Mercurial > sdl-ios-xcode
view src/thread/linux/clone.S @ 892:dc29e5907694
Date: Sun, 18 Apr 2004 16:09:53 -0400 (EDT)
From: David MacCormack
Subject: [SDL] Linux joystick patch
I recently got myself a PS2 -> USB converter (a super joybox 5). It
accepts 4 PSX/PS2 controllers. It's implemented as a HID, which is nice
because it doesn't require its own driver, but the problem is that it's
implemented as a *single* HID -- that is, it shows up as a single
joystick with 19 axes, 4 hats, and 48 buttons. This poses a problem for a
number of apps which use SDL (stella, fce ultra, zsnes, to name a few) and
see only a single (physical) joystick even though there are really 4
(logical) joysticks. There are a number of these types of devices on the
market, and I've seen others post messages (in the zsnes forum, for
example) with the same problem, so I came up with what I think is a pretty
generic solution.
I patched src/joystick/linux/SDL_sysjoystic.c to include support for
logical joysticks; basically, it's a static array and supporting functions
that map a single physical joystick to multiple logical joysticks. The
attached patch has the new code. It's wrapped inside #ifndef
statements so that you can get the old behavior if you want.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 16 May 2004 18:46:24 +0000 (2004-05-16) |
parents | 74212992fb08 |
children | 974ba6ae0fa3 |
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/* Taken with thanks from LinuxThreads 0.6 */ /* This is no longer necessary with glibc-2.1, which has it's own clone() */ #ifdef linux /* Look to see if glibc is available, and if so, what version */ #include <features.h> #if (__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 1)) #define HAVE_CLONE #endif /* glibc 2.1 or newer */ #endif /* linux */ #if defined(linux) && !defined(SDL_USE_PTHREADS) && !defined(HAVE_CLONE) #if defined(__i386__) /************************************************************************/ /* Copyright (C) 1996, 1997 Free Software Foundation, Inc. Contributed by Richard Henderson (rth@tamu.edu) The GNU C 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. The GNU C 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 the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 675 Mass Ave, #ifdef SAVE_RCSID static char rcsid = "@(#) $Id$"; #endif Cambridge, MA 02139, USA. */ /* clone() is even more special than fork() as it mucks with stacks and invokes a function in the right context after its all over. */ #include <asm/errno.h> #include <asm/unistd.h> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ .text .align 4 .globl __clone .type __clone,@function .weak clone clone = __clone __clone: /* Sanity check arguments. */ movl $-EINVAL,%eax movl 4(%esp),%ecx /* no NULL function pointers */ testl %ecx,%ecx jz syscall_error movl 8(%esp),%ecx /* no NULL stack pointers */ testl %ecx,%ecx jz syscall_error /* Insert the argument onto the new stack. */ subl $8,%ecx movl 16(%esp),%eax movl %eax,4(%ecx) /* Save the function pointer as the zeroth argument. */ /* It will be popped off in the child in the ebx frobbing below. */ movl 4(%esp),%eax movl %eax,0(%ecx) /* Do the system call */ pushl %ebx movl 16(%esp),%ebx movl $__NR_clone,%eax int $0x80 popl %ebx test %eax,%eax jl syscall_error jz thread_start ret syscall_error: negl %eax pushl %eax #ifdef __PIC__ call __errno_location@PLT #else call __errno_location #endif popl 0(%eax) movl $-1, %eax ret thread_start: subl %ebp,%ebp /* terminate the stack frame */ call *%ebx pushl %eax #ifdef __PIC__ call _exit@PLT #else call _exit #endif /************************************************************************/ #elif defined(sparc) /************************************************************************/ /* Copyright (C) 1996, 1997 Free Software Foundation, Inc. Contributed by Miguel de Icaza (miguel@nuclecu.unam.mx) Based on code written for the Intel by Richard Henderson (rth@tamu.edu) The GNU C 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. The GNU C 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 the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* clone() is even more special than fork() as it mucks with stacks and invokes a function in the right context after its all over. */ #include <asm/errno.h> #include <asm/unistd.h> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ .text .align 4 .globl __clone .type __clone,@function .weak clone clone = __clone __clone: save %sp,-96,%sp /* sanity check arguments */ tst %i0 be __clone_syscall_error tst %i1 be __clone_syscall_error nop /* Do the system call */ mov %i1,%o1 mov %i2,%o0 set __NR_clone,%g1 ta 0x10 bcs __clone_syscall_error tst %o1 bne __thread_start nop mov %o0,%i0 ret restore __clone_syscall_error: call __errno_location set EINVAL,%i0 st %i0,[%o0] mov -1,%i0 ret restore __thread_start: call %i0 mov %i3,%o0 call _exit,0 nop /************************************************************************/ #else #error "Unknown Linux architecture" #endif #endif /* Linux && ! SDL_USE_PTHREADS */