From d6f20ae74619fa4b3071867016fa7ae7253df98f Mon Sep 17 00:00:00 2001
From: Adelaide Walter <adelaidekwalter@gmail.com>
Date: Mon, 8 Jan 2018 17:13:37 -0500
Subject: Use BANK for hardcoded SRAM banks (except for vestigial refs to JP's
 banks 4-7)

---
 engine/save.asm | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'engine/save.asm')

diff --git a/engine/save.asm b/engine/save.asm
index af24b4d2f..a869d903e 100644
--- a/engine/save.asm
+++ b/engine/save.asm
@@ -418,7 +418,7 @@ EraseHallOfFame: ; 14d06
 Function14d18: ; 14d18
 ; XXX
 ; copy .Data to SRA4:a007
-	ld a, $4
+	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	ld hl, .Data
 	ld de, $a007
@@ -454,7 +454,7 @@ SaveData: ; 14d68
 
 Function14d6c: ; 14d6c
 ; XXX
-	ld a, $4
+	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	ld a, [$a60b]
 	ld b, $0
@@ -471,7 +471,7 @@ Function14d6c: ; 14d6c
 
 Function14d83: ; 14d83
 ; XXX
-	ld a, $4
+	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	xor a
 	ld [$a60c], a
@@ -482,7 +482,7 @@ Function14d83: ; 14d83
 
 Function14d93: ; 14d93
 ; XXX
-	ld a, $7
+	ld a, 7 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	xor a
 	ld [$a000], a
-- 
cgit v1.2.3


From 94f32db7bc4a5e4e4d8837d3110d0876146783af Mon Sep 17 00:00:00 2001
From: Adelaide Walter <adelaidekwalter@gmail.com>
Date: Mon, 8 Jan 2018 22:48:58 -0500
Subject: Document hardcoded SRAM addresses.

---
 engine/save.asm | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

(limited to 'engine/save.asm')

diff --git a/engine/save.asm b/engine/save.asm
index a869d903e..12e5964b9 100644
--- a/engine/save.asm
+++ b/engine/save.asm
@@ -421,7 +421,7 @@ Function14d18: ; 14d18
 	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	ld hl, .Data
-	ld de, $a007
+	ld de, $a007 ; address of MBC30 bank
 	ld bc, .DataEnd - .Data
 	call CopyBytes
 	jp CloseSRAM
@@ -456,7 +456,7 @@ Function14d6c: ; 14d6c
 ; XXX
 	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
-	ld a, [$a60b]
+	ld a, [$a60b] ; address of MBC30 bank
 	ld b, $0
 	and a
 	jr z, .ok
@@ -464,7 +464,7 @@ Function14d6c: ; 14d6c
 
 .ok
 	ld a, b
-	ld [$a60b], a
+	ld [$a60b], a ; address of MBC30 bank
 	call CloseSRAM
 	ret
 ; 14d83
@@ -474,8 +474,8 @@ Function14d83: ; 14d83
 	ld a, 4 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	xor a
-	ld [$a60c], a
-	ld [$a60d], a
+	ld [$a60c], a ; address of MBC30 bank
+	ld [$a60d], a ; address of MBC30 bank
 	call CloseSRAM
 	ret
 ; 14d93
@@ -485,7 +485,7 @@ Function14d93: ; 14d93
 	ld a, 7 ; MBC30 bank used by JP Crystal; inaccessible by MBC3
 	call GetSRAMBank
 	xor a
-	ld [$a000], a
+	ld [$a000], a ; address of MBC30 bank
 	call CloseSRAM
 	ret
 ; 14da0
@@ -873,6 +873,11 @@ VerifyBackupChecksum: ; 1507c (5:507c)
 
 
 _SaveData: ; 1509a
+	; This is called within two scenarios:
+	;   a) ErasePreviousSave (the process of erasing the save from a previous game file)
+	;   b) unused mobile functionality
+	; It is not part of a regular save.
+	
 	ld a, BANK(sCrystalData)
 	call GetSRAMBank
 	ld hl, wCrystalData
@@ -880,7 +885,11 @@ _SaveData: ; 1509a
 	ld bc, wCrystalDataEnd - wCrystalData
 	call CopyBytes
 
-	; XXX SRAM bank 7
+	; This block originally had some mobile functionality, but since we're still in
+	; BANK(sCrystalData), it instead overwrites the sixteen EventFlags starting at 1:a603 with
+	; garbage from wd479. This isn't an issue, since ErasePreviousSave is followed by a regular
+	; save that unwrites the garbage.
+	
 	ld hl, wd479
 	ld a, [hli]
 	ld [$a60e + 0], a
@@ -897,8 +906,10 @@ _LoadData: ; 150b9
 	ld de, wCrystalData
 	ld bc, wCrystalDataEnd - wCrystalData
 	call CopyBytes
-
-	; XXX SRAM bank 7
+	
+	; This block originally had some mobile functionality to mirror _SaveData above, but instead it
+	; (harmlessly) writes the aforementioned EventFlags to the unused wd479.
+	
 	ld hl, wd479
 	ld a, [$a60e + 0]
 	ld [hli], a
-- 
cgit v1.2.3