ABOUT sysenter instruction The SYSENTER instruction is part of the “Fast System Call” facility introduced on the Pentium(R) II processor. The SYSENTER instruction is optimized to provide the maximum performance for transitions to protection ring 0 (CPL 0). The SYSENTER instruction sets the following registers according to values specified by the operating system in certain …
Category Archives: operating system
What is a PUSH instruction ?
ABOUT PUSH INSTRUCTION RELATED In 8086, the main stack register is called stack pointer – SP. The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program. SP points to current stack top. By default, the stack grows downward in memory, so …
| pause | Suspends processing ..
software | Windows | H:\>pause Press any key to continue . . . H:\>pause /? Suspends processing of a batch program and displays the message Press any key to continue . . . H:\>pause Press any key to continue . . . Pause Suspends processing of a batch program and displays a message prompting the …
eip in 32-bit mode and rip in 64-bit mode
ABOUT Processor Register In computer architecture, a processor register is a quickly accessible location available to a computer’s central processing unit (CPU). Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only. Registers are typically addressed by mechanisms other than main memory, …
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16 bits into the segment register…(GS)
software | Windows | These instructions read a full pointer from memory and store it in the selected segment register:register pair. The full pointer loads 16 bits into the segment register SS, DS, ES, FS, or GS source : http://pdos.csail.mit.edu/6.828/2008/readings/i386/LGS.htm software |GNU/Linux| (gdb) info registers rax 0xfffffffffffffdfc -516 rbx 0x5dc 1500 rcx 0xffffffffffffffff -1 rdx …
wcwidth programming
wcwidth – determine columns needed for a wide character #define _XOPEN_SOURCE #include <wchar.h> #include<stdio.h> main() { int value; wchar_t cr; cr=’H’; value=wcwidth(cr); printf(“\n %d \n”,value); } http://gcc.gnu.org/ml/gcc-bugs/2000-10/msg00540.html
chmod – change file mode bits
ABOUT chmod In Unix and Unix-like operating systems, chmod is the command and system call which is used to change the access permissions of file system objects (files and directories). It is also used to change special mode flags. The request is filtered by the umask. The name is an abbreviation of change mode.[1] TYPICAL …
glxinfo
ahiliation:~$glxinfo name of display: :0.0 display: :0 screen: 0 direct rendering: Yes server glx vendor string: NVIDIA Corporation server glx version string: 1.4 The glxinfo program shows information about the OpenGL and GLX implementations running on a given X display. http://www.opengl.org/documentation/ http://en.wikipedia.org/wiki/OpenGL
HOWTO run badblocks command
Block I $badblocks /dev/hda1 ^C Interrupted at block 137600 $badblocks -b 1 -c 0 /dev/hda1 badblocks: File too large while trying to determine device size $badblocks -b 1500 -c 0 /dev/hda1 ^C Interrupted at block 0 Block II $badblocks -b 1500 -c 64 /dev/hda1 Weird value (96000) in do_read Weird value (96000) in do_read Weird …
badblocks
Block I debianlabs:~# badblocks /dev/hda1 ^C Interrupted at block 137600 debianlabs:~# badblocks -b 1 -c 0 /dev/hda1 badblocks: File too large while trying to determine device size debianlabs:~# badblocks -b 1500 -c 0 /dev/hda1 ^C Interrupted at block 0 Block II debianlabs:~# badblocks -b 1500 -c 64 /dev/hda1 Weird value (96000) in do_read Weird value …