Most of our lab machine consoles are on serial ports, and controlled via minicom on Agatha’s workstation using this device. Well, somehow during Agatha’s recent kernel upgrade to 2.6.8.1, serial support was missed:
root@srv-1 usr-1 # minicom minicom: cannot open /dev/ttyS0: No such file or directory |
To add serial support quickly, we just added 8250/16550 and compatible serial support in device drivers / character devices / serial drivers as a module. Now, make the modules, (assuming you have module support in your kernel):
root@srv-1 linux-2.6.8.1 # make modules SPLIT include/linux/autoconf.h -> include/config/* make[1]: `arch/i386/kernel/asm-offsets.s' is up to date. CC [M] drivers/serial/serial_core.o CC [M] drivers/serial/8250.o CC [M] drivers/serial/8250_pci.o CC [M] drivers/serial/8250_pnp.o Building modules, stage 2. MODPOST CC drivers/serial/8250.mod.o LD [M] drivers/serial/8250.ko CC drivers/serial/8250_pci.mod.o LD [M] drivers/serial/8250_pci.ko CC drivers/serial/8250_pnp.mod.o LD [M] drivers/serial/8250_pnp.ko CC drivers/serial/serial_core.mod.o LD [M] drivers/serial/serial_core.ko root@srv-1 linux-2.6.8.1 # |
Install the modules:
root@srv-1 linux-2.6.8.1 # make modules_install INSTALL arch/i386/kernel/cpuid.ko INSTALL arch/i386/kernel/microcode.ko INSTALL arch/i386/kernel/msr.ko INSTALL drivers/block/loop.ko INSTALL drivers/char/lp.ko INSTALL drivers/net/dummy.ko INSTALL drivers/parport/parport.ko INSTALL drivers/parport/parport_pc.ko INSTALL drivers/scsi/ide-scsi.ko INSTALL drivers/scsi/ppa.ko INSTALL drivers/scsi/sr_mod.ko INSTALL drivers/serial/8250.ko INSTALL drivers/serial/8250_pci.ko INSTALL drivers/serial/8250_pnp.ko INSTALL drivers/serial/serial_core.ko INSTALL fs/fat/fat.ko INSTALL fs/msdos/msdos.ko INSTALL fs/romfs/romfs.ko INSTALL fs/vfat/vfat.ko if [ -r System.map ]; then /sbin/depmod -ae -F System.map 2.6.8.1; fi root@srv-1 linux-2.6.8.1 # root@srv-1 / # ls /lib/modules/2.6.8.1/kernel/drivers/serial 8250.ko 8250_pci.ko 8250_pnp.ko serial_core.ko |
Let’s start up the modules and look at the results in the logs:
root@srv-1 / # root@srv-1 / # insmod /lib/modules/2.6.8.1/kernel/drivers/serial/serial_core.ko root@srv-1 / # insmod /lib/modules/2.6.8.1/kernel/drivers/serial/8250.ko root@srv-1 / # dmesg . . . Serial: 8250/16550 driver $Revision: 1.90 $ 8 ports, IRQ sharing disabled ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A root@srv-1 / # |
Now, can we get to our console?
root@srv-1 / # minicom Welcome to minicom 2.00.0 OPTIONS: History Buffer, F-key Macros, Search History Buffer, I18n Compiled on May 21 2003, 07:02:24. Press CTRL-A Z for help on special keys Fedora Core release 1 (Yarrow) Kernel 2.4.20 on an i586 srv-2 login: |
Yes we can. 🙂
