GegOS/io.h at main · greg-webdev/GegOS · GitHub

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/*
 * io.h - I/O Port Operations for GegOS
 * Low-level hardware access functions
 */

#ifndef IO_H
#define IO_H

#include <stdint.h>

/* Output a byte to a port */
static inline void outb(uint16_t port, uint8_t value) {
    __asm__ volatile ("outb %0, %1" : : "a"(value), "Nd"(port));
}

/* Input a byte from a port */
static inline uint8_t inb(uint16_t port) {
    uint8_t value;
    __asm__ volatile ("inb %1, %0" : "=a"(value) : "Nd"(port));
    return value;
}

/* Output a word to a port */
static inline void outw(uint16_t port, uint16_t value) {
    __asm__ volatile ("outw %0, %1" : : "a"(value), "Nd"(port));
}

/* Input a word from a port */
static inline uint16_t inw(uint16_t port) {
    uint16_t value;
    __asm__ volatile ("inw %1, %0" : "=a"(value) : "Nd"(port));
    return value;
}

/* I/O wait (small delay) */
static inline void io_wait(void) {
    outb(0x80, 0);
}

/* Enable interrupts */
static inline void sti(void) {
    __asm__ volatile ("sti");
}

/* Disable interrupts */
static inline void cli(void) {
    __asm__ volatile ("cli");
}

/* Halt CPU */
static inline void hlt(void) {
    __asm__ volatile ("hlt");
}

#endif /* IO_H */