diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/m68k/sysdep.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/m68k/sysdep.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/m68k/sysdep.h b/sysdeps/unix/sysv/linux/m68k/sysdep.h new file mode 100644 index 0000000000..9b6c8e1975 --- /dev/null +++ b/sysdeps/unix/sysv/linux/m68k/sysdep.h @@ -0,0 +1,131 @@ +/* Copyright (C) 1996 Free Software Foundation, Inc. +This file is part of the GNU C Library. +Written by Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>, +December 1995. + +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. */ + +/* In the Linux/ELF world, C symbols are asm symbols. */ +#define NO_UNDERSCORES + +#include <sysdeps/unix/sysdep.h> + +#ifdef ASSEMBLER + +#define POUND # + +/* Define an entry point visible from C. */ +#define ENTRY(name) \ + .globl name; \ + .type name, @function; \ + .align 4; \ + name##: + +/* Since C identifiers are not normally prefixed with an underscore + on this system, the asm identifier `syscall_error' intrudes on the + C name space. Make sure we use an innocuous name. */ +#define syscall_error __syscall_error + +/* Linux uses a negative return value to indicate syscall errors, unlike + most Unices, which use the condition codes' carry flag. */ +#define PSEUDO(name, syscall_name, args) \ + .text; \ + SYSCALL_ERROR_HANDLER \ + ENTRY (name) \ + DO_CALL (POUND SYS_ify (syscall_name), args); \ + tst.l %d0; \ + jmi syscall_error; + +#ifdef PIC +/* Store (- %d0) into errno through the GOT. */ +#define SYSCALL_ERROR_HANDLER \ +syscall_error: \ + move.l (errno@GOTPC.l, %pc), %a0; \ + neg.l %d0; \ + move.l %d0, (%a0); \ + move.l POUND -1, %d0; \ + /* Copy return value to %a0 for syscalls that are declared to return \ + a pointer (e.g., mmap). */ \ + move.l %d0, %a0; \ + rts; +#else +#define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ +#endif + +/* Linux takes system call arguments in registers: + + syscall number %d0 call-clobbered + arg 1 %d1 call-clobbered + arg 2 %d2 call-saved + arg 3 %d3 call-saved + arg 4 %d4 call-saved + arg 5 %d5 call-saved + + The stack layout upon entering the function is: + + 20(%sp) Arg# 5 + 16(%sp) Arg# 4 + 12(%sp) Arg# 3 + 8(%sp) Arg# 2 + 4(%sp) Arg# 1 + (%sp) Return address + + (Of course a function with say 3 arguments does not have entries for + arguments 4 and 5.) + + Separate move's are faster than movem, but need more space. Since + speed is more important, we don't use movem. Since %a0 and %a1 are + scratch registers, we can use them for saving as well. */ + +#define DO_CALL(syscall, args) \ + move.l syscall, %d0; \ + DOARGS_##args \ + trap POUND 0; \ + UNDOARGS_##args + +#define DOARGS_0 /* No arguments to frob. */ +#define UNDOARGS_0 /* No arguments to unfrob. */ +#define _DOARGS_0(n) /* No arguments to frob. */ + +#define DOARGS_1 _DOARGS_1 (4) +#define _DOARGS_1(n) move.l n(%sp), %d1; _DOARGS_0 (n) +#define UNDOARGS_1 UNDOARGS_0 + +#define DOARGS_2 _DOARGS_2 (8) +#define _DOARGS_2(n) move.l %d2, %a0; move.l n(%sp), %d2; _DOARGS_1 (n-4) +#define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2 + +#define DOARGS_3 _DOARGS_3 (12) +#define _DOARGS_3(n) move.l %d3, %a1; move.l n(%sp), %d3; _DOARGS_2 (n-4) +#define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3 + +#define DOARGS_4 _DOARGS_4 (16) +#define _DOARGS_4(n) move.l %d4, -(%sp); move.l n+4(%sp), %d4; _DOARGS_3 (n) +#define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4 + +#define DOARGS_5 _DOARGS_5 (20) +#define _DOARGS_5(n) move.l %d5, -(%sp); move.l n+4(%sp), %d5; _DOARGS_4 (n) +#define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5 + + +#define ret rts +#if 0 /* Not used by Linux */ +#define r0 %d0 +#define r1 %d1 +#define MOVE(x,y) movel x , y +#endif + +#endif /* ASSEMBLER */ |