vendor/redox_syscall/src/arch/x86.rs

   1 use core::{mem, slice};
   2 use core::arch::asm;
   3 use core::ops::{Deref, DerefMut};
   4
   5 use super::error::{Error, Result};
   6
   7 macro_rules! syscall {
   8     ($($name:ident($a:ident, $($b:ident, $($c:ident, $($d:ident, $($e:ident, $($f:ident, )?)?)?)?)?);)+) => {
   9         $(
  10             pub unsafe fn $name(mut $a: usize, $($b: usize, $($c: usize, $($d: usize, $($e: usize, $($f: usize)?)?)?)?)?) -> Result<usize> {
  11                 asm!(
  12                     "int 0x80",
  13                     inout("eax") $a,
  14                     $(
  15                         in("ebx") $b,
  16                         $(
  17                             in("ecx") $c,
  18                             $(
  19                                 in("edx") $d,
  20                                 $(
  21                                     in("esi") $e,
  22                                     $(
  23                                         in("edi") $f,
  24                                     )?
  25                                 )?
  26                             )?
  27                         )?
  28                     )?
  29                     options(nostack),
  30                 );
  31
  32                 Error::demux($a)
  33             }
  34         )+
  35     };
  36 }
  37
  38 syscall! {
  39     syscall0(a,);
  40     syscall1(a, b,);
  41     syscall2(a, b, c,);
  42     syscall3(a, b, c, d,);
  43     // Must be done custom because LLVM reserves ESI
  44     //syscall4(a, b, c, d, e,);
  45     //syscall5(a, b, c, d, e, f,);
  46 }
  47
  48 pub unsafe fn syscall4(mut a: usize, b: usize, c: usize, d: usize, e: usize)
  49                        -> Result<usize> {
  50     asm!(
  51         "xchg esi, {e}
  52         int 0x80
  53         xchg esi, {e}",
  54         e = in(reg) e,
  55         inout("eax") a,
  56         in("ebx") b,
  57         in("ecx") c,
  58         in("edx") d,
  59         options(nostack),
  60     );
  61
  62     Error::demux(a)
  63 }
  64
  65 pub unsafe fn syscall5(mut a: usize, b: usize, c: usize, d: usize, e: usize, f: usize)
  66                        -> Result<usize> {
  67     asm!(
  68         "xchg esi, {e}
  69         int 0x80
  70         xchg esi, {e}",
  71         e = in(reg) e,
  72         inout("eax") a,
  73         in("ebx") b,
  74         in("ecx") c,
  75         in("edx") d,
  76         in("edi") f,
  77         options(nostack),
  78     );
  79
  80     Error::demux(a)
  81 }
  82
  83 #[derive(Clone, Copy, Debug, Default)]
  84 #[repr(packed)]
  85 pub struct EnvRegisters {
  86     pub fsbase: u32,
  87     pub gsbase: u32,
  88 }
  89
  90 impl Deref for EnvRegisters {
  91     type Target = [u8];
  92     fn deref(&self) -> &[u8] {
  93         unsafe {
  94             slice::from_raw_parts(self as *const EnvRegisters as *const u8, mem::size_of::<EnvRegisters>())
  95         }
  96     }
  97 }
  98
  99 impl DerefMut for EnvRegisters {
 100     fn deref_mut(&mut self) -> &mut [u8] {
 101         unsafe {
 102             slice::from_raw_parts_mut(self as *mut EnvRegisters as *mut u8, mem::size_of::<EnvRegisters>())
 103         }
 104     }
 105 }