| static void outb(unsigned char value, unsigned short port) |
| { |
| __builtin_outb(value, port); |
| } |
| |
| static unsigned char inb(unsigned short port) |
| { |
| return __builtin_inb(port); |
| } |
| static int uart_can_tx_byte(void) |
| { |
| return inb(0x3f8 + 0x05) & 0x20; |
| } |
| |
| static void uart_wait_to_tx_byte(void) |
| { |
| while(!uart_can_tx_byte()) |
| ; |
| } |
| |
| static void uart_wait_until_sent(void) |
| { |
| while(!(inb(0x3f8 + 0x05) & 0x40)) |
| ; |
| } |
| |
| static void uart_tx_byte(unsigned char data) |
| { |
| uart_wait_to_tx_byte(); |
| outb(data, 0x3f8 + 0x00); |
| |
| uart_wait_until_sent(); |
| } |
| |
| static void print_debug(const char *str) |
| { |
| unsigned char ch; |
| while((ch = *str++) != '\0') { |
| uart_tx_byte(ch); |
| } |
| } |
| |
| static void main(void) |
| { |
| print_debug("one\r\n"); |
| print_debug("two\r\n"); |
| } |