Has anyone run into boot/init issues due to the serial console appearing to be exceedingly slow, particularly when using the 'serial_port_address' BIOS setting?
I want to make serial port COM1 (aka ttyS0, hardware port 3F8h) be connected to the IPMI serial-over-LAN (SoL) console, to make the serial console settings unified and standardized across all the server vendors and models that we have: ttyS0 at 115'200 baud, for the BIOS, the boot loader (GRUB), the Linux kernel console, and the getty logins. So I set the Dell C8220 BIOS setting 'serial_port_address' to the non-default value '2f8h_3f8h'. This will remap the serial ports so that the front/back physical serial port ends up being connected to COM2, as observed in the operating system; the internal SoL serial port ends up at COM1. This COM1/COM2 remapping does not apply to the BIOS stage, so early programs that use BIOS text-printing functions will have to write to COM2 to get the output to the SoL console. So my GRUB config uses COM2. When the kernel boots, it uses 'console=tty0 console=ttyS0,115200', which works well up until init starts. With both systemd and sysv, the console suddenly stops, and every console write operation seems to block for exactly 30 seconds. This makes the boot/init take several tens of minutes. If I use 'console=ttyS0,115200 console=tty0', the boot/init goes quickly, but I am not able to get a serial getty prompt on either ttyS0 nor ttyS1. That is very strange. I posted my experience here, too: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=763601#20 So, to sum up: With BIOS setting 'serial_port_address' set to '3f8h_2f8h': 'console=tty0 console=ttyS1,115200': boot ok, getty ok. 'console=ttyS1,115200 console=tty0': boot ok, getty ok. With BIOS setting 'serial_port_address' set to '2f8h_3f8h': 'console=tty0 console=ttyS0,115200': boot slow, getty ok(?). 'console=ttyS0,115200 console=tty0': boot ok, getty missing. sven _______________________________________________ Poweredgec-tools mailing list Poweredgec-tools@dell.com https://lists.us.dell.com/mailman/listinfo/poweredgec-tools
