/* Copyright (c) 2013 ARM LIMITED

   All rights reserved.
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are met:
   - Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
   - Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
   - Neither the name of ARM nor the names of its contributors may be used
     to endorse or promote products derived from this software without
     specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE.
   ---------------------------------------------------------------------------*/

    .syntax unified
    .arch armv6-m

#ifdef __STARTUP_CONFIG
#include "startup_config.h"
#endif

    .section .stack
    .align 3
#if defined(__STARTUP_CONFIG)
    .equ    Stack_Size, __STARTUP_CONFIG_STACK_SIZE
#elif defined(__STACK_SIZE)
    .equ    Stack_Size, __STACK_SIZE
#else
    .equ    Stack_Size, 2048
#endif
    .globl __StackTop
    .globl __StackLimit
__StackLimit:
    .space Stack_Size
    .size __StackLimit, . - __StackLimit
__StackTop:
    .size __StackTop, . - __StackTop

    .section .heap
    .align 3
#if defined(__STARTUP_CONFIG)
    .equ Heap_Size, __STARTUP_CONFIG_HEAP_SIZE
#elif defined(__HEAP_SIZE)
    .equ Heap_Size, __HEAP_SIZE
#else
    .equ    Heap_Size, 2048
#endif
    .globl __HeapBase
    .globl __HeapLimit
__HeapBase:
    .if Heap_Size
    .space Heap_Size
    .endif
    .size __HeapBase, . - __HeapBase
__HeapLimit:
    .size __HeapLimit, . - __HeapLimit

    .section .isr_vector
    .align 2
    .globl __isr_vector
__isr_vector:
    .long   __StackTop                  /* Top of Stack */
    .long   Reset_Handler
    .long   NMI_Handler
    .long   HardFault_Handler
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   SVC_Handler
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   PendSV_Handler
    .long   SysTick_Handler

  /* External Interrupts */
    .long   POWER_CLOCK_IRQHandler
    .long   RADIO_IRQHandler
    .long   UART0_IRQHandler
    .long   SPI0_TWI0_IRQHandler
    .long   SPI1_TWI1_IRQHandler
    .long   0                           /*Reserved */
    .long   GPIOTE_IRQHandler
    .long   ADC_IRQHandler
    .long   TIMER0_IRQHandler
    .long   TIMER1_IRQHandler
    .long   TIMER2_IRQHandler
    .long   RTC0_IRQHandler
    .long   TEMP_IRQHandler
    .long   RNG_IRQHandler
    .long   ECB_IRQHandler
    .long   CCM_AAR_IRQHandler
    .long   WDT_IRQHandler
    .long   RTC1_IRQHandler
    .long   QDEC_IRQHandler
    .long   LPCOMP_IRQHandler
    .long   SWI0_IRQHandler
    .long   SWI1_IRQHandler
    .long   SWI2_IRQHandler
    .long   SWI3_IRQHandler
    .long   SWI4_IRQHandler
    .long   SWI5_IRQHandler
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */
    .long   0                           /*Reserved */

    .size __isr_vector, . - __isr_vector

/* Reset Handler */

    .equ    NRF_POWER_RAMON_ADDRESS,             0x40000524
    .equ    NRF_POWER_RAMONB_ADDRESS,            0x40000554
    .equ    NRF_POWER_RAMONx_RAMxON_ONMODE_Msk,  0x3  

    .text
    .thumb
    .thumb_func
    .align 1
    .globl Reset_Handler
    .type Reset_Handler, %function
Reset_Handler:

    MOVS    R1, #NRF_POWER_RAMONx_RAMxON_ONMODE_Msk
    
    LDR     R0, =NRF_POWER_RAMON_ADDRESS
    LDR     R2, [R0]
    ORRS    R2, R1
    STR     R2, [R0]

    LDR     R0, =NRF_POWER_RAMONB_ADDRESS
    LDR     R2, [R0]
    ORRS    R2, R1
    STR     R2, [R0]

/* Loop to copy data from read only memory to RAM.
 * The ranges of copy from/to are specified by following symbols:
 *      __etext: LMA of start of the section to copy from. Usually end of text
 *      __data_start__: VMA of start of the section to copy to.
 *      __bss_start__: VMA of end of the section to copy to. Normally __data_end__ is used, but by using __bss_start__
 *                    the user can add their own initialized data section before BSS section with the INTERT AFTER command.
 *
 * All addresses must be aligned to 4 bytes boundary.
 */
    ldr r1, =__etext
    ldr r2, =__data_start__
    ldr r3, =__bss_start__

    subs r3, r2
    ble .L_loop1_done

.L_loop1:
    subs r3, #4
    ldr r0, [r1,r3]
    str r0, [r2,r3]
    bgt .L_loop1

.L_loop1_done:

/* This part of work usually is done in C library startup code. Otherwise,
 * define __STARTUP_CLEAR_BSS to enable it in this startup. This section
 * clears the RAM where BSS data is located.
 *
 * The BSS section is specified by following symbols
 *    __bss_start__: start of the BSS section.
 *    __bss_end__: end of the BSS section.
 *
 * All addresses must be aligned to 4 bytes boundary.
 */
#ifdef __STARTUP_CLEAR_BSS
    ldr r1, =__bss_start__
    ldr r2, =__bss_end__

    movs r0, 0

    subs r2, r1
    ble .L_loop3_done

.L_loop3:
    subs r2, #4
    str r0, [r1, r2]
    bgt .L_loop3

.L_loop3_done:
#endif /* __STARTUP_CLEAR_BSS */

/* Execute SystemInit function. */
    bl SystemInit

/* Call _start function provided by libraries.
 * If those libraries are not accessible, define __START as your entry point.
 */
#ifndef __START
#define __START _start
#endif
    bl __START

    .pool
    .size   Reset_Handler,.-Reset_Handler

    .section ".text"


/* Dummy Exception Handlers (infinite loops which can be modified) */

    .weak   NMI_Handler
    .type   NMI_Handler, %function
NMI_Handler:
    b       .
    .size   NMI_Handler, . - NMI_Handler


    .weak   HardFault_Handler
    .type   HardFault_Handler, %function
HardFault_Handler:
    b       .
    .size   HardFault_Handler, . - HardFault_Handler


    .weak   SVC_Handler
    .type   SVC_Handler, %function
SVC_Handler:
    b       .
    .size   SVC_Handler, . - SVC_Handler


    .weak   PendSV_Handler
    .type   PendSV_Handler, %function
PendSV_Handler:
    b       .
    .size   PendSV_Handler, . - PendSV_Handler


    .weak   SysTick_Handler
    .type   SysTick_Handler, %function
SysTick_Handler:
    b       .
    .size   SysTick_Handler, . - SysTick_Handler


/* IRQ Handlers */

    .globl  Default_Handler
    .type   Default_Handler, %function
Default_Handler:
    b       .
    .size   Default_Handler, . - Default_Handler

    .macro  IRQ handler
    .weak   \handler
    .set    \handler, Default_Handler
    .endm

    IRQ  POWER_CLOCK_IRQHandler
    IRQ  RADIO_IRQHandler
    IRQ  UART0_IRQHandler
    IRQ  SPI0_TWI0_IRQHandler
    IRQ  SPI1_TWI1_IRQHandler
    IRQ  GPIOTE_IRQHandler
    IRQ  ADC_IRQHandler
    IRQ  TIMER0_IRQHandler
    IRQ  TIMER1_IRQHandler
    IRQ  TIMER2_IRQHandler
    IRQ  RTC0_IRQHandler
    IRQ  TEMP_IRQHandler
    IRQ  RNG_IRQHandler
    IRQ  ECB_IRQHandler
    IRQ  CCM_AAR_IRQHandler
    IRQ  WDT_IRQHandler
    IRQ  RTC1_IRQHandler
    IRQ  QDEC_IRQHandler
    IRQ  LPCOMP_IRQHandler
    IRQ  SWI0_IRQHandler
    IRQ  SWI1_IRQHandler
    IRQ  SWI2_IRQHandler
    IRQ  SWI3_IRQHandler
    IRQ  SWI4_IRQHandler
    IRQ  SWI5_IRQHandler

  .end
