| /* Assembler macros for ARM. |
| Copyright (C) 1997, 1998, 2003 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| 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 |
| |
| #include <common/sysdep.h> |
| #include <bits/arm_asm.h> |
| |
| #include <sys/syscall.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__ |
| |
| /* Syntactic details of assembler. */ |
| |
| #define ALIGNARG(log2) log2 |
| /* For ELF we need the `.type' directive to make shared libs work right. */ |
| #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,%##typearg; |
| #define ASM_SIZE_DIRECTIVE(name) .size name,.-name |
| |
| /* In ELF C symbols are asm symbols. */ |
| #undef NO_UNDERSCORES |
| #define NO_UNDERSCORES |
| |
| #define PLTJMP(_x) _x##(PLT) |
| |
| /* APCS-32 doesn't preserve the condition codes across function call. */ |
| #ifdef __APCS_32__ |
| #define LOADREGS(cond, base, reglist...)\ |
| ldm##cond base,reglist |
| #ifdef __USE_BX__ |
| #define RETINSTR(cond, reg) \ |
| bx##cond reg |
| #define DO_RET(_reg) \ |
| bx _reg |
| #else |
| #define RETINSTR(cond, reg) \ |
| mov##cond pc, reg |
| #define DO_RET(_reg) \ |
| mov pc, _reg |
| #endif |
| #else /* APCS-26 */ |
| #define LOADREGS(cond, base, reglist...) \ |
| ldm##cond base,reglist^ |
| #define RETINSTR(cond, reg) \ |
| mov##cond##s pc, reg |
| #define DO_RET(_reg) \ |
| movs pc, _reg |
| #endif |
| |
| /* Define an entry point visible from C. */ |
| #define ENTRY(name) \ |
| ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \ |
| ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),function) \ |
| .align ALIGNARG(4); \ |
| name##: \ |
| CALL_MCOUNT |
| |
| #undef END |
| #define END(name) \ |
| ASM_SIZE_DIRECTIVE(name) |
| |
| /* If compiled for profiling, call `mcount' at the start of each function. */ |
| #ifdef PROF |
| #define CALL_MCOUNT \ |
| str lr,[sp, #-4]! ; \ |
| bl PLTJMP(mcount) ; \ |
| ldr lr, [sp], #4 ; |
| #else |
| #define CALL_MCOUNT /* Do nothing. */ |
| #endif |
| |
| #ifdef NO_UNDERSCORES |
| /* 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 |
| #define mcount _mcount |
| #endif |
| /* 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 safely |
| 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 defined NOT_IN_libc |
| # define SYSCALL_ERROR __local_syscall_error |
| # ifdef RTLD_PRIVATE_ERRNO |
| # define SYSCALL_ERROR_HANDLER \ |
| __local_syscall_error: \ |
| ldr r1, 1f; \ |
| rsb r0, r0, #0; \ |
| 0: str r0, [pc, r1]; \ |
| mvn r0, #0; \ |
| DO_RET(lr); \ |
| 1: .word C_SYMBOL_NAME(rtld_errno) - 0b - 8; |
| # else |
| # 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; |
| # endif |
| #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 |
| #if defined(__ARM_EABI__) |
| #define DO_CALL(syscall_name, args) \ |
| DOARGS_##args \ |
| mov ip, r7; \ |
| ldr r7, =SYS_ify (syscall_name); \ |
| swi 0x0; \ |
| mov r7, ip; \ |
| UNDOARGS_##args |
| #else |
| #define DO_CALL(syscall_name, args) \ |
| DOARGS_##args \ |
| swi SYS_ify (syscall_name); \ |
| UNDOARGS_##args |
| #endif |
| |
| #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 _inline_sys_result = INTERNAL_SYSCALL (name, , nr, args); \ |
| if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_inline_sys_result, ), 0)) \ |
| { \ |
| __set_errno (INTERNAL_SYSCALL_ERRNO (_inline_sys_result, )); \ |
| _inline_sys_result = (unsigned int) -1; \ |
| } \ |
| (int) _inline_sys_result; }) |
| |
| #undef INTERNAL_SYSCALL_DECL |
| #define INTERNAL_SYSCALL_DECL(err) do { } while (0) |
| |
| #undef INTERNAL_SYSCALL_RAW |
| #if defined(__thumb__) |
| /* Hide the use of r7 from the compiler, this would be a lot |
| * easier but for the fact that the syscalls can exceed 255. |
| * For the moment the LOAD_ARG_7 is sacrificed. |
| * We can't use push/pop inside the asm because that breaks |
| * unwinding (ie. thread cancellation). |
| */ |
| #define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \ |
| ({ unsigned int _internal_sys_result; \ |
| { \ |
| int _sys_buf[2]; \ |
| register int __a1 __asm__ ("a1"); \ |
| register int *_v3 __asm__ ("v3") = _sys_buf; \ |
| LOAD_ARGS_##nr (args) \ |
| *_v3 = (int) (name); \ |
| __asm__ __volatile__ ("str r7, [v3, #4]\n" \ |
| "\tldr r7, [v3]\n" \ |
| "\tswi 0 @ syscall " #name "\n" \ |
| "\tldr r7, [v3, #4]" \ |
| : "=r" (__a1) \ |
| : "r" (_v3) ASM_ARGS_##nr \ |
| : "memory"); \ |
| _internal_sys_result = __a1; \ |
| } \ |
| (int) _internal_sys_result; }) |
| #elif defined(__ARM_EABI__) |
| #define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \ |
| ({unsigned int _internal_sys_result; \ |
| { \ |
| register int __a1 __asm__ ("r0"), _nr __asm__ ("r7"); \ |
| LOAD_ARGS_##nr (args) \ |
| _nr = name; \ |
| __asm__ __volatile__ ("swi 0x0 @ syscall " #name \ |
| : "=r" (__a1) \ |
| : "r" (_nr) ASM_ARGS_##nr \ |
| : "memory"); \ |
| _internal_sys_result = __a1; \ |
| } \ |
| (int) _internal_sys_result; }) |
| #else /* !defined(__ARM_EABI__) */ |
| #define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \ |
| ({ unsigned int _internal_sys_result; \ |
| { \ |
| register int __a1 __asm__ ("a1"); \ |
| LOAD_ARGS_##nr (args) \ |
| __asm__ __volatile__ ("swi %1 @ syscall " #name \ |
| : "=r" (__a1) \ |
| : "i" (name) ASM_ARGS_##nr \ |
| : "memory"); \ |
| _internal_sys_result = __a1; \ |
| } \ |
| (int) _internal_sys_result; }) |
| #endif |
| |
| #undef INTERNAL_SYSCALL |
| #define INTERNAL_SYSCALL(name, err, nr, args...) \ |
| INTERNAL_SYSCALL_RAW(SYS_ify(name), err, nr, args) |
| |
| #undef INTERNAL_SYSCALL_ARM |
| #define INTERNAL_SYSCALL_ARM(name, err, nr, args...) \ |
| INTERNAL_SYSCALL_RAW(__ARM_NR_##name, err, nr, args) |
| |
| #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)) |
| |
| #if defined(__ARM_EABI__) |
| #undef INTERNAL_SYSCALL_NCS |
| #define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \ |
| INTERNAL_SYSCALL_RAW(number, err, nr, args) |
| #else |
| /* We can't implement non-constant syscalls directly since the syscall |
| number is normally encoded in the instruction. So use SYS_syscall. */ |
| #undef INTERNAL_SYSCALL_NCS |
| #define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \ |
| INTERNAL_SYSCALL_NCS_##nr (number, err, args) |
| |
| #define INTERNAL_SYSCALL_NCS_0(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 1, number, args) |
| #define INTERNAL_SYSCALL_NCS_1(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 2, number, args) |
| #define INTERNAL_SYSCALL_NCS_2(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 3, number, args) |
| #define INTERNAL_SYSCALL_NCS_3(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 4, number, args) |
| #define INTERNAL_SYSCALL_NCS_4(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 5, number, args) |
| #define INTERNAL_SYSCALL_NCS_5(number, err, args...) \ |
| INTERNAL_SYSCALL (syscall, err, 6, number, args) |
| #endif |
| |
| #endif /* __ASSEMBLER__ */ |
| |
| /* Pointer mangling is not yet supported for ARM. */ |
| #define PTR_MANGLE(var) (void) (var) |
| #define PTR_DEMANGLE(var) (void) (var) |
| |
| #endif /* linux/arm/sysdep.h */ |