Appendix a – Acrosser AR-B6051 User Manual
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Appendix A
Users have to modify the boot loader configuration to support COM6. Take the grub configuration
file as an example. Add ‘8250.nr_uarts=XX noirqdebug’ at the setting of kernel. Here, XX represents the
number of COM ports the system will support. Because the power subsystem connects to main system
via COM6, the XX must be greater or equal to 6.
1. Modify the grub.conf.
[root@linux ~]# vi /boot/grub/grub.conf
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Fedora Core (2.6.27.5.117.FC10)
root (hd0,0)
kernel /vmlinuz-2.6.27.5.117.FC10 ro root=/dev/hda2 rhgb quiet
8250.nr_uarts=6 noirqdebug
initrd /initrd-2.6.27.5.117.FC10.img
3. List the status of the COM ports in the system.
# setserial -g /dev/ttyS*
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: 16550A, Port: 0x03e8, IRQ: 11
/dev/ttyS3, UART: 16550A, Port: 0x02e8, IRQ: 10
/dev/ttyS4, UART: 16550A, Port: 0x04f8, IRQ: 11
/dev/ttyS5, UART: 16550A, Port: 0x04e8, IRQ: 10
The node ‘/dev/ttyS5’ corresponds to COM6. The IO port is 0x4e8, IRQ 10.