kvisc/ka/crt/lib/time.k

; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; struct TIME
; {
;       byte sec;       +0      (0-59)
;       byte min;       +1      (0-59)
;       byte hour;      +2      (0-23)
;       byte mday;      +3      (0-31)
;       byte month;     +4      (0-11)
;       byte;           +5      (pad)
;       word year;      +6      (0-65536)
;       word yday;      +8      (0-365)
;       word;           +10     (pad)
;       dword;          +12     (pad)
; }                     16 bytes
;

;
; int DaysInYear(int year)
;
DaysInYear:
    mov rax, 365
    
    ; divisible by 4?
    rem rcx, ax0, 4
    jmp.cxnz .end

    ; divisible by 100?
    rem rcx, ax0, 100
    jmp.cxnz .leap

    ; divisible by 400?
    rem rcx, ax0, 400
    jmp.cxnz .end

.leap:
    inc rax, 1

.end:
    ret

;
; TIME *GetTimeUTC(void)
;
GetTimeUTC:
    ytime ax0, ax1, ax2
    mov rdx, .buf

    ; seconds
    rem rcx, ax0, 60
    mov b[rdx], rcx

    ; minutes
    div rcx, ax0, 60
    rem rcx, rcx, 60
    mov b[rdx+1], rcx

    ; hours
    div rcx, ax0, 3600
    rem rcx, rcx, 24
    mov b[rdx+2], rcx

    ; month days
    div rcx, ax0, 3600*24
    mov b[rdx+3], rcx

    ; month
    mov b[rdx+4], ax1

    ; years
    mov w[rdx+6], ax2

    ;
    ; ydays (TODO)
    ;

    mov rax, .buf
    ret

.buf = [24]