diff options
Diffstat (limited to 'kernel/drivers/uart.c')
| -rw-r--r-- | kernel/drivers/uart.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/drivers/uart.c b/kernel/drivers/uart.c index c999e45..6dcfe63 100644 --- a/kernel/drivers/uart.c +++ b/kernel/drivers/uart.c @@ -3,12 +3,14 @@ #define PORT 0x3F8 -int uart_init(void) { +int uart_init(void) +{ outb(PORT + 1, 0x00); // disable interrupts outb(PORT + 3, 0x80); // enable DLAB (divisor latch access bit) outb(PORT + 0, 0x03); // (lo) Set baud divisor to 3 38400 baud outb(PORT + 1, 0x00); // (hi) - outb(PORT + 3, 0x03); // disable DLAB, set 8 bits per word, one stop bit, no parity + outb(PORT + 3, + 0x03); // disable DLAB, set 8 bits per word, one stop bit, no parity outb(PORT + 2, 0xC7); // enable and clear FIFOs, set to maximum threshold outb(PORT + 4, 0x0B); // ??? outb(PORT + 4, 0x1E); // set in loopback mode for test @@ -25,19 +27,24 @@ int uart_init(void) { return 0; } -uint8_t uart_in(void) { +uint8_t uart_in(void) +{ // wait for data to be available - while ((inb(PORT + 5) & 0x01) == 0); + while ((inb(PORT + 5) & 0x01) == 0) + ; return inb(PORT); } -void uart_out(uint8_t ch) { +void uart_out(uint8_t ch) +{ // wait for output to be free - while ((inb(PORT + 5) & 0x20) == 0); + while ((inb(PORT + 5) & 0x20) == 0) + ; outb(PORT, ch); } -void uart_out_str(const char *str) { +void uart_out_str(const char *str) +{ while (*str) uart_out(*str++); } |