xyou
f1a2a110d7
Add the current OS source tree, build scripts, system image layout, and development notes covering DMA page allocation, e1000 bring-up, net API dispatch, and DHCP work in progress.
46 lines
802 B
C
46 lines
802 B
C
#include <utsm/types.h>
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void outb(u16 port, u8 value);
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u8 inb(u16 port);
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#define COM1 0x3F8
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static int serial_ready(void) {
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return (inb(COM1 + 5) & 0x20) != 0;
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}
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static int serial_wait_ready(void) {
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for (u64 spin = 0; spin < 1000000ULL; spin++) {
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if (serial_ready()) {
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return 1;
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}
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}
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return 0;
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}
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void serial_init(void) {
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outb(COM1 + 1, 0x00);
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outb(COM1 + 3, 0x80);
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outb(COM1 + 0, 0x03);
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outb(COM1 + 1, 0x00);
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outb(COM1 + 3, 0x03);
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outb(COM1 + 2, 0xC7);
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outb(COM1 + 4, 0x0B);
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}
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void serial_putc(char c) {
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if (c == '\n') {
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serial_putc('\r');
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}
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if (!serial_wait_ready()) {
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return;
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}
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outb(COM1, (u8)c);
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}
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void serial_write(const char *s) {
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while (*s) {
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serial_putc(*s++);
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}
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}
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