6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-11-05 08:05:51 +00:00
Code Issues Projects Releases Wiki Activity
6d560f4236
cc65/libsrc/c64/settime.s

85 lines
1.8 KiB
ArmAsm
Raw Normal View History

Added clock_settime() for some CBMs. The CIA TOD only stores the time but not the date. Therefore the date set by clock_settime() ist just stored inside the C library for retrieval via clock_gettime(). The "very special" handling of 12AM/PM is based on https://groups.google.com/d/msg/comp.sys.cbm/ysVYSX4AMbc/vHrXCWEhCOUJ saying: ========== 24hr: Wr => Rd => Nx -------------------- 0 : 92 => 12 => 01 <= Switch from 00 to 01 (24-hour notation) 1 : 01 => 01 => 02 2 : 02 => 02 => 03 11 : 11 => 11 => 92 12 : 12 => 92 => 81 <= Switch from 12 to 13 (24-hour notation) 13 : 81 => 81 => 82 14 : 82 => 82 => 83 23 : 91 => 91 => 12 1. column ("24hr"): hour to be tested (decimal) 2. column ("Wr"): hour written to TOD register (BCD) 3. column ("Rd"): hour read from TOD register (BCD) immediately after writing the value in column 2 to see the conversion between AM/PM, if any 4. column ("Nx"): next hour (BCD) after the hour switch ========== Thanks Paul!
2018-08-17 23:13:02 +00:00
;
; Oliver Schmidt, 16.8.2018
;
Adjusted comments to match actual prototypes.
2018-11-06 10:13:23 +00:00
; int __fastcall__ clock_settime (clockid_t clk_id, const struct timespec *tp);
Added clock_settime() for some CBMs. The CIA TOD only stores the time but not the date. Therefore the date set by clock_settime() ist just stored inside the C library for retrieval via clock_gettime(). The "very special" handling of 12AM/PM is based on https://groups.google.com/d/msg/comp.sys.cbm/ysVYSX4AMbc/vHrXCWEhCOUJ saying: ========== 24hr: Wr => Rd => Nx -------------------- 0 : 92 => 12 => 01 <= Switch from 00 to 01 (24-hour notation) 1 : 01 => 01 => 02 2 : 02 => 02 => 03 11 : 11 => 11 => 92 12 : 12 => 92 => 81 <= Switch from 12 to 13 (24-hour notation) 13 : 81 => 81 => 82 14 : 82 => 82 => 83 23 : 91 => 91 => 12 1. column ("24hr"): hour to be tested (decimal) 2. column ("Wr"): hour written to TOD register (BCD) 3. column ("Rd"): hour read from TOD register (BCD) immediately after writing the value in column 2 to see the conversion between AM/PM, if any 4. column ("Nx"): next hour (BCD) after the hour switch ========== Thanks Paul!
2018-08-17 23:13:02 +00:00
;
.include "time.inc"
.include "c64.inc"
.importzp sreg, ptr1
.import pushax, pusheax, ldax0sp, ldeaxidx
.import tosdiveax, incsp3, return0
.import TM, load_tenth
;----------------------------------------------------------------------------
.code
.proc _clock_settime
jsr pushax
Express assumption about struct timespec. We basically cast a struct timespec pointer to a time_t pointer when we pass the clock_settime() paramter to localtime(). Explicitly express that in the source code.
2018-08-17 23:28:30 +00:00
.assert timespec::tv_sec = 0, error
Added clock_settime() for some CBMs. The CIA TOD only stores the time but not the date. Therefore the date set by clock_settime() ist just stored inside the C library for retrieval via clock_gettime(). The "very special" handling of 12AM/PM is based on https://groups.google.com/d/msg/comp.sys.cbm/ysVYSX4AMbc/vHrXCWEhCOUJ saying: ========== 24hr: Wr => Rd => Nx -------------------- 0 : 92 => 12 => 01 <= Switch from 00 to 01 (24-hour notation) 1 : 01 => 01 => 02 2 : 02 => 02 => 03 11 : 11 => 11 => 92 12 : 12 => 92 => 81 <= Switch from 12 to 13 (24-hour notation) 13 : 81 => 81 => 82 14 : 82 => 82 => 83 23 : 91 => 91 => 12 1. column ("24hr"): hour to be tested (decimal) 2. column ("Wr"): hour written to TOD register (BCD) 3. column ("Rd"): hour read from TOD register (BCD) immediately after writing the value in column 2 to see the conversion between AM/PM, if any 4. column ("Nx"): next hour (BCD) after the hour switch ========== Thanks Paul!
2018-08-17 23:13:02 +00:00
jsr _localtime
sta ptr1
stx ptr1+1
ldy #.sizeof(tm)-1
@L1: lda (ptr1),y
sta TM,y
dey
bpl @L1
lda TM + tm::tm_hour
jsr dec2BCD
tax ; Force flags
bne @L2
lda #$92 ; 12 AM
bne @L3
@L2: cmp #$13 ; 1 PM
bcc @L3
sed
sbc #$12
cld
ora #%10000000
@L3: sta CIA1_TODHR
lda TM + tm::tm_min
jsr dec2BCD
sta CIA1_TODMIN
lda TM + tm::tm_sec
jsr dec2BCD
sta CIA1_TODSEC
jsr ldax0sp
ldy #3+timespec::tv_nsec
jsr ldeaxidx
jsr pusheax
jsr load_tenth
jsr tosdiveax
sta CIA1_TOD10
jsr incsp3
jmp return0
.endproc
;----------------------------------------------------------------------------
; Just sum up the value in BCD mode.
; http://forum.6502.org/viewtopic.php?p=7629#p7629
.proc dec2BCD
tax
dex
bmi @L9
lda #0
clc
sed
@L1: adc #1
dex
bpl @L1
cld
@L9: rts
.endproc
Reference in New Issue Copy Permalink