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Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/m68k/sysdep.h')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/m68k/sysdep.h | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/m68k/sysdep.h b/ports/sysdeps/unix/sysv/linux/m68k/sysdep.h new file mode 100644 index 0000000000..b288712541 --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/m68k/sysdep.h @@ -0,0 +1,326 @@ +/* Copyright (C) 1996, 1997, 1998, 2000, 2003, 2004, 2006, 2010, 2012 + 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#include <tls.h> + +/* Defines RTLD_PRIVATE_ERRNO. */ +#include <dl-sysdep.h> + +/* For Linux we can use the system call table in the header file + /usr/include/asm/unistd.h + of the kernel. But these symbols do not follow the SYS_* syntax + so we have to redefine the `SYS_ify' macro here. */ +#undef SYS_ify +#define SYS_ify(syscall_name) __NR_##syscall_name + +#ifdef __ASSEMBLER__ + +/* Linux uses a negative return value to indicate syscall errors, unlike + most Unices, which use the condition codes' carry flag. + + Since version 2.1 the return value of a system call might be negative + even if the call succeeded. E.g., the `lseek' system call might return + a large offset. Therefore we must not anymore test for < 0, but test + for a real error by making sure the value in %d0 is a real error + number. Linus said he will make sure the no syscall returns a value + in -1 .. -4095 as a valid result so we can savely test with -4095. */ + +/* We don't want the label for the error handler to be visible in the symbol + table when we define it here. */ +#ifdef PIC +#define SYSCALL_ERROR_LABEL .Lsyscall_error +#else +#define SYSCALL_ERROR_LABEL __syscall_error +#endif + +#undef PSEUDO +#define PSEUDO(name, syscall_name, args) \ + .text; \ + ENTRY (name) \ + DO_CALL (syscall_name, args); \ + cmp.l &-4095, %d0; \ + jcc SYSCALL_ERROR_LABEL + +#undef PSEUDO_END +#define PSEUDO_END(name) \ + SYSCALL_ERROR_HANDLER; \ + END (name) + +#undef PSEUDO_NOERRNO +#define PSEUDO_NOERRNO(name, syscall_name, args) \ + .text; \ + ENTRY (name) \ + DO_CALL (syscall_name, args) + +#undef PSEUDO_END_NOERRNO +#define PSEUDO_END_NOERRNO(name) \ + END (name) + +#define ret_NOERRNO rts + +/* The function has to return the error code. */ +#undef PSEUDO_ERRVAL +#define PSEUDO_ERRVAL(name, syscall_name, args) \ + .text; \ + ENTRY (name) \ + DO_CALL (syscall_name, args); \ + negl %d0 + +#undef PSEUDO_END_ERRVAL +#define PSEUDO_END_ERRVAL(name) \ + END (name) + +#define ret_ERRVAL rts + +#ifdef PIC +# if RTLD_PRIVATE_ERRNO +# define SYSCALL_ERROR_HANDLER \ +SYSCALL_ERROR_LABEL: \ + PCREL_OP (lea, rtld_errno, %a0, %a0); \ + neg.l %d0; \ + move.l %d0, (%a0); \ + move.l &-1, %d0; \ + /* Copy return value to %a0 for syscalls that are declared to return \ + a pointer (e.g., mmap). */ \ + move.l %d0, %a0; \ + rts; +# elif defined _LIBC_REENTRANT +# ifndef NOT_IN_libc +# define SYSCALL_ERROR_ERRNO __libc_errno +# else +# define SYSCALL_ERROR_ERRNO errno +# endif +# define SYSCALL_ERROR_HANDLER \ +SYSCALL_ERROR_LABEL: \ + neg.l %d0; \ + move.l %d0, -(%sp); \ + cfi_adjust_cfa_offset (4); \ + jbsr __m68k_read_tp@PLTPC; \ + SYSCALL_ERROR_LOAD_GOT (%a1); \ + add.l (SYSCALL_ERROR_ERRNO@TLSIE, %a1), %a0; \ + move.l (%sp)+, (%a0); \ + cfi_adjust_cfa_offset (-4); \ + move.l &-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 /* !_LIBC_REENTRANT */ +/* Store (- %d0) into errno through the GOT. */ +# define SYSCALL_ERROR_HANDLER \ +SYSCALL_ERROR_LABEL: \ + move.l (errno@GOTPC, %pc), %a0; \ + neg.l %d0; \ + move.l %d0, (%a0); \ + move.l &-1, %d0; \ + /* Copy return value to %a0 for syscalls that are declared to return \ + a pointer (e.g., mmap). */ \ + move.l %d0, %a0; \ + rts; +# endif /* _LIBC_REENTRANT */ +#else +# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ +#endif /* PIC */ + +/* 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 + arg 6 %a0 call-clobbered + + The stack layout upon entering the function is: + + 24(%sp) Arg# 6 + 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_name, args) \ + move.l &SYS_ify(syscall_name), %d0; \ + DOARGS_##args \ + trap &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; cfi_register (%d2, %a0); \ + move.l n(%sp), %d2; _DOARGS_1 (n-4) +#define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2; cfi_restore (%d2) + +#define DOARGS_3 _DOARGS_3 (12) +#define _DOARGS_3(n) move.l %d3, %a1; cfi_register (%d3, %a1); \ + move.l n(%sp), %d3; _DOARGS_2 (n-4) +#define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3; cfi_restore (%d3) + +#define DOARGS_4 _DOARGS_4 (16) +#define _DOARGS_4(n) move.l %d4, -(%sp); \ + cfi_adjust_cfa_offset (4); cfi_rel_offset (%d4, 0); \ + move.l n+4(%sp), %d4; _DOARGS_3 (n) +#define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4; \ + cfi_adjust_cfa_offset (-4); cfi_restore (%d4) + +#define DOARGS_5 _DOARGS_5 (20) +#define _DOARGS_5(n) move.l %d5, -(%sp); \ + cfi_adjust_cfa_offset (4); cfi_rel_offset (%d5, 0); \ + move.l n+4(%sp), %d5; _DOARGS_4 (n) +#define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5; \ + cfi_adjust_cfa_offset (-4); cfi_restore (%d5) + +#define DOARGS_6 _DOARGS_6 (24) +#define _DOARGS_6(n) _DOARGS_5 (n-4); move.l %a0, -(%sp); \ + cfi_adjust_cfa_offset (4); \ + move.l n+12(%sp), %a0; +#define UNDOARGS_6 move.l (%sp)+, %a0; cfi_adjust_cfa_offset (-4); \ + UNDOARGS_5 + + +#define ret rts +#if 0 /* Not used by Linux */ +#define r0 %d0 +#define r1 %d1 +#define MOVE(x,y) movel x , y +#endif + +#else /* not __ASSEMBLER__ */ + +/* Define a macro which expands into the inline wrapper code for a system + call. */ +#undef INLINE_SYSCALL +#define INLINE_SYSCALL(name, nr, args...) \ + ({ unsigned int _sys_result = INTERNAL_SYSCALL (name, , nr, args); \ + if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0))\ + { \ + __set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \ + _sys_result = (unsigned int) -1; \ + } \ + (int) _sys_result; }) + +#undef INTERNAL_SYSCALL_DECL +#define INTERNAL_SYSCALL_DECL(err) do { } while (0) + +/* Define a macro which expands inline into the wrapper code for a system + call. This use is for internal calls that do not need to handle errors + normally. It will never touch errno. This returns just what the kernel + gave back. */ +#undef INTERNAL_SYSCALL +#define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ + ({ unsigned int _sys_result; \ + { \ + /* Load argument values in temporary variables + to perform side effects like function calls + before the call used registers are set. */ \ + LOAD_ARGS_##nr (args) \ + LOAD_REGS_##nr \ + register int _d0 asm ("%d0") = name; \ + asm volatile ("trap #0" \ + : "=d" (_d0) \ + : "0" (_d0) ASM_ARGS_##nr \ + : "memory"); \ + _sys_result = _d0; \ + } \ + (int) _sys_result; }) +#define INTERNAL_SYSCALL(name, err, nr, args...) \ + INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args) + +#undef INTERNAL_SYSCALL_ERROR_P +#define INTERNAL_SYSCALL_ERROR_P(val, err) \ + ((unsigned int) (val) >= -4095U) + +#undef INTERNAL_SYSCALL_ERRNO +#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) + +#define LOAD_ARGS_0() +#define LOAD_REGS_0 +#define ASM_ARGS_0 +#define LOAD_ARGS_1(a1) \ + LOAD_ARGS_0 () \ + int __arg1 = (int) (a1); +#define LOAD_REGS_1 \ + register int _d1 asm ("d1") = __arg1; \ + LOAD_REGS_0 +#define ASM_ARGS_1 ASM_ARGS_0, "d" (_d1) +#define LOAD_ARGS_2(a1, a2) \ + LOAD_ARGS_1 (a1) \ + int __arg2 = (int) (a2); +#define LOAD_REGS_2 \ + register int _d2 asm ("d2") = __arg2; \ + LOAD_REGS_1 +#define ASM_ARGS_2 ASM_ARGS_1, "d" (_d2) +#define LOAD_ARGS_3(a1, a2, a3) \ + LOAD_ARGS_2 (a1, a2) \ + int __arg3 = (int) (a3); +#define LOAD_REGS_3 \ + register int _d3 asm ("d3") = __arg3; \ + LOAD_REGS_2 +#define ASM_ARGS_3 ASM_ARGS_2, "d" (_d3) +#define LOAD_ARGS_4(a1, a2, a3, a4) \ + LOAD_ARGS_3 (a1, a2, a3) \ + int __arg4 = (int) (a4); +#define LOAD_REGS_4 \ + register int _d4 asm ("d4") = __arg4; \ + LOAD_REGS_3 +#define ASM_ARGS_4 ASM_ARGS_3, "d" (_d4) +#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \ + LOAD_ARGS_4 (a1, a2, a3, a4) \ + int __arg5 = (int) (a5); +#define LOAD_REGS_5 \ + register int _d5 asm ("d5") = __arg5; \ + LOAD_REGS_4 +#define ASM_ARGS_5 ASM_ARGS_4, "d" (_d5) +#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \ + LOAD_ARGS_5 (a1, a2, a3, a4, a5) \ + int __arg6 = (int) (a6); +#define LOAD_REGS_6 \ + register int _a0 asm ("a0") = __arg6; \ + LOAD_REGS_5 +#define ASM_ARGS_6 ASM_ARGS_5, "a" (_a0) + +#endif /* not __ASSEMBLER__ */ + +/* Pointer mangling is not yet supported for M68K. */ +#define PTR_MANGLE(var) (void) (var) +#define PTR_DEMANGLE(var) (void) (var) + +#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO +/* M68K needs system-supplied DSO to access TLS helpers + even when statically linked. */ +# define NEED_STATIC_SYSINFO_DSO 1 +#endif |