‡ doom [duːm] n. U ① 운명 ( 보통 , 악운 ), 숙명 ; 불운 ; 파멸 ; 죽음 . ② ( 불리한 ) 판결 . ③ ( 신이 내리는 ) 최후의 심판 . ④ 〖역사〗 법령 .
The x86 in real mode and 16-bit protected mode contains 6 general 16-bit registers (AX, BX, CX, DX, SI, DI), 2 special stack registers (BP and SP), one 16-bit flags register ( FLAGS ), and 4 segment registers (CS, SS, DS, ES). The first 4 of the general registers are split into top and bottom half 8-bit registers (AX = AH:AL, BX = BH:BL, CX = CH:CL, DX = DH:DL) which are independently usable in 8-bit instruction forms. The instruction pointer (IP) register exists, but is only used in an implicit manner (though its value can be stored on the stack and accessed without a problem). Starting with the Intel 80386 processor, the x86 in 32-bit protected mode extended the 16-bit registers to 32 bits (EAX, EBX, ECX, EDX, ESI, EDI, EBP, ESP, EFLAGS, EIP). The older 16-bit registers were overlayed with the bottom half of the 32-bit registers and could be accessed with an instruction override. There is no &quot;high-half&quot; 16-bit register access; instead, Intel chose to generalize the addressing so that every register could be used for scaled index addressing, and so that EBP could be used as a general register, as well as a stack register. CLI/HALT :CLI - Clear Interrupt Flag (disable) Of course you can do that unless you use your app under a NT based (W2K, XP, Vista) OS. Even on those OSes where there îsn't a real DOS but an emulation layer, the mulation layer works to some extent unless you want to manipulate hardware directly, try to cross memory boundary of your application or any kind of memory protection, and last but not the least you can't use privileged opcodes as your code will reside on user spacethus running on Ring3 of CPU and only Kernel space code runs on Ring0 allowing privileged opcodes such as sti, cli, halt and many others.
What kind is VMware?
Initially, a block of source instruction is interpreted, and profiling is used to determine which instruction sequence are frequently executed. Then a frequently executed block may be binary translated. Multiprogramming State : Mapped 1:1 Instructions : Native State materialization : Provided by hardware Dynamic translation State : Registers mapped to host registers as available (overflow to memory). Memory mapped to host memory. Instructions : Emulated State materialization : Provided by VM software HLL VMs State : Mapped to host resources as available. Instructions : Emulated, JIT compiled State materialization : Provided by VM software
In computing , just-in-time compilation ( JIT ), also known as dynamic translation , is a technique for improving the runtime performance of a computer program . It converts, at runtime, code from one format into another, for example bytecode into native machine code. The performance improvement originates from caching the results of translating blocks of code, and not simply evaluating each line or operand separately (see Interpreted language ), or compiling the code at development time. JIT builds upon two earlier ideas in run-time environments: bytecode compilation and dynamic compilation . Several modern runtime environments, such as Microsoft 's .NET Framework and most implementations of Java , rely on JIT compilation for high-speed code execution.
“ Classic” VMs State Mapped 1:1, except for privileged registers. Instructions Native, except trapping for priveleged instructions State materialization Provided by hardware Whole System VMs State Mapped to available memory, not 1:1 Instructions Emulated State materialization Provided by VM software Co-Designed VMs State Mapped 1:1 Instructions Block-level translated State materialization Provided by hardware/VM software combination
bane [bein] n. U 독 ( 毒 ), 해악 ; 재해 ; 파멸 ( 의 원인 ); 죽음 (death). ┈┈• Gambling was the ∼ of his existence. 도박이 그의 파멸의 원인이 되었다 .
PALO ALTO, Calif., January 31, 2001 -- VMware, Inc. today announced a cooperative research and development agreement for a joint initiative with the U.S. National Security Agency (NSA) to enhance and certify the security of VMware's virtual machine technology. The project, which builds upon VMware's patent pending MultipleWorlds(tm) technology, will enable government users to safely use commercial off-the-shelf software for certain sensitive or classified applications and environments. NSA's project NetTop plans to use security enhanced virtual machines as building blocks for applications requiring separation of information domains, such as providing secure remote access to classified computer networks over the Internet. NSA expects NetTop to deliver components suitable for use by the national security community. VMware plans to incorporate the security enhancements resulting from the agreement in its future product releases.
POPF : Pop data into f lags register Cs : The segment containing the currently executing sequence of instructions is known as the current code segment; it is specified by means of the CS register. The 80386 fetches all instructions from this code segment, using as an offset the contents of the instruction pointer. CS is changed implicitly as the result of intersegment control-transfer instructions (for example, CALL and JMP ), interrupts, and exceptions.
Windows XP Service Pack 1a When you try to start a Pre-Boot Execution Environment (PXE) client computer, you may receive one of the following error messages:
Windows Vista was known by its codename &quot; Longhorn &quot;. 
0.10U rack space machine - Better power, cooling, floor space,etc.
Server consolidation trend: N machine -> 1 real machine
Isolation of environments
Printer server doesn’t take down Exchange server
Compromise of one VM can’t get at data of others
Provide service-level agreements
Linux, FreeBSD, Windows, etc.
Scenario : Server Consolidation Web Server App Server Web Server App Server Database Server Database Server App Server App Server Web Server Web Server VMware MultipleWorlds + Physical Hardware
VMM Arrangements Host OS VMM Guest 1 Guest 2 VMM Guest 1 Guest 2 Host OS VMM Guest 1 Guest 2 Type-2 VMM Type-1 VMM (Hypervisor) Hybrid VMM Examples: JVM CLR Examples: Virtual PC & Virtual Server Examples: Windows Virtualization Hardware Hardware Hardware What we have today What we’re building for the future
Some privileged instructions fail silently. (Why is this a problem?) (What’s the solution?)
PC hardware diversity
Why is this problematic for a “classic” VM?
Pre-existing PC software
Must stay compatible
To address these, VMware uses a hosted VM. (Not a “classic” VM.)
Hosted VMware Architecture VMware achieves both near-native execution speed and broad device support by transparently switching* between Host Mode and VMM Mode. Guest OS Applications Guest Operating System Host OS Apps Host OS PC Hardware Disks Memory CPU NIC VMware App Virtual Machine VMware Driver Virtual Machine Monitor *VMware typically switches modes 1000 times per second The VMware Virtual machine monitor allows each guest OS to directly access the processor (direct execution) VMware, acting as an application, uses the host to access other devices such as the hard disk, floppy, or network card VMM Mode Host Mode