/*
 * GCC linker script for STM32 microcontrollers (ARM Cortex-M).
 *
 * It exports the symbols needed for the CMSIS assembler startup script for GCC
 * ARM toolchains (_sidata, _sdata, _edata, _sbss, _ebss) and sets the entry
 * point to Reset_Handler.
 *
 * Adapt FLASH/RAM size for your particular device below.
 *
 * @author Bjørn Forsman
 */

MEMORY
{
    flash (rx) : ORIGIN = 0x08000000, LENGTH = 320K
    ccmram (rw) : ORIGIN = 0x10000000, LENGTH = 64k
    ram  (rwx) : ORIGIN = 0x20000000, LENGTH = 2048K
}

ENTRY(Reset_Handler)

/*
 * Reserve memory for heap and stack. The linker will issue an error if there
 * is not enough memory.
 *
 * NOTE: The reserved heap and stack will be added to the bss column of the
 * binutils size command.
 */
_heap_size = 0x200;    /* required amount of heap  */
_stack_size = 0x400;   /* required amount of stack */

/*
 * The stack starts at the end of RAM and grows downwards. Full-descending
 * stack; decrement first, then store.
 */
_estack = ORIGIN(ram) + LENGTH(ram);

SECTIONS
{
    /* Reset and ISR vectors */
    .isr_vector :
    {
        __isr_vector_start__ = .;
        KEEP(*(.isr_vector)) /* without 'KEEP' the garbage collector discards this section */
        ASSERT(. != __isr_vector_start__, "The .isr_vector section is empty");
    } >flash


    /* Text section (code and read-only data) */
    .text :
    {
        . = ALIGN(4);
        _stext = .;
        *(.text*)   /* code */
        *(.rodata*) /* read only data */

        /*
         * NOTE: .glue_7 and .glue_7t sections are not needed because Cortex-M
         * only supports Thumb instructions, no ARM/Thumb interworking.
         */

        /* Static constructors and destructors */
        KEEP(*(.init))
        KEEP(*(.fini))

        . = ALIGN(4);
        _etext = .;
    } >flash


    /*
     * Stack unwinding and exception handling sections.
     *
     * ARM compilers emit object files with .ARM.extab and .ARM.exidx sections
     * when using C++ exceptions. Also, at least GCC emits those sections when
     * dividing large numbers (64-bit) in C. So we have to handle them.
     *
     * (ARM uses .ARM.extab and .ARM.exidx instead of the .eh_frame section
     * used on x86.)
     */
    .ARM.extab : /* exception unwinding information */
    {
        *(.ARM.extab*)
    } >flash
    .ARM.exidx : /* index entries for section unwinding */
    {
        *(.ARM.exidx*)
    } >flash


    /*
     * Newlib and Eglibc (at least) need these for C++ support.
     *
     * (Copied from Sourcery CodeBench Lite: arm-none-eabi-gcc -V)
     */
    .preinit_array :
    {
        PROVIDE_HIDDEN(__preinit_array_start = .);
        KEEP(*(.preinit_array*))
        PROVIDE_HIDDEN(__preinit_array_end = .);
    } >flash
    .init_array :
    {
        PROVIDE_HIDDEN(__init_array_start = .);
        KEEP(*(SORT(.init_array.*)))
        KEEP(*(.init_array*))
        PROVIDE_HIDDEN(__init_array_end = .);
    } >flash
    .fini_array :
    {
        PROVIDE_HIDDEN(__fini_array_start = .);
        KEEP(*(SORT(.fini_array.*)))
        KEEP(*(.fini_array*))
        PROVIDE_HIDDEN(__fini_array_end = .);
    } >flash


    /*
     * Initialized data section. This section is programmed into FLASH (LMA
     * address) and copied to RAM (VMA address) in startup code.
     */
    _sidata = .;
    .data : AT(_sidata) /* LMA address is _sidata (in FLASH) */
    {
        . = ALIGN(4);
        _sdata = .;     /* data section VMA address (in RAM) */
        *(.data*)
        . = ALIGN(4);
        _edata = .;
    } >ram
    
    /* 
    * CCM-RAM data section. Initialization variables can be placed here
    * when the initialization code is provided by the user. Else it is used
    * as an extra piece of memory for heap/stack
    */
    _eidata = (_sidata + SIZEOF(.data));
    .ccm : AT(_sidata + SIZEOF(.data)) /* We want LMA address to be in FLASH (if used for init data) */
    {
        . = ALIGN(4);
        _sccm = .;      /* data section VMA address (in CCMRAM) */
        *(.ccm)
        . = ALIGN(4);
        _eccm = .;
    } >ccmram


    /* Uninitialized data section (zeroed out by startup code) */
    .bss :
    {
        . = ALIGN(4);
        _sbss = .;
        __bss_start__ = _sbss;
        *(.bss*)
        *(COMMON)
        . = ALIGN(4);
        _ebss = .;
        __bss_end__ = _ebss;
    } >ram


    /*
     * Reserve memory for heap and stack. The linker will issue an error if
     * there is not enough memory.
     */
    ._heap :
    {
        . = ALIGN(4);
        _end = .;
        __end__ = _end;
        . = . + _heap_size;
        . = ALIGN(4);
    } >ram
    ._stack :
    {
        . = ALIGN(4);
        . = . + _stack_size;
        . = ALIGN(4);
    } >ram
}

/* Nice to have */
__isr_vector_size__ = SIZEOF(.isr_vector);
__text_size__ = SIZEOF(.text);
__data_size__ = SIZEOF(.data);
__bss_size__ = SIZEOF(.bss);