StrNCpyAsm, Assembly Language

Assignment Help:
;StrNCpyAsm - copy zero terminated string2 to zero terminated string1,
; but copy no more than count (parameter) characters
; or the length of string2, whichever comes first
; entry: - addStr1 contains the address of string1
; - addStr2 contains the address of string2
; - count contains the max number of characters to copy
; exit: NONE (no return value so do not use edi to return an address)
;
; Note: StrNCpyAsm does not zero terminate the copied string
; unless the 0 is within count characters copied.
;
; example1: char str1[]= {''h'',''e'',''l'',''l'',''o'','' '',''w'',''o'',''r'',''l'',''d'',0};
; char str2[]= {''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0};
; StrNCpyAsm(str1,str2,4);//terminating 0 not copied since only 4 characters copied
; ;//and terminating 0 not within the 4 characters
; after copy str1 contains: ''G'',''o'',''o'',''d'',''o'','' '',''w'',''o'',''r'',''l'',''d'',0
;
; example2: use str1 and str2 from example1
;
; StrNCpyAsm(str1,str2,9); //terminating 0 copied since terminating 0
; //within 9 characters copied
; str1 contains: ''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0,''l'',''d'',0
;
; example3: use str1 and str2 from example1
;
; StrNCpyAsm(str1,str2,20);//copy 20 characters upto and including 0,
; //whichever comes first
; //only 9 characters including 0 copied
; after copy str1 contains: ''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0,''l'',''d'',0
;
; The above is how you would call StrNCpyAsm from C++.
;
; To call StrNCpyAsm from an asm function use:
;
; push 20 ;max num of characters to copy
; push str2Add ;address of string 2
; push str1Add ;address of string 1
; call StrNCpyAsm
; ;no add esp, 12 needed because stack cleaup automatically done
;
;Do not use a loop in this function.
;Choose 2 instructions from the following string instructions to use:
; rep, repe, repne, movsb,stosb,cmpsb,scasb
;
; hint1: use StrLenAsm to get the number of characters in str2
; hint2: the length returned by StrLenAsm does not include terminating 0
; hint3: copy the lesser of the length of the string (including terminating 0)
; or count characters
;copy to ecx the lesser of count or the length of string2 (including terminating 0)
; Please note for the above, you need the length of string2 including terminating 0.
; StrLenAsm returns the length not including terminating 0
;populate esi and edi with the correct values
;clear the direction flag
;use rep and movsb to copy
;
;

StrNCpyAsm PROC uses eax esi edi ecx , ;save registers used
addStr1:DWORD, ;address of string1
addStr2:DWORD, ;address of string2
count:DWORD ;max chars to copy

Related Discussions:- StrNCpyAsm

Rics/cisc architecture-microprocessor, RICS/CISC Architecture An essent...

RICS/CISC Architecture An essential aspect of computer architecture is the design of the instruction set for the processor.  The instruction set selected for a specific compute

The real time system (rts)-microprocessor, The real time System (RTS) : ...

The real time System (RTS) : Calling the clock real-time is somewhat of a misnomer because it only shows the time setting it has been given. The RTC is the other half of chip

Minecraft/Terminal issues, I am running a small minecraft server off of my ...

I am running a small minecraft server off of my old mac mini, and am having a big issue. My computer isn''t very good, and even just running this server is an issue. I use a comma

Flow chart and pseudocode, #question.flow chart for a program to find out t...

#question.flow chart for a program to find out the number of even and odd numbers from a given series of 16-bit hexadecimal numbers.

PIC, LIST p=18f4550 #include org 0x0000 movlw 0x00 _________ movlw 0xFF ...

LIST p=18f4550 #include org 0x0000 movlw 0x00 _________ movlw 0xFF movwf PORTB end .

Interrupt-microprocessor, Interrupt When the CPU detects an interrupt s...

Interrupt When the CPU detects an interrupt signal, it stops activity of current and jumps to a special routine, known an interrupt handler. This handler then detects why the i

Lds/les instruction execution-microprocessor, LDS/LES Instruction execution...

LDS/LES Instruction execution :  LAHF : Load AH from Lower Byte of Flag: - This instruction loads the AH register with the lower byte of the flag register. This instruction ca

Dma controller-microprocessor, DMA controller :     Steps in...

DMA controller :     Steps include in transferring a block of data from I/O devices (for example a disk) to memory: 1. CPU sends a signal to initiate disk transfe

Fourth generation microprocessor, Fourth  Generation Microprocessor : T...

Fourth  Generation Microprocessor : The single chip 32-bit microprocessor was introduced in 1981 by Intel as iAPX 432. The other 4th generation  microprocessors  were;  Hewlett

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd