git.y1.nz

commit 371c705f862c49bde17fbae0ad441f216915d52f
parent 9a559a426a209ae93ed786ea021bb517caf0987f
Author: Toxa <56631470+untoxa@users.noreply.github.com>
Date:   Wed, 31 Aug 2022 23:10:09 +0300

Merge pull request #403 from michel-iwaniec/nes_relocate_attribute_shadow

NES: Fix bug with global initialized data being initialized to zero
Diffstat:
M
gbdk-lib/libc/targets/mos6502/nes/crt0.s
5
++---
M
gbdk-lib/libc/targets/mos6502/nes/set_bk_attributes.s
4
+++-

2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/gbdk-lib/libc/targets/mos6502/nes/crt0.s b/gbdk-lib/libc/targets/mos6502/nes/crt0.s
@@ -10,6 +10,8 @@
 
 ; OAM CPU page
 _shadow_OAM             = 0x200
+; Attribute shadow (64 bytes, leaving 56 bytes available for CPU stack)
+_attribute_shadow       = 0x188
 ; Transfer buffer (lower half of hardware stack)
 _vram_transfer_buffer   = 0x100
 
@@ -98,9 +100,6 @@ _attribute_row_dirty::                  .ds 1
         .area _HEAP
         .area _HEAP_END
 
-.area DATA
-_attribute_shadow::     .ds 64
-
 .area CODE
 
 .bndry 0x100
diff --git a/gbdk-lib/libc/targets/mos6502/nes/set_bk_attributes.s b/gbdk-lib/libc/targets/mos6502/nes/set_bk_attributes.s
@@ -89,9 +89,11 @@ _set_bkg_attributes::
     asl
     asl
     ora *.xpos
-    ora #<_attribute_shadow
+    clc
+    adc #<_attribute_shadow
     sta *.dst
     lda #>_attribute_shadow
+    adc #0
     sta *.dst+1
     jsr .attribute_set_dirty
     ; Branch into distinct routines based on whether x / y are aligned

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