forked from AbleOS/holey-bytes
18 lines
785 B
Plaintext
18 lines
785 B
Plaintext
jmp r0, start
|
|
start:
|
|
jmp r0, init_serial_port
|
|
|
|
-- Uses r20 to set the port
|
|
init_serial_port:
|
|
add r20, r30, r10
|
|
li r20, 00
|
|
|
|
-- 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) |