ttyS0 at MMIO 0x40100000 (irq = 15) is a FFUART ttyS1 at MMIO 0x40200000 (irq = 14) is a BTUART ttyS2 at MMIO 0x40700000 (irq = 13) is a STUART dev/ttyS0, Line 0, UART: undefined, Port: 0x0000, IRQ: 15 Baud_base: 921600, close_delay: 50, divisor: 0 closing_wait: 3000 Flags: spd_normal /dev/ttyS1, Line 1, UART: undefined, Port: 0x0000, IRQ: 14 Baud_base: 921600, close_delay: 50, divisor: 0 closing_wait: 3000 Flags: spd_normal /dev/ttyS2, Line 2, UART: undefined, Port: 0x0000, IRQ: 13 Baud_base: 921600, close_delay: 50, divisor: 0 closing_wait: 3000 Flags: spd_normal