General :: How Is Kernel Extracted

We know that the ROM is installed to the /system partition. Likewise the kernel ie boot.img is installed to the /boot partition of the device. I tried hard but could not find any reference to such a /boot partition(directory) in the root of the device. I would like know whether it is hidden or disguised as something else. The script that flashes the custom kernels has the following line

Code:
package_extract_file("boot.img", "/dev/block/mmcblk0p9");
(What is the block code for system and other partitions?)

Is mmcblk0p9 the /boot partition? Moreover /dev/block has no reference to boot or mmcblk0p9. So where exactly is the kernel being extracted? The boot.img comes packaged as zImage + ramdisk, In other words where are zImage and ramdisk extracted to, in the root file system and in what form? Is the ramdisk responsible for the creation of the root files system(/dev, /proc, /data. /system, /sys, /sbin etc)?