More RTC-related functions

4 files changed, 145 insertions, 2 deletions

diff --git a/home/time.asm b/home/time.asm
new file mode 100644
index 0000000..3eba96c
--- /dev/null
+++ b/home/time.asm
@@ -0,0 +1,138 @@
+include "constants.asm"
+
+SECTION "RTC and Time Functions", ROM0 [$042B]
+
+LatchClock: ; 42b (0:042b)
+	ld a, 0
+	ld [MBC3LatchClock], a
+	ld a, 1
+	ld [MBC3LatchClock], a
+	ret
+
+UpdateTime:: ; 436 (0:0436)
+	ldh a, [hRTCStatusFlags]
+	bit 0, a
+	ret nz
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+	call LatchClock
+	ld a, RTC_S
+	ld [MBC3SRamBank], a
+	ld a, [MBC3RTC]
+	and $7f
+	ldh [hRTCSeconds], a
+	ld a, RTC_M
+	ld [MBC3SRamBank], a
+	ld a, [MBC3RTC]
+	and $7f
+	ldh [hRTCMinutes], a
+	ld a, RTC_H
+	ld [MBC3SRamBank], a
+	ld a, [MBC3RTC]
+	and $1f
+	ldh [hRTCHours], a
+	call CloseSRAM
+	ld a, [wce63]
+	bit 1, a
+	jr z, .asm_0478
+	ld a, [wd153]
+	bit 7, a
+	jr nz, .asm_048a
+.asm_0478
+	ldh a, [hRTCHours]
+	ld b, a
+	ld hl, .Data_049c
+.asm_047e
+	ld a, [hli]
+	cp b
+	jr nc, .asm_0485
+	inc hl
+	jr .asm_047e
+
+.asm_0485
+	ld a, [hl]
+	ld [wTimeOfDay], a
+	ret
+
+.asm_048a
+	ldh a, [hRTCSeconds]
+	ld b, a
+	ld hl, .Data_04a4
+.asm_0490
+	ld a, [hli]
+	cp b
+	jr nc, .asm_0497
+	inc hl
+	jr .asm_0490
+
+.asm_0497
+	ld a, [hl]
+	ld [wTimeOfDay], a
+	ret
+
+.Data_049c:
+	db $06, $01
+	db $09, $03
+	db $0f, $00
+	db $18, $01
+
+.Data_04a4:
+	db $1e, $00
+	db $23, $01
+	db $32, $02
+	db $3b, $03
+	
+Function04ac::
+	ld hl, hRTCStatusFlags
+	set 0, [hl]
+	call Function04ea
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+	call LatchClock
+
+	ld a, RTC_S
+	ld [MBC3SRamBank], a
+	ld a, 0
+	ld [MBC3RTC], a
+
+	ld a, RTC_M
+	ld [MBC3SRamBank], a
+	ld a, [wStartMinute]
+	ld [MBC3RTC], a
+
+	ld a, RTC_H
+	ld [MBC3SRamBank], a
+	ld a, [wStartHour]
+	ld [MBC3RTC], a
+
+	ld a, [wStartDay]
+	ldh [hRTCDays], a
+
+	call CloseSRAM
+	ld hl, hRTCStatusFlags
+	res 0, [hl]
+	ret
+
+Function04ea:: ; 4ea (0:04ea)
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+	call LatchClock
+	ld a, RTC_DH
+	ld [MBC3SRamBank], a
+	ld a, [MBC3RTC]
+	set 6, a
+	ld [MBC3RTC], a
+	call CloseSRAM
+	ret
+
+Function0502:: ; 0502
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+	call LatchClock
+	ld a, RTC_DH
+	ld [MBC3SRamBank], a
+	ld a, [MBC3RTC]
+	res 6, a
+	ld [MBC3RTC], a
+	call CloseSRAM
+	ret
diff --git a/hram.asm b/hram.asm
index 8e59150..977c5b5 100644
--- a/hram.asm
+++ b/hram.asm
@@ -9,7 +9,9 @@ hRTCHours:: db ; ff8d
 hRTCMinutes:: db ; ff8e
 hRTCSeconds:: db ; ff8f
 hRTCDays:: db ; ff90
-    ds 6 ; TODO
+    ds 2 ; TODO
+hRTCStatusFlags:: db ; ff93
+	ds 3 ; TODO
 
 hVBlankCounter:: ; ff97
     db
diff --git a/shim.sym b/shim.sym
index 2a3fc3f..a052b10 100644
--- a/shim.sym
+++ b/shim.sym
@@ -1,5 +1,4 @@
 ; ROM0
-00:0436 UpdateTime
 00:051C Reset
 00:0D0A LoadFont
 00:0D1A LoadFontExtra
diff --git a/wram.asm b/wram.asm
index c0b1f13..01b5cf1 100644
--- a/wram.asm
+++ b/wram.asm
@@ -316,9 +316,13 @@ wcd26:: ; cd26
 
 SECTION "CD31", WRAM0[$CD31]
 
+wStartDay::
 wcd31:: ; cd31
     db
 
+wStartHour:: db
+wStartMinute:: db
+
 SECTION "CD3E", WRAM0[$CD3D]
 
 wRegularItemsCursor:: db ; cd3d