git.y1.nz

commit b75f9701da9212fa27759748afd85a341219d611
parent 53445a6b8e0287542193381bb5402906ebb7a024
Author: Michel Iwaniec <46843052+michel-iwaniec@users.noreply.github.com>
Date:   Thu,  4 Jan 2024 23:03:45 +0000

Merge pull request #607 from michel-iwaniec/nes_optimize_crt0_zeropage_use

NES: Trim away 2 bytes of zeropage
Diffstat:
M
gbdk-lib/libc/targets/mos6502/font.s
12
++++++------
M
gbdk-lib/libc/targets/mos6502/mode.s
4
++--
M
gbdk-lib/libc/targets/mos6502/nes/crt0.s
9
++++-----

3 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/gbdk-lib/libc/targets/mos6502/font.s b/gbdk-lib/libc/targets/mos6502/font.s
@@ -114,7 +114,7 @@ font_load_found:
         tya
         pha
         ; Only copy the tiles in if were in text mode
-        lda *.mode
+        lda .mode
         and #.T_MODE
         beq font_load_skip_copy_current
         jsr font_copy_current
@@ -217,7 +217,7 @@ font_set::
         bne 1$
 
 ; Now see if were checking special chars
-        lda *.mode
+        lda .mode
         and #.M_NO_INTERP
         bne 2$
         jsr .cr_curs
@@ -339,7 +339,7 @@ _gotoxy::
         rts
 
 _posx::
-        lda *.mode
+        lda .mode
         and #.T_MODE
         bne 1$
         jsr .tmode
@@ -348,7 +348,7 @@ _posx::
         rts
 
 _posy::
-        lda *.mode
+        lda .mode
         and #.T_MODE
         bne 1$
         jsr .tmode
@@ -401,7 +401,7 @@ _posy::
         jmp 99$
 2$:
         ;; See if scrolling is disabled
-        lda *.mode
+        lda .mode
         and #.M_NO_SCROLL
         beq 3$
         ;; Nope - reset the cursor to (0,0)
@@ -437,5 +437,5 @@ _posy::
         ;; Clear screen
         jsr .cls_no_reset_pos
         lda #.T_MODE
-        sta *.mode
+        sta .mode
         rts
diff --git a/gbdk-lib/libc/targets/mos6502/mode.s b/gbdk-lib/libc/targets/mos6502/mode.s
@@ -11,7 +11,7 @@
 
 _mode::
 .set_mode::
-    sta *.mode
+    sta .mode
     ;; AND to get rid of the extra flags
     and #0x03
     asl                     ; Multiply mode by 4
@@ -25,5 +25,5 @@ _mode::
     jmp [*temp_word]        ; Jump to initialization routine
 
 _get_mode::
-    lda *.mode
+    lda .mode
     rts
diff --git a/gbdk-lib/libc/targets/mos6502/nes/crt0.s b/gbdk-lib/libc/targets/mos6502/nes/crt0.s
@@ -42,6 +42,7 @@ _attribute_shadow       = 0x188
         .area _BASE
         ;; Constant data
         .area _LIT
+        .area _RODATA
         ;; Constant data, used to init _DATA
         .area _INITIALIZER
         .area _XINIT
@@ -66,10 +67,8 @@ _sys_time::                             .ds 2
 _shadow_PPUCTRL::                       .ds 1
 _shadow_PPUMASK::                       .ds 1
 __crt0_spritePageValid:                 .ds 1
-__crt0_NMI_Done:                        .ds 1
 __crt0_NMI_insideNMI:                   .ds 1
 __crt0_ScrollHV:                        .ds 1
-.mode::                                 .ds 1
 _bkg_scroll_x::                         .ds 1
 _bkg_scroll_y::                         .ds 1
 _attribute_row_dirty::                  .ds 1
@@ -80,6 +79,7 @@ _attribute_column_dirty::               .ds 1
 
 .area _BSS
 __crt0_paletteShadow::                  .ds 25
+.mode::                                 .ds 1
 
 .area _CODE
 
@@ -232,9 +232,6 @@ NotInsideNMI:
     lda *(_sys_time+1)
     adc #0
     sta *(_sys_time+1)
-
-    lda #0x80
-    sta __crt0_NMI_Done
     
     lda *_shadow_PPUCTRL
     ora *__crt0_ScrollHV
@@ -249,6 +246,8 @@ NotInsideNMI:
     nop
     nop
     nop
+    lda #0x00
+    lda 0x0000
     ; Call the handler
     jsr .jmp_to_LCD_isr
 

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