newlib/libgloss/arm/syscalls.c

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/* 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 <string.h>
#include <time.h>
#include <sys/time.h>
#include <sys/times.h>
#include <errno.h>
#include <reent.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 *);
int _unlink (const char *);
int _link (const char *, const char *);
int _stat (const char *, struct stat *);
int _fstat (int, struct stat *);
int _swistat (int fd, struct stat * st);
void * _sbrk (ptrdiff_t);
pid_t _getpid (void);
int _close (int);
clock_t _clock (void);
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 checkerror (int);
static int error (int);
static int get_errno (void);
/* Semihosting utilities. */
static void initialise_semihosting_exts (void);
/* Struct used to keep track of the file position, just so we
can implement fseek(fh,x,SEEK_CUR). */
struct fdent
{
int handle;
int pos;
};
#define MAX_OPEN_FILES 20
/* User file descriptors (fd) are integer indexes into
the openfiles[] array. Error checking is done by using
findslot().
This openfiles array is manipulated directly by only
these 5 functions:
findslot() - Translate entry.
newslot() - Find empty entry.
initilise_monitor_handles() - Initialize entries.
_swiopen() - Initialize entry.
_close() - Handle stdout == stderr case.
Every other function must use findslot(). */
static struct fdent openfiles [MAX_OPEN_FILES];
static struct fdent* findslot (int);
static int newslot (void);
/* 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)->__sdidinit) \
__sinit (ptr); \
} \
while (0)
static int monitor_stdin;
static int monitor_stdout;
static int monitor_stderr;
static int supports_ext_exit_extended = -1;
static int supports_ext_stdout_stderr = -1;
/* Return a pointer to the structure associated with
the user file descriptor fd. */
static struct fdent*
findslot (int fd)
{
CHECK_INIT(_REENT);
/* User file descriptor is out of range. */
if ((unsigned int)fd >= MAX_OPEN_FILES)
return NULL;
/* User file descriptor is open? */
if (openfiles[fd].handle == -1)
return NULL;
/* Valid. */
return &openfiles[fd];
}
/* Return the next lowest numbered free file
structure, or -1 if we can't find one. */
static int
newslot (void)
{
int i;
for (i = 0; i < MAX_OPEN_FILES; i++)
if (openfiles[i].handle == -1)
break;
if (i == MAX_OPEN_FILES)
return -1;
return i;
}
void
initialise_monitor_handles (void)
{
int i;
/* Open the standard file descriptors by opening the special
* teletype device, ":tt", read-only to obtain a descritpor 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);
for (i = 0; i < MAX_OPEN_FILES; i ++)
openfiles[i].handle = -1;
if (_has_ext_stdout_stderr ())
{
block[0] = (int) ":tt";
block[2] = 3; /* length of filename */
block[1] = 4; /* mode "w" */
monitor_stdout = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
block[0] = (int) ":tt";
block[2] = 3; /* length of filename */
block[1] = 8; /* mode "a" */
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;
if (_has_ext_stdout_stderr ())
{
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 = fh;
name = ":tt";
asm ("mov r0,%2; mov r1, #8; swi %a1; mov %0, r0"
: "=r"(fh)
: "i" (SWI_Open),"r"(name)
: "r0","r1");
monitor_stderr = fh;
}
#endif
/* If we failed to open stderr, redirect to stdout. */
if (monitor_stderr == -1)
monitor_stderr = monitor_stdout;
openfiles[0].handle = monitor_stdin;
openfiles[0].pos = 0;
if (_has_ext_stdout_stderr ())
{
openfiles[1].handle = monitor_stdout;
openfiles[1].pos = 0;
openfiles[2].handle = monitor_stderr;
openfiles[2].pos = 0;
}
}
int
_has_ext_exit_extended (void)
{
if (supports_ext_exit_extended < 0)
{
initialise_semihosting_exts ();
}
return supports_ext_exit_extended;
}
int
_has_ext_stdout_stderr (void)
{
if (supports_ext_stdout_stderr < 0)
{
initialise_semihosting_exts ();
}
return supports_ext_stdout_stderr;
}
static void
initialise_semihosting_exts (void)
{
supports_ext_exit_extended = 0;
supports_ext_stdout_stderr = 1;
#if SEMIHOST_V2
char features[1];
if (_get_semihosting_exts (features, 0, 1) > 0)
{
supports_ext_exit_extended
= features[0] & (1 << SH_EXT_EXIT_EXTENDED_BITNUM);
supports_ext_stdout_stderr
= features[0] & (1 << SH_EXT_STDOUT_STDERR_BITNUM);
}
#endif
}
int
_get_semihosting_exts (char* features, int offset, int num)
{
int len;
struct fdent *pfd;
int fd = _open (":semihosting-features", O_RDONLY);
memset (features, 0, num);
if (fd == -1)
{
return -1;
}
pfd = findslot (fd);
#ifdef ARM_RDI_MONITOR
len = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
#else
asm ("mov r0,%2; swi %a1; mov %0, r0"
: "=r"(len)
: "i" (SWI_Flen),"r"(pfd->handle)
: "r0");
#endif
if (len < NUM_SHFB_MAGIC
|| num > (len - NUM_SHFB_MAGIC))
{
_close (fd);
return -1;
}
char buffer[NUM_SHFB_MAGIC];
int n_read = _read (fd, buffer, NUM_SHFB_MAGIC);
if (n_read < NUM_SHFB_MAGIC
|| buffer[0] != SHFB_MAGIC_0
|| buffer[1] != SHFB_MAGIC_1
|| buffer[2] != SHFB_MAGIC_2
|| buffer[3] != SHFB_MAGIC_3)
{
_close (fd);
return -1;
}
if (_lseek (fd, offset, SEEK_CUR) < 0)
{
_close (fd);
return -1;
}
n_read = _read (fd, features, num);
_close (fd);
return checkerror (n_read);
}
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;
}
/* Check the return and set errno appropriately. */
static int
checkerror (int result)
{
if (result == -1)
return error (-1);
return result;
}
/* fh, is a valid internal 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 fh,
void * ptr,
size_t len)
{
#ifdef ARM_RDI_MONITOR
int block[3];
block[0] = fh;
block[1] = (int) ptr;
block[2] = (int) len;
return checkerror (do_AngelSWI (AngelSWI_Reason_Read, block));
#else
register int r0 asm("r0");
register int r1 asm("r1");
register int r2 asm("r2");
r0 = fh;
r1 = (int) ptr;
r2 = (int) len;
asm ("swi %a4"
: "=r" (r0)
: "0"(r0), "r"(r1), "r"(r2), "i"(SWI_Read));
return checkerror (r0);
#endif
}
/* fd, is a valid user file handle.
Translates the return of _swiread into
bytes read. */
int __attribute__((weak))
_read (int fd,
void * ptr,
size_t len)
{
int res;
struct fdent *pfd;
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return -1;
}
res = _swiread (pfd->handle, ptr, len);
if (res == -1)
return res;
pfd->pos += len - res;
/* res == len is not an error,
at least if we want feof() to work. */
return len - res;
}
/* fd, is a user file descriptor. */
off_t
_swilseek (int fd,
off_t ptr,
int dir)
{
off_t res;
struct fdent *pfd;
/* Valid file descriptor? */
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return -1;
}
/* Valid whence? */
if ((dir != SEEK_CUR)
&& (dir != SEEK_SET)
&& (dir != SEEK_END))
{
errno = EINVAL;
return -1;
}
/* Convert SEEK_CUR to SEEK_SET */
if (dir == SEEK_CUR)
{
ptr = pfd->pos + ptr;
/* The resulting file offset would be negative. */
if (ptr < 0)
{
errno = EINVAL;
if ((pfd->pos > 0) && (ptr > 0))
errno = EOVERFLOW;
return -1;
}
dir = SEEK_SET;
}
#ifdef ARM_RDI_MONITOR
int block[2];
if (dir == SEEK_END)
{
block[0] = pfd->handle;
res = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, block));
if (res == -1)
return -1;
ptr += res;
}
/* This code only does absolute seeks. */
block[0] = pfd->handle;
block[1] = (int) ptr;
res = checkerror (do_AngelSWI (AngelSWI_Reason_Seek, block));
#else
if (dir == SEEK_END)
{
asm ("mov r0, %2; swi %a1; mov %0, r0"
: "=r" (res)
: "i" (SWI_Flen), "r" (pfd->handle)
: "r0");
checkerror (res);
if (res == -1)
return -1;
ptr += res;
}
/* This code only does absolute seeks. */
asm ("mov r0, %2; mov r1, %3; swi %a1; mov %0, r0"
: "=r" (res)
: "i" (SWI_Seek), "r" (pfd->handle), "r" (ptr)
: "r0", "r1");
checkerror (res);
#endif
/* At this point ptr is the current file position. */
if (res >= 0)
{
pfd->pos = ptr;
return ptr;
}
else
return -1;
}
off_t
_lseek (int fd,
off_t ptr,
int dir)
{
return _swilseek (fd, ptr, dir);
}
/* fh, is a valid internal file handle.
Returns the number of bytes *not* written. */
int
_swiwrite (
int fh,
const void * ptr,
size_t len)
{
#ifdef ARM_RDI_MONITOR
int block[3];
block[0] = fh;
block[1] = (int) ptr;
block[2] = (int) len;
return checkerror (do_AngelSWI (AngelSWI_Reason_Write, block));
#else
register int r0 asm("r0");
register int r1 asm("r1");
register int r2 asm("r2");
r0 = fh;
r1 = (int)ptr;
r2 = len;
asm ("swi %a4"
: "=r" (r0)
: "0"(r0), "r"(r1), "r"(r2), "i"(SWI_Write));
return checkerror (r0);
#endif
}
/* fd, is a user file descriptor. */
int __attribute__((weak))
_write (int fd,
const void * ptr,
size_t len)
{
int res;
struct fdent *pfd;
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return -1;
}
res = _swiwrite (pfd->handle, ptr,len);
/* Clearly an error. */
if (res < 0)
return -1;
pfd->pos += len - res;
/* We wrote 0 bytes?
Retrieve errno just in case. */
if ((len - res) == 0)
return error (0);
return (len - res);
}
int
_swiopen (const char * path, int flags)
{
int aflags = 0, fh;
#ifdef ARM_RDI_MONITOR
int block[3];
#endif
int fd = newslot ();
if (fd == -1)
{
errno = EMFILE;
return -1;
}
/* It is an error to open a file that already exists. */
if ((flags & O_CREAT)
&& (flags & O_EXCL))
{
struct stat st;
int res;
res = _stat (path, &st);
if (res != -1)
{
errno = EEXIST;
return -1;
}
}
/* The flags are Unix-style, so we need to convert them. */
#ifdef O_BINARY
if (flags & O_BINARY)
aflags |= 1;
#endif
/* In O_RDONLY we expect aflags == 0. */
if (flags & O_RDWR)
aflags |= 2;
if ((flags & O_CREAT)
|| (flags & O_TRUNC)
|| (flags & O_WRONLY))
aflags |= 4;
if (flags & O_APPEND)
{
/* Can't ask for w AND a; means just 'a'. */
aflags &= ~4;
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
asm ("mov r0,%2; mov r1, %3; swi %a1; mov %0, r0"
: "=r"(fh)
: "i" (SWI_Open),"r"(path),"r"(aflags)
: "r0","r1");
#endif
/* Return a user file descriptor or an error. */
if (fh >= 0)
{
openfiles[fd].handle = fh;
openfiles[fd].pos = 0;
return fd;
}
else
return error (fh);
}
int
_open (const char * path, int flags, ...)
{
return _swiopen (path, flags);
}
/* fh, is a valid internal file handle. */
int
_swiclose (int fh)
{
#ifdef ARM_RDI_MONITOR
return checkerror (do_AngelSWI (AngelSWI_Reason_Close, &fh));
#else
register int r0 asm("r0");
r0 = fh;
asm ("swi %a2"
: "=r"(r0)
: "0"(r0), "i" (SWI_Close));
return checkerror (r0);
#endif
}
/* fd, is a user file descriptor. */
int
_close (int fd)
{
int res;
struct fdent *pfd;
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return -1;
}
/* Handle stderr == stdout. */
if ((fd == 1 || fd == 2)
&& (openfiles[1].handle == openfiles[2].handle))
{
pfd->handle = -1;
return 0;
}
/* Attempt to close the handle. */
res = _swiclose (pfd->handle);
/* Reclaim handle? */
if (res == 0)
pfd->handle = -1;
return res;
}
pid_t __attribute__((weak))
_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;
}
int
_swistat (int fd, struct stat * st)
{
struct fdent *pfd;
int res;
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return -1;
}
/* Always assume a character device,
with 1024 byte blocks. */
st->st_mode |= S_IFCHR;
st->st_blksize = 1024;
#ifdef ARM_RDI_MONITOR
res = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
#else
asm ("mov r0, %2; swi %a1; mov %0, r0"
: "=r" (res)
: "i" (SWI_Flen), "r" (pfd->handle)
: "r0");
checkerror (res);
#endif
if (res == -1)
return -1;
/* Return the file size. */
st->st_size = res;
return 0;
}
int __attribute__((weak))
_fstat (int fd, struct stat * st)
{
memset (st, 0, sizeof (* st));
return _swistat (fd, st);
}
int __attribute__((weak))
_stat (const char *fname, struct stat *st)
{
int fd, res;
memset (st, 0, sizeof (* st));
/* 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 ((fd = _open (fname, O_RDONLY)) == -1)
return -1;
st->st_mode |= S_IFREG | S_IREAD;
res = _swistat (fd, st);
/* Not interested in the error. */
_close (fd);
return res;
}
int __attribute__((weak))
_link (const char *__path1 __attribute__ ((unused)), const char *__path2 __attribute__ ((unused)))
{
errno = ENOSYS;
return -1;
}
int
_unlink (const char *path)
{
int res;
#ifdef ARM_RDI_MONITOR
int block[2];
block[0] = (int)path;
block[1] = strlen(path);
res = do_AngelSWI (AngelSWI_Reason_Remove, block);
#else
register int r0 asm("r0");
r0 = (int)path;
asm ("swi %a2"
: "=r"(r0)
: "0"(r0), "i" (SWI_Remove));
res = r0;
#endif
if (res == -1)
return error (res);
return 0;
}
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
{
int value;
asm ("swi %a1; mov %0, r0" : "=r" (value): "i" (SWI_Time) : "r0");
tp->tv_sec = value;
}
#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
_clock (void)
{
clock_t timeval;
#ifdef ARM_RDI_MONITOR
timeval = do_AngelSWI (AngelSWI_Reason_Clock,NULL);
#else
asm ("swi %a1; mov %0, r0" : "=r" (timeval): "i" (SWI_Clock) : "r0");
#endif
return timeval;
}
/* Return a clock that ticks at 100Hz. */
clock_t
_times (struct tms * tp)
{
clock_t timeval = _clock();
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)
{
struct fdent *pfd;
int tty;
pfd = findslot (fd);
if (pfd == NULL)
{
errno = EBADF;
return 0;
}
#ifdef ARM_RDI_MONITOR
tty = do_AngelSWI (AngelSWI_Reason_IsTTY, &pfd->handle);
#else
register int r0 asm("r0");
r0 = pfd->handle;
asm ("swi %a2"
: "=r" (r0)
: "0"(r0), "i" (SWI_IsTTY));
tty = r0;
#endif
if (tty == 1)
return 1;
errno = get_errno ();
return 0;
}
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 = checkerror (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
register int r0 asm("r0");
r0 = (int)s;
asm ("swi %a2"
: "=r" (r0)
: "0"(r0), "i" (SWI_CLI));
return checkerror (r0);
#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 checkerror (do_AngelSWI (AngelSWI_Reason_Rename, block)) ? -1 : 0;
#else
register int r0 asm("r0");
register int r1 asm("r1");
r0 = (int)oldpath;
r1 = (int)newpath;
asm ("swi %a3"
: "=r" (r0)
: "0" (r0), "r" (r1), "i" (SWI_Rename));
return checkerror (r0);
#endif
}