Luna/kernel/src/arch/x86_64/CPU.h

#pragma once
#include <luna/Types.h>

struct Registers // Saved CPU registers for x86-64
{
    u64 r15, r14, r13, r12, r11, r10, r9, r8;
    u64 rbp, rdi, rsi, rdx, rcx, rbx, rax;
    u64 isr, error;
    u64 rip, cs, rflags, rsp, ss;
};

struct FPData
{
    void save();
    void restore();

  private:
    char m_data[512] alignas(16);
    bool m_already_saved;
};

struct [[gnu::packed]] TSS
{
    u32 reserved0;
    u64 rsp[3];
    u64 reserved1;
    u64 ist[7];
    u64 reserved2;
    u16 reserved3;
    u16 iomap_base;
};

static_assert(sizeof(TSS) == 104UL);

extern TSS task_state_segment;