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view runtime_win.S @ 1637:95880d947257
Fix for VRAM byte write order broke VDP FIFO testing ROM results. This change cleans up VRAM writes and fixes the regression while preserving the correct VRAM byte write order
author | Michael Pavone <pavone@retrodev.com> |
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date | Sun, 11 Nov 2018 22:39:29 -0800 |
parents | 80a67be1770b |
children |
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invalid_msg: .asciz "Invalid instruction at %X\n" .global _m68k_invalid _m68k_invalid: push %ecx push invalid_msg xor %eax, %eax call _printf push $1 call _exit .global _bcd_add _bcd_add: xchg %eax, %edi mov %cl, %ch mov %al, %ah and $0xF, %ch and $0xF, %ah and $0xF0, %cl and $0xF0, %al add %ah, %ch cmp $10, %ch jb no_adjust add $6, %ch no_adjust: add %ch, %al add %al, %cl mov $0, %ch jc def_adjust cmp $0xA0, %cl jb no_adjust_h def_adjust: add $0x60, %cl mov $1, %ch no_adjust_h: mov %edi, %eax ret .global _bcd_sub _bcd_sub: xchg %eax, %edi mov %cl, %ch mov %al, %ah and $0xF, %ch and $0xF, %ah and $0xF0, %cl and $0xF0, %al sub %ah, %ch cmp $10, %ch jb no_adjusts sub $6, %ch no_adjusts: add %ch, %cl sub %al, %cl mov $0, %ch jc def_adjusts cmp $0xA0, %cl jb no_adjust_hs def_adjusts: sub $0x60, %cl mov $1, %ch no_adjust_hs: mov %edi, %eax ret