This article is about the x86 processor mode. For Internet Explorer Protected Mode, see Mandatory Integrity Control.
Part of a series on
Microprocessor modes for the x86 architecture
Real mode (Intel 8086)
8080 emulation mode (NEC V20/V30 only)
Protected mode (Intel 80286)
Unreal mode (Intel 80286)
Virtual 8086 mode (Intel 80386)
System Management Mode (Intel 386SL)
Long mode (AMD Athlon 64)
x86 virtualization (Intel Pentium 4, AMD Athlon 64)
AIS mode (VIA C3 only)
First supported platform shown in parentheses
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In computing, protected mode, also called protected virtual address mode,[1] is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as segmentation, virtual memory, paging and safe multi-tasking designed to increase an operating system's control over application software.[2][3]
When a processor that supports x86 protected mode is powered on, it begins executing instructions in real mode, in order to maintain backward compatibility with earlier x86 processors.[4] Protected mode may only be entered after the system software sets up one descriptor table and enables the Protection Enable (PE) bit in the control register 0 (CR0).[5]
Protected mode was first added to the x86 architecture in 1982,[6] with the release of Intel's 80286 (286) processor, and later extended with the release of the 80386 (386) in 1985.[7] Due to the enhancements added by protected mode, it has become widely adopted and has become the foundation for all subsequent enhancements to the x86 (IA-32) architecture,[8] although many of those enhancements, such as added instructions and new registers, also brought benefits to the real mode.
^"Memory access control method and system for realizing the same". US Patent 5483646. May 23, 1995. Archived from the original (Patent) on September 26, 2007. Retrieved 2007-07-14. The memory access control system according to claim 4, wherein said first address mode is a real address mode, and said second address mode is a protected virtual address mode.
^Intel 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture. Intel. May 2019. Section 2.1.3 The Intel 386 Processor (1985).
^root (July 14, 2007). "Guide: What does protected mode mean?" (Guide). Delorie Software. Retrieved 2007-07-14. The purpose of protected mode is not to protect your program. The purpose is to protect everyone else (including the operating system) from your program.
^Intel 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture. Intel. May 2019. Section 3.1 Modes of Operation.
^Collins, Robert (2007). "Protected Mode Basics" (PDF). ftp.utcluj.ro. Archived from the original (PDF) on 2011-07-07. Retrieved 2009-07-31.
^Intel 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture. Intel. May 2019. Section 2.1.2 The Intel 286 Processor (1982).
^"Intel Global Citizenship Report 2003". Archived from the original (Timeline) on 2008-03-22. Retrieved 2007-07-14. 1985 Intel launches Intel386 processor
^Intel 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture. Intel. May 2019. Section 2.1 Brief History of Intel 64 and IA-32 Architecture.
In computing, protectedmode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs). It...
some use of protectedmode, and this was more fully realized in Windows 3.0, which could run in either real mode or make use of protectedmode in the manner...
computing, the DOS ProtectedMode Interface (DPMI) is a specification introduced in 1989 which allows a DOS program to run in protectedmode, giving access...
The Intel 80386 featured three operating modes: real mode, protectedmode and virtual mode. The protectedmode which debuted in the 80286 was extended...
DOS ProtectedMode Services (DPMS) is a set of extended DOS memory management services to allow DPMS-enabled DOS drivers to load and execute in extended...
created in real mode, but are subject to protectedmode's memory paging mechanism. The virtual 8086 mode is a mode for a protected-mode task. Consequently...
mode, while 32-bit programs and 16-bit protectedmode programs are executed in a sub-mode called compatibility mode. Real mode or virtual 8086 mode programs...
protection. At this point the original mode was renamed to real mode, and the new version was named protectedmode. The x86-64 architecture, introduced...
protectedmode can (or must) be used in real mode to set up and switch to protectedmode, and a few (such as SMSW and LMSW) are useful for real mode itself...
same way as it is done with the IDT (Interrupt descriptor table) in protectedmode (i.e., via the LIDT (Load Interrupt Descriptor Table Register) instruction)...
slower in protectedmode than in real mode, and changing segments very frequently is to be avoided. Actual memory operations using protectedmode segments...
(however, this is exclusive to the case where protected-mode drivers or DOS extenders are used; as a real-mode OS, the system runs with effectively no protection)...
VBE provide only a real mode interface, which cannot be used without a significant performance penalty from within protectedmode operating systems. Consequently...
Safe mode is a diagnostic mode of a computer operating system (OS). It can also refer to a mode of operation by application software. Safe mode is intended...
driver. However unreal mode is incompatible with protectedmode operating systems such as Windows 3.x/9x/NT and OS/2. Big real mode has a 1 MiB code segment...
debugging. The 80386 featured three operating modes: real mode, protectedmode and virtual mode. The protectedmode, which debuted in the 80286, was extended...
run in protectedmode, granting access to many features of the processor not available in real mode. It was supplanted by DOS ProtectedMode Interface...
to these protectedmode operating systems, DOS, by default, is a real-mode operating system, switching to protectedmode and virtual 86 mode only on behalf...
under another multitasking system like DESQview, which used the 286 ProtectedMode. Microsoft Windows scored a significant success with Windows 3.0, released...
8086 mode allows the creation of a virtual machine to allow the running of programs that require real mode in order to run under a protectedmode environment...
DOS programs running in protectedmode using VCPI or DPMI, two (different and incompatible) methods of using protectedmode under DOS. Extended memory...
Real mode, or Virtual 8086 mode. v8086 is not an option in Long mode. This means that a modern operating system, which operates in Protectedmode (32 bit)...
not essential to set the graphics mode through the BIOS; it is possible to switch graphics mode in 32-bit protectedmode, if a little more complicated. It...
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