diff options
Diffstat (limited to 'devices/uart/uart_16550.c')
| -rw-r--r-- | devices/uart/uart_16550.c | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/devices/uart/uart_16550.c b/devices/uart/uart_16550.c index 47a7fd3..0e19842 100644 --- a/devices/uart/uart_16550.c +++ b/devices/uart/uart_16550.c @@ -22,6 +22,7 @@ uart_putc(const FILE *self, char a) int uart_puts(const FILE *self, const char *string, int length) { + int i; int written = 0; if (length == -1) @@ -32,7 +33,7 @@ uart_puts(const FILE *self, const char *string, int length) } else - for (int i = 0; i < length; ++i) { + for (i = 0; i < length; ++i) { uart_putc(self, string[i]); ++written; } @@ -50,22 +51,22 @@ FILE uart_stream; FILE * uart_init(enum UART port) { - outb(0x00, port + 1); // Disable all interrupts - outb(0x80, port + 3); // Enable DLAB (set baud rate divisor) - outb(0x03, port + 0); // Set divisor to 3 (lo byte) 38400 baud - outb(0x00, port + 1); // (hi byte) - outb(0x03, port + 3); // 8 bits, no parity, one stop bit - outb(0xc7, port + 2); // Enable FIFO, clear them, with 14-byte threshold - outb(0x0b, port + 4); // IRQs enabled, RTS/DSR set - outb(0x1e, port + 4); // Set in loopback mode, test the serial chip - outb(0xae, port + 0); // Test serial chip (send byte 0xAE and check if serial - // returns same byte) + outb(0x00, port + 1); /* Disable all interrupts */ + outb(0x80, port + 3); /* Enable DLAB (set baud rate divisor) */ + outb(0x03, port + 0); /* Set divisor to 3 (lo byte) 38400 baud */ + outb(0x00, port + 1); /* (hi byte) */ + outb(0x03, port + 3); /* 8 bits, no parity, one stop bit */ + outb(0xc7, port + 2); /* Enable FIFO, clear them, with 14-byte threshold */ + outb(0x0b, port + 4); /* IRQs enabled, RTS/DSR set */ + outb(0x1e, port + 4); /* Set in loopback mode, test the serial chip */ + outb(0xae, port + 0); /* Test serial chip (send byte 0xAE and check if serial */ + /* returns same byte) */ - // Check if serial is faulty (i.e: not same byte as sent) + /* Check if serial is faulty (i.e: not same byte as sent) */ if (inb(port + 0) != 0xae) { return NULL; } - // If serial is not faulty set it in normal operation mode - // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled) + /* If serial is not faulty set it in normal operation mode */ + /* (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled) */ outb(0x0f, port + 4); uart_stream.id = port; uart_stream.putc = &uart_putc; |