/* Programme assembleur ARM Raspberry */ /* Assembleur ARM Raspberry : Vincent Leboulou */ /* Blog : http://assembleurarmpi.blogspot.fr/ */ /* modèle B 512MO */ /************************************/ /* Constantes */ /************************************/ .equ STDIN, 0 @ Linux input console .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ READ, 3 @ Linux syscall .equ WRITE, 4 @ Linux syscall .equ IOCTL, 0x36 @ Linux syscall .equ SIGACTION, 0x43 @ Linux syscall .equ SYSPOLL, 0xA8 @ Linux syscall .equ TCGETS, 0x5401 .equ TCSETS, 0x5402 .equ ICANON, 2 .equ ECHO, 10 .equ POLLIN, 1 .equ SIGINT, 2 @ Issued if the user sends an interrupt signal (Ctrl + C) .equ SIGQUIT, 3 @ Issued if the user sends a quit signal (Ctrl + D) .equ SIGTERM, 15 @ Software termination signal (sent by kill by default) .equ SIGTTOU, 22 @ .equ TAILLEBUFFER, 10 /*******************************************/ /* Structures */ /********************************************/ /* structure termios see doc linux*/ .struct 0 term_c_iflag: @ input modes .struct term_c_iflag + 4 term_c_oflag: @ output modes .struct term_c_oflag + 4 term_c_cflag: @ control modes .struct term_c_cflag + 4 term_c_lflag: @ local modes .struct term_c_lflag + 4 term_c_cc: @ special characters .struct term_c_cc + 20 @ see length if necessary term_fin: /* structure sigaction see doc linux */ .struct 0 sa_handler: .struct sa_handler + 4 sa_mask: .struct sa_mask + 4 sa_flags: .struct sa_flags + 4 sa_sigaction: .struct sa_sigaction + 4 sa_fin: /* structure poll see doc linux */ .struct 0 poll_fd: @ File Descriptor .struct poll_fd + 4 poll_events: @ events mask .struct poll_events + 4 poll_revents: @ events returned .struct poll_revents + 4 poll_fin: /*********************************/ /* Initialized data */ /*********************************/ .data szMessPgmOk: .asciz "End program OK.\n" szMessErreur: .asciz "Error detected.\n" sMessResult: .ascii "Value : " sMessValeur: .fill 11, 1, ' ' @ size => 11 szCarriageReturn: .asciz "\n" /*************************************************/ szMessErr: .ascii "Error code hexa : " sHexa: .space 9,' ' .ascii " decimal : " sDeci: .space 15,' ' .asciz "\n" szMessKey: .ascii "Value key ==>" sHexaKey: .space 9,' ' .asciz "\n" .align 4 /*********************************/ /* UnInitialized data */ /*********************************/ .bss .align 4 iEnd: .skip 4 @ 0 loop 1 = end loop iTouche: .skip 4 @ value key pressed stOldtio: .skip term_fin @ old terminal state stCurtio: .skip term_fin @ current terminal state stSigAction: .skip sa_fin @ area signal structure stSigAction1: .skip sa_fin stPoll1: .skip poll_fin @ area poll structure stPoll2: .skip poll_fin /*********************************/ /* code section */ /*********************************/ .text .global main main: @ entry of program /* read terminal state */ mov r0,#STDIN @ input console mov r1,#TCGETS ldr r2,iAdrstOldtio mov r7, #IOCTL @ call system Linux svc #0 cmp r0,#0 @ error ? beq 1f ldr r1,iAdrszMessErreur @ error message bl displayError b 100f 1: adr r0,sighandler @ adresse routine traitement signal ldr r1,iAdrstSigAction @ adresse structure sigaction str r0,[r1,#sa_handler] @ maj handler mov r0,#SIGINT @ signal type ldr r1,iAdrstSigAction mov r2,#0 @ NULL mov r7, #SIGACTION @ call system svc #0 cmp r0,#0 @ error ? bne 98f mov r0,#SIGQUIT ldr r1,iAdrstSigAction mov r2,#0 @ NULL mov r7, #SIGACTION @ call system svc #0 cmp r0,#0 @ error ? bne 98f mov r0,#SIGTERM ldr r1,iAdrstSigAction mov r2,#0 @ NULL mov r7, #SIGACTION @ appel systeme svc #0 cmp r0,#0 bne 98f @ adr r0,iAdrSIG_IGN @ address signal igonre function ldr r1,iAdrstSigAction1 str r0,[r1,#sa_handler] mov r0,#SIGTTOU @invalidate other process signal ldr r1,iAdrstSigAction1 mov r2,#0 @ NULL mov r7,#SIGACTION @ call system svc #0 cmp r0,#0 bne 98f @ /* read terminal current state */ mov r0,#STDIN mov r1,#TCGETS ldr r2,iAdrstCurtio @ address current termio mov r7,#IOCTL @ call systeme svc #0 cmp r0,#0 @ error ? bne 98f mov r2,#ICANON | ECHO @ no key pressed echo on display mvn r2,r2 @ and one key ldr r1,iAdrstCurtio ldr r3,[r1,#term_c_lflag] and r3,r2 @ add flags str r3,[r1,#term_c_lflag] @ and store mov r0,#STDIN @ maj terminal current state mov r1,#TCSETS ldr r2,iAdrstCurtio mov r7, #IOCTL @ call system svc #0 cmp r0,#0 bne 98f @ 2: @ loop waiting key ldr r0,iAdriEnd @ if signal ctrl-c -> end ldr r0,[r0] cmp r0,#0 bne 3f ldr r0,iAdrstPoll1 @ address structure poll mov r1,#STDIN str r1,[r0,#poll_fd] @ maj FD mov r1,#POLLIN @ action code str r1,[r0,#poll_events] mov r1,#1 @ items number structure poll mov r2,#0 @ timeout = 0 mov r7,#SYSPOLL @ call system POLL svc #0 cmp r0,#0 @ key pressed ? ble 2b @ no key pressed -> loop @ read key mov r0,#STDIN @ File Descriptor ldr r1,iAdriTouche @ buffer address mov r2,#TAILLEBUFFER @ buffer size mov r7,#READ @ read key svc #0 cmp r0,#0 @ error ? ble 98f ldr r2,iAdriTouche @ key address ldr r0,[r2] ldr r1,iAdrsHexaKey bl conversion16 @ conversion hexa ldr r0,iAdrszMessKey @ display key value in hexa bl affichageMess ldrb r0,[r2] @ key value cmp r0,#113 @ saisie q ? beq 3f cmp r0,#81 @ saisie Q ? beq 3f mov r0,#0 str r0,[r2] @ raz key area b 2b @ loop 3: @ end loop display Ok message ldr r0,iAdrszMessPgmOk bl affichageMess b 99f 98: @ error display ldr r1,iAdrszMessErreur @ error message bl displayError 99: @ end then restaur begin state terminal mov r0,#STDIN mov r1,#TCSETS ldr r2,iAdrstOldtio mov r7,#IOCTL @ call system svc #0 cmp r0,#0 beq 100f ldr r1,iAdrszMessErreur @ error message bl displayError 100: @ standard end of the program mov r0, #0 @ return code mov r7, #EXIT @ request to exit program svc #0 @ perform the system call iAdrsMessValeur: .int sMessValeur iAdrszMessErreur: .int szMessErreur iAdrszCarriageReturn: .int szCarriageReturn iAdrstOldtio: .int stOldtio iAdrstCurtio: .int stCurtio iAdrstSigAction: .int stSigAction iAdrstSigAction1: .int stSigAction1 iAdrszMessPgmOk: .int szMessPgmOk iAdrsMessResult: .int sMessResult iAdrSIG_IGN: .int 1 iAdriEnd: .int iEnd iAdrstPoll1: .int stPoll1 iAdriTouche: .int iTouche iAdrszMessKey: .int szMessKey iAdrsHexaKey: .int sHexaKey /******************************************************************/ /* traitement du signal */ /******************************************************************/ /* r0 contains */ sighandler: push {r0,r1} ldr r0,iAdriEnd mov r1,#1 @ maj zone end str r1,[r0] pop {r0,r1} bx lr /***************************************************/ /* display error message */ /***************************************************/ /* r0 contains error code r1 : message address */ displayError: push {r0-r2,lr} @ save registers mov r2,r0 @ save error code mov r0,r1 bl affichageMess mov r0,r2 @ error code ldr r1,iAdrsHexa bl conversion16 @ conversion hexa mov r0,r2 @ error code ldr r1,iAdrsDeci @ result address bl conversion10 @ conversion decimale ldr r0,iAdrszMessErr @ display error message bl affichageMess 100: pop {r0-r2,lr} @ restaur registers bx lr @ return iAdrszMessErr: .int szMessErr iAdrsHexa: .int sHexa iAdrsDeci: .int sDeci /******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess: push {r0,r1,r2,r7,lr} @ save registres mov r2,#0 @ counter length 1: @ loop length calculation ldrb r1,[r0,r2] @ read octet start position + index cmp r1,#0 @ if 0 its over addne r2,r2,#1 @ else add 1 in the length bne 1b @ and loop @ so here r2 contains the length of the message mov r1,r0 @ address message in r1 mov r0,#STDOUT @ code to write to the standard output Linux mov r7, #WRITE @ code call system "write" svc #0 @ call systeme pop {r0,r1,r2,r7,lr} @ restaur registers bx lr @ return /******************************************************************/ /* Converting a register to a decimal unsigned */ /******************************************************************/ /* r0 contains value and r1 address area */ /* r0 return size of result (no zero final in area) */ /* area size => 11 bytes */ .equ LGZONECAL, 10 conversion10: push {r1-r4,lr} @ save registers mov r3,r1 mov r2,#LGZONECAL 1: @ start loop bl divisionpar10U @ unsigned r0 <- dividende. quotient ->r0 reste -> r1 add r1,#48 @ digit strb r1,[r3,r2] @ store digit on area cmp r0,#0 @ stop if quotient = 0 subne r2,#1 @ else previous position bne 1b @ and loop @ and move digit from left of area mov r4,#0 2: ldrb r1,[r3,r2] strb r1,[r3,r4] add r2,#1 add r4,#1 cmp r2,#LGZONECAL ble 2b @ and move spaces in end on area mov r0,r4 @ result length mov r1,#' ' @ space 3: strb r1,[r3,r4] @ store space in area add r4,#1 @ next position cmp r4,#LGZONECAL ble 3b @ loop if r4 <= area size 100: pop {r1-r4,lr} @ restaur registres bx lr @return /***************************************************/ /* division par 10 unsigned */ /***************************************************/ /* r0 dividende */ /* r0 quotient */ /* r1 remainder */ divisionpar10U: push {r2,r3,r4, lr} mov r4,r0 @ save value //mov r3,#0xCCCD @ r3 <- magic_number lower raspberry 3 //movt r3,#0xCCCC @ r3 <- magic_number higter raspberry 3 ldr r3,iMagicNumber @ r3 <- magic_number raspberry 1 2 umull r1, r2, r3, r0 @ r1<- Lower32Bits(r1*r0) r2<- Upper32Bits(r1*r0) mov r0, r2, LSR #3 @ r2 <- r2 >> shift 3 add r2,r0,r0, lsl #2 @ r2 <- r0 * 5 sub r1,r4,r2, lsl #1 @ r1 <- r4 - (r2 * 2) = r4 - (r0 * 10) pop {r2,r3,r4,lr} bx lr @ leave function iMagicNumber: .int 0xCCCCCCCD /******************************************************************/ /* Converting a register to hexadecimal */ /******************************************************************/ /* r0 contains value and r1 address area */ conversion16: push {r1-r4,lr} @ save registers mov r2,#28 @ start bit position mov r4,#0xF0000000 @ mask mov r3,r0 @ save entry value 1: @ start loop and r0,r3,r4 @value register and mask lsr r0,r2 @ move right cmp r0,#10 @ compare value addlt r0,#48 @ <10 ->digit addge r0,#55 @ >10 ->letter A-F strb r0,[r1],#1 @ store digit on area and + 1 in area address lsr r4,#4 @ shift mask 4 positions subs r2,#4 @ counter bits - 4 <= zero ? bge 1b @ no -> loop 100: pop {r1-r4,lr} @ restaur registers bx lr @return