//! Processor state stored in the RFLAGS register.
//!
//! In 64-bit mode, EFLAGS is extended to 64 bits and called RFLAGS.
//! The upper 32 bits of RFLAGS register is reserved.
//! The lower 32 bits of RFLAGS is the same as EFLAGS.
use bitflags::*;
use crate::Ring;
#[cfg(target_arch = "x86_64")]
use core::arch::asm;
bitflags! {
/// The RFLAGS register.
/// This is duplicated code from bits32 eflags.rs.
pub struct RFlags: u64 {
/// ID Flag (ID)
const FLAGS_ID = 1 << 21;
/// Virtual Interrupt Pending (VIP)
const FLAGS_VIP = 1 << 20;
/// Virtual Interrupt Flag (VIF)
const FLAGS_VIF = 1 << 19;
/// Alignment Check (AC)
const FLAGS_AC = 1 << 18;
/// Virtual-8086 Mode (VM)
const FLAGS_VM = 1 << 17;
/// Resume Flag (RF)
const FLAGS_RF = 1 << 16;
/// Nested Task (NT)
const FLAGS_NT = 1 << 14;
/// I/O Privilege Level (IOPL) 0
const FLAGS_IOPL0 = 0b00 << 12;
/// I/O Privilege Level (IOPL) 1
const FLAGS_IOPL1 = 0b01 << 12;
/// I/O Privilege Level (IOPL) 2
const FLAGS_IOPL2 = 0b10 << 12;
/// I/O Privilege Level (IOPL) 3
const FLAGS_IOPL3 = 0b11 << 12;
/// Overflow Flag (OF)
const FLAGS_OF = 1 << 11;
/// Direction Flag (DF)
const FLAGS_DF = 1 << 10;
/// Interrupt Enable Flag (IF)
const FLAGS_IF = 1 << 9;
/// Trap Flag (TF)
const FLAGS_TF = 1 << 8;
/// Sign Flag (SF)
const FLAGS_SF = 1 << 7;
/// Zero Flag (ZF)
const FLAGS_ZF = 1 << 6;
/// Auxiliary Carry Flag (AF)
const FLAGS_AF = 1 << 4;
/// Parity Flag (PF)
const FLAGS_PF = 1 << 2;
/// Bit 1 is always 1.
const FLAGS_A1 = 1 << 1;
/// Carry Flag (CF)
const FLAGS_CF = 1 << 0;
}
}
impl RFlags {
/// Creates a new Flags entry. Ensures bit 1 is set.
pub const fn new() -> RFlags {
RFlags::FLAGS_A1
}
/// Creates a new Flags with the given I/O privilege level.
pub const fn from_priv(iopl: Ring) -> RFlags {
RFlags {
bits: (iopl as u64) << 12,
}
}
pub const fn from_raw(bits: u64) -> RFlags {
RFlags { bits }
}
}
#[cfg(target_arch = "x86_64")]
#[inline(always)]
pub fn read() -> RFlags {
let r: u64;
unsafe { asm!("pushfq; popq {0}", out(reg) r, options(att_syntax)) };
RFlags::from_bits_truncate(r)
}
#[cfg(target_arch = "x86_64")]
#[inline(always)]
pub fn set(val: RFlags) {
unsafe {
asm!("pushq {0}; popfq", in(reg) val.bits(), options(att_syntax));
}
}
// clac and stac are also usable in 64-bit mode
pub use crate::bits32::eflags::{clac, stac};