Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_m68k.c @ 4355:9b464226e541 SDL-1.2
Fixed bug #855
Ludwig Nussel 2009-10-18 06:31:52 PDT
an mprotect call was added to fix bug 528. However that results in a buffer
that allows writing and code execution. Ie the no-execute security features of
modern operating systems are defeated this way. Two mprotect calls are needed.
One to make the buffer executable but not writeable when done and another one
to make the buffer writeable again if the content needs to be changed.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 18 Oct 2009 17:31:37 +0000 |
parents | a1b03ba2fcd0 |
children | 124629b76853 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* m68k assembly mix routines Patrice Mandin */ #if defined(__M68000__) && defined(__GNUC__) void SDL_MixAudio_m68k_U8(char* dst, char* src, long len, long volume, char* mix8) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_u8\n" "mixloop_u8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " sub #128,%%d0\n" /* d0 -= 128 */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add #128,%%d0\n" /* d0 += 128 */ " add %%d1,%%d0\n" " moveb %4@(%%d0:w),%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_u8\n" "stoploop_u8:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8) : /* clobbered registers */ "d0", "d1", "cc", "memory" ); } void SDL_MixAudio_m68k_S8(char* dst, char* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s8\n" " moveq #-128,%%d2\n" " moveq #127,%%d3\n" "mixloop_s8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add %%d1,%%d0\n" " cmp %%d2,%%d0\n" " bges lower_limit_s8\n" " move %%d2,%%d0\n" "lower_limit_s8:\n" " cmp %%d3,%%d0\n" " bles upper_limit_s8\n" " move %%d3,%%d0\n" "upper_limit_s8:\n" " moveb %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s8\n" "stoploop_s8:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } void SDL_MixAudio_m68k_S16MSB(short* dst, short* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s16msb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16msb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16msb\n" " move %%d2,%%d0\n" "lower_limit_s16msb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16msb\n" " move %%d3,%%d0\n" "upper_limit_s16msb:\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16msb\n" "stoploop_s16msb:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } void SDL_MixAudio_m68k_S16LSB(short* dst, short* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s16lsb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16lsb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " rorw #8,%%d0\n" " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " rorw #8,%%d1\n" " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16lsb\n" " move %%d2,%%d0\n" "lower_limit_s16lsb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16lsb\n" " move %%d3,%%d0\n" "upper_limit_s16lsb:\n" " rorw #8,%%d0\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16lsb\n" "stoploop_s16lsb:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } #endif