less /etc/sysconfig/hwconf : to get installed hardware information.
less /proc/cpuinfo : to get installed CPUs specification.
less /var/log/dmesg or dmesg :to get the Linux boot up information.
less /proc/interrupts :to list the IRQ used by system devices.
less /proc/ioports :to list I/O ports used by system.
less /proc/dma :to list DMA channels and device used by system.
less /proc/version or uname -a or less /etc/redhat-release or lsb_release -a :to show the Linux version.
kudzu -p to show the probe information about hardware detected
/usr/bin/lsdev to list devices and information on system hardware.
/sbin/lspci to list detected PCI devices.
/sbin/lsmod to list loadable modules.
/sbin/lsraid to list raid device.
/sbin/lsusb to list USB device.
/sbin/usbmodules to list kernel driver modules available for USB devices.