[SOLVED] According to this thread <https://www.raspberrypi.org/forums/viewtopic.php?t=148713&p=978725> just adding the following line in the '/boot/config.txt' is enough to have '/dev/ttyS0' back again. enable_uart=1 Thanks. On 07/13/2016 12:03 PM, Jordi Sanfeliu wrote: > Hello, > > I've discovered that with the new kernel the standard UART 16550 > (/dev/ttyS0) is not detected: > > with kernel 4.1.9-v7: > --------------------- > # dmesg | grep tty > [ 0.000000] Kernel command line: 8250.nr_uarts=1 dma.dmachans=0x7f35 > bcm2708_fb.fbwidth=976 bcm2708_fb.fbheight=736 bcm2709.boardrev=0xa02082 > bcm2709.serial=0xfa9d86a7 smsc95xx.macaddr=B8:27:EB:9D:86:A7 > bcm2708_fb.fbswap=1 bcm2709.uart_clock=48000000 > vc_mem.mem_base=0x3dc00000 vc_mem.mem_size=0x3f000000 > dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p3 rootfstype=ext4 > elevator=deadline rootwait ipv6.disable=1 > [ 0.001289] console [tty1] enabled > [ 0.283910] 3f215040.uart: ttyS0 at MMIO 0x3f215040 (irq = 29, > base_baud = 31250000) is a 16550 > [ 0.998791] 3f201000.uart: ttyAMA0 at MMIO 0x3f201000 (irq = 83, > base_baud = 0) is a PL011 rev2 > [ 2.511900] systemd[1]: Created slice system-getty.slice. > [ 2.515620] systemd[1]: Starting system-getty.slice. > > > with kernel 4.4.14-v7: > --------------------- > # dmesg | grep tty > [ 0.000000] Kernel command line: 8250.nr_uarts=0 dma.dmachans=0x7f35 > bcm2708_fb.fbwidth=1232 bcm2708_fb.fbheight=992 > bcm2709.boardrev=0xa02082 bcm2709.serial=0xda72ae64 > smsc95xx.macaddr=B8:27:EB:72:AE:64 bcm2708_fb.fbswap=1 > bcm2709.uart_clock=48000000 vc_mem.mem_base=0x3dc00000 > vc_mem.mem_size=0x3f000000 dwc_otg.lpm_enable=0 console=tty1 > root=/dev/mmcblk0p3 rootfstype=ext4 elevator=deadline rootwait > ipv6_disable=1 > [ 0.001336] console [tty1] enabled > [ 1.997145] 3f201000.uart: ttyAMA0 at MMIO 0x3f201000 (irq = 87, > base_baud = 0) is a PL011 rev2 > [ 3.271457] systemd[1]: Created slice system-getty.slice. > [ 3.276833] systemd[1]: Starting system-getty.slice. > > > Can anyone confirm this? > Thanks. > -- Jordi Sanfeliu FIBRANET Network Services Provider http://www.fibranet.cat