Merge PRGA_Reset into PRGC_Title

mdsteele · Aug 5, 2024 · 6a9707e · 6a9707e
1 parent 49602ab
commit 6a9707e
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Showing 4 changed files with 22 additions and 28 deletions.
diff --git a/src/linker.cfg b/src/linker.cfg
@@ -260,12 +260,11 @@ SEGMENTS {
   PRGA_Machine:      load=PRGA_15, type=ro;
   PRGA_Objects:      load=PRGA_17, type=ro;
   PRGA_Pause:        load=PRGA_19, type=ro;
-  PRGA_Reset:        load=PRGA_1B, type=ro;
-  PRGA_Room:         load=PRGA_1D, type=ro;
-  PRGA_Terrain:      load=PRGA_2F, type=ro;
-  PRGA_Pcm0:         load=PRGA_21, type=ro;
-  PRGA_Pcm1:         load=PRGA_23, type=ro;
-  PRGA_Pcm2:         load=PRGA_25, type=ro;
+  PRGA_Room:         load=PRGA_1B, type=ro;
+  PRGA_Terrain:      load=PRGA_1D, type=ro;
+  PRGA_Pcm0:         load=PRGA_1F, type=ro;
+  PRGA_Pcm1:         load=PRGA_21, type=ro;
+  PRGA_Pcm2:         load=PRGA_23, type=ro;
   # Fixed-bank PRG segments:
   PRG8:              load=PRG8,    type=ro;
   PRGE_Pcm:          load=PRGE,    type=ro, align=$100;

diff --git a/src/mmc3.asm b/src/mmc3.asm
@@ -33,7 +33,7 @@ Zp_MainSelect_bMmc3Bank: .res 1
 
 ;;;=========================================================================;;;
 
-.SEGMENT "PRGE_Reset"
+.SEGMENT "PRG8"
 
 ;;; Switches PRGA banks to the given bank number.  This is called by the
 ;;; main_prga macro in mmc3.inc.  Putting these few loads and stores in a
@@ -42,10 +42,6 @@ Zp_MainSelect_bMmc3Bank: .res 1
 ;;; adds up to a significant space savings.  (PRGC and CHR bank switches are
 ;;; less common, so we don't bother for those.)
 ;;;
-;;; This function must be in PRGE rather than PRG8, so that it can be used in
-;;; Main_Reset to initialize the MMC3 (PRG8 can't be used until the MMC3 has
-;;; been initialized).
-;;;
 ;;; @param A The PRGA bank number to switch to.
 ;;; @preserve X, Y, T0+
 .PROC FuncM_SwitchPrgaBank

diff --git a/src/reset.asm b/src/reset.asm
@@ -27,7 +27,7 @@
 .IMPORT Func_AudioReset
 .IMPORT Func_ClearRestOfOam
 .IMPORT Int_NoopIrq
-.IMPORT Main_Title
+.IMPORT MainC_Title_Menu
 .IMPORT Ppu_ChrBgFontLower
 .IMPORT Ppu_ChrObjAnnaNormal
 .IMPORTZP Zp_Active_sIrq
@@ -52,15 +52,24 @@ kSharedBgColor = $0f  ; black
     ;; Initialize stack pointer.
     dex  ; now x is $ff
     txs
-    ;; Set mapper PRG ROM bank for $a000 and jump to rest of reset code.
-    jmp_prga MainA_Reset_Ext
+    ;; Initialize the MMC and load PRGC_Title.  Since all NMI/IRQ interrupts
+    ;; are disabled at this point, we can just do this directly rather than
+    ;; using the main_prgc_bank macro, which uses extra instructions in order
+    ;; to be interrupt-safe.
+    lda #kSelectPrgc
+    sta Hw_Mmc3BankSelect_wo
+    lda #<.bank(MainC_Title_Reset)
+    sta Hw_Mmc3BankData_wo
+    ;; Jump to the rest of the reset code (stored in a swappable bank, to save
+    ;; valuable space in PRG8 and PRGE).
+    jmp MainC_Title_Reset
 .ENDPROC
 
 ;;;=========================================================================;;;
 
-.SEGMENT "PRGA_Reset"
+.SEGMENT "PRGC_Title"
 
-.PROC MainA_Reset_Ext
+.PROC MainC_Title_Reset
     ;; Enable SRAM, but disable writes for now.
     lda #bMmc3PrgRam::Enable | bMmc3PrgRam::DenyWrites
     sta Hw_Mmc3PrgRamProtect_wo
@@ -153,7 +162,7 @@ _Finish:
     sta Hw_PpuCtrl_wo        ; enable VBlank NMI
     sta Hw_Mmc3IrqEnable_wo  ; enable HBlank IRQ
     cli                      ; enable maskable (IRQ) interrupts
-    jmp Main_Title
+    jmp MainC_Title_Menu
 .ENDPROC
 
 ;;;=========================================================================;;;
diff --git a/src/title.asm b/src/title.asm
@@ -224,17 +224,6 @@ Ram_TitleLetterOffset_i8_arr: .res .sizeof(DataC_Title_Letters_u8_arr)
 
 ;;;=========================================================================;;;
 
-.SEGMENT "PRG8"
-
-;;; Mode for displaying the title screen.
-;;; @prereq Rendering is disabled.
-.EXPORT Main_Title
-.PROC Main_Title
-    jmp_prgc MainC_Title_Menu
-.ENDPROC
-
-;;;=========================================================================;;;
-
 .SEGMENT "PRGC_Title"
 
 ;;; The tile ID grid for the game title (stored in row-major order).
@@ -277,6 +266,7 @@ Ram_TitleLetterOffset_i8_arr: .res .sizeof(DataC_Title_Letters_u8_arr)
 ;;; Mode for displaying the title screen.
 ;;; @prereq PRGC_Title is loaded.
 ;;; @prereq Rendering is disabled.
+.EXPORT MainC_Title_Menu
 .PROC MainC_Title_Menu
     jsr FuncC_Title_InitAndFadeIn
 _GameLoop: