.section .stack, "aw", @nobits

.align 16
.global stack_top
stack_bottom: .skip 1 << 20
stack_top:
stack_size = stack_top - stack_bottom

.section .bss, "aw", @nobits

//! A structure containing information gathered during the bootstrap process.
//! Expected layout (as described by teachos::boot::information):
//!
//! struct
//! {
//!   multiboot2::information_view const * mbi;
//!   std::size_t vga_buffer_index;
//! }
.global bootstrap_information
bootstrap_information: .skip 16

.section .boot_text, "ax", @progbits
.code64

.global _entry64
_entry64:
    mov $global_descriptor_table_data, %rax
    mov %rax, %ss
    mov %rax, %ds
    mov %rax, %es
    mov %rax, %fs
    mov %rax, %gs

    mov $stack_top, %rsp
    mov %rsp, %rbp

    mov multiboot_information_pointer, %rax
    or $TEACHOS_VMA, %rax
    mov vga_buffer_pointer, %rdx
    sub $0xb8000, %rdx
    mov %rax, (bootstrap_information)
    mov %rdx, (bootstrap_information + 8)

    call invoke_global_constructors
    
    xor %rax, %rax
    mov %rax, %rbp
    mov %rax, %rdx
    mov %rax, %rsi

    mov $stack_size, %rcx
    shr $3, %rcx
    lea (stack_bottom), %rdi
    rep stosq

    mov %rax, %rdi

    call main

1:
    hlt
    jmp 1b