x86/registers/
io.rs

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1// Licensed under the Apache License, Version 2.0 or the MIT License.
2// SPDX-License-Identifier: Apache-2.0 OR MIT
3// Copyright Tock Contributors 2025.
4
5// This is inspired and adapted for Tock from the [x86](https://github.com/gz/rust-x86) crate.
6
7//! I/O port functionality.
8
9#[cfg(target_arch = "x86")]
10use core::arch::asm;
11
12/// Write 8 bits to port
13///
14/// # Safety
15/// Needs IO privileges.
16#[cfg(target_arch = "x86")]
17#[inline]
18pub unsafe fn outb(port: u16, val: u8) {
19    unsafe {
20        asm!("outb %al, %dx", in("al") val, in("dx") port, options(att_syntax));
21    }
22}
23
24/// Read 8 bits from port
25///
26/// # Safety
27/// Needs IO privileges.
28#[cfg(target_arch = "x86")]
29#[inline]
30pub unsafe fn inb(port: u16) -> u8 {
31    let ret: u8;
32    unsafe {
33        asm!("inb %dx, %al", in("dx") port, out("al") ret, options(att_syntax));
34    }
35    ret
36}
37
38/// Write 16 bits to port
39///
40/// # Safety
41/// Needs IO privileges.
42#[cfg(target_arch = "x86")]
43#[inline]
44pub unsafe fn outw(port: u16, val: u16) {
45    unsafe {
46        asm!("outw %ax, %dx", in("ax") val, in("dx") port, options(att_syntax));
47    }
48}
49
50/// Read 16 bits from port
51///
52/// # Safety
53/// Needs IO privileges.
54#[cfg(target_arch = "x86")]
55#[inline]
56pub unsafe fn inw(port: u16) -> u16 {
57    let ret: u16;
58    unsafe {
59        asm!("inw %dx, %ax", in("dx") port, out("ax") ret, options(att_syntax));
60    }
61    ret
62}
63
64/// Write 32 bits to port
65///
66/// # Safety
67/// Needs IO privileges.
68#[cfg(target_arch = "x86")]
69#[inline]
70pub unsafe fn outl(port: u16, val: u32) {
71    unsafe {
72        asm!("outl %eax, %dx", in("eax") val, in("dx") port, options(att_syntax));
73    }
74}
75
76/// Read 32 bits from port
77///
78/// # Safety
79/// Needs IO privileges.
80#[cfg(target_arch = "x86")]
81#[inline]
82pub unsafe fn inl(port: u16) -> u32 {
83    let ret: u32;
84    unsafe {
85        asm!("inl %dx, %eax", out("eax") ret, in("dx") port, options(att_syntax));
86    }
87    ret
88}
89
90//For CI only
91
92#[cfg(not(any(doc, target_arch = "x86")))]
93pub unsafe fn outb(_port: u16, _val: u8) {
94    unimplemented!()
95}
96
97#[cfg(not(any(doc, target_arch = "x86")))]
98pub unsafe fn inb(_port: u16) -> u8 {
99    unimplemented!()
100}
101
102#[cfg(not(any(doc, target_arch = "x86")))]
103pub unsafe fn outw(_port: u16, _val: u16) {
104    unimplemented!()
105}
106
107#[cfg(not(any(doc, target_arch = "x86")))]
108pub unsafe fn inw(_port: u16) -> u16 {
109    unimplemented!()
110}
111
112#[cfg(not(any(doc, target_arch = "x86")))]
113pub unsafe fn outl(_port: u16, _val: u32) {
114    unimplemented!()
115}
116
117#[cfg(not(any(doc, target_arch = "x86")))]
118pub unsafe fn inl(_port: u16) -> u32 {
119    unimplemented!()
120}
x86/registers/io.rs

x86/registers/
io.rs
