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

CONSTANTS, Ask question #MinimuWHAT ARE CONSTANTS AND WHAT DO THEY DO?m 100...

Ask question #MinimuWHAT ARE CONSTANTS AND WHAT DO THEY DO?m 100 words accepted#

Dec-micro processor, DEC : A powerful new Alpha 64 bit RISC computer ch...

DEC : A powerful new Alpha 64 bit RISC computer chip was introduced in the year 1977, as new VAX (Virtual Address Extension) Computer. The VAX was 32 bit computer line based on

Program, Write a program to separate out positive and negative numbers from...

Write a program to separate out positive and negative numbers from a given series of 16-bit hexadecimal numbers.

Read architecture:look aside cache-microprocessor, Read Architecture : Look...

Read Architecture : Look Aside Cache In "look aside" cache architecture the main memory is located conflictingthe system interface. Both the cache main memory sees a bus cycle

Display triangular shape using stars, write an assembly program to display ...

write an assembly program to display triangular star like shape

The intel processors , The Intel Processors :         The Intel Co...

The Intel Processors :         The Intel Corporation is the biggest manufacturer  of microchips  in the world,  in addition  to being  the leading provider of chips for PCs. I

Read file in 8086, Write a procedure to read a text file and copy its cont...

Write a procedure to read a text file and copy its contents to another text file using 8086 assembly language .

Addsub, Using the AddSub program from Ch3 under c:\Masm615\examples as a re...

Using the AddSub program from Ch3 under c:\Masm615\examples as a reference, write a program that subtracts three 16-bit integers using only registers. Insert a call DumpRegs statem

Program to move string from offset-assembly program, Program : A program t...

Program : A program to move a string of the data words from offset 2000H to offset 3000H the length of the string is OFH. Solution : For writing this program, we will use

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