class __attribute__((packed)) interrupt_wrapper
{
    using function_ptr = void(*)(unsigned);
    unsigned int_vector;            // [eax-0x1C]
    selector ds;                    // [eax-0x18]
    selector es;                    // [eax-0x16]
    selector fs;                    // [eax-0x14]
    selector gs;                    // [eax-0x12]
    function_ptr entry_point;       // [eax-0x10]
    std::array<byte, 0x40> code;    // [eax-0x0C]

public:
    interrupt_wrapper(unsigned vec, function_ptr f) : int_vector(vec), entry_point(f)
    {
        byte* start;
        std::size_t size;
        asm volatile (
            ".intel_syntax noprefix;"
            "jmp interrupt_wrapper_end%=;"
            // --- \/\/\/\/\/\/ --- //
            "interrupt_wrapper_begin%=:;"   // On entry, the only known register is CS.
            "push ds; push es; push fs; push gs; pusha;"    // 7 bytes
            "call get_eip%=;"  // call near/relative (E8)   // 5 bytes
            "get_eip%=: pop eax;"           // Pop EIP into EAX and use it to find our vars
            "mov ds, cs:[eax-0x18];"        // Restore segment registers
            "mov es, cs:[eax-0x16];"
            "mov fs, cs:[eax-0x14];"
            "mov gs, cs:[eax-0x12];"
            "push cs:[eax-0x1C];"           // Pass our interrupt vector along
            "call cs:[eax-0x10];"           // Call the entry point
            "add esp, 4;"
            "popa; pop gs; pop fs; pop es; pop ds;"
            "sti;"                          // IRET may or may not reset the interrupt flag.
            "iret;"
            "interrupt_wrapper_end%=:;"
            // --- /\/\/\/\/\/\ --- //
            "mov %0, offset interrupt_wrapper_begin%=;"
            "mov %1, offset interrupt_wrapper_end%=;"
            "sub %1, %0;"
            ".att_syntax prefix"
            : "=r" (start)
            , "=r" (size));
        assert(size <= code.size());

        auto* ptr = memory_descriptor(get_cs(), start).get_ptr<byte>();
        std::copy_n(ptr, size, code.data());

        asm volatile (
            ".intel_syntax noprefix;"
            "mov ax, ds;"
            "mov bx, es;"
            "mov cx, fs;"
            "mov dx, gs;"
            ".att_syntax prefix"
            : "=a" (ds)
            , "=b" (es)
            , "=c" (fs)
            , "=d" (gs));
    }

    auto get_ptr(selector cs) { return far_ptr32 { cs, reinterpret_cast<std::size_t>(code.data()) }; }
};