68 lines
2.7 KiB
Text
68 lines
2.7 KiB
Text
/* ARM assembly Raspberry PI */
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/* program defList.s */
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/* Constantes */
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.equ STDOUT, 1 @ Linux output console
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.equ EXIT, 1 @ Linux syscall
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.equ READ, 3
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.equ WRITE, 4
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.equ NBELEMENTS, 100 @ list size
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/*******************************************/
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/* Structures */
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/********************************************/
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/* structure linkedlist*/
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.struct 0
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llist_next: @ next element
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.struct llist_next + 4
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llist_value: @ element value
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.struct llist_value + 4
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llist_fin:
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/* Initialized data */
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.data
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szMessInitListe: .asciz "List initialized.\n"
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szCarriageReturn: .asciz "\n"
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/* datas error display */
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szMessErreur: .asciz "Error detected.\n"
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/* UnInitialized data */
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.bss
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lList1: .skip llist_fin * NBELEMENTS @ list memory place
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/* code section */
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.text
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.global main
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main:
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ldr r0,iAdrlList1
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mov r1,#0
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str r1,[r0,#llist_next]
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ldr r0,iAdrszMessInitListe
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bl affichageMess
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100: @ standard end of the program
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mov r7, #EXIT @ request to exit program
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svc 0 @ perform system call
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iAdrszMessInitListe: .int szMessInitListe
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iAdrszMessErreur: .int szMessErreur
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iAdrszCarriageReturn: .int szCarriageReturn
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iAdrlList1: .int lList1
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/******************************************************************/
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/* display text with size calculation */
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/******************************************************************/
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/* r0 contains the address of the message */
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affichageMess:
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push {r0,r1,r2,r7,lr} @ save registers
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mov r2,#0 @ counter length */
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1: @ loop length calculation
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ldrb r1,[r0,r2] @ read octet start position + index
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cmp r1,#0 @ if 0 its over
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addne r2,r2,#1 @ else add 1 in the length
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bne 1b @ and loop
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@ so here r2 contains the length of the message
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mov r1,r0 @ address message in r1
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mov r0,#STDOUT @ code to write to the standard output Linux
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mov r7, #WRITE @ code call system "write"
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svc #0 @ call system
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pop {r0,r1,r2,r7,lr} @ restaur registers
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bx lr @ return
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