diff --git a/.gitignore b/.gitignore index b97f196..9d1f296 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,5 @@ +*~ +*# *.iso isodir tools diff --git a/kernel/kernel/kernel.c b/kernel/kernel/kernel.c index 76778d4..aac93e9 100644 --- a/kernel/kernel/kernel.c +++ b/kernel/kernel/kernel.c @@ -1,8 +1,15 @@ +#define PORT 0x3f8 + #include #include +#include "serial.h" void kernel_main(void) { terminal_initialize(); printf("Hello from OrionOS!\n"); + printf("Testing serial\n"); + init_serial(); + write_serial('t'); + printf("Test finished success!\n"); } diff --git a/kernel/kernel/serial.h b/kernel/kernel/serial.h new file mode 100644 index 0000000..1e40274 --- /dev/null +++ b/kernel/kernel/serial.h @@ -0,0 +1,67 @@ +#include + +#define PORT 0x3f8 // COM1 + +static int init_serial() { + outb(PORT + 1, 0x00); // Disable all interrupts + outb(PORT + 3, 0x80); // Enable DLAB (set baud rate divisor) + outb(PORT + 0, 0x03); // Set divisor to 3 (lo byte) 38400 baud + outb(PORT + 1, 0x00); // (hi byte) + outb(PORT + 3, 0x03); // 8 bits, no parity, one stop bit + outb(PORT + 2, 0xC7); // Enable FIFO, clear them, with 14-byte threshold + outb(PORT + 4, 0x0B); // IRQs enabled, RTS/DSR set + outb(PORT + 4, 0x1E); // Set in loopback mode, test the serial chip + outb(PORT + 0, 0xAE); // 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) + if(inb(PORT + 0) != 0xAE) { + return 1; + } + + // 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(PORT + 4, 0x0F); + return 0; +} + +int serial_received() { + return inb(PORT + 5) & 1; +} + +char read_serial() { + while (serial_received() == 0); + + return inb(PORT); +} + +int is_transmit_empty() { + return inb(PORT + 5) & 0x20; +} + +void write_serial(char a) { + while (is_transmit_empty() == 0); + + outb(PORT, a); +} + +void serial_printf() { + +} + +inline void outb(uint16_t port, uint8_t val) +{ + asm volatile ( "outb %0, %1" : : "a"(val), "Nd"(port) ); + /* There's an outb %al, $imm8 encoding, for compile-time constant port numbers that fit in 8b. (N constraint). + * Wider immediate constants would be truncated at assemble-time (e.g. "i" constraint). + * The outb %al, %dx encoding is the only option for all other cases. + * %1 expands to %dx because port is a uint16_t. %w1 could be used if we had the port number a wider C type */ +} + +inline int inb(int port) +{ + uint8_t ret; + asm volatile ( "inb %1, %0" + : "=a"(ret) + : "Nd"(port) ); + return ret; +}