| 1 | #if defined (BIOS) |
| 2 | |
| 3 | #include <stdint.h> |
| 4 | #include <stdbool.h> |
| 5 | #include <lib/misc.h> |
| 6 | #include <drivers/serial.h> |
| 7 | #include <sys/cpu.h> |
| 8 | |
| 9 | static bool serial_initialised = false; |
| 10 | uint32_t serial_baudrate; |
| 11 | |
| 12 | static void serial_initialise(void) { |
| 13 | if (serial_initialised || !serial) { |
| 14 | return; |
| 15 | } |
| 16 | |
| 17 | // Init com1 |
| 18 | outb(0x3f8 + 3, 0x00); |
| 19 | outb(0x3f8 + 1, 0x00); |
| 20 | outb(0x3f8 + 3, 0x80); |
| 21 | |
| 22 | uint16_t divisor = (uint16_t)(115200 / serial_baudrate); |
| 23 | outb(0x3f8 + 0, divisor & 0xff); |
| 24 | outb(0x3f8 + 1, (divisor >> 8) & 0xff); |
| 25 | |
| 26 | outb(0x3f8 + 3, 0x03); |
| 27 | outb(0x3f8 + 2, 0xc7); |
| 28 | outb(0x3f8 + 4, 0x0b); |
| 29 | |
| 30 | serial_initialised = true; |
| 31 | } |
| 32 | |
| 33 | void serial_out(uint8_t b) { |
| 34 | serial_initialise(); |
| 35 | |
| 36 | while ((inb(0x3f8 + 5) & 0x20) == 0); |
| 37 | outb(0x3f8, b); |
| 38 | } |
| 39 | |
| 40 | int serial_in(void) { |
| 41 | serial_initialise(); |
| 42 | |
| 43 | if ((inb(0x3f8 + 5) & 0x01) == 0) { |
| 44 | return -1; |
| 45 | } |
| 46 | return inb(0x3f8); |
| 47 | } |
| 48 | |
| 49 | #endif |
