.section .head,"ax"
.global _image_start
_image_start:
    b _start
    .word 0
    .quad 0x80000
    .quad _image_end - _image_start
    .quad 0x2
    .quad 0
    .quad 0
    .quad 0
    .word 0x644d5241
    .word 0

.section .text.boot,"ax"
.global _start
_start:
    msr daifset, #0xf
    mov x20, x1
    mrs x1, mpidr_el1
    and x1, x1, #0xff
    cbnz x1, .Lpark

    mov x19, x0
    // Rust may use Advanced SIMD even for integer/array operations. Enable it
    // before entering compiled code; IRQs remain masked and there are no tasks.
    mrs x1, CurrentEL
    cmp x1, #4
    b.eq .Lenable_el1_simd
    cmp x1, #8
    b.eq .Lenable_el2_simd
    b .Lpark
.Lenable_el1_simd:
    mrs x1, CPACR_EL1
    orr x1, x1, #(3 << 20)
    msr CPACR_EL1, x1
    isb
    b .Lsimd_ready
.Lenable_el2_simd:
    mrs x1, CPTR_EL2
    bic x1, x1, #(1 << 10)
    msr CPTR_EL2, x1
    isb
.Lsimd_ready:
    adrp x1, __bss_start
    add x1, x1, :lo12:__bss_start
    adrp x2, __bss_end
    add x2, x2, :lo12:__bss_end
.Lzero_bss:
    cmp x1, x2
    b.hs .Lstack
    str xzr, [x1], #8
    b .Lzero_bss
.Lstack:
    adrp x1, __stack_top
    add x1, x1, :lo12:__stack_top
    mov sp, x1
    mov x0, x19
    mov x1, x20
    bl kernel_main
.Lpark:
    wfe
    b .Lpark

.section .bss.stack,"aw",%nobits
.align 12
.global __stack_start
__stack_start:
    .skip 16384
.global __stack_top
__stack_top:

// Isolated return-path experiment stack. The low guard is initialized and
// checked by Rust; the vector itself always switches away from the boot stack.
.section .bss.irq_stack,"aw",%nobits
.align 12
.global __irq_guard_page_start
__irq_guard_page_start:
    .skip 4096
.global __irq_stack_guard
__irq_stack_guard:
    .skip 16
.global __irq_stack_start
__irq_stack_start:
    .skip 16384
.global __irq_stack_top
__irq_stack_top: