1.2.1

--Initial program to run, this called bootstrapprogram.


--It initalizes all the aspects of system,from CPU registers to device controllers.


--The bootstrap program must locate andload into memory the OS kernel.


--The occurrence of an event is usuallysignaled by an interrupt.


--The interrupt must transfer control theappropriate interrupt service routine.


--The table of pointers is stored in lowmemory; these locations hold the addresses of the interrupt service routine forvarious devices, called Interrupt Vector(中断向量)


1.2.2 Storage Structure

--The CPU only loads instructions from thememory, exchange data with memory (the north birdge).


--All forms of memory contain an array ofwords; eachword has its own address.


--Hierarchy 存储山


--This section is easy.


1.2.3 I/O StructureD

--A device concoller maintains some local bufferstorage and some registers.


--The device is reponsible for moving databetween its device and the local buffer storage.


--OS has a device driver for each deviceconcoller.


--DMA (direct memory acess), exchange datastrightforward with memory.