From a1faeb9ca1e8751e714dcff4dd92a374a376e9e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
Date: Mon, 11 Jul 2016 06:33:14 +0200
Subject: [PATCH] newlib: Use vfs for file I/O syscalls
---
sys/newlib/syscalls.c | 330 +++++++++++++++++++++++++++++++-----------
1 file changed, 244 insertions(+), 86 deletions(-)
diff --git a/sys/newlib/syscalls.c b/sys/newlib/syscalls.c
index d44d4c9e7b..c2e1a9e7b9 100644
--- a/sys/newlib/syscalls.c
+++ b/sys/newlib/syscalls.c
@@ -39,6 +39,9 @@
#include "irq.h"
#include "log.h"
#include "periph/pm.h"
+#if MODULE_VFS
+#include "vfs.h"
+#endif
#include "uart_stdio.h"
@@ -152,137 +155,307 @@ int _kill_r(struct _reent *r, pid_t pid, int sig)
return -1;
}
+#if MODULE_VFS
/**
* @brief Open a file
*
- * @param r TODO
- * @param name TODO
- * @param mode TODO
+ * This is a wrapper around @c vfs_open
*
- * @return TODO
+ * @param r pointer to reent structure
+ * @param name file name to open
+ * @param flags flags, see man 3p open
+ * @param mode mode, file creation mode if the file is created when opening
+ *
+ * @return fd number (>= 0) on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
int _open_r(struct _reent *r, const char *name, int flags, int mode)
{
- (void) name;
- (void) flags;
- (void) mode;
- r->_errno = ENODEV; /* not implemented yet */
- return -1;
+ int fd = vfs_open(name, flags, mode);
+ if (fd < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -fd;
+ return -1;
+ }
+ return fd;
}
/**
- * @brief Read from a file
+ * @brief Read bytes from an open file
*
- * All input is read from UART_0. The function will block until a byte is actually read.
+ * This is a wrapper around @c vfs_read
*
- * Note: the read function does not buffer - data will be lost if the function is not
- * called fast enough.
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
+ * @param[out] dest destination buffer
+ * @param[in] count maximum number of bytes to read
*
- * TODO: implement more sophisticated read call.
+ * @return number of bytes read on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
+ */
+_ssize_t _read_r(struct _reent *r, int fd, void *dest, size_t count)
+{
+ int res = vfs_read(fd, dest, count);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return res;
+}
+
+/**
+ * @brief Write bytes to an open file
*
- * @param r TODO
- * @param fd TODO
- * @param buffer TODO
- * @param int TODO
+ * This is a wrapper around @c vfs_write
*
- * @return TODO
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
+ * @param[in] src source data buffer
+ * @param[in] count maximum number of bytes to write
+ *
+ * @return number of bytes written on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
-_ssize_t _read_r(struct _reent *r, int fd, void *buffer, size_t count)
+_ssize_t _write_r(struct _reent *r, int fd, const void *src, size_t count)
{
- (void)r;
- (void)fd;
- return uart_stdio_read(buffer, count);
+ int res = vfs_write(fd, src, count);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return res;
}
/**
- * @brief Write characters to a file
+ * @brief Close an open file
*
- * All output is currently directed to UART_0, independent of the given file descriptor.
- * The write call will further block until the byte is actually written to the UART.
+ * This is a wrapper around @c vfs_close
*
- * TODO: implement more sophisticated write call.
+ * If this call returns an error, the fd should still be considered invalid and
+ * no further attempt to use it shall be made, not even to retry @c close()
*
- * @param r TODO
- * @param fd TODO
- * @param data TODO
- * @param int TODO
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
*
- * @return TODO
+ * @return 0 on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
-_ssize_t _write_r(struct _reent *r, int fd, const void *data, size_t count)
+int _close_r(struct _reent *r, int fd)
{
- (void) r;
- (void) fd;
- return uart_stdio_write(data, count);
+ int res = vfs_close(fd);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return res;
}
/**
- * @brief Close a file
+ * @brief Query or set options on an open file
*
- * @param r TODO
- * @param fd TODO
+ * This is a wrapper around @c vfs_fcntl
*
- * @return TODO
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
+ * @param[in] cmd fcntl command, see man 3p fcntl
+ * @param[in] arg argument to fcntl command, see man 3p fcntl
+ *
+ * @return 0 on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
-int _close_r(struct _reent *r, int fd)
+int _fcntl_r (struct _reent *r, int fd, int cmd, int arg)
{
- (void) fd;
- r->_errno = ENODEV; /* not implemented yet */
- return -1;
+ int res = vfs_fcntl(fd, cmd, arg);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return res;
}
/**
- * @brief Set position in a file
+ * @brief Seek to position in file
*
- * @param r TODO
- * @param fd TODO
- * @param pos TODO
- * @param dir TODO
+ * This is a wrapper around @c vfs_lseek
*
- * @return TODO
+ * @p whence determines the function of the seek and should be set to one of
+ * the following values:
+ *
+ * - @c SEEK_SET: Seek to absolute offset @p off
+ * - @c SEEK_CUR: Seek to current location + @p off
+ * - @c SEEK_END: Seek to end of file + @p off
+ *
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
+ * @param[in] off seek offset
+ * @param[in] whence determines the seek method, see detailed description
+ *
+ * @return the new seek location in the file on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
-_off_t _lseek_r(struct _reent *r, int fd, _off_t pos, int dir)
+_off_t _lseek_r(struct _reent *r, int fd, _off_t off, int whence)
{
- (void) fd;
- (void) pos;
- (void) dir;
- r->_errno = ENODEV; /* not implemented yet */
- return -1;
+ int res = vfs_lseek(fd, off, whence);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return res;
}
/**
- * @brief Status of an open file
+ * @brief Get status of an open file
*
- * @param r TODO
- * @param fd TODO
- * @param stat TODO
+ * This is a wrapper around @c vfs_fstat
*
- * @return TODO
+ * @param[in] r pointer to reent structure
+ * @param[in] fd open file descriptor obtained from @c open()
+ * @param[out] buf pointer to stat struct to fill
+ *
+ * @return 0 on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
-int _fstat_r(struct _reent *r, int fd, struct stat *st)
+int _fstat_r(struct _reent *r, int fd, struct stat *buf)
{
- (void) fd;
- (void) st;
- r->_errno = ENODEV; /* not implemented yet */
- return -1;
+ int res = vfs_fstat(fd, buf);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return 0;
}
/**
* @brief Status of a file (by name)
*
- * @param r TODO
- * @param name TODO
- * @param stat TODO
+ * This is a wrapper around @c vfs_fstat
*
- * @return TODO
+ * @param[in] r pointer to reent structure
+ * @param[in] name path to file
+ * @param[out] buf pointer to stat struct to fill
+ *
+ * @return 0 on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
+ */
+int _stat_r(struct _reent *r, const char *name, struct stat *st)
+{
+ int res = vfs_stat(name, st);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return 0;
+}
+
+/**
+ * @brief Unlink (delete) a file
+ *
+ * @param[in] r pointer to reent structure
+ * @param[in] path path to file to be deleted
+ *
+ * @return 0 on success
+ * @return -1 on error, @c r->_errno set to a constant from errno.h to indicate the error
*/
+int _unlink_r(struct _reent *r, const char *path)
+{
+ int res = vfs_unlink(path);
+ if (res < 0) {
+ /* vfs returns negative error codes */
+ r->_errno = -res;
+ return -1;
+ }
+ return 0;
+}
+
+#else /* MODULE_VFS */
+
+/* Fallback stdio_uart wrappers for when VFS is not used, does not allow any
+ * other file access */
+/*
+ * Fallback read function
+ *
+ * All input is read from uart_stdio regardless of fd number. The function will
+ * block until a byte is actually read.
+ *
+ * Note: the read function does not buffer - data will be lost if the function is not
+ * called fast enough.
+ */
+_ssize_t _read_r(struct _reent *r, int fd, void *buffer, size_t count)
+{
+ (void)r;
+ (void)fd;
+ return uart_stdio_read(buffer, count);
+}
+
+/*
+ * Fallback write function
+ *
+ * All output is directed to uart_stdio, independent of the given file descriptor.
+ * The write call will further block until the byte is actually written to the UART.
+ */
+_ssize_t _write_r(struct _reent *r, int fd, const void *data, size_t count)
+{
+ (void) r;
+ (void) fd;
+ return uart_stdio_write(data, count);
+}
+
+/* Stubs to avoid linking errors, these functions do not have any effect */
+int _open_r(struct _reent *r, const char *name, int flags, int mode)
+{
+ (void) name;
+ (void) flags;
+ (void) mode;
+ r->_errno = ENODEV;
+ return -1;
+}
+
+int _close_r(struct _reent *r, int fd)
+{
+ (void) fd;
+ r->_errno = ENODEV;
+ return -1;
+}
+
+_off_t _lseek_r(struct _reent *r, int fd, _off_t pos, int dir)
+{
+ (void) fd;
+ (void) pos;
+ (void) dir;
+ r->_errno = ENODEV;
+ return -1;
+}
+
+int _fstat_r(struct _reent *r, int fd, struct stat *st)
+{
+ (void) fd;
+ (void) st;
+ r->_errno = ENODEV;
+ return -1;
+}
+
int _stat_r(struct _reent *r, const char *name, struct stat *st)
{
(void) name;
(void) st;
- r->_errno = ENODEV; /* not implemented yet */
+ r->_errno = ENODEV;
+ return -1;
+}
+
+int _unlink_r(struct _reent *r, const char *path)
+{
+ (void) path;
+ r->_errno = ENODEV;
return -1;
}
+#endif /* MODULE_VFS */
/**
* @brief Query whether output stream is a terminal
@@ -303,21 +476,6 @@ int _isatty_r(struct _reent *r, int fd)
return 0;
}
-/**
- * @brief Remove a file's directory entry
- *
- * @param r TODO
- * @param path TODO
- *
- * @return TODO
- */
-int _unlink_r(struct _reent *r, const char *path)
-{
- (void) path;
- r->_errno = ENODEV; /* not implemented yet */
- return -1;
-}
-
/**
* @brief Send a signal to a thread
*
--
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