97 lines
3.2 KiB
C
97 lines
3.2 KiB
C
// SPDX-License-Identifier: BSD-3-Clause
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/******************************************************************************
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*
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* Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/
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*
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******************************************************************************/
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#include <stdint.h>
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/* Entry point for the application. */
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extern int main();
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/* Reserve space for the system stack. */
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extern uint32_t __stack_top;
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typedef void(*pFunc)(void);
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/* Interrupt handler prototypes */
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void default_handler(void);
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void reset_handler(void);
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/*
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* The vector table. Note that the proper constructs must be placed on this to
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* ensure that it ends up at physical address 0x0000.0000 or at the start of
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* the program if located at a start address other than 0.
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*/
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void (* const intr_vectors[])(void) __attribute__((section(".intvecs"))) = {
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(pFunc)&__stack_top, /* The initial stack pointer */
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reset_handler, /* The reset handler */
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default_handler, /* The NMI handler */
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default_handler, /* The hard fault handler */
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default_handler, /* The MPU fault handler */
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default_handler, /* The bus fault handler */
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default_handler, /* The usage fault handler */
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0, /* Reserved */
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0, /* Reserved */
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0, /* Reserved */
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0, /* Reserved */
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default_handler, /* SVCall handler */
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default_handler, /* Debug monitor handler */
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0, /* Reserved */
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default_handler, /* The PendSV handler */
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default_handler /* The SysTick handler */
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};
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/*
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* The following are constructs created by the linker, indicating where
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* the "data" and "bss" segments reside in memory. The initializers for
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* the "data" segment resides immediately following the "text" segment.
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*/
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extern uint32_t __bss_start__;
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extern uint32_t __bss_end__;
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/*
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* This is the code that gets called when the processor first starts execution
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* following a reset event. Only the absolutely necessary set is performed,
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* after which the application supplied entry() routine is called. Any fancy
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* actions (such as making decisions based on the reset cause register, and
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* resetting the bits in that register) are left solely in the hands of the
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* application.
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*/
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__attribute__((section(".reset"))) __attribute__((naked))
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void reset_handler(void)
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{
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/* Set stack pointer */
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__asm(" MOVW.W r0, #0x1700\n"
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" MOVT.W r0, #0x2000\n"
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" mov sp, r0\n");
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/* Zero fill the bss segment. */
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__asm(" ldr r0, =__bss_start__\n"
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" ldr r1, =__bss_end__\n"
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" mov r2, #0\n"
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" .thumb_func\n"
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"zero_loop:\n"
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" cmp r0, r1\n"
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" it lt\n"
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" strlt r2, [r0], #4\n"
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" blt zero_loop");
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/* Call the application's entry point. */
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main();
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}
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/*
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* This is the code that gets called when the processor receives an unexpected
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* interrupt. This simply enters an infinite loop, preserving the system state
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* for examination by a debugger.
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*/
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void default_handler(void)
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{
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/* Enter an infinite loop. */
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while (1)
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;
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}
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