/* ARM assembly Raspberry PI  */
/*  program dateFormat.s   */

/* REMARK 1 : this program use routines in a include file
   see task Include a file language arm assembly
   for the routine affichageMess conversion10
   see at end of this program the instruction include */

/*******************************************/
/* Constantes                              */
/*******************************************/
.equ STDOUT, 1           @ Linux output console
.equ EXIT,   1           @ Linux syscall
.equ WRITE,  4           @ Linux syscall
.equ BRK,    0x2d        @ Linux syscall
.equ CHARPOS,     '@'

.equ GETTIME,   0x4e     @ call system linux gettimeofday

/*******************************************/
/* Structures                               */
/********************************************/
/* example structure  time  */
    .struct  0
timeval_sec:                     @
    .struct  timeval_sec + 4
timeval_usec:                     @
    .struct  timeval_usec + 4
timeval_end:
    .struct  0
timezone_min:                     @
    .struct  timezone_min + 4
timezone_dsttime:                 @
    .struct  timezone_dsttime + 4
timezone_end:

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessError:       .asciz "Error detected !!!!. \n"
szMessResult:      .asciz "Date : @/@/@ \n"  @ message result
szMessResult1:     .asciz "Date day : @ @ @ @ \n"  @ message result
szJan:             .asciz "Janvier"
szFev:             .asciz "Février"
szMars:            .asciz "Mars"
szAvril:            .asciz "Avril"
szMai:             .asciz "Mai"
szJuin:            .asciz "Juin"
szJuil:            .asciz "Juillet"
szAout:            .asciz "Aout"
szSept:            .asciz "Septembre"
szOct:             .asciz "Octobre"
szNov:             .asciz "Novembre"
szDec:             .asciz "Décembre"
szLundi:           .asciz "Lundi"
szMardi:           .asciz "Mardi"
szMercredi:        .asciz "Mercredi"
szJeudi:           .asciz "Jeudi"
szVendredi:        .asciz "Vendredi"
szSamedi:          .asciz "Samedi"
szDimanche:        .asciz "Dimanche"
szCarriageReturn:  .asciz "\n"
.align 4
tbDayMonthYear:    .int  0,  31,  60,  91, 121, 152, 182, 213, 244, 274, 305, 335
                   .int 366, 397, 425, 456, 486, 517, 547, 578, 609, 639, 670, 700
                   .int 731, 762, 790, 821, 851, 882, 912, 943, 974,1004,1035,1065
                   .int 1096,1127,1155,1186,1216,1247,1277,1308,1339,1369,1400,1430
tbMonthName:       .int szJan
                   .int szFev
                   .int szMars
                   .int szAvril
                   .int szMai
                   .int szJuin
                   .int szJuil
                   .int szAout
                   .int szSept
                   .int szOct
                   .int szNov
                   .int szDec
tbDayName:         .int szLundi
                   .int szMardi
                   .int szMercredi
                   .int szJeudi
                   .int szVendredi
                   .int szSamedi
                   .int szDimanche

/*********************************/
/* UnInitialized data            */
/*********************************/
.bss
.align 4
stTVal:                .skip timeval_end
stTZone:               .skip timezone_end
sZoneConv:             .skip 100
/*********************************/
/*  code section                 */
/*********************************/
.text
.global main
main:                              @ entry of program
    ldr r0,iAdrstTVal
    ldr r1,iAdrstTZone
    mov r7,#GETTIME
    svc 0
    cmp r0,#-1                     @ error ?
    beq 99f
    ldr r1,iAdrstTVal
    ldr r0,[r1,#timeval_sec]       @ timestemp in second
    bl dateFormatNum
    ldr r0,[r1,#timeval_sec]       @ timestemp in second
    bl dateFormatAlpha
    ldr r0,iTStest1
    bl dateFormatNum
    ldr r0,iTStest1
    bl dateFormatAlpha
    ldr r0,iTStest2
    bl dateFormatNum
    ldr r0,iTStest2
    bl dateFormatAlpha
    ldr r0,iTStest3
    bl dateFormatNum
    ldr r0,iTStest3
    bl dateFormatAlpha
    b 100f
99:
    ldr r0,iAdrszMessError
    bl affichageMess
100:                               @ standard end of the program
    mov r0,#0                      @ return code
    mov r7,#EXIT                   @ request to exit program
    svc 0                          @ perform the system call

iAdrszMessError:          .int szMessError
iAdrstTVal:               .int stTVal
iAdrstTZone:              .int stTZone
iAdrszCarriageReturn:     .int szCarriageReturn
iAdrsZoneConv:            .int sZoneConv
iTStest1:                 .int 1609508339    @ 01/01/2021
iTStest2:                 .int 1657805939    @ 14/07/2022
iTStest3:                 .int 1767221999    @ 31/12/2025
/******************************************************************/
/*     date format numeric                                        */
/******************************************************************/
/* r0 contains the  timestamp in seconds */
dateFormatNum:
    push {r1-r11,lr}                             @ save  registers
    ldr r2,iSecJan2020
    sub r0,r0,r2                   @ total secondes to 01/01/2020
    mov r1,#60
    bl division
    mov r0,r2
    mov r6,r3                      @ compute secondes
    mov r1,#60
    bl division
    mov r7,r3                      @ compute minutes
    mov r0,r2
    mov r1,#24
    bl division
    mov r8,r3                      @ compute hours
    mov r0,r2
    mov r11,r0
    mov r1,#(365 * 4 + 1)
    bl division
    lsl r9,r2,#2                   @ multiply by 4 = year1
    mov r1,#(365 * 4 + 1)
    mov r0,r11
    bl division
    mov r10,r3

    ldr r1,iAdrtbDayMonthYear
    mov r2,#3
    mov r3,#12
1:
    mul r11,r3,r2
    ldr r4,[r1,r11,lsl #2]         @ load days by year
    cmp r10,r4
    bge 2f
    sub r2,r2,#1
    cmp r2,#0
    bne 1b
2:                                 @ r2 = year2
    mov r5,#11
    mul r11,r3,r2
    lsl r11,#2
    add r11,r1                     @ table address
3:
    ldr r4,[r11,r5,lsl #2]         @ load days by month
    cmp r10,r4
    bge 4f
    subs r5,r5,#1
    bne 3b
4:                                 @ r5 = month - 1
    mul r11,r3,r2
    add r11,r5
    ldr r1,iAdrtbDayMonthYear
    ldr r3,[r1,r11,lsl #2]
    sub r0,r10,r3
    add r0,r0,#1                   @ final compute day
    ldr r1,iAdrsZoneConv
    bl conversion10                @ this function do not zero final
    mov r11,#0                     @ store zero final
    strb r11,[r1,r0]
    ldr r0,iAdrszMessResult
    ldr r1,iAdrsZoneConv
    bl strInsertAtCharInc          @ insert result at first @ character
    mov r3,r0
    add r0,r5,#1                   @ final compute month
    cmp r0,#12
    subgt r0,#12
    ldr r1,iAdrsZoneConv
    bl conversion10
    mov r11,#0                      @ store zero final
    strb r11,[r1,r0]
    mov r0,r3
    ldr r1,iAdrsZoneConv
    bl strInsertAtCharInc          @ insert result at next @ character
    mov r3,r0
    ldr r11,iYearStart
    add r0,r9,r11
    add r0,r0,r2                   @ final compute year = 2020 + year1 + year2
    ldr r1,iAdrsZoneConv
    bl conversion10
    mov r11,#0                     @ store zero final
    strb r11,[r1,r0]
    mov r0,r3
    ldr r1,iAdrsZoneConv
    bl strInsertAtCharInc          @ insert result at next @ character
    bl affichageMess
100:
    pop {r1-r11,lr}                @ restaur registers
    bx lr                          @ return
iAdrszMessResult:         .int szMessResult
/******************************************************************/
/*     date format alphanumeric                                   */
/******************************************************************/
/* r0 contains the  timestamp in seconds */
dateFormatAlpha:
    push {r1-r10,lr}               @ save  registers
    ldr r2,iSecJan2020
    sub r0,r0,r2                   @ total secondes to 01/01/2020
    mov r6,r0
    mov r1,#60
    bl division
    mov r0,r2
    mov r1,#60
    bl division
    mov r0,r2
    mov r1,#24
    bl division
    mov r0,r2
    mov r8,r0
    mov r1,#(365 * 4 + 1)
    bl division
    lsl r9,r2,#2                   @ multiply by 4 = year1
    mov r1,#(365 * 4 + 1)
    mov r0,r8
    bl division
    mov r10,r3                     @ reste

    ldr r1,iAdrtbDayMonthYear
    mov r7,#3
    mov r3,#12
1:
    mul r8,r3,r7
    ldr r4,[r1,r8,lsl #2]          @ load days by year
    cmp r10,r4
    bge 2f
    sub r7,r7,#1
    cmp r7,#0
    bne 1b
2:                                 @ r7 = year2
    mov r5,#11
    mul r8,r3,r7
    lsl r8,#2
    add r8,r1
3:
    ldr r4,[r8,r5,lsl #2]          @ load days by month
    cmp r10,r4
    bge 4f
    subs r5,r5,#1
    bne 3b
4:                                 @ r5 = month - 1

    mov r0,r6                      @ number secondes depuis 01/01/2020
    ldr r1,iNbSecByDay
    bl division
    mov r0,r2
    mov r1,#7
    bl division
    add r2,r3,#2
    cmp r2,#7
    subge r2,#7
    ldr r1,iAdrtbDayName
    ldr r1,[r1,r2,lsl #2]
    ldr r0,iAdrszMessResult1
    bl strInsertAtCharInc          @ insert result at next @ character
    mov r3,r0
    mov r8,#12
    mul r11,r8,r7
    add r11,r5
    ldr r1,iAdrtbDayMonthYear
    ldr r8,[r1,r11,lsl #2]
    sub r0,r10,r8
    add r0,r0,#1                   @ final compute day
    ldr r1,iAdrsZoneConv
    bl conversion10                @ this function do not zero final
    mov r8,#0                      @ store zero final
    strb r8,[r1,r0]
    mov r0,r3
    ldr r1,iAdrsZoneConv
    bl strInsertAtCharInc          @ insert result at first @ character
    mov r3,r0
    ldr r1,iAdrtbMonthName
    cmp r5,#12
    subge r5,#12
    ldr r1,[r1,r5,lsl #2]          @ month name
    mov r0,r3
    bl strInsertAtCharInc          @ insert result at first @ character
    mov r3,r0
    ldr r0,iYearStart
    add r0,r7
    add r0,r9                      @ final compute year = 2020 + year1 + year2

    ldr r1,iAdrsZoneConv
    bl conversion10                @ this function do not zero final
    mov r8,#0                      @ store zero final
    strb r8,[r1,r0]
    mov r0,r3
    ldr r1,iAdrsZoneConv
    bl strInsertAtCharInc          @ insert result at first @ character
    bl affichageMess
100:
    pop {r1-r10,lr}                @ restaur registers
    bx lr                          @ return
iAdrszMessResult1:         .int szMessResult1
iSecJan2020:              .int 1577836800
iAdrtbDayMonthYear:       .int tbDayMonthYear
iYearStart:               .int 2020
iAdrtbMonthName:          .int tbMonthName
iAdrtbDayName:            .int tbDayName
iNbSecByDay:              .int 3600 * 24
/***************************************************/
/*      ROUTINES INCLUDE                 */
/***************************************************/
.include "../affichage.inc"