/**
 * @file    bootloader.ld
 * @brief   Linker script for Donghui OTA Bootloader
 *
 * Memory layout:
 *   FLASH (bootloader): 0x08000000 - 0x08006FFF (28KB)
 *   SRAM:               0x20000000 - 0x2001FFFF (128KB)
 */

MEMORY
{
    FLASH (rx)  : ORIGIN = 0x08000000, LENGTH = 28K
    RAM   (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}

SECTIONS
{
    /* Vector table */
    .isr_vector :
    {
        . = ALIGN(4);
        KEEP(*(.isr_vector))
        . = ALIGN(4);
    } > FLASH

    /* Program code */
    .text :
    {
        . = ALIGN(4);
        *(.text)
        *(.text*)
        *(.glue_7)
        *(.glue_7t)
        *(.eh_frame)
        KEEP(*(.init))
        KEEP(*(.fini))
        . = ALIGN(4);
        _etext = .;
    } > FLASH

    /* Read-only data */
    .rodata :
    {
        . = ALIGN(4);
        *(.rodata)
        *(.rodata*)
        . = ALIGN(4);
    } > FLASH

    /* Initialized data - copy from flash to RAM */
    _sidata = LOADADDR(.data);
    .data :
    {
        . = ALIGN(4);
        _sdata = .;
        *(.data)
        *(.data*)
        . = ALIGN(4);
        _edata = .;
    } > RAM AT > FLASH

    /* Zero-initialized data */
    .bss :
    {
        . = ALIGN(4);
        _sbss = .;
        *(.bss)
        *(.bss*)
        *(COMMON)
        . = ALIGN(4);
        _ebss = .;
    } > RAM

    /* Stack */
    ._user_stack :
    {
        . = ALIGN(8);
        . = . + 0x2000;     /* 8KB stack */
        . = ALIGN(8);
        _estack = .;
    } > RAM

    /* Heap (for mbedTLS if used) */
    ._user_heap :
    {
        . = ALIGN(8);
        . = . + 0x1000;     /* 4KB heap */
        . = ALIGN(8);
        _eheap = .;
    } > RAM
}