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Diffstat (limited to 'sysdeps/unix/sysv/linux/arm/sysdep.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/arm/sysdep.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h new file mode 100644 index 0000000000..668aa1a2f1 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/sysdep.h @@ -0,0 +1,236 @@ +/* Copyright (C) 1992, 93, 1995-2000, 2002, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995. + ARM changes by Philip Blundell, <pjb27@cam.ac.uk>, May 1997. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _LINUX_ARM_SYSDEP_H +#define _LINUX_ARM_SYSDEP_H 1 + +/* There is some commonality. */ +#include <sysdeps/unix/arm/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 SWI_BASE (0x900000) +#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 R0 + 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. */ + +#undef PSEUDO +#define PSEUDO(name, syscall_name, args) \ + .text; \ + ENTRY (name); \ + DO_CALL (syscall_name, args); \ + cmn r0, $4096; + +#define PSEUDO_RET \ + RETINSTR(cc, lr); \ + b PLTJMP(SYSCALL_ERROR) +#undef ret +#define ret PSEUDO_RET + +#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); + +#define PSEUDO_RET_NOERRNO \ + DO_RET (lr); + +#undef ret_NOERRNO +#define ret_NOERRNO PSEUDO_RET_NOERRNO + +#undef PSEUDO_END_NOERRNO +#define PSEUDO_END_NOERRNO(name) \ + END (name) + +/* 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); \ + rsb r0, r0, #0 + +#undef PSEUDO_END_ERRVAL +#define PSEUDO_END_ERRVAL(name) \ + END (name) + +#define ret_ERRVAL PSEUDO_RET_NOERRNO + +#if NOT_IN_libc +# define SYSCALL_ERROR __local_syscall_error +# define SYSCALL_ERROR_HANDLER \ +__local_syscall_error: \ + str lr, [sp, #-4]!; \ + str r0, [sp, #-4]!; \ + bl PLTJMP(C_SYMBOL_NAME(__errno_location)); \ + ldr r1, [sp], #4; \ + rsb r1, r1, #0; \ + str r1, [r0]; \ + mvn r0, #0; \ + ldr pc, [sp], #4; +#else +# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ +# define SYSCALL_ERROR __syscall_error +#endif + +/* Linux takes system call args in registers: + syscall number in the SWI instruction + arg 1 r0 + arg 2 r1 + arg 3 r2 + arg 4 r3 + arg 5 r4 (this is different from the APCS convention) + arg 6 r5 + arg 7 r6 + + The compiler is going to form a call by coming here, through PSEUDO, with + arguments + syscall number in the DO_CALL macro + arg 1 r0 + arg 2 r1 + arg 3 r2 + arg 4 r3 + arg 5 [sp] + arg 6 [sp+4] + arg 7 [sp+8] + + We need to shuffle values between R4..R6 and the stack so that the + caller's v1..v3 and stack frame are not corrupted, and the kernel + sees the right arguments. + +*/ + +#undef DO_CALL +#define DO_CALL(syscall_name, args) \ + DOARGS_##args \ + swi SYS_ify (syscall_name); \ + UNDOARGS_##args + +#define DOARGS_0 /* nothing */ +#define DOARGS_1 /* nothing */ +#define DOARGS_2 /* nothing */ +#define DOARGS_3 /* nothing */ +#define DOARGS_4 /* nothing */ +#define DOARGS_5 str r4, [sp, $-4]!; ldr r4, [sp, $4]; +#define DOARGS_6 mov ip, sp; stmfd sp!, {r4, r5}; ldmia ip, {r4, r5}; +#define DOARGS_7 mov ip, sp; stmfd sp!, {r4, r5, r6}; ldmia ip, {r4, r5, r6}; + +#define UNDOARGS_0 /* nothing */ +#define UNDOARGS_1 /* nothing */ +#define UNDOARGS_2 /* nothing */ +#define UNDOARGS_3 /* nothing */ +#define UNDOARGS_4 /* nothing */ +#define UNDOARGS_5 ldr r4, [sp], $4; +#define UNDOARGS_6 ldmfd sp!, {r4, r5}; +#define UNDOARGS_7 ldmfd sp!, {r4, r5, r6}; + +#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) + +#undef INTERNAL_SYSCALL +#define INTERNAL_SYSCALL(name, err, nr, args...) \ + ({ unsigned int _sys_result; \ + { \ + register int _a1 asm ("a1"); \ + LOAD_ARGS_##nr (args) \ + asm volatile ("swi %1 @ syscall " #name \ + : "=r" (_a1) \ + : "i" (SYS_ify(name)) ASM_ARGS_##nr \ + : "memory"); \ + _sys_result = _a1; \ + } \ + (int) _sys_result; }) + +#undef INTERNAL_SYSCALL_ERROR_P +#define INTERNAL_SYSCALL_ERROR_P(val, err) \ + ((unsigned int) (val) >= 0xfffff001u) + +#undef INTERNAL_SYSCALL_ERRNO +#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) + +#define LOAD_ARGS_0() +#define ASM_ARGS_0 +#define LOAD_ARGS_1(a1) \ + _a1 = (int) (a1); \ + LOAD_ARGS_0 () +#define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1) +#define LOAD_ARGS_2(a1, a2) \ + register int _a2 asm ("a2") = (int) (a2); \ + LOAD_ARGS_1 (a1) +#define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2) +#define LOAD_ARGS_3(a1, a2, a3) \ + register int _a3 asm ("a3") = (int) (a3); \ + LOAD_ARGS_2 (a1, a2) +#define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3) +#define LOAD_ARGS_4(a1, a2, a3, a4) \ + register int _a4 asm ("a4") = (int) (a4); \ + LOAD_ARGS_3 (a1, a2, a3) +#define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4) +#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \ + register int _v1 asm ("v1") = (int) (a5); \ + LOAD_ARGS_4 (a1, a2, a3, a4) +#define ASM_ARGS_5 ASM_ARGS_4, "r" (_v1) +#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \ + register int _v2 asm ("v2") = (int) (a6); \ + LOAD_ARGS_5 (a1, a2, a3, a4, a5) +#define ASM_ARGS_6 ASM_ARGS_5, "r" (_v2) +#define LOAD_ARGS_7(a1, a2, a3, a4, a5, a6, a7) \ + register int _v3 asm ("v3") = (int) (a7); \ + LOAD_ARGS_6 (a1, a2, a3, a4, a5, a6) +#define ASM_ARGS_7 ASM_ARGS_6, "r" (_v3) + +#endif /* __ASSEMBLER__ */ + +#endif /* linux/arm/sysdep.h */ |