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In the x86 assembly language, the TEST instruction performs a bitwise AND on two operands. The flags SF, ZF, PF are modified while the result of the AND is discarded. The OF and CF flags are set to 0, while AF flag is undefined. There are 9 different opcodes for the TEST instruction depending on the type and size of the operands. It can compare ...
The TIB of the current thread can be accessed as an offset of segment register FS (x86) or GS (x64). It is not common to access the TIB fields by an offset from FS:[0], but rather first getting a linear self-referencing pointer to it stored at FS:[18h]. That pointer can be used with pointer arithmetic or be cast to a struct pointer.
The FLAGS register is the status register that contains the current state of an x86 CPU.The size and meanings of the flag bits are architecture dependent. It usually reflects the result of arithmetic operations as well as information about restrictions placed on the CPU operation at the current time.
The MSR to read is specified in ECX. The value of the MSR is then returned as a 64-bit value in EDX:EAX. 0 IBM 386SLC, [34] Intel Pentium, AMD K5, Cyrix 6x86MX,MediaGXm, IDT WinChip C6, Transmeta Crusoe, DM&P Vortex86DX3 WRMSR: 0F 30: Write Model-specific register. The MSR to write is specified in ECX, and the data to write is given in EDX:EAX. [a]
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) [note 1] is a 64-bit extension of the x86 instruction set architecture first announced in 1999. It introduces two new operating modes: 64-bit mode and compatibility mode, along with a new four-level paging mechanism.
Destination operand is initialized with information about the source and attributes of the key (this matches the value that was provided in EAX for the most recent invocation of LOADIWKEY) These instructions may also modify XMM4-6 (zeroed out in existing implementations, but this should not be relied on). ENCODEKEY256 r32,r32: F3 0F 3A FB /r
The reset vector for the Intel 80386 and later x86 processors is physical address FFFFFFF0h (16 bytes below 4 GB). The value of the selector portion of the CS register at reset is F000h, the value of the base portion of the CS register is FFFF0000h, and the value of the IP register at reset is FFF0h [ 4 ] to form the segmented address FFFF0000h ...
In 2003, 64-bit CPUs were introduced to the mainstream PC market in the form of x86-64 processors and the PowerPC G5. A 64-bit register can hold any of 2 64 (over 18 quintillion or 1.8×10 19) different values. The range of integer values that can be stored in 64 bits depends on the integer representation used.