53 lines
2.3 KiB
Plaintext
53 lines
2.3 KiB
Plaintext
/* ARM assembly Raspberry PI */
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/* program forfunction.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 WRITE, 4 @ Linux syscall
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/* Initialized data */
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.data
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szString: .asciz "Hello word\n"
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/* UnInitialized data */
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.bss
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/* code section */
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.text
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.global main
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main: @ entry of program
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push {fp,lr} @ saves registers
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ldr r0,iAdrszString @ string address
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bl strdup @ call function C
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@ return new pointer
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bl affichageMess @ display dup string
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bl free @ free heap
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100: @ standard end of the program */
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mov r0, #0 @ return code
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pop {fp,lr} @restaur 2 registers
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mov r7, #EXIT @ request to exit program
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swi 0 @ perform the system call
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iAdrszString: .int szString
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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 registres
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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 systeme
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pop {r0,r1,r2,r7,lr} @ restaur des 2 registres */
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bx lr @ return
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