Files
mop3/kernel/amd64/debug.c
2026-02-20 15:33:16 +01:00

73 lines
1.6 KiB
C

#include <amd64/debug.h>
#include <amd64/io.h>
#include <libk/printf.h>
#include <libk/std.h>
#include <libk/string.h>
#include <sync/spin_lock.h>
#include <sys/debug.h>
/* Port for printing to serial */
/* TODO: Make this configurable */
#define PORT_COM1 0x03F8
/* debugprintf buffer size */
#define BUFFER_SIZE 1024
/*
* Lock, which ensures that prints to the serial port are atomic (ie. one debugprintf is atomic in
* itself).
*/
static spin_lock_t serial_lock = SPIN_LOCK_INIT;
static bool debug_is_init = false;
/* Block until TX buffer is empty */
static bool debug_serial_tx_empty (void) { return (bool)(inb (PORT_COM1 + 5) & 0x20); }
/* Write a single character to serial */
static void debug_serial_write (char x) {
while (!debug_serial_tx_empty ())
;
outb (PORT_COM1, (uint8_t)x);
}
/*
* Formatted printing to serial. serial_lock ensures that all prints are atomic.
*/
void debugprintf (const char* fmt, ...) {
if (!debug_is_init)
return;
char buffer[BUFFER_SIZE];
memset (buffer, 0, sizeof (buffer));
va_list ap;
va_start (ap, fmt);
vsnprintf (buffer, sizeof (buffer), fmt, ap);
va_end (ap);
buffer[sizeof (buffer) - 1] = '\0';
const char* p = buffer;
spin_lock (&serial_lock);
while (*p) {
debug_serial_write (*p);
p++;
}
spin_unlock (&serial_lock);
}
/* Initialize serial */
void debug_init (void) {
outb (PORT_COM1 + 1, 0x00);
outb (PORT_COM1 + 3, 0x80);
outb (PORT_COM1 + 0, 0x03);
outb (PORT_COM1 + 1, 0x00);
outb (PORT_COM1 + 3, 0x03);
outb (PORT_COM1 + 2, 0xC7);
outb (PORT_COM1 + 4, 0x0B);
debug_is_init = true;
}