/*
 * Universalisos Linker Script
 * PikeOS 5.0 Feature Parity - Memory Layout Definition
 *
 * Defines memory regions for ARM and RISC-V architectures
 * with proper alignment and section placement for safety-critical systems.
 */

/*
 * Entry point
 */
ENTRY(kernel_main)

/*
 * Memory regions for QEMU virt machine
 */
MEMORY
{
    /* QEMU virt machine memory layout */
    RAM (rwxai) : ORIGIN = 0x40000000, LENGTH = 128M
    FLASH (rx)  : ORIGIN = 0x00000000, LENGTH = 64M
}

/*
 * Stack sizes
 */
__stack_size = 0x4000; /* 16KB stack */
__irq_stack_size = 0x1000; /* 4KB IRQ stack */
__fiq_stack_size = 0x1000; /* 4KB FIQ stack */
__system_stack_size = 0x2000; /* 8KB system stack */

/*
 * Heap configuration
 */
__heap_start = 0x60000000;
__heap_end = 0x60800000; /* 8MB heap */
__heap_size = __heap_end - __heap_start;

/*
 * Section definitions
 */
SECTIONS
{
    /*
     * Exception vector table (must be at offset 0x00000000)
     */
    .vectors : {
        . = ALIGN(4);
        KEEP(*(.text.vectors))
        . = ALIGN(4);
    } > FLASH

    /*
     * Code and read-only data
     */
    .text : {
        . = ALIGN(4);
        *(.text)
        *(.text*)
        *(.rodata)
        *(.rodata*)
        . = ALIGN(4);
    } > RAM AT> FLASH

    /*
     * Constructor and destructor tables
     */
    .ctors : {
        . = ALIGN(4);
        __ctor_start = .;
        KEEP(*(.ctors))
        KEEP(*(SORT(.ctors.*)))
        __ctor_end = .;
        . = ALIGN(4);
    } > RAM

    .dtors : {
        . = ALIGN(4);
        __dtor_start = .;
        KEEP(*(.dtors))
        KEEP(*(SORT(.dtors.*)))
        __dtor_end = .;
        . = ALIGN(4);
    } > RAM

    /*
     * Exception vectors (data section)
     */
    .data : {
        . = ALIGN(4);
        *(.data)
        *(.data*)
        . = ALIGN(4);
    } > RAM

    /*
     * KDEV driver descriptors (self-registered via UOS_DRV_REGISTER)
     */
    .uos_drv : {
        __uos_drv_start = .;
        KEEP(*(.uos_drv))
        __uos_drv_end = .;
    } > RAM

    /*
     * Embedded configuration manifest (config/cfg_blob.S .incbin)
     */
    .uoscfg : {
        . = ALIGN(4);
        _uos_cfg_start = .;
        KEEP(*(.uoscfg))
        . = ALIGN(4);
        _uos_cfg_end = .;
    } > RAM

    /*
     * BSS section (zero-initialized data)
     */
    .bss : {
        . = ALIGN(4);
        __bss_start = .;
        *(.bss)
        *(.bss*)
        *(COMMON)
        . = ALIGN(4);
        __bss_end = .;
    } > RAM

    /*
     * Stack definitions
     */
    .stack : {
        . = ALIGN(16);
        . = . + __stack_size;
        __stack_top = .;
    } > RAM

    .irq_stack : {
        . = ALIGN(16);
        . = . + __irq_stack_size;
        __irq_stack_top = .;
    } > RAM

    .fiq_stack : {
        . = ALIGN(16);
        . = . + __fiq_stack_size;
        __fiq_stack_top = .;
    } > RAM

    .system_stack : {
        . = ALIGN(16);
        . = . + __system_stack_size;
        __system_stack_top = .;
    } > RAM

    /*
     * Heap definition
     */
    .heap : {
        . = ALIGN(8);
        __heap_start = .;
        . = . + __heap_size;
        __heap_end = .;
        . = ALIGN(8);
    } > RAM

    /*
     * Debug sections
     */
    /DISCARD/ : {
        *(.comment)
        *(.ARM.attributes)
        *(.note.*)
    }

    /*
     * Stack protection (optional for safety)
     */
    .stack_protector : {
        . = ALIGN(8);
        __stack_chk_guard = .;
        . = . + 8;
    } > RAM
}