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Showing posts from August, 2011

Poetry - When I see my baby What do I see - by Johnny Tillostson

Poetry in motion walking by my side Her lovely locomotion Keeps my eyes open wide Poetry in motion see her gentle swaying A wave out on the ocean Could never move that way I love every movement There's nothing I would change She doesn't need improvement She's much too nice to rearrange Poetry in motion dancing close to me A flower of devotion a-swaying gracefully Woh-woh-woh-woh-woh-woh Woh-woh-woh-woh-woh..... Poetry in motion see her gentle swaying A wave out on the ocean Could never move that way I love every movement There's nothing I would change She doesn't need improvement She's much too nice to rearrange Poetry in motion all that I adore her No number nine love potion Could make me love her more Woh-woh-woh-woh-woh-woh Woh-woh-woh-woh-woh.....

Bengali to english tools

বেঙ্গলি ভাষা tools http://bengali.changathi.com/ http://dsal.uchicago.edu/dictionaries/biswas-bengali/ অভিধানhttp://dictionary.evergreenbangla.com/ is bengali avidhan Somewhat good http://translate.google.com/?hl=en

Differencce of address pointer manipulation in vxworksDiab and GNU GCC

I was wondering what was happening for vxWorks Diab compiler and GNU gcc compiler. GNU gcc needs void *  for printing%p where diab dont generate such warning. for %x also gnu expect unsigned int * as argument where diab also don't generate any warning.

Copy_to_user or copy_from_user instead of memcpy

Quite the contrary, it does handle the case for swapped out memory. Lets take a look at it, shall we? copy_to/from_user boils down to __copy_user in arch/i386/lib/usercopy.c: #define __copy_user(to,from,size) \ do { \ int __d0, __d1, __d2; \ __asm__ __volatile__( \ " cmp $7,%0\n" \ " jbe 1f\n" \ " movl %1,%0\n" \ " negl %0\n" \ " andl $7,%0\n" \ " subl %0,%3\n" \ "4: rep; movsb\n" \ " movl %3,%0\n"

Interrupt and exceptions

x386 Specific   The 386 recognizes two event classes: exceptions and interrupts. Both cause a forced context switch to new a procedure or task. Interrupts can occur at unexpected times during the execution of a program and are used to respond to signals from hardware. Exceptions are caused by the execution of instructions. According to source Interrupts are of two types 1) Masakble 2)Non-Maskable According to Source Exceptions are of two types 1)Processor Detected 2) Programmed Exception Non-maskable interrupts and processor exceptions are assigned vector from 0-31.2 to 255 vectors can be used for maskable interrupt or programmed exception.Those are assigned/put in databus by external interrupt controller during interrupt acknowledgemt.  Vector Description 0 divide error 1 debug exception 2 NMI interrupt 3 Breakpoint 4 INTO-detected Overflow 5 BOUND range exceeded

Simulation vs Emulation

Simulation is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system. Simulation is used in many contexts, such as simulation of technology for performance optimization, safety engineering , testing , training , education, and video games. Training simulators include flight simulators for training aircraft pilots in order to provide them with a lifelike experience. The simulator simulates the behavior of your system through software, so you can simulate a program that will run on a microcontroller or on a FPGA. And you can simulate the behavior of a hardware system using mathematical equations. In computing, an emulator is hardware and/or software that duplicates (or emulates ) the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles t

Working of System Calls in Operating Systems

System call is used in user application to request some hardware/Operating system service access. When user call a system call it actually call some user level library (glibc/ulibc) which is in between User and Operating System.They are implemented as short pieces of assembly code named as system call stub.Which actually place system call number associated to the particular system call to a register (For x86 EAX) , place the arguments other registers (for x86 EBX,ECX etc.)  and issue a trap instruction ( in X86 calling assembly call INT 0x80 , " sc " for powerpc) to switch from user mode to kernel privileged mode. In trap handler kernel code copies arguments to kernel stack and call corresponding system call handler. According to system call dispatcher a new system call may be attached to kernel in compile time or run time. After running system code handler it return by putting return value in some register. (In PPC r3 register) Note: While passing arguments fro