Mercurial > repos > blastem
changeset 887:fb4d09f874dd
Prevent the current interrupt number from being changed while interrupt is being processed. This fixes a bug in Sonic 2 split screen that showed up when interrupt timing was adjusted
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Sat, 14 Nov 2015 13:56:41 -0800 |
| parents | fb1f11fd0692 |
| children | bc127fa1f800 |
| files | m68k_core_x86.c |
| diffstat | 1 files changed, 6 insertions(+), 2 deletions(-) [+] |
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--- a/m68k_core_x86.c Sat Nov 14 10:01:43 2015 -0800 +++ b/m68k_core_x86.c Sat Nov 14 13:56:41 2015 -0800 @@ -2525,6 +2525,8 @@ mov_irdisp(code, 1, opts->gen.context_reg, offsetof(m68k_context, int_pending), SZ_B); retn(code); *do_int = code->cur - (do_int + 1); + //save interrupt number so it can't change during interrupt processing + push_rdisp(code, opts->gen.context_reg, offsetof(m68k_context, int_num)); //save PC as stored in scratch1 for later push_r(code, opts->gen.scratch1); //set target cycle to sync cycle @@ -2580,9 +2582,11 @@ add_ir(code, 2, opts->gen.scratch2, SZ_D); call(code, opts->write_32_lowfirst); - //calculate interrupt vector address - mov_rdispr(code, opts->gen.context_reg, offsetof(m68k_context, int_num), opts->gen.scratch1, SZ_D); + //restore saved interrupt number + pop_r(code, opts->gen.scratch1); + //ack the interrupt (happens earlier on hardware, but shouldn't be an observable difference) mov_rrdisp(code, opts->gen.scratch1, opts->gen.context_reg, offsetof(m68k_context, int_ack), SZ_W); + //calculate the vector address shl_ir(code, 2, opts->gen.scratch1, SZ_D); add_ir(code, 0x60, opts->gen.scratch1, SZ_D); call(code, opts->read_32);