cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
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__sdcc_critical.s (1755B)


      1;--------------------------------------------------------------------------
      2;  __sdcc_critical.s
      3;
      4;  Copyright (C) 2020, Sergey Belyashov
      5;
      6;  This library is free software; you can redistribute it and/or modify it
      7;  under the terms of the GNU General Public License as published by the
      8;  Free Software Foundation; either version 2, or (at your option) any
      9;  later version.
     10;
     11;  This library is distributed in the hope that it will be useful,
     12;  but WITHOUT ANY WARRANTY; without even the implied warranty of
     13;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     14;  GNU General Public License for more details.
     15;
     16;  You should have received a copy of the GNU General Public License 
     17;  along with this library; see the file COPYING. If not, write to the
     18;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
     19;   MA 02110-1301, USA.
     20;
     21;  As a special exception, if you link this library with other files,
     22;  some of which are compiled with SDCC, to produce an executable,
     23;  this library does not by itself cause the resulting executable to
     24;  be covered by the GNU General Public License. This exception does
     25;  not however invalidate any other reasons why the executable file
     26;   might be covered by the GNU General Public License.
     27;--------------------------------------------------------------------------
     28
     29	.area   _CODE
     30
     31	.globl ___sdcc_critical_enter
     32;
     33; NMOS Z80 compatible
     34; this function cannot be placed at 0x0000...0x00ff addresses
     35;
     36___sdcc_critical_enter::
     37	xor	a, a
     38	push	af
     39	pop	af
     40	ld	a, i
     41	di
     42	ret	pe	;enabled interrupts
     43	dec	sp
     44	dec	sp
     45	pop	af
     46	or	a, a	;A = 0 if interrupts disabled
     47	jr	NZ, 00100$
     48;inetrrupts disabled
     49	sub	a, a	;force P/V = 0
     50	ret
     51;interrupts enabled
     5200100$:
     53	xor	a, a	;force P/V = 1
     54	ret