79 lines
3.3 KiB
Plaintext
79 lines
3.3 KiB
Plaintext
/* ARM assembly Raspberry PI */
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/* program stringsEx.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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szMessString: .asciz "String with final zero \n"
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szMessString1: .string "Other string with final zero \n"
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sString: .ascii "String without final zero"
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.byte 0 @ add final zero for display
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sLineSpaces: .byte '>'
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.fill 10,1,' ' @ 10 spaces
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.asciz "<\n" @ add <, CR and final zero for display
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sSpaces1: .space 10,' ' @ other 10 spaces
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.byte 0 @ add final zero for display
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sCharA: .space 10,'A' @ curious !! 10 A with space instruction
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.asciz "\n" @ add CR and final zero for display
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cChar1: .byte 'A' @ character A
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cChar2: .byte 0x41 @ character A
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szCarriageReturn: .asciz "\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:
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ldr r0,iAdrszMessString
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bl affichageMess @ display message
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ldr r0,iAdrszMessString1
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bl affichageMess
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ldr r0,iAdrsString
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bl affichageMess
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ldr r0,iAdrszCarriageReturn
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bl affichageMess
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ldr r0,iAdrsLineSpaces
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bl affichageMess
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ldr r0,iAdrsCharA
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bl affichageMess
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100: @ standard end of the program
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mov r0, #0 @ return code
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mov r7, #EXIT @ request to exit program
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svc 0 @ perform system call
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iAdrszMessString: .int szMessString
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iAdrszMessString1: .int szMessString1
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iAdrsString: .int sString
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iAdrsLineSpaces: .int sLineSpaces
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iAdrszCarriageReturn: .int szCarriageReturn
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iAdrsCharA: .int sCharA
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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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