boot.cpp


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#include <array>
#include <cstdint>
#include <span>

extern void (*__init_array_start)();
extern void (*__init_array_end)();
extern void kernel_main();

alignas(16)
static std::array<std::uint8_t, 16384> stack;

static void init_array()
{
    std::span initArray (&__init_array_start, &__init_array_end);
    for (auto& fn : initArray)
        fn();
}

extern "C"
__attribute__((naked))
void _start()
{
    asm volatile(R"(
        mov %%eax, multiboot_magic
        mov %%ebx, multiboot_ptr
        mov %0, %%esp
    )" :: "i" (stack.data() + stack.size()));

    init_array();
    kernel_main();

    asm volatile("cli");
    for (;;)
        asm volatile("hlt");
}