newlib-cygwin/newlib/libc/sys/arm/syscalls.c

717 lines
15 KiB
C

/* Support files for GNU libc. Files in the system namespace go here.
Files in the C namespace (ie those that do not start with an
underscore) go in .c. */
#include <_ansi.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <stdio.h>
#include <time.h>
#include <sys/time.h>
#include <sys/times.h>
#include <errno.h>
#include <reent.h>
#include <signal.h>
#include <unistd.h>
#include <sys/wait.h>
#include "swi.h"
/* Forward prototypes. */
int _system (const char *);
int _rename (const char *, const char *);
int _isatty (int);
clock_t _times (struct tms *);
int _gettimeofday (struct timeval *, void *);
void _raise (void);
int _unlink (const char *);
int _link (const char *, const char *);
int _stat (const char *, struct stat *);
int _fstat (int, struct stat *);
void * _sbrk (ptrdiff_t);
pid_t _getpid (void);
int _kill (int, int);
void _exit (int);
int _close (int);
int _swiclose (int);
int _open (const char *, int, ...);
int _swiopen (const char *, int);
int _write (int, const void *, size_t);
int _swiwrite (int, const void *, size_t);
_off_t _lseek (int, _off_t, int);
_off_t _swilseek (int, _off_t, int);
int _read (int, void *, size_t);
int _swiread (int, void *, size_t);
void initialise_monitor_handles (void);
static int wrap (int);
static int error (int);
static int get_errno (void);
static int remap_handle (int);
static int findslot (int);
static int _kill_shared (int, int, int) __attribute__((__noreturn__));
/* Register name faking - works in collusion with the linker. */
register char * stack_ptr asm ("sp");
/* following is copied from libc/stdio/local.h to check std streams */
extern void __sinit (struct _reent *);
#define CHECK_INIT(ptr) \
do \
{ \
if ((ptr) && !(ptr)->__cleanup) \
__sinit (ptr); \
} \
while (0)
/* Adjust our internal handles to stay away from std* handles. */
#define FILE_HANDLE_OFFSET (0x20)
static int monitor_stdin;
static int monitor_stdout;
static int monitor_stderr;
/* Struct used to keep track of the file position, just so we
can implement fseek(fh,x,SEEK_CUR). */
typedef struct
{
int handle;
off_t pos;
}
poslog;
#define MAX_OPEN_FILES 20
static poslog openfiles [MAX_OPEN_FILES];
static int
findslot (int fh)
{
int i;
for (i = 0; i < MAX_OPEN_FILES; i ++)
if (openfiles[i].handle == fh)
break;
return i;
}
/* Function to convert std(in|out|err) handles to internal versions. */
static int
remap_handle (int fh)
{
CHECK_INIT(_REENT);
if (fh == STDIN_FILENO)
return monitor_stdin;
if (fh == STDOUT_FILENO)
return monitor_stdout;
if (fh == STDERR_FILENO)
return monitor_stderr;
return fh - FILE_HANDLE_OFFSET;
}
void
initialise_monitor_handles (void)
{
int i;
/* Open the standard file descriptors by opening the special
* teletype device, ":tt", read-only to obtain a descriptor for
* standard input and write-only to obtain a descriptor for standard
* output. Finally, open ":tt" in append mode to obtain a descriptor
* for standard error. Since this is a write mode, most kernels will
* probably return the same value as for standard output, but the
* kernel can differentiate the two using the mode flag and return a
* different descriptor for standard error.
*/
#ifdef ARM_RDI_MONITOR
int volatile block[3];
block[0] = (int) ":tt";
block[2] = 3; /* length of filename */
block[1] = 0; /* mode "r" */
monitor_stdin = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
block[0] = (int) ":tt";
block[2] = 3; /* length of filename */
block[1] = 4; /* mode "w" */
monitor_stdout = monitor_stderr
= do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
#else
int fh;
const char * name;
name = ":tt";
asm ("mov r0,%2; mov r1, #0; swi %a1; mov %0, r0"
: "=r"(fh)
: "i" (SWI_Open),"r"(name)
: "r0","r1");
monitor_stdin = fh;
name = ":tt";
asm ("mov r0,%2; mov r1, #4; swi %a1; mov %0, r0"
: "=r"(fh)
: "i" (SWI_Open),"r"(name)
: "r0","r1");
monitor_stdout = monitor_stderr = fh;
#endif
for (i = 0; i < MAX_OPEN_FILES; i ++)
openfiles[i].handle = -1;
openfiles[0].handle = monitor_stdin;
openfiles[0].pos = 0;
openfiles[1].handle = monitor_stdout;
openfiles[1].pos = 0;
}
static int
get_errno (void)
{
#ifdef ARM_RDI_MONITOR
return do_AngelSWI (AngelSWI_Reason_Errno, NULL);
#else
register int r0 asm("r0");
asm ("swi %a1" : "=r"(r0) : "i" (SWI_GetErrno));
return r0;
#endif
}
/* Set errno and return result. */
static int
error (int result)
{
errno = get_errno ();
return result;
}
static int
wrap (int result)
{
if (result == -1)
return error (-1);
return result;
}
/* file, is a valid user file handle.
ptr, is a null terminated string.
len, is the length in bytes to read.
Returns the number of bytes *not* written. */
int
_swiread (int file, void * ptr, size_t len)
{
int fh = remap_handle (file);
#ifdef ARM_RDI_MONITOR
int block[3];
block[0] = fh;
block[1] = (int) ptr;
block[2] = (int) len;
return do_AngelSWI (AngelSWI_Reason_Read, block);
#else
register int r0 asm("r0") = fh;
register int r1 asm("r1") = (int) ptr;
register int r2 asm("r2") = (int) len;
asm ("swi %a4"
: "=r" (r0)
: "0"(r0), "r"(r1), "r"(r2), "i"(SWI_Read));
return r0;
#endif
}
/* file, is a valid user file handle.
Translates the return of _swiread into
bytes read. */
int __attribute__((weak))
_read (int file, void * ptr, size_t len)
{
int slot = findslot (remap_handle (file));
int x = _swiread (file, ptr, len);
if (x < 0)
return error (-1);
if (slot != MAX_OPEN_FILES)
openfiles [slot].pos += len - x;
/* x == len is not an error, at least if we want feof() to work. */
return len - x;
}
/* file, is a user file descriptor. */
off_t
_swilseek (int file, off_t ptr, int dir)
{
_off_t res;
int fh = remap_handle (file);
int slot = findslot (fh);
if (dir == SEEK_CUR)
{
off_t pos;
if (slot == MAX_OPEN_FILES)
return -1;
pos = openfiles[slot].pos;
/* Avoid SWI SEEK command when just querying file position. */
if (ptr == 0)
return pos;
ptr += pos;
dir = SEEK_SET;
}
#ifdef ARM_RDI_MONITOR
int block[2];
if (dir == SEEK_END)
{
block[0] = fh;
ptr += do_AngelSWI (AngelSWI_Reason_FLen, block);
}
/* This code only does absolute seeks. */
block[0] = remap_handle (file);
block[1] = ptr;
res = do_AngelSWI (AngelSWI_Reason_Seek, block);
#else
register int r0 asm("r0");
register int r1 asm("r1");
if (dir == SEEK_END)
{
r0 = (int) fh;
asm ("swi %a2"
: "=r" (r0)
: "0"(r0), "i" (SWI_Flen));
res = r0;
ptr += res;
}
/* This code only does absolute seeks. */
r0 = (int) fh;
r1 = (int) ptr;
asm ("swi %a3"
: "=r" (r0)
: "0"(r0), "r"(r1), "i" (SWI_Seek));
res = r0;
#endif
if (slot != MAX_OPEN_FILES && res == 0)
openfiles[slot].pos = ptr;
/* This is expected to return the position in the file. */
return res == 0 ? ptr : -1;
}
off_t
_lseek (int file, off_t ptr, int dir)
{
return wrap (_swilseek (file, ptr, dir));
}
/* file, is a valid internal file handle.
Returns the number of bytes *not* written. */
int
_swiwrite (int file, const void * ptr, size_t len)
{
int fh = remap_handle (file);
#ifdef ARM_RDI_MONITOR
int block[3];
block[0] = fh;
block[1] = (int) ptr;
block[2] = (int) len;
return do_AngelSWI (AngelSWI_Reason_Write, block);
#else
register int r0 asm("r0") = fh;
register int r1 asm("r1") = (int) ptr;
register int r2 asm("r2") = (int) len;
asm ("swi %a4"
: "=r" (r0)
: "0"(fh), "r"(r1), "r"(r2), "i"(SWI_Write));
return r0;
#endif
}
/* file, is a user file descriptor. */
int __attribute__((weak))
_write (int file, const void * ptr, size_t len)
{
int slot = findslot (remap_handle (file));
int x = _swiwrite (file, ptr, len);
if (x == -1 || x == len)
return error (-1);
if (slot != MAX_OPEN_FILES)
openfiles[slot].pos += len - x;
return len - x;
}
extern int strlen (const char *);
int
_swiopen (const char * path, int flags)
{
int aflags = 0, fh;
#ifdef ARM_RDI_MONITOR
int block[3];
#endif
int i = findslot (-1);
if (i == MAX_OPEN_FILES)
return -1;
/* The flags are Unix-style, so we need to convert them. */
#ifdef O_BINARY
if (flags & O_BINARY)
aflags |= 1;
#endif
if (flags & O_RDWR)
aflags |= 2;
if (flags & O_CREAT)
aflags |= 4;
if (flags & O_TRUNC)
aflags |= 4;
if (flags & O_APPEND)
{
aflags &= ~4; /* Can't ask for w AND a; means just 'a'. */
aflags |= 8;
}
#ifdef ARM_RDI_MONITOR
block[0] = (int) path;
block[2] = strlen (path);
block[1] = aflags;
fh = do_AngelSWI (AngelSWI_Reason_Open, block);
#else
register int r0 asm("r0") = (int) path;
register int r1 asm("r1") = (int) aflags;;
asm ("swi %a3"
: "=r"(r0)
: "0"(r0), "r"(r1), "i" (SWI_Open));
fh = r0;
#endif
if (fh >= 0)
{
openfiles[i].handle = fh;
openfiles[i].pos = 0;
}
return fh >= 0 ? fh + FILE_HANDLE_OFFSET : error (fh);
}
int
_open (const char * path, int flags, ...)
{
return wrap (_swiopen (path, flags));
}
int
_swiclose (int file)
{
int myhan = remap_handle (file);
int slot = findslot (myhan);
if (slot != MAX_OPEN_FILES)
openfiles[slot].handle = -1;
#ifdef ARM_RDI_MONITOR
return do_AngelSWI (AngelSWI_Reason_Close, & myhan);
#else
register int r0 asm("r0") = myhan;
asm ("swi %a2" : "=r"(r0): "0"(r0), "i" (SWI_Close));
return r0;
#endif
}
int
_close (int file)
{
return wrap (_swiclose (file));
}
static int
_kill_shared (int pid, int sig, int reason)
{
(void) pid; (void) sig;
#ifdef ARM_RDI_MONITOR
/* Note: The pid argument is thrown away. */
int block[2];
block[1] = sig;
block[0] = reason;
int insn;
#if SEMIHOST_V2
if (_has_ext_exit_extended ())
{
insn = AngelSWI_Reason_ReportExceptionExtended;
}
else
#endif
{
insn = AngelSWI_Reason_ReportException;
}
#if SEMIHOST_V2
if (_has_ext_exit_extended ())
do_AngelSWI (insn, block);
else
#endif
do_AngelSWI (insn, (void*)block[0]);
#else
asm ("swi %a0" :: "i" (SWI_Exit));
#endif
__builtin_unreachable();
}
int
_kill (int pid, int sig)
{
if (sig == SIGABRT)
_kill_shared (pid, sig, ADP_Stopped_RunTimeError);
else
_kill_shared (pid, sig, ADP_Stopped_ApplicationExit);
}
void
_exit (int status)
{
/* The same SWI is used for both _exit and _kill.
For _exit, call the SWI with "reason" set to ADP_Stopped_ApplicationExit
to mark a standard exit.
Note: The RDI implementation of _kill_shared throws away all its
arguments and all implementations ignore the first argument. */
_kill_shared (-1, status, ADP_Stopped_ApplicationExit);
}
pid_t
_getpid (void)
{
return (pid_t)1;
}
/* Heap limit returned from SYS_HEAPINFO Angel semihost call. */
uint __heap_limit = 0xcafedead;
void * __attribute__((weak))
_sbrk (ptrdiff_t incr)
{
extern char end asm ("end"); /* Defined by the linker. */
static char * heap_end;
char * prev_heap_end;
if (heap_end == NULL)
heap_end = & end;
prev_heap_end = heap_end;
if ((heap_end + incr > stack_ptr)
/* Honour heap limit if it's valid. */
|| (__heap_limit != 0xcafedead && heap_end + incr > (char *)__heap_limit))
{
/* Some of the libstdc++-v3 tests rely upon detecting
out of memory errors, so do not abort here. */
#if 0
extern void abort (void);
_write (1, "_sbrk: Heap and stack collision\n", 32);
abort ();
#else
errno = ENOMEM;
return (void *) -1;
#endif
}
heap_end += incr;
return (void *) prev_heap_end;
}
extern void memset (struct stat *, int, unsigned int);
int __attribute__((weak))
_fstat (int file, struct stat * st)
{
memset (st, 0, sizeof (* st));
st->st_mode = S_IFCHR;
st->st_blksize = 1024;
return 0;
file = file;
}
int __attribute__((weak))
_stat (const char *fname, struct stat *st)
{
int file;
/* The best we can do is try to open the file readonly. If it exists,
then we can guess a few things about it. */
if ((file = _open (fname, O_RDONLY)) < 0)
return -1;
memset (st, 0, sizeof (* st));
st->st_mode = S_IFREG | S_IREAD;
st->st_blksize = 1024;
_swiclose (file); /* Not interested in the error. */
return 0;
}
int __attribute__((weak))
_link (const char *__path1 __attribute__ ((unused)), const char *__path2 __attribute__ ((unused)))
{
errno = ENOSYS;
return -1;
}
int
_unlink (const char *path)
{
#ifdef ARM_RDI_MONITOR
int block[2];
block[0] = (int)path;
block[1] = strlen(path);
return wrap (do_AngelSWI (AngelSWI_Reason_Remove, block)) ? -1 : 0;
#else
errno = ENOSYS;
return -1;
#endif
}
void
_raise (void)
{
return;
}
int
_gettimeofday (struct timeval * tp, void * tzvp)
{
struct timezone *tzp = tzvp;
if (tp)
{
/* Ask the host for the seconds since the Unix epoch. */
#ifdef ARM_RDI_MONITOR
tp->tv_sec = do_AngelSWI (AngelSWI_Reason_Time,NULL);
#else
{
register int r0 asm("r0");
asm ("swi %a1" : "=r" (r0): "i" (SWI_Time));
tp->tv_sec = r0;
}
#endif
tp->tv_usec = 0;
}
/* Return fixed data for the timezone. */
if (tzp)
{
tzp->tz_minuteswest = 0;
tzp->tz_dsttime = 0;
}
return 0;
}
/* Return a clock that ticks at 100Hz. */
clock_t
_times (struct tms * tp)
{
clock_t timeval;
#ifdef ARM_RDI_MONITOR
timeval = do_AngelSWI (AngelSWI_Reason_Clock, NULL);
#else
register int r0 asm("r0");
asm ("swi %a1" : "=r" (r0): "i" (SWI_Clock));
timeval = (clock_t) r0;
#endif
if (tp)
{
tp->tms_utime = timeval; /* user time */
tp->tms_stime = 0; /* system time */
tp->tms_cutime = 0; /* user time, children */
tp->tms_cstime = 0; /* system time, children */
}
return timeval;
};
int
_isatty (int fd)
{
#ifdef ARM_RDI_MONITOR
int fh = remap_handle (fd);
return wrap (do_AngelSWI (AngelSWI_Reason_IsTTY, &fh));
#else
return (fd <= 2) ? 1 : 0; /* one of stdin, stdout, stderr */
#endif
}
int
_system (const char *s)
{
#ifdef ARM_RDI_MONITOR
int block[2];
int e;
/* Hmmm. The ARM debug interface specification doesn't say whether
SYS_SYSTEM does the right thing with a null argument, or assign any
meaning to its return value. Try to do something reasonable.... */
if (!s)
return 1; /* maybe there is a shell available? we can hope. :-P */
block[0] = (int)s;
block[1] = strlen (s);
e = wrap (do_AngelSWI (AngelSWI_Reason_System, block));
if ((e >= 0) && (e < 256))
{
/* We have to convert e, an exit status to the encoded status of
the command. To avoid hard coding the exit status, we simply
loop until we find the right position. */
int exit_code;
for (exit_code = e; e && WEXITSTATUS (e) != exit_code; e <<= 1)
continue;
}
return e;
#else
if (s == NULL)
return 0;
errno = ENOSYS;
return -1;
#endif
}
int
_rename (const char * oldpath, const char * newpath)
{
#ifdef ARM_RDI_MONITOR
int block[4];
block[0] = (int) oldpath;
block[1] = strlen(oldpath);
block[2] = (int) newpath;
block[3] = strlen(newpath);
return wrap (do_AngelSWI (AngelSWI_Reason_Rename, block)) ? -1 : 0;
#else
errno = ENOSYS;
return -1;
#endif
}