//*****************************************************************************
//   +--+
//   | ++----+
//   +-++    |
//     |     |
//   +-+--+  |
//   | +--+--+
//   +----+    Copyright (c) 2012 Code Red Technologies Ltd.
//
// LPC8xx Microcontroller Startup code for use with Red Suite
//
// Version : 121107
//
// Software License Agreement
//
// The software is owned by Code Red Technologies and/or its suppliers, and is
// protected under applicable copyright laws.  All rights are reserved.  Any
// use in violation of the foregoing restrictions may subject the user to criminal
// sanctions under applicable laws, as well as to civil liability for the breach
// of the terms and conditions of this license.
//
// THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// USE OF THIS SOFTWARE FOR COMMERCIAL DEVELOPMENT AND/OR EDUCATION IS SUBJECT
// TO A CURRENT END USER LICENSE AGREEMENT (COMMERCIAL OR EDUCATIONAL) WITH
// CODE RED TECHNOLOGIES LTD.
//
//*****************************************************************************
#if defined (__cplusplus)
#ifdef __REDLIB__
#error Redlib does not support C++
#else
//*****************************************************************************
//
// The entry point for the C++ library startup
//
//*****************************************************************************
extern "C" {
	extern void __libc_init_array(void);
}
#endif
#endif

#define WEAK __attribute__ ((weak))
#define ALIAS(f) __attribute__ ((weak, alias (#f)))

#if defined (__USE_CMSIS)
#include "LPC8xx.h"
#endif

//*****************************************************************************
#if defined (__cplusplus)
extern "C" {
#endif

//*****************************************************************************
//
// Forward declaration of the default handlers. These are aliased.
// When the application defines a handler (with the same name), this will
// automatically take precedence over these weak definitions
//
//*****************************************************************************
     void ResetISR(void);
WEAK void NMI_Handler(void);
WEAK void HardFault_Handler(void);
WEAK void SVC_Handler(void);
WEAK void PendSV_Handler(void);
WEAK void SysTick_Handler(void);
WEAK void IntDefaultHandler(void);

//*****************************************************************************
//
// Forward declaration of the specific IRQ handlers. These are aliased
// to the IntDefaultHandler, which is a 'forever' loop. When the application
// defines a handler (with the same name), this will automatically take
// precedence over these weak definitions
//
//*****************************************************************************
void SPI0_IRQHandler(void) ALIAS(IntDefaultHandler);
void SPI1_IRQHandler(void) ALIAS(IntDefaultHandler);
void UART0_IRQHandler(void) ALIAS(IntDefaultHandler);
void UART1_IRQHandler(void) ALIAS(IntDefaultHandler);
void UART2_IRQHandler(void) ALIAS(IntDefaultHandler);
void I2C_IRQHandler(void) ALIAS(IntDefaultHandler);
void SCT_IRQHandler(void) ALIAS(IntDefaultHandler);
void MRT_IRQHandler(void) ALIAS(IntDefaultHandler);
void CMP_IRQHandler(void) ALIAS(IntDefaultHandler);
void WDT_IRQHandler(void) ALIAS(IntDefaultHandler);
void BOD_IRQHandler(void) ALIAS(IntDefaultHandler);
void WKT_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT0_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT1_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT2_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT3_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT4_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT5_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT6_IRQHandler(void) ALIAS(IntDefaultHandler);
void PININT7_IRQHandler(void) ALIAS(IntDefaultHandler);
//*****************************************************************************
//
// The entry point for the application.
// __main() is the entry point for Redlib based applications
// main() is the entry point for Newlib based applications
//
//*****************************************************************************
#if defined (__REDLIB__)
extern void __main(void);
#endif
extern int main(void);
//*****************************************************************************
//
// External declaration for the pointer to the stack top from the Linker Script
//
//*****************************************************************************
extern void _vStackTop(void);

//*****************************************************************************
#if defined (__cplusplus)
} // extern "C"
#endif
//*****************************************************************************
//
// The vector table.
// This relies on the linker script to place at correct location in memory.
//
//*****************************************************************************
extern void (* const g_pfnVectors[])(void);
__attribute__ ((section(".isr_vector")))
void (* const g_pfnVectors[])(void) = {
	// Core Level - CM0plus
	&_vStackTop, // The initial stack pointer
	ResetISR,							// The reset handler
	NMI_Handler,							// The NMI handler
	HardFault_Handler,						// The hard fault handler
	0,								// Reserved
	0,								// Reserved
	0,								// Reserved
	0,								// Reserved
	0,								// Reserved
	0,								// Reserved
	0,								// Reserved
	SVC_Handler,							// SVCall handler
	0,								// Reserved
	0,								// Reserved
	PendSV_Handler,							// The PendSV handler
	SysTick_Handler,						// The SysTick handler

	// Chip Level - LPC8xx
    SPI0_IRQHandler,                         // SPI0 controller
    SPI1_IRQHandler,                         // SPI1 controller
    0,                                       // Reserved
    UART0_IRQHandler,                        // UART0
    UART1_IRQHandler,                        // UART1
    UART2_IRQHandler,                        // UART2
    0,                                       // Reserved
    0,                                       // Reserved
    I2C_IRQHandler,                          // I2C controller
    SCT_IRQHandler,                          // Smart Counter Timer
    MRT_IRQHandler,                          // Multi-Rate Timer
    CMP_IRQHandler,                          // Comparator
    WDT_IRQHandler,                          // PIO1 (0:11)
    BOD_IRQHandler,                          // Brown Out Detect
    0,                                       // Reserved
    WKT_IRQHandler,                          // Wakeup timer
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    0,                                       // Reserved
    PININT0_IRQHandler,                      // PIO INT0
    PININT1_IRQHandler,                      // PIO INT1
    PININT2_IRQHandler,                      // PIO INT2
    PININT3_IRQHandler,                      // PIO INT3
    PININT4_IRQHandler,                      // PIO INT4
    PININT5_IRQHandler,                      // PIO INT5
    PININT6_IRQHandler,                      // PIO INT6
    PININT7_IRQHandler,                      // PIO INT7

}; /* End of g_pfnVectors */ 

//*****************************************************************************
// Functions to carry out the initialization of RW and BSS data sections. These
// are written as separate functions rather than being inlined within the
// ResetISR() function in order to cope with MCUs with multiple banks of
// memory.
//*****************************************************************************
__attribute__ ((section(".after_vectors")))
void data_init(unsigned int romstart, unsigned int start, unsigned int len) {
	unsigned int *pulDest = (unsigned int*) start;
	unsigned int *pulSrc = (unsigned int*) romstart;
	unsigned int loop;
	for (loop = 0; loop < len; loop = loop + 4)
		*pulDest++ = *pulSrc++;
}

__attribute__ ((section(".after_vectors")))
void bss_init(unsigned int start, unsigned int len) {
	unsigned int *pulDest = (unsigned int*) start;
	unsigned int loop;
	for (loop = 0; loop < len; loop = loop + 4)
		*pulDest++ = 0;
}

//*****************************************************************************
// The following symbols are constructs generated by the linker, indicating
// the location of various points in the "Global Section Table". This table is
// created by the linker via the Code Red managed linker script mechanism. It
// contains the load address, execution address and length of each RW data
// section and the execution and length of each BSS (zero initialized) section.
//*****************************************************************************
extern unsigned int __data_section_table;
extern unsigned int __data_section_table_end;
extern unsigned int __bss_section_table;
extern unsigned int __bss_section_table_end;


//*****************************************************************************
// Reset entry point for your code.
// Sets up a simple runtime environment and initializes the C/C++
// library.
//*****************************************************************************
__attribute__ ((section(".after_vectors")))
void
ResetISR(void) {

    //
    // Copy the data sections from flash to SRAM.
    //
	unsigned int LoadAddr, ExeAddr, SectionLen;
	unsigned int *SectionTableAddr;

	// Load base address of Global Section Table
	SectionTableAddr = &__data_section_table;

    // Copy the data sections from flash to SRAM.
	while (SectionTableAddr < &__data_section_table_end) {
		LoadAddr = *SectionTableAddr++;
		ExeAddr = *SectionTableAddr++;
		SectionLen = *SectionTableAddr++;
		data_init(LoadAddr, ExeAddr, SectionLen);
	}
	// At this point, SectionTableAddr = &__bss_section_table;
	// Zero fill the bss segment
	while (SectionTableAddr < &__bss_section_table_end) {
		ExeAddr = *SectionTableAddr++;
		SectionLen = *SectionTableAddr++;
		bss_init(ExeAddr, SectionLen);
	}
#ifdef __USE_CMSIS
	SystemInit();
#endif

#if defined (__cplusplus)
	//
	// Call C++ library initialisation
	//
	__libc_init_array();
#endif

#if defined (__REDLIB__)
	// Call the Redlib library, which in turn calls main()
	__main() ;
#else
	main();
#endif

	//
	// main() shouldn't return, but if it does, we'll just enter an infinite loop
	//
	while (1) {
		;
	}
}

//*****************************************************************************
// Default exception handlers. Override the ones here by defining your own
// handler routines in your application code.
//*****************************************************************************
__attribute__ ((section(".after_vectors")))
void NMI_Handler(void)
{
    while(1)
    {
    }
}
__attribute__ ((section(".after_vectors")))
void HardFault_Handler(void)
{
    while(1)
    {
    }
}
__attribute__ ((section(".after_vectors")))
void SVCall_Handler(void)
{
    while(1)
    {
    }
}
__attribute__ ((section(".after_vectors")))
void PendSV_Handler(void)
{
    while(1)
    {
    }
}
__attribute__ ((section(".after_vectors")))
void SysTick_Handler(void)
{
    while(1)
    {
    }
}

//*****************************************************************************
//
// Processor ends up here if an unexpected interrupt occurs or a specific
// handler is not present in the application code.
//
//*****************************************************************************
__attribute__ ((section(".after_vectors")))
void IntDefaultHandler(void)
{
    while(1)
    {
    }
}

デフォルトの割り込みハンドラを定義していて、void SysTick_Handler(void)もここで定義されている。
しかし、Forward declarationで
WEAK void SysTick_Handler(void);
のようにWEAK付きで定義されている。
これは、
__attribute__ ((weak))
というマクロでリンクする際に、同じ名前の関数があったらそっちを優先的にリンクするという機能。
で、割り込みハンドラをベクターテーブルに設定している。

その割り込みハンドラの中のvoid ResetISR(void);(リセット時に呼ばれる)内でSystemInit();を呼び、最後にmain関数を呼んでいる。
(実際にはmainから帰ってきてもループするだけ。)

カテゴリー: ARM, ソフトウェア パーマリンク

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