git.y1.nz

commit c2bdc936b37300f0e8adc43d1a7b21eef583cee5
parent 827817c4ad0c24e3ccbec75291225744d82b73ba
Author: Toxa <56631470+untoxa@users.noreply.github.com>
Date:   Sat,  8 Jul 2023 23:55:53 +0300

Merge pull request #535 from michel-iwaniec/nes_move_palette_shadow_to_regular_ram

NES: Move palette shadow from zeropage to regular RAM
Diffstat:
M
gbdk-lib/libc/targets/mos6502/nes/crt0.s
56
++++++++++++++++++++------------------------------------
M
gbdk-lib/libc/targets/mos6502/nes/global.s
2
+-
M
gbdk-lib/libc/targets/mos6502/nes/nes_palettes.s
8
++++----

3 files changed, 25 insertions(+), 41 deletions(-)
diff --git a/gbdk-lib/libc/targets/mos6502/nes/crt0.s b/gbdk-lib/libc/targets/mos6502/nes/crt0.s
@@ -23,15 +23,15 @@ b_wait_frames = 0
     sta PPUADDR
     lda #<0x3F00
     sta PPUADDR
-    ldx *__crt0_paletteShadow
+    ldx __crt0_paletteShadow
     i = 0
 .rept 8
     stx PPUDATA
-    lda *(__crt0_paletteShadow+1+3*i+0)
+    lda (__crt0_paletteShadow+1+3*i+0)
     sta PPUDATA
-    lda *(__crt0_paletteShadow+1+3*i+1)
+    lda (__crt0_paletteShadow+1+3*i+1)
     sta PPUDATA
-    lda *(__crt0_paletteShadow+1+3*i+2)
+    lda (__crt0_paletteShadow+1+3*i+2)
     sta PPUDATA
     i = i + 1
 .endm
@@ -69,7 +69,6 @@ __current_bank::                        .ds 1
 _sys_time::                             .ds 2
 _shadow_PPUCTRL::                       .ds 1
 _shadow_PPUMASK::                       .ds 1
-__crt0_paletteShadow::                  .ds 25
 __crt0_spritePageValid:                 .ds 1
 __crt0_NMI_Done:                        .ds 1
 __crt0_NMI_insideNMI:                   .ds 1
@@ -83,6 +82,9 @@ _attribute_column_dirty::               .ds 1
 
 .define __crt0_NMITEMP "___SDCC_m6502_ret4"
 
+.area _BSS
+__crt0_paletteShadow::                  .ds 25
+
 .area _CODE
 
 .bndry 0x100
@@ -273,39 +275,21 @@ __crt0_IRQ:
 __crt0_setPalette:
     ; Set background color to 30 (white)
     lda #0x30
-    sta *__crt0_paletteShadow
+    sta __crt0_paletteShadow
     ; set all background / sprite sub-palettes to 10, 00, 1D
+    ldx #0x1F
+1$:
+    lda #0x1D
+    sta __crt0_paletteShadow,x
+    dex
+    lda #0x00
+    sta __crt0_paletteShadow,x
+    dex
     lda #0x10
-    ldx #0x00
-    ldy #0x1D
-    ;
-    sta *(__crt0_paletteShadow+1)
-    sta *(__crt0_paletteShadow+1+12)
-    stx *(__crt0_paletteShadow+2)
-    stx *(__crt0_paletteShadow+2+12)
-    sty *(__crt0_paletteShadow+3)
-    sty *(__crt0_paletteShadow+3+12)
-    ;
-    sta *(__crt0_paletteShadow+4)
-    sta *(__crt0_paletteShadow+4+12)
-    stx *(__crt0_paletteShadow+5)
-    stx *(__crt0_paletteShadow+5+12)
-    sty *(__crt0_paletteShadow+6)
-    sty *(__crt0_paletteShadow+6+12)
-    ;
-    sta *(__crt0_paletteShadow+7)
-    sta *(__crt0_paletteShadow+7+12)
-    stx *(__crt0_paletteShadow+8)
-    stx *(__crt0_paletteShadow+8+12)
-    sty *(__crt0_paletteShadow+9)
-    sty *(__crt0_paletteShadow+9+12)
-    ;
-    sta *(__crt0_paletteShadow+10)
-    sta *(__crt0_paletteShadow+10+12)
-    stx *(__crt0_paletteShadow+11)
-    stx *(__crt0_paletteShadow+11+12)
-    sty *(__crt0_paletteShadow+12)
-    sty *(__crt0_paletteShadow+12+12)
+    sta __crt0_paletteShadow,x
+    dex
+    dex
+    bpl 1$
     rts
 
 __crt0_waitPPU:
diff --git a/gbdk-lib/libc/targets/mos6502/nes/global.s b/gbdk-lib/libc/targets/mos6502/nes/global.s
@@ -1,7 +1,7 @@
         ;; Transfer buffer (lower half of hardware stack)
         __vram_transfer_buffer = 0x100
         ;; Number of 8-cycles available each frame for transfer buffer
-        VRAM_DELAY_CYCLES_X8  = 170
+        VRAM_DELAY_CYCLES_X8  = 167
 
         ;;  Keypad
         .UP             = 0x10
diff --git a/gbdk-lib/libc/targets/mos6502/nes/nes_palettes.s b/gbdk-lib/libc/targets/mos6502/nes/nes_palettes.s
@@ -47,7 +47,7 @@ _set_sprite_palette::
     stx *.tmp
     tax
     lda [*.src],y
-    sta *__crt0_paletteShadow,x
+    sta __crt0_paletteShadow,x
     ldx *.tmp
 1$:
     inx
@@ -72,12 +72,12 @@ _set_bkg_palette_entry::
     adc .identity,x
     tax
     lda *.src
-    sta *__crt0_paletteShadow+1,x
+    sta __crt0_paletteShadow+1,x
     rts
 2$:
     ; Set UBC
     lda *.src
-    sta *__crt0_paletteShadow
+    sta __crt0_paletteShadow
     rts
 
 ; void set_sprite_palette_entry(uint8_t palette, uint8_t entry, palette_color_t rgb_data) OLDCALL;
@@ -94,7 +94,7 @@ _set_sprite_palette_entry::
     adc .identity,x
     tax
     lda *.src
-    sta *__crt0_paletteShadow+13,x
+    sta __crt0_paletteShadow+13,x
     rts
 
 .paletteShadowLUT:

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