I can confirm that adding: earlycon=uart8250,mmio32,0x1c020000 console=ttyS0,115200 console=tty0 produces exactly the desired results - everything appears on the serial port, and as much as usual also appears on the VGA output. Gordan On 18/03/16 08:11, Chuong Tran wrote: > Hi, > > You can add "earlycon=uart8250,mmio32,0x1c020000" to see how far the > kernel boot on serial console can go. > > Also, make sure to say Y to CONFIG_SERIAL_8250 & relevant config in your > kernel .config. > > Best regards, > > Chuong. > > > On Fri, Mar 18, 2016 at 2:49 PM, Michael Howard > <mike at dewberryfields.co.uk <mailto:mike at dewberryfields.co.uk>> wrote: > > On 18/03/2016 03:18, Chuong Tran wrote: > > Hi Gordan, > > If you want to retain the output on serial console, please add > kernel command "console=ttyS0,115200" at the grub config. > If you want to see the kernel boot at both serial and vga, add > "console=tty0" (for vga) along side with "console=ttyS0,115200". > The output from VGA will come after kernel configure the video card. > > > I use this setting ("console=ttyS0,115200 console=tty0") but output > is not retained on the serial console. Maybe this is kernel specific. > > -- > Mike Howard > > > _______________________________________________ > Arm-dev mailing list > Arm-dev at centos.org <mailto:Arm-dev at centos.org> > https://lists.centos.org/mailman/listinfo/arm-dev > > > > > _______________________________________________ > Arm-dev mailing list > Arm-dev at centos.org > https://lists.centos.org/mailman/listinfo/arm-dev >