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#include <stdint.h>
#include <serial.h>
//you can add more options if you need to later
// PORT + 3: values are from bit zero (right) to left
// dlab(1) | misteryyy bone(1) | paraty(3) | stop bits (1) | character length (2)
static inline void outb(uint16_t port, uint8_t value) {
//here "a" is the a register, and "Nd" is inteter (I think?) in the d register
asm volatile(
"outb %0, %1" :: "a"(value), "Nd"(port)
);
}
static inline uint8_t inb(uint16_t port) {
uint8_t ret;
asm volatile(
"inb %1, %0" : "=a"(ret) : "Nd"(port)
);
return(ret);
}
int init_serial(uint16_t port) {
outb(port + 1, 0x00); // disable them fuckin interupts
outb(port + 3, 0x80); // sets dlab, allowing custom serial speeds
outb(port + 0, 0x06); // speed is 115200/6
outb(port + 1, 0x00);
outb(port + 3, 0x03); // disables dlab, as well as 8 bit char len, 1 stop bit, no paraty, no mystery
outb(port + 2, 0xc7); // I have no fucking clue what this means
outb(port + 4, 0x0b); // don't know what this means eather... delete if you can
outb(port + 4, 0x1e); // loopback mode (where the hell is this documented????)
outb(port + 0, 0xae); // test char
if(inb(port + 0) != 0xae)
return 1;
outb(port + 4, 0x0f); // dissable interupts
return 0;
}
void _putchar_serial(uint16_t port, char msg) {
while(!(inb(port + 5) & 0x20)); //wait for transmit to be doneroni
outb(port, msg);
}
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