lib: posix: Add Posix Style File System API support

Add IEEE 1003.1 Posix Style file system API support.
These API's will internally use corresponding Zephyr
File System API's.

Signed-off-by: Ramakrishna Pallala <[email protected]>

Author: Ramakrishna Pallala

arch/posix/include/posix_cheats.h

@@ -45,6 +45,8 @@
 #define mqueue_desc	       zap_mqueue_desc
 #define mqd_t		       zap_mqd_t
 #define mq_attr		       zap_mq_attr
+#define dirent		       zap_dirent
+#define DIR		       zap_DIR
 
 /* Condition variables */
 
@@ -163,6 +165,20 @@
 #define mq_timedreceive(...)	zap_mq_timedreceive(__VA_ARGS__)
 #define mq_timedsend(...)	zap_mq_timedsend(__VA_ARGS__)
 
+/* File system */
+#define open		zap_open
+#define close		zap_close
+#define write		zap_write
+#define read		zap_read
+#define lseek		zap_lseek
+#define opendir		zap_opendir
+#define closedir	zap_closedir
+#define readdir		zap_readdir
+#define rename		zap_rename
+#define unlink		zap_unlink
+#define stat		zap_stat
+#define mkdir		zap_mkdir
+
 #endif /* CONFIG_PTHREAD_IPC */
 
 #endif /* CONFIG_ARCH_POSIX */

include/fs.h

@@ -7,7 +7,25 @@
 #ifndef _FS_H_
 #define _FS_H_
 
+#ifdef CONFIG_ARCH_POSIX
+#ifndef __ssize_t_defined
+typedef __SIZE_TYPE__ ssize_t;
+#define __ssize_t_defined
+#endif
+
+#ifndef __off_t_defined
+#ifndef __USE_FILE_OFFSET64
+typedef long int off_t;
+#else
+typedef long long int off_t;
+#endif
+#define __off_t_defined
+#endif
+
+#else
 #include <sys/types.h>
+#endif
+
 #include <misc/dlist.h>
 #include <fs/fs_interface.h>
 

include/posix/sys/stat.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2018 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __POSIX_STAT_H__
+#define __POSIX_STAT_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef CONFIG_PTHREAD_IPC
+#include <kernel.h>
+
+#ifdef CONFIG_POSIX_FS
+#define S_IRWXU 00700
+#define S_IRUSR 00400
+#define S_IWUSR 00200
+#define S_IXUSR 00100
+
+#define S_IRWXG 00070
+#define S_IRGRP 00040
+#define S_IWGRP 00020
+#define S_IXGRP 00010
+
+#define S_IRWXO 00007
+#define S_IROTH 00004
+#define S_IWOTH 00002
+#define S_IXOTH 00001
+
+/* File open modes */
+#define O_ACCMODE	   0003
+#define O_RDONLY	     00
+#define O_WRONLY	     01
+#define O_RDWR		     02
+
+#define SEEK_SET	0	/* Seek from beginning of file.  */
+#define SEEK_CUR	1	/* Seek from current position.  */
+#define SEEK_END	2	/* Seek from end of file.  */
+
+struct stat {
+	unsigned long st_size;
+	unsigned long st_blksize;
+	unsigned long st_blocks;
+};
+
+#endif	/* CONFIG_POSIX_FS */
+
+#endif	/* CONFIG_PTHREAD_IPC */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* __POSIX_STAT_H__ */

include/posix/sys/types.h

@@ -11,7 +11,9 @@
 extern "C" {
 #endif
 
+#ifndef CONFIG_ARCH_POSIX
 #include_next <sys/types.h>
+#endif
 
 #ifdef CONFIG_PTHREAD_IPC
 #include <kernel.h>

include/posix/unistd.h

@@ -11,11 +11,46 @@ extern "C" {
 #endif
 
 #include "sys/types.h"
+#include "sys/stat.h"
+
+#ifdef CONFIG_POSIX_FS
+#include <fs.h>
+
+#undef PATH_MAX
+#define PATH_MAX        256
+
+typedef struct fs_dir_t DIR;
+typedef unsigned int mode_t;
+
+struct dirent {
+	unsigned int d_ino;
+	char d_name[PATH_MAX + 1];
+};
+
+/* File related operations */
+extern int open(const char *name, int flags);
+extern int close(int file);
+extern ssize_t write(int file, char *buffer, unsigned int count);
+extern ssize_t read(int file, char *buffer, unsigned int count);
+extern int lseek(int file, int offset, int whence);
+
+/* Directory related operations */
+extern DIR *opendir(const char *dirname);
+extern int closedir(DIR *dirp);
+extern struct dirent *readdir(DIR *dirp);
+
+/* File System related operations */
+extern int rename(const char *old, const char *newp);
+extern int unlink(const char *path);
+extern int stat(const char *path, struct stat *buf);
+extern int mkdir(const char *path, mode_t mode);
+#endif
 
 unsigned sleep(unsigned int seconds);
 int usleep(useconds_t useconds);
 
-#endif
 #ifdef __cplusplus
 }
+#endif
+
 #endif	/* __POSIX_UNISTD_H__ */

lib/libc/newlib/libc-hooks.c

@@ -75,6 +75,7 @@ void __stdin_hook_install(unsigned char (*hook)(void))
 	_stdin_hook = hook;
 }
 
+#ifndef CONFIG_POSIX_FS
 int _read(int fd, char *buf, int nbytes)
 {
 	int i = 0;
@@ -104,6 +105,28 @@ int _write(int fd, char *buf, int nbytes)
 }
 FUNC_ALIAS(_write, write, int);
 
+int _open(const char *name, int mode)
+{
+	return -1;
+}
+FUNC_ALIAS(_open, open, int);
+
+int _close(int file)
+{
+	return -1;
+}
+FUNC_ALIAS(_close, close, int);
+
+int _lseek(int file, int ptr, int dir)
+{
+	return 0;
+}
+FUNC_ALIAS(_lseek, lseek, int);
+#else
+extern ssize_t write(int file, char *buffer, unsigned int count);
+#define _write	write
+#endif
+
 int _isatty(int file)
 {
 	return 1;
@@ -137,24 +160,6 @@ void _exit(int status)
 	}
 }
 
-int _open(const char *name, int mode)
-{
-	return -1;
-}
-FUNC_ALIAS(_open, open, int);
-
-int _close(int file)
-{
-	return -1;
-}
-FUNC_ALIAS(_close, close, int);
-
-int _lseek(int file, int ptr, int dir)
-{
-	return 0;
-}
-FUNC_ALIAS(_lseek, lseek, int);
-
 void *_sbrk(int count)
 {
 	void *ptr = heap_base + heap_sz;

lib/posix/CMakeLists.txt

@@ -16,6 +16,7 @@ zephyr_library_sources(timer.c)
 zephyr_library_sources(pthread_rwlock.c)
 zephyr_library_sources(semaphore.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_MQUEUE mqueue.c)
+zephyr_library_sources_ifdef(CONFIG_POSIX_FS fs.c)
 
 zephyr_library_link_libraries(PTHREAD)
 target_link_libraries(PTHREAD INTERFACE zephyr_interface)

lib/posix/Kconfig

@@ -70,4 +70,23 @@ config	MQUEUE_NAMELEN_MAX
 	  Mention length of message queue name in number of characters.
 
 endif
+
+if FILE_SYSTEM
+config POSIX_FS
+	bool
+	prompt "Enable POSIX file system API support"
+	default n
+	help
+	  This enabled POSIX style file system related APIs.
+
+if POSIX_FS
+config	POSIX_MAX_OPEN_FILES
+	int
+	prompt "Maximum number of open file descriptors"
+	default 16
+	help
+	  Mention maximum number of open file descriptors.
+endif
+endif
+
 endif