115 lines
4.8 KiB
Plaintext
115 lines
4.8 KiB
Plaintext
/* ARM assembly AARCH64 Raspberry PI 3B */
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/* program appendstr64.s */
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/*******************************************/
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/* Constantes file */
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/*******************************************/
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/* for this file see task include a file in language AArch64 assembly*/
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.include "../includeConstantesARM64.inc"
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/*******************************************/
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/* Initialized data */
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/*******************************************/
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.data
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szMessString: .asciz "British Museum.\n"
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szComplement: .skip 80
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szStringStart: .asciz "The rosetta stone is at "
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szCarriageReturn: .asciz "\n"
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/*******************************************/
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/* UnInitialized data */
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/*******************************************/
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.bss
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/*******************************************/
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/* code section */
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/*******************************************/
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.text
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.global main
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main:
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ldr x0,qAdrszMessString // display message
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bl affichageMess
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ldr x0,qAdrszMessString
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ldr x1,qAdrszStringStart
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bl prepend // append sting2 to string1
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ldr x0,qAdrszMessString
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bl affichageMess
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ldr x0,qAdrszCarriageReturn
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bl affichageMess
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100: // standard end of the program
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mov x0,0 // return code
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mov x8,EXIT // request to exit program
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svc 0 // perform system call
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qAdrszMessString: .quad szMessString
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qAdrszStringStart: .quad szStringStart
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qAdrszCarriageReturn: .quad szCarriageReturn
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/**************************************************/
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/* append two strings */
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/**************************************************/
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/* x0 contains the address of the string1 */
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/* x1 contains the address of the string2 */
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prepend:
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stp x1,lr,[sp,-16]! // save registers
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mov x3,#0 // length counter
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1: // compute length of string 1
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ldrb w4,[x0,x3]
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cmp w4,#0
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cinc x3,x3,ne // increment to one if not equal
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bne 1b // loop if not equal
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mov x5,#0 // length counter insertion string
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2: // compute length of insertion string
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ldrb w4,[x1,x5]
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cmp x4,#0
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cinc x5,x5,ne // increment to one if not equal
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bne 2b
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cmp x5,#0
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beq 99f // string empty -> error
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add x3,x3,x5 // add 2 length
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add x3,x3,#1 // +1 for final zero
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mov x6,x0 // save address string 1
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mov x0,#0 // allocation place heap
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mov x8,BRK // call system 'brk'
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svc #0
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mov x5,x0 // save address heap for output string
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add x0,x0,x3 // reservation place x3 length
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mov x8,BRK // call system 'brk'
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svc #0
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cmp x0,#-1 // allocation error
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beq 99f
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mov x4,#0 // counter byte string 2
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3:
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ldrb w3,[x1,x4] // load byte string 2
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cbz x3,4f // zero final ?
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strb w3,[x5,x4] // store byte string 2 in heap
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add x4,x4,1 // increment counter 1
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b 3b // no -> loop
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4:
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mov x2,#0 // counter byte string 1
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5:
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ldrb w3,[x6,x2] // load byte string 1
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strb w3,[x5,x4] // store byte string in heap
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cbz x3,6f // zero final ?
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add x2,x2,1 // no -> increment counter 1
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add x4,x4,1 // no -> increment counter 2
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b 5b // no -> loop
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6: // recopie heap in string 1
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mov x2,#0 // counter byte string
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7:
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ldrb w3,[x5,x2] // load byte string in heap
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strb w3,[x6,x2] // store byte string 1
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cbz x3,100f // zero final ?
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add x2,x2,1 // no -> increment counter 1
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b 7b // no -> loop
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100:
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ldp x1,lr,[sp],16 // restaur 2 registers
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ret // return to address lr x30
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/********************************************************/
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/* File Include fonctions */
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/********************************************************/
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/* for this file see task include a file in language AArch64 assembly */
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.include "../includeARM64.inc"
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