this is my code which copies 1st string into 2nd String.
AREA StrCopy1, CODE
SWI_WriteC EQU &2
ENTRY ; mark the first instruction
main
ADR r1, srcstr ; pointer to first string
ADR r0, dststr ; pointer to second string
BL strcopy ; copy the first into second
SWI 0x11 ; and exit
srcstr DCB " This is my first (source) string",&0a,&0d,0
dststr DCB " This is my second (destination) string",&0a,&0d,0
ALIGN ; realign address to word boundary
strcopy
LDRB r2, [r1], #1 ; load byte, then update address
STRB r2, [r0], #1 ; store byte, then update address
CMP r2, #0 ; check for zero terminator
BNE printout ; branch if not equal, to Printout
printOut
SWINE SWI_WriteC ; Print the content
B strcopy ; branch to strcopy
MOV pc, lr ; return
END
*******
Now i want to modify the above code so that it encrypts the dststr
using Caesar cipher method and which of course will be printed out on the screen aswell.
Thanks for ur reply and i hope it makes the point clear if not feel free to ask me.
Br.