decompile fldeff_flash

4 files changed, 309 insertions, 754 deletions

diff --git a/asm/fldeff_flash.s b/asm/fldeff_flash.s
deleted file mode 100644
index dcd485d9f..000000000
--- a/asm/fldeff_flash.s
+++ /dev/null
@@ -1,753 +0,0 @@
-	.include "constants/gba_constants.inc"
-	.include "constants/species_constants.inc"
-	.include "asm/macros.inc"
-
-	.syntax unified
-
-	.text
-
-	thumb_func_start SetUpFieldMove_Flash
-SetUpFieldMove_Flash: @ 810CBB4
-	push {lr}
-	ldr r0, _0810CBDC @ =gMapHeader
-	ldrb r0, [r0, 0x15]
-	cmp r0, 0x1
-	bne _0810CBF4
-	ldr r0, _0810CBE0 @ =0x00000828
-	bl FlagGet
-	lsls r0, 24
-	cmp r0, 0
-	bne _0810CBF4
-	ldr r1, _0810CBE4 @ =gFieldCallback
-	ldr r0, _0810CBE8 @ =sub_808AB90
-	str r0, [r1]
-	ldr r1, _0810CBEC @ =gUnknown_03005CE4
-	ldr r0, _0810CBF0 @ =sub_810CBFC
-	str r0, [r1]
-	movs r0, 0x1
-	b _0810CBF6
-	.align 2, 0
-_0810CBDC: .4byte gMapHeader
-_0810CBE0: .4byte 0x00000828
-_0810CBE4: .4byte gFieldCallback
-_0810CBE8: .4byte sub_808AB90
-_0810CBEC: .4byte gUnknown_03005CE4
-_0810CBF0: .4byte sub_810CBFC
-_0810CBF4:
-	movs r0, 0
-_0810CBF6:
-	pop {r1}
-	bx r1
-	thumb_func_end SetUpFieldMove_Flash
-
-	thumb_func_start sub_810CBFC
-sub_810CBFC: @ 810CBFC
-	push {lr}
-	bl oei_task_add
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810CC24 @ =gUnknown_0202FF84
-	ldr r1, _0810CC28 @ =gLastFieldPokeMenuOpened
-	ldrb r1, [r1]
-	str r1, [r2]
-	ldr r2, _0810CC2C @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r1, r2
-	ldr r2, _0810CC30 @ =sub_810CC34
-	lsrs r0, r2, 16
-	strh r0, [r1, 0x18]
-	strh r2, [r1, 0x1A]
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CC24: .4byte gUnknown_0202FF84
-_0810CC28: .4byte gLastFieldPokeMenuOpened
-_0810CC2C: .4byte gTasks
-_0810CC30: .4byte sub_810CC34
-	thumb_func_end sub_810CBFC
-
-	thumb_func_start sub_810CC34
-sub_810CC34: @ 810CC34
-	push {lr}
-	movs r0, 0xCF
-	bl PlaySE
-	ldr r0, _0810CC4C @ =0x00000828
-	bl FlagSet
-	ldr r0, _0810CC50 @ =gUnknown_081B694A
-	bl ScriptContext1_SetupScript
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CC4C: .4byte 0x00000828
-_0810CC50: .4byte gUnknown_081B694A
-	thumb_func_end sub_810CC34
-
-	thumb_func_start sub_810CC54
-sub_810CC54: @ 810CC54
-	push {lr}
-	bl RunTasks
-	bl AnimateSprites
-	bl BuildOamBuffer
-	bl UpdatePaletteFade
-	pop {r0}
-	bx r0
-	thumb_func_end sub_810CC54
-
-	thumb_func_start sub_810CC6C
-sub_810CC6C: @ 810CC6C
-	push {lr}
-	bl LoadOam
-	bl ProcessSpriteCopyRequests
-	bl TransferPlttBuffer
-	pop {r0}
-	bx r0
-	thumb_func_end sub_810CC6C
-
-	thumb_func_start sub_810CC80
-sub_810CC80: @ 810CC80
-	push {r4,lr}
-	sub sp, 0x8
-	movs r0, 0
-	bl SetVBlankCallback
-	movs r0, 0x80
-	lsls r0, 19
-	movs r1, 0
-	strh r1, [r0]
-	adds r0, 0xC
-	strh r1, [r0]
-	subs r0, 0x2
-	strh r1, [r0]
-	subs r0, 0x2
-	strh r1, [r0]
-	adds r0, 0x10
-	strh r1, [r0]
-	adds r0, 0x2
-	strh r1, [r0]
-	subs r0, 0x6
-	strh r1, [r0]
-	adds r0, 0x2
-	strh r1, [r0]
-	subs r0, 0x6
-	strh r1, [r0]
-	adds r0, 0x2
-	strh r1, [r0]
-	mov r0, sp
-	strh r1, [r0]
-	ldr r1, _0810CD34 @ =0x040000d4
-	str r0, [r1]
-	movs r0, 0xC0
-	lsls r0, 19
-	str r0, [r1, 0x4]
-	ldr r0, _0810CD38 @ =0x8100c000
-	str r0, [r1, 0x8]
-	ldr r0, [r1, 0x8]
-	movs r4, 0
-	str r4, [sp, 0x4]
-	add r0, sp, 0x4
-	str r0, [r1]
-	movs r0, 0xE0
-	lsls r0, 19
-	str r0, [r1, 0x4]
-	ldr r0, _0810CD3C @ =0x85000100
-	str r0, [r1, 0x8]
-	ldr r0, [r1, 0x8]
-	mov r0, sp
-	strh r4, [r0]
-	str r0, [r1]
-	ldr r0, _0810CD40 @ =0x05000002
-	str r0, [r1, 0x4]
-	ldr r0, _0810CD44 @ =0x810001ff
-	str r0, [r1, 0x8]
-	ldr r0, [r1, 0x8]
-	bl ResetPaletteFade
-	bl ResetTasks
-	bl ResetSpriteData
-	ldr r3, _0810CD48 @ =0x04000208
-	ldrh r2, [r3]
-	strh r4, [r3]
-	ldr r4, _0810CD4C @ =0x04000200
-	ldrh r0, [r4]
-	movs r1, 0x1
-	orrs r0, r1
-	strh r0, [r4]
-	strh r2, [r3]
-	ldr r0, _0810CD50 @ =sub_810CC6C
-	bl SetVBlankCallback
-	ldr r0, _0810CD54 @ =sub_810CC54
-	bl SetMainCallback2
-	bl sub_810CD5C
-	lsls r0, 24
-	cmp r0, 0
-	bne _0810CD2A
-	ldr r0, _0810CD58 @ =gMain
-	ldr r0, [r0, 0x8]
-	bl SetMainCallback2
-_0810CD2A:
-	add sp, 0x8
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CD34: .4byte 0x040000d4
-_0810CD38: .4byte 0x8100c000
-_0810CD3C: .4byte 0x85000100
-_0810CD40: .4byte 0x05000002
-_0810CD44: .4byte 0x810001ff
-_0810CD48: .4byte 0x04000208
-_0810CD4C: .4byte 0x04000200
-_0810CD50: .4byte sub_810CC6C
-_0810CD54: .4byte sub_810CC54
-_0810CD58: .4byte gMain
-	thumb_func_end sub_810CC80
-
-	thumb_func_start sub_810CD5C
-sub_810CD5C: @ 810CD5C
-	push {r4-r7,lr}
-	bl get_map_light_from_warp0
-	lsls r0, 24
-	lsrs r6, r0, 24
-	bl sav1_map_get_light_level
-	lsls r0, 24
-	lsrs r5, r0, 24
-	movs r3, 0
-	ldr r4, _0810CD9C @ =gUnknown_083F7FC4
-	ldrb r0, [r4]
-	cmp r0, 0
-	beq _0810CDB0
-	adds r7, r4, 0
-	adds r0, r4, 0x4
-	mov r12, r0
-_0810CD7E:
-	lsls r2, r3, 3
-	adds r1, r2, r7
-	ldrb r0, [r1]
-	cmp r0, r6
-	bne _0810CDA0
-	ldrb r0, [r1, 0x1]
-	cmp r0, r5
-	bne _0810CDA0
-	mov r1, r12
-	adds r0, r2, r1
-	ldr r0, [r0]
-	bl _call_via_r0
-	movs r0, 0x1
-	b _0810CDB2
-	.align 2, 0
-_0810CD9C: .4byte gUnknown_083F7FC4
-_0810CDA0:
-	adds r0, r3, 0x1
-	lsls r0, 24
-	lsrs r3, r0, 24
-	lsls r0, r3, 3
-	adds r0, r4
-	ldrb r0, [r0]
-	cmp r0, 0
-	bne _0810CD7E
-_0810CDB0:
-	movs r0, 0
-_0810CDB2:
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_810CD5C
-
-	thumb_func_start sub_810CDB8
-sub_810CDB8: @ 810CDB8
-	push {r4-r6,lr}
-	lsls r0, 24
-	lsls r1, 24
-	lsrs r5, r0, 24
-	lsrs r4, r1, 24
-	movs r3, 0
-	ldr r1, _0810CDE4 @ =gUnknown_083F7FC4
-	ldrb r0, [r1]
-	cmp r0, 0
-	beq _0810CDF8
-	adds r6, r1, 0
-_0810CDCE:
-	lsls r0, r3, 3
-	adds r2, r0, r6
-	ldrb r0, [r2]
-	cmp r0, r5
-	bne _0810CDE8
-	ldrb r0, [r2, 0x1]
-	cmp r0, r4
-	bne _0810CDE8
-	ldrb r0, [r2, 0x2]
-	b _0810CDFA
-	.align 2, 0
-_0810CDE4: .4byte gUnknown_083F7FC4
-_0810CDE8:
-	adds r0, r3, 0x1
-	lsls r0, 24
-	lsrs r3, r0, 24
-	lsls r0, r3, 3
-	adds r0, r1
-	ldrb r0, [r0]
-	cmp r0, 0
-	bne _0810CDCE
-_0810CDF8:
-	movs r0, 0
-_0810CDFA:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_810CDB8
-
-	thumb_func_start fade_type_for_given_maplight_pair
-fade_type_for_given_maplight_pair: @ 810CE00
-	push {r4-r6,lr}
-	lsls r0, 24
-	lsls r1, 24
-	lsrs r5, r0, 24
-	lsrs r4, r1, 24
-	movs r3, 0
-	ldr r1, _0810CE2C @ =gUnknown_083F7FC4
-	ldrb r0, [r1]
-	cmp r0, 0
-	beq _0810CE40
-	adds r6, r1, 0
-_0810CE16:
-	lsls r0, r3, 3
-	adds r2, r0, r6
-	ldrb r0, [r2]
-	cmp r0, r5
-	bne _0810CE30
-	ldrb r0, [r2, 0x1]
-	cmp r0, r4
-	bne _0810CE30
-	ldrb r0, [r2, 0x3]
-	b _0810CE42
-	.align 2, 0
-_0810CE2C: .4byte gUnknown_083F7FC4
-_0810CE30:
-	adds r0, r3, 0x1
-	lsls r0, 24
-	lsrs r3, r0, 24
-	lsls r0, r3, 3
-	adds r0, r1
-	ldrb r0, [r0]
-	cmp r0, 0
-	bne _0810CE16
-_0810CE40:
-	movs r0, 0
-_0810CE42:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end fade_type_for_given_maplight_pair
-
-	thumb_func_start sub_810CE48
-sub_810CE48: @ 810CE48
-	push {lr}
-	ldr r0, _0810CE58 @ =sub_810CE5C
-	movs r1, 0
-	bl CreateTask
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CE58: .4byte sub_810CE5C
-	thumb_func_end sub_810CE48
-
-	thumb_func_start sub_810CE5C
-sub_810CE5C: @ 810CE5C
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810CE70 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r1, r2
-	ldr r0, _0810CE74 @ =sub_810CE78
-	str r0, [r1]
-	bx lr
-	.align 2, 0
-_0810CE70: .4byte gTasks
-_0810CE74: .4byte sub_810CE78
-	thumb_func_end sub_810CE5C
-
-	thumb_func_start sub_810CE78
-sub_810CE78: @ 810CE78
-	push {r4-r6,lr}
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	movs r6, 0x80
-	lsls r6, 19
-	movs r5, 0
-	strh r5, [r6]
-	ldr r0, _0810CEE8 @ =gCaveTransitionTiles
-	ldr r1, _0810CEEC @ =0x0600c000
-	bl LZ77UnCompVram
-	ldr r0, _0810CEF0 @ =gCaveTransitionTilemap
-	ldr r1, _0810CEF4 @ =0x0600f800
-	bl LZ77UnCompVram
-	ldr r0, _0810CEF8 @ =gCaveTransitionPalette_White
-	movs r1, 0xE0
-	movs r2, 0x20
-	bl LoadPalette
-	ldr r0, _0810CEFC @ =gUnknown_083F809C
-	movs r1, 0xE0
-	movs r2, 0x10
-	bl LoadPalette
-	ldr r1, _0810CF00 @ =REG_BLDCNT
-	ldr r2, _0810CF04 @ =0x00003e41
-	adds r0, r2, 0
-	strh r0, [r1]
-	ldr r0, _0810CF08 @ =REG_BLDALPHA
-	strh r5, [r0]
-	adds r0, 0x2
-	strh r5, [r0]
-	subs r1, 0x48
-	ldr r2, _0810CF0C @ =0x00001f0c
-	adds r0, r2, 0
-	strh r0, [r1]
-	movs r1, 0x8A
-	lsls r1, 5
-	adds r0, r1, 0
-	strh r0, [r6]
-	ldr r1, _0810CF10 @ =gTasks
-	lsls r0, r4, 2
-	adds r0, r4
-	lsls r0, 3
-	adds r0, r1
-	ldr r1, _0810CF14 @ =sub_810CF18
-	str r1, [r0]
-	movs r2, 0
-	movs r1, 0x10
-	strh r1, [r0, 0x8]
-	strh r2, [r0, 0xA]
-	pop {r4-r6}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CEE8: .4byte gCaveTransitionTiles
-_0810CEEC: .4byte 0x0600c000
-_0810CEF0: .4byte gCaveTransitionTilemap
-_0810CEF4: .4byte 0x0600f800
-_0810CEF8: .4byte gCaveTransitionPalette_White
-_0810CEFC: .4byte gUnknown_083F809C
-_0810CF00: .4byte REG_BLDCNT
-_0810CF04: .4byte 0x00003e41
-_0810CF08: .4byte REG_BLDALPHA
-_0810CF0C: .4byte 0x00001f0c
-_0810CF10: .4byte gTasks
-_0810CF14: .4byte sub_810CF18
-	thumb_func_end sub_810CE78
-
-	thumb_func_start sub_810CF18
-sub_810CF18: @ 810CF18
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810CF44 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r3, r1, r2
-	ldrh r2, [r3, 0xA]
-	movs r1, 0x80
-	lsls r1, 5
-	adds r0, r2, r1
-	lsls r0, 16
-	lsrs r0, 16
-	ldr r1, _0810CF48 @ =REG_BLDALPHA
-	strh r0, [r1]
-	cmp r2, 0x10
-	bhi _0810CF4C
-	ldrh r0, [r3, 0xA]
-	adds r0, 0x1
-	strh r0, [r3, 0xA]
-	b _0810CF54
-	.align 2, 0
-_0810CF44: .4byte gTasks
-_0810CF48: .4byte REG_BLDALPHA
-_0810CF4C:
-	movs r0, 0
-	strh r0, [r3, 0xC]
-	ldr r0, _0810CF58 @ =sub_810CF5C
-	str r0, [r3]
-_0810CF54:
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CF58: .4byte sub_810CF5C
-	thumb_func_end sub_810CF18
-
-	thumb_func_start sub_810CF5C
-sub_810CF5C: @ 810CF5C
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810CF94 @ =REG_BLDALPHA
-	ldr r3, _0810CF98 @ =0x00001010
-	adds r1, r3, 0
-	strh r1, [r2]
-	ldr r2, _0810CF9C @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r4, r1, r2
-	ldrh r1, [r4, 0xC]
-	cmp r1, 0x7
-	bhi _0810CFA4
-	adds r0, r1, 0x1
-	strh r0, [r4, 0xC]
-	lsls r1, 1
-	ldr r0, _0810CFA0 @ =gUnknown_083F809C
-	adds r0, r1, r0
-	movs r2, 0x10
-	subs r2, r1
-	lsls r2, 16
-	lsrs r2, 16
-	movs r1, 0xE0
-	bl LoadPalette
-	b _0810CFB6
-	.align 2, 0
-_0810CF94: .4byte REG_BLDALPHA
-_0810CF98: .4byte 0x00001010
-_0810CF9C: .4byte gTasks
-_0810CFA0: .4byte gUnknown_083F809C
-_0810CFA4:
-	ldr r0, _0810CFBC @ =gCaveTransitionPalette_White
-	movs r1, 0
-	movs r2, 0x20
-	bl LoadPalette
-	ldr r0, _0810CFC0 @ =sub_810CFC4
-	str r0, [r4]
-	movs r0, 0x8
-	strh r0, [r4, 0xC]
-_0810CFB6:
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CFBC: .4byte gCaveTransitionPalette_White
-_0810CFC0: .4byte sub_810CFC4
-	thumb_func_end sub_810CF5C
-
-	thumb_func_start sub_810CFC4
-sub_810CFC4: @ 810CFC4
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810CFE4 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r1, r2
-	ldrh r2, [r1, 0xC]
-	movs r3, 0xC
-	ldrsh r0, [r1, r3]
-	cmp r0, 0
-	beq _0810CFE8
-	subs r0, r2, 0x1
-	strh r0, [r1, 0xC]
-	b _0810CFF0
-	.align 2, 0
-_0810CFE4: .4byte gTasks
-_0810CFE8:
-	ldr r0, _0810CFF4 @ =gMain
-	ldr r0, [r0, 0x8]
-	bl SetMainCallback2
-_0810CFF0:
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810CFF4: .4byte gMain
-	thumb_func_end sub_810CFC4
-
-	thumb_func_start sub_810CFF8
-sub_810CFF8: @ 810CFF8
-	push {lr}
-	ldr r0, _0810D008 @ =sub_810D00C
-	movs r1, 0
-	bl CreateTask
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810D008: .4byte sub_810D00C
-	thumb_func_end sub_810CFF8
-
-	thumb_func_start sub_810D00C
-sub_810D00C: @ 810D00C
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810D020 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r1, r2
-	ldr r0, _0810D024 @ =sub_810D028
-	str r0, [r1]
-	bx lr
-	.align 2, 0
-_0810D020: .4byte gTasks
-_0810D024: .4byte sub_810D028
-	thumb_func_end sub_810D00C
-
-	thumb_func_start sub_810D028
-sub_810D028: @ 810D028
-	push {r4-r6,lr}
-	adds r5, r0, 0
-	lsls r5, 24
-	lsrs r5, 24
-	movs r6, 0x80
-	lsls r6, 19
-	movs r4, 0
-	strh r4, [r6]
-	ldr r0, _0810D098 @ =gCaveTransitionTiles
-	ldr r1, _0810D09C @ =0x0600c000
-	bl LZ77UnCompVram
-	ldr r0, _0810D0A0 @ =gCaveTransitionTilemap
-	ldr r1, _0810D0A4 @ =0x0600f800
-	bl LZ77UnCompVram
-	ldr r0, _0810D0A8 @ =REG_BLDCNT
-	strh r4, [r0]
-	adds r0, 0x2
-	strh r4, [r0]
-	adds r0, 0x2
-	strh r4, [r0]
-	ldr r1, _0810D0AC @ =REG_BG0CNT
-	ldr r2, _0810D0B0 @ =0x00001f0c
-	adds r0, r2, 0
-	strh r0, [r1]
-	movs r1, 0x8A
-	lsls r1, 5
-	adds r0, r1, 0
-	strh r0, [r6]
-	ldr r0, _0810D0B4 @ =gCaveTransitionPalette_White
-	movs r1, 0xE0
-	movs r2, 0x20
-	bl LoadPalette
-	ldr r0, _0810D0B8 @ =gCaveTransitionPalette_Black
-	movs r1, 0
-	movs r2, 0x20
-	bl LoadPalette
-	ldr r1, _0810D0BC @ =gTasks
-	lsls r0, r5, 2
-	adds r0, r5
-	lsls r0, 3
-	adds r0, r1
-	ldr r1, _0810D0C0 @ =sub_810D0C4
-	str r1, [r0]
-	movs r2, 0
-	movs r1, 0x10
-	strh r1, [r0, 0x8]
-	strh r2, [r0, 0xA]
-	strh r2, [r0, 0xC]
-	pop {r4-r6}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810D098: .4byte gCaveTransitionTiles
-_0810D09C: .4byte 0x0600c000
-_0810D0A0: .4byte gCaveTransitionTilemap
-_0810D0A4: .4byte 0x0600f800
-_0810D0A8: .4byte REG_BLDCNT
-_0810D0AC: .4byte REG_BG0CNT
-_0810D0B0: .4byte 0x00001f0c
-_0810D0B4: .4byte gCaveTransitionPalette_White
-_0810D0B8: .4byte gCaveTransitionPalette_Black
-_0810D0BC: .4byte gTasks
-_0810D0C0: .4byte sub_810D0C4
-	thumb_func_end sub_810D028
-
-	thumb_func_start sub_810D0C4
-sub_810D0C4: @ 810D0C4
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810D0F8 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r3, r1, r2
-	ldrh r1, [r3, 0xC]
-	cmp r1, 0xF
-	bhi _0810D100
-	adds r2, r1, 0x1
-	adds r0, r2, 0x1
-	strh r0, [r3, 0xC]
-	movs r0, 0xF
-	subs r0, r1
-	lsls r0, 1
-	ldr r1, _0810D0FC @ =gUnknown_083F808C
-	adds r0, r1
-	lsls r2, 17
-	lsrs r2, 16
-	movs r1, 0xE0
-	bl LoadPalette
-	b _0810D114
-	.align 2, 0
-_0810D0F8: .4byte gTasks
-_0810D0FC: .4byte gUnknown_083F808C
-_0810D100:
-	ldr r1, _0810D118 @ =REG_BLDALPHA
-	ldr r2, _0810D11C @ =0x00001010
-	adds r0, r2, 0
-	strh r0, [r1]
-	subs r1, 0x2
-	ldr r2, _0810D120 @ =0x00003e41
-	adds r0, r2, 0
-	strh r0, [r1]
-	ldr r0, _0810D124 @ =sub_810D128
-	str r0, [r3]
-_0810D114:
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810D118: .4byte REG_BLDALPHA
-_0810D11C: .4byte 0x00001010
-_0810D120: .4byte 0x00003e41
-_0810D124: .4byte sub_810D128
-	thumb_func_end sub_810D0C4
-
-	thumb_func_start sub_810D128
-sub_810D128: @ 810D128
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r2, _0810D158 @ =gTasks
-	lsls r1, r0, 2
-	adds r1, r0
-	lsls r1, 3
-	adds r3, r1, r2
-	ldrh r0, [r3, 0xA]
-	movs r1, 0x10
-	subs r1, r0
-	lsls r1, 16
-	movs r2, 0x80
-	lsls r2, 21
-	adds r0, r1, r2
-	lsrs r0, 16
-	ldr r2, _0810D15C @ =REG_BLDALPHA
-	strh r0, [r2]
-	cmp r1, 0
-	beq _0810D160
-	ldrh r0, [r3, 0xA]
-	adds r0, 0x1
-	strh r0, [r3, 0xA]
-	b _0810D172
-	.align 2, 0
-_0810D158: .4byte gTasks
-_0810D15C: .4byte REG_BLDALPHA
-_0810D160:
-	ldr r0, _0810D178 @ =gCaveTransitionPalette_Black
-	movs r1, 0
-	movs r2, 0x20
-	bl LoadPalette
-	ldr r0, _0810D17C @ =gMain
-	ldr r0, [r0, 0x8]
-	bl SetMainCallback2
-_0810D172:
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0810D178: .4byte gCaveTransitionPalette_Black
-_0810D17C: .4byte gMain
-	thumb_func_end sub_810D128
-	
-	.align 2, 0 @ Don't pad with nop.
diff --git a/include/field_effect.h b/include/field_effect.h
index cd84652b1..294844b3e 100644
--- a/include/field_effect.h
+++ b/include/field_effect.h
@@ -243,4 +243,6 @@ void MultiplyInvertedPaletteRGBComponents(u16, u8, u8, u8);
 void sub_80878A8(void);
 void sub_8087BA8(void);
 
+extern u32 gUnknown_0202FF84[8];
+
 #endif // GUARD_FIELD_EFFECT_H
diff --git a/ld_script.txt b/ld_script.txt
index 43fb78ecd..5bc3a4cee 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -213,7 +213,7 @@ SECTIONS {
         src/wallclock.o(.text);
         src/rom6.o(.text);
         src/pokeblock.o(.text);
-        asm/fldeff_flash.o(.text);
+        src/fldeff_flash.o(.text);
         src/post_battle_event_funcs.o(.text);
         src/time_events.o(.text);
         src/birch_pc.o(.text);
diff --git a/src/fldeff_flash.c b/src/fldeff_flash.c
new file mode 100644
index 000000000..6c2633567
--- /dev/null
+++ b/src/fldeff_flash.c
@@ -0,0 +1,306 @@
+#include "global.h"
+#include "event_data.h"
+#include "field_effect.h"
+#include "main.h"
+#include "palette.h"
+#include "pokemon_menu.h"
+#include "rom4.h"
+#include "rom6.h"
+#include "script.h"
+#include "songs.h"
+#include "sound.h"
+#include "sprite.h"
+#include "task.h"
+
+struct FlashStruct
+{
+    u8 unk0;
+    u8 unk1;
+    u8 unk2;
+    u8 unk3;
+    void (*func)(void);
+};
+
+extern struct FlashStruct gUnknown_083F7FC4[];
+extern u16 gCaveTransitionPalette_White[];
+extern u16 gCaveTransitionPalette_Black[];
+extern u16 gUnknown_083F808C[];
+extern u16 gUnknown_083F809C[];
+extern u16 gCaveTransitionTilemap[];
+extern u8 gCaveTransitionTiles[];
+
+extern u8 gLastFieldPokeMenuOpened;
+extern void (*gUnknown_03005CE4)(void);
+
+extern u8 gUnknown_081B694A[];
+
+void sub_810CBFC(void);
+void sub_810CC34(void);
+bool8 sub_810CD5C(void);
+void sub_810CE5C(u8);
+void sub_810CE78(u8);
+void sub_810CF18(u8);
+void sub_810CF5C(u8);
+void sub_810CFC4(u8);
+void sub_810D00C(u8);
+void sub_810D028(u8);
+void sub_810D0C4(u8);
+void sub_810D128(u8);
+
+bool8 SetUpFieldMove_Flash(void)
+{
+    if (gMapHeader.cave == TRUE && !FlagGet(SYS_USE_FLASH))
+    {
+        gFieldCallback = sub_808AB90;
+        gUnknown_03005CE4 = sub_810CBFC;
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+void sub_810CBFC(void)
+{
+    u8 taskId = oei_task_add();
+    gUnknown_0202FF84[0] = gLastFieldPokeMenuOpened;
+    gTasks[taskId].data[8] = (uintptr_t)sub_810CC34 >> 16;
+    gTasks[taskId].data[9] = (uintptr_t)sub_810CC34;
+}
+
+void sub_810CC34(void)
+{
+    PlaySE(SE_W115);
+    FlagSet(SYS_USE_FLASH);
+    ScriptContext1_SetupScript(gUnknown_081B694A);
+}
+
+void sub_810CC54(void)
+{
+    RunTasks();
+    AnimateSprites();
+    BuildOamBuffer();
+    UpdatePaletteFade();
+}
+
+static void VBlankCB(void)
+{
+    LoadOam();
+    ProcessSpriteCopyRequests();
+    TransferPlttBuffer();
+}
+
+void sub_810CC80(void)
+{
+    u16 ime;
+
+    SetVBlankCallback(NULL);
+    REG_DISPCNT = 0;
+    REG_BG2CNT = 0;
+    REG_BG1CNT = 0;
+    REG_BG0CNT = 0;
+    REG_BG2HOFS = 0;
+    REG_BG2VOFS = 0;
+    REG_BG1HOFS = 0;
+    REG_BG1VOFS = 0;
+    REG_BG0HOFS = 0;
+    REG_BG0VOFS = 0;
+    DmaFill16(3, 0, (void *)VRAM, VRAM_SIZE);
+    DmaFill32(3, 0, (void *)OAM, OAM_SIZE);
+    DmaFill16(3, 0, (void *)(PLTT + 2), PLTT_SIZE - 2);
+    ResetPaletteFade();
+    ResetTasks();
+    ResetSpriteData();
+    ime = REG_IME;
+    REG_IME = 0;
+    REG_IE |= INTR_FLAG_VBLANK;
+    REG_IME = ime;
+    SetVBlankCallback(VBlankCB);
+    SetMainCallback2(sub_810CC54);
+    if (!sub_810CD5C())
+        SetMainCallback2(gMain.savedCallback);
+}
+
+bool8 sub_810CD5C(void)
+{
+    u8 i;
+    u8 v0 = get_map_light_from_warp0();
+    u8 v1 = sav1_map_get_light_level();
+
+    for (i = 0; gUnknown_083F7FC4[i].unk0; i++)
+    {
+        if (gUnknown_083F7FC4[i].unk0 == v0 && gUnknown_083F7FC4[i].unk1 == v1)
+        {
+            gUnknown_083F7FC4[i].func();
+            return TRUE;
+        }
+    }
+
+    return FALSE;
+}
+
+u8 sub_810CDB8(u8 a1, u8 a2)
+{
+    u8 i;
+    u8 v0 = a1;
+    u8 v1 = a2;
+
+    for (i = 0; gUnknown_083F7FC4[i].unk0; i++)
+    {
+        if (gUnknown_083F7FC4[i].unk0 == v0 && gUnknown_083F7FC4[i].unk1 == v1)
+        {
+            return gUnknown_083F7FC4[i].unk2;
+        }
+    }
+
+    return FALSE;
+}
+
+u8 fade_type_for_given_maplight_pair(u8 a1, u8 a2)
+{
+    u8 i;
+    u8 v0 = a1;
+    u8 v1 = a2;
+
+    for (i = 0; gUnknown_083F7FC4[i].unk0; i++)
+    {
+        if (gUnknown_083F7FC4[i].unk0 == v0 && gUnknown_083F7FC4[i].unk1 == v1)
+        {
+            return gUnknown_083F7FC4[i].unk3;
+        }
+    }
+
+    return FALSE;
+}
+
+void sub_810CE48(void)
+{
+    CreateTask(sub_810CE5C, 0);
+}
+
+void sub_810CE5C(u8 taskId)
+{
+    gTasks[taskId].func = sub_810CE78;
+}
+
+void sub_810CE78(u8 taskId)
+{
+    REG_DISPCNT = 0;
+    LZ77UnCompVram(gCaveTransitionTiles, (void *)0x600C000);
+    LZ77UnCompVram(gCaveTransitionTilemap, (void *)0x600F800);
+    LoadPalette(gCaveTransitionPalette_White, 0xE0, 0x20);
+    LoadPalette(gUnknown_083F809C, 0xE0, 0x10);
+    REG_BLDCNT = 15937;
+    REG_BLDALPHA = 0;
+    REG_BLDY = 0;
+    REG_BG0CNT = 7948;
+    REG_DISPCNT = 4416;
+    gTasks[taskId].func = sub_810CF18;
+    gTasks[taskId].data[0] = 16;
+    gTasks[taskId].data[1] = 0;
+}
+
+void sub_810CF18(u8 taskId)
+{
+    u16 count = gTasks[taskId].data[1];
+    u16 blend = count + 0x1000;
+    REG_BLDALPHA = blend;
+    if (count <= 0x10)
+    {
+        gTasks[taskId].data[1]++;
+    }
+    else
+    {
+        gTasks[taskId].data[2] = 0;
+        gTasks[taskId].func = sub_810CF5C;
+    }
+}
+
+void sub_810CF5C(u8 taskId)
+{
+    u16 count;
+
+    REG_BLDALPHA = 4112;
+
+    count = gTasks[taskId].data[2];
+
+    if (count < 8)
+    {
+        gTasks[taskId].data[2]++;
+        LoadPalette(&gUnknown_083F809C[count], 0xE0, 16 - 2 * count);
+    }
+    else
+    {
+        LoadPalette(gCaveTransitionPalette_White, 0, 0x20);
+        gTasks[taskId].func = sub_810CFC4;
+        gTasks[taskId].data[2] = 8;
+    }
+}
+
+void sub_810CFC4(u8 taskId)
+{
+    if (gTasks[taskId].data[2])
+        gTasks[taskId].data[2]--;
+    else
+        SetMainCallback2(gMain.savedCallback);
+}
+
+void sub_810CFF8(void)
+{
+    CreateTask(sub_810D00C, 0);
+}
+
+void sub_810D00C(u8 taskId)
+{
+    gTasks[taskId].func = sub_810D028;
+}
+
+void sub_810D028(u8 taskId)
+{
+    REG_DISPCNT = 0;
+    LZ77UnCompVram(gCaveTransitionTiles, (void *)0x600C000);
+    LZ77UnCompVram(gCaveTransitionTilemap, (void *)0x600F800);
+    REG_BLDCNT = 0;
+    REG_BLDALPHA = 0;
+    REG_BLDY = 0;
+    REG_BG0CNT = 7948;
+    REG_DISPCNT = 4416;
+    LoadPalette(gCaveTransitionPalette_White, 0xE0, 0x20);
+    LoadPalette(gCaveTransitionPalette_Black, 0, 0x20);
+    gTasks[taskId].func = sub_810D0C4;
+    gTasks[taskId].data[0] = 16;
+    gTasks[taskId].data[1] = 0;
+    gTasks[taskId].data[2] = 0;
+}
+
+void sub_810D0C4(u8 taskId)
+{
+    u16 count = gTasks[taskId].data[2];
+    if (count < 16)
+    {
+        gTasks[taskId].data[2]++;
+        gTasks[taskId].data[2]++;
+        LoadPalette(&gUnknown_083F808C[15 - count], 0xE0, 2 * (count + 1));
+    }
+    else
+    {
+        REG_BLDALPHA = 4112;
+        REG_BLDCNT = 15937;
+        gTasks[taskId].func = sub_810D128;
+    }
+}
+
+void sub_810D128(u8 taskId)
+{
+    u16 count = 16 - gTasks[taskId].data[1];
+    u16 blend = count + 0x1000;
+    REG_BLDALPHA = blend;
+    if (count)
+    {
+        gTasks[taskId].data[1]++;
+    }
+    else
+    {
+        LoadPalette(gCaveTransitionPalette_Black, 0, 0x20);
+        SetMainCallback2(gMain.savedCallback);
+    }
+}