| /***************************************************************************** |
| * SEGGER Microcontroller GmbH & Co. KG * |
| * Solutions for real time microcontroller applications * |
| ***************************************************************************** |
| * * |
| * (c) 2017 SEGGER Microcontroller GmbH & Co. KG * |
| * * |
| * Internet: www.segger.com Support: support@segger.com * |
| * * |
| *****************************************************************************/ |
| |
| /***************************************************************************** |
| * Preprocessor Definitions * |
| * ------------------------ * |
| * NO_FPU_ENABLE * |
| * * |
| * If defined, FPU will not be enabled. * |
| * * |
| * NO_STACK_INIT * |
| * * |
| * If defined, the stack pointer will not be initialised. * |
| * * |
| * NO_SYSTEM_INIT * |
| * * |
| * If defined, the SystemInit() function will not be called. By default * |
| * SystemInit() is called after reset to enable the clocks and memories to * |
| * be initialised prior to any C startup initialisation. * |
| * * |
| * NO_VTOR_CONFIG * |
| * * |
| * If defined, the vector table offset register will not be configured. * |
| * * |
| * MEMORY_INIT * |
| * * |
| * If defined, the MemoryInit() function will be called. By default * |
| * MemoryInit() is called after SystemInit() to enable an external memory * |
| * controller. * |
| * * |
| * STACK_INIT_VAL * |
| * * |
| * If defined, specifies the initial stack pointer value. If undefined, * |
| * the stack pointer will be initialised to point to the end of the * |
| * RAM segment. * |
| * * |
| * VECTORS_IN_RAM * |
| * * |
| * If defined, the exception vectors will be copied from Flash to RAM. * |
| * * |
| *****************************************************************************/ |
| |
| .syntax unified |
| |
| .global Reset_Handler |
| #ifdef INITIALIZE_USER_SECTIONS |
| .global InitializeUserMemorySections |
| #endif |
| .extern _vectors |
| |
| .section .init, "ax" |
| .thumb_func |
| |
| .equ VTOR_REG, 0xE000ED08 |
| .equ FPU_CPACR_REG, 0xE000ED88 |
| |
| #ifndef STACK_INIT_VAL |
| #define STACK_INIT_VAL __RAM_segment_end__ |
| #endif |
| |
| Reset_Handler: |
| #ifndef NO_STACK_INIT |
| /* Initialise main stack */ |
| ldr r0, =STACK_INIT_VAL |
| ldr r1, =0x7 |
| bics r0, r1 |
| mov sp, r0 |
| #endif |
| |
| #ifndef NO_SYSTEM_INIT |
| /* Initialise system */ |
| ldr r0, =SystemInit |
| blx r0 |
| #endif |
| |
| #ifdef MEMORY_INIT |
| ldr r0, =MemoryInit |
| blx r0 |
| #endif |
| |
| #ifdef VECTORS_IN_RAM |
| /* Copy exception vectors into RAM */ |
| ldr r0, =__vectors_start__ |
| ldr r1, =__vectors_end__ |
| ldr r2, =__vectors_ram_start__ |
| 1: |
| cmp r0, r1 |
| beq 2f |
| ldr r3, [r0] |
| str r3, [r2] |
| adds r0, r0, #4 |
| adds r2, r2, #4 |
| b 1b |
| 2: |
| #endif |
| |
| #ifndef NO_VTOR_CONFIG |
| /* Configure vector table offset register */ |
| ldr r0, =VTOR_REG |
| #ifdef VECTORS_IN_RAM |
| ldr r1, =_vectors_ram |
| #else |
| ldr r1, =_vectors |
| #endif |
| str r1, [r0] |
| #endif |
| |
| #if (defined(__ARM_ARCH_FPV4_SP_D16__) || defined(__ARM_ARCH_FPV5_D16__)) && !defined(NO_FPU_ENABLE) |
| /* Enable FPU */ |
| ldr r0, =FPU_CPACR_REG |
| ldr r1, [r0] |
| orr r1, r1, #(0xF << 20) |
| str r1, [r0] |
| dsb |
| isb |
| #endif |
| |
| /* Jump to program start */ |
| b _start |
| |
| #ifdef INITIALIZE_USER_SECTIONS |
| .thumb_func |
| InitializeUserMemorySections: |
| ldr r0, =__start_nrf_sections |
| ldr r1, =__start_nrf_sections_run |
| ldr r2, =__end_nrf_sections_run |
| cmp r0, r1 |
| beq 2f |
| subs r2, r2, r1 |
| beq 2f |
| 1: |
| ldrb r3, [r0] |
| adds r0, r0, #1 |
| strb r3, [r1] |
| adds r1, r1, #1 |
| subs r2, r2, #1 |
| bne 1b |
| 2: |
| bx lr |
| #endif |
