xref: /openbmc/u-boot/include/os.h (revision 3949d2a7)
1 /*
2  * Operating System Interface
3  *
4  * This provides access to useful OS routines for the sandbox architecture.
5  * They are kept in a separate file so we can include system headers.
6  *
7  * Copyright (c) 2011 The Chromium OS Authors.
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #ifndef __OS_H__
12 #define __OS_H__
13 
14 #include <linux/types.h>
15 
16 struct rtc_time;
17 struct sandbox_state;
18 
19 /**
20  * Access to the OS read() system call
21  *
22  * \param fd	File descriptor as returned by os_open()
23  * \param buf	Buffer to place data
24  * \param count	Number of bytes to read
25  * \return number of bytes read, or -1 on error
26  */
27 ssize_t os_read(int fd, void *buf, size_t count);
28 
29 /**
30  * Access to the OS read() system call with non-blocking access
31  *
32  * \param fd	File descriptor as returned by os_open()
33  * \param buf	Buffer to place data
34  * \param count	Number of bytes to read
35  * \return number of bytes read, or -1 on error
36  */
37 ssize_t os_read_no_block(int fd, void *buf, size_t count);
38 
39 /**
40  * Access to the OS write() system call
41  *
42  * \param fd	File descriptor as returned by os_open()
43  * \param buf	Buffer containing data to write
44  * \param count	Number of bytes to write
45  * \return number of bytes written, or -1 on error
46  */
47 ssize_t os_write(int fd, const void *buf, size_t count);
48 
49 /**
50  * Access to the OS lseek() system call
51  *
52  * \param fd	File descriptor as returned by os_open()
53  * \param offset	File offset (based on whence)
54  * \param whence	Position offset is relative to (see below)
55  * \return new file offset
56  */
57 off_t os_lseek(int fd, off_t offset, int whence);
58 
59 /* Defines for "whence" in os_lseek() */
60 #define OS_SEEK_SET	0
61 #define OS_SEEK_CUR	1
62 #define OS_SEEK_END	2
63 
64 /**
65  * Access to the OS open() system call
66  *
67  * \param pathname	Pathname of file to open
68  * \param flags		Flags, like OS_O_RDONLY, OS_O_RDWR
69  * \return file descriptor, or -1 on error
70  */
71 int os_open(const char *pathname, int flags);
72 
73 #define OS_O_RDONLY	0
74 #define OS_O_WRONLY	1
75 #define OS_O_RDWR	2
76 #define OS_O_MASK	3	/* Mask for read/write flags */
77 #define OS_O_CREAT	0100
78 
79 /**
80  * Access to the OS close() system call
81  *
82  * \param fd	File descriptor to close
83  * \return 0 on success, -1 on error
84  */
85 int os_close(int fd);
86 
87 /**
88  * Access to the OS unlink() system call
89  *
90  * \param pathname Path of file to delete
91  * \return 0 for success, other for error
92  */
93 int os_unlink(const char *pathname);
94 
95 /**
96  * Access to the OS exit() system call
97  *
98  * This exits with the supplied return code, which should be 0 to indicate
99  * success.
100  *
101  * @param exit_code	exit code for U-Boot
102  */
103 void os_exit(int exit_code) __attribute__((noreturn));
104 
105 /**
106  * Put tty into raw mode to mimic serial console better
107  *
108  * @param fd		File descriptor of stdin (normally 0)
109  * @param allow_sigs	Allow Ctrl-C, Ctrl-Z to generate signals rather than
110  *			be handled by U-Boot
111  */
112 void os_tty_raw(int fd, bool allow_sigs);
113 
114 /**
115  * Restore the tty to its original mode
116  *
117  * Call this to restore the original terminal mode, after it has been changed
118  * by os_tty_raw(). This is an internal function.
119  */
120 void os_fd_restore(void);
121 
122 /**
123  * Acquires some memory from the underlying os.
124  *
125  * \param length	Number of bytes to be allocated
126  * \return Pointer to length bytes or NULL on error
127  */
128 void *os_malloc(size_t length);
129 
130 /**
131  * Free memory previous allocated with os_malloc()/os_realloc()
132  *
133  * This returns the memory to the OS.
134  *
135  * \param ptr		Pointer to memory block to free
136  */
137 void os_free(void *ptr);
138 
139 /**
140  * Reallocate previously-allocated memory to increase/decrease space
141  *
142  * This works in a similar way to the C library realloc() function. If
143  * length is 0, then ptr is freed. Otherwise the space used by ptr is
144  * expanded or reduced depending on whether length is larger or smaller
145  * than before.
146  *
147  * If ptr is NULL, then this is similar to calling os_malloc().
148  *
149  * This function may need to move the memory block to make room for any
150  * extra space, in which case the new pointer is returned.
151  *
152  * \param ptr		Pointer to memory block to reallocate
153  * \param length	New length for memory block
154  * \return pointer to new memory block, or NULL on failure or if length
155  *	is 0.
156  */
157 void *os_realloc(void *ptr, size_t length);
158 
159 /**
160  * Access to the usleep function of the os
161  *
162  * \param usec Time to sleep in micro seconds
163  */
164 void os_usleep(unsigned long usec);
165 
166 /**
167  * Gets a monotonic increasing number of nano seconds from the OS
168  *
169  * \return A monotonic increasing time scaled in nano seconds
170  */
171 uint64_t os_get_nsec(void);
172 
173 /**
174  * Parse arguments and update sandbox state.
175  *
176  * @param state		Sandbox state to update
177  * @param argc		Argument count
178  * @param argv		Argument vector
179  * @return 0 if ok, and program should continue;
180  *	1 if ok, but program should stop;
181  *	-1 on error: program should terminate.
182  */
183 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
184 
185 /*
186  * Types of directory entry that we support. See also os_dirent_typename in
187  * the C file.
188  */
189 enum os_dirent_t {
190 	OS_FILET_REG,		/* Regular file */
191 	OS_FILET_LNK,		/* Symbolic link */
192 	OS_FILET_DIR,		/* Directory */
193 	OS_FILET_UNKNOWN,	/* Something else */
194 
195 	OS_FILET_COUNT,
196 };
197 
198 /** A directory entry node, containing information about a single dirent */
199 struct os_dirent_node {
200 	struct os_dirent_node *next;	/* Pointer to next node, or NULL */
201 	ulong size;			/* Size of file in bytes */
202 	enum os_dirent_t type;		/* Type of entry */
203 	char name[0];			/* Name of entry */
204 };
205 
206 /**
207  * Get a directionry listing
208  *
209  * This allocates and returns a linked list containing the directory listing.
210  *
211  * @param dirname	Directory to examine
212  * @param headp		Returns pointer to head of linked list, or NULL if none
213  * @return 0 if ok, -ve on error
214  */
215 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
216 
217 /**
218  * Free directory list
219  *
220  * This frees a linked list containing a directory listing.
221  *
222  * @param node		Pointer to head of linked list
223  */
224 void os_dirent_free(struct os_dirent_node *node);
225 
226 /**
227  * Get the name of a directory entry type
228  *
229  * @param type		Type to check
230  * @return string containing the name of that type, or "???" if none/invalid
231  */
232 const char *os_dirent_get_typename(enum os_dirent_t type);
233 
234 /**
235  * Get the size of a file
236  *
237  * @param fname		Filename to check
238  * @param size		size of file is returned if no error
239  * @return 0 on success or -1 if an error ocurred
240  */
241 int os_get_filesize(const char *fname, loff_t *size);
242 
243 /**
244  * Write a character to the controlling OS terminal
245  *
246  * This bypasses the U-Boot console support and writes directly to the OS
247  * stdout file descriptor.
248  *
249  * @param ch	Character to write
250  */
251 void os_putc(int ch);
252 
253 /**
254  * Write a string to the controlling OS terminal
255  *
256  * This bypasses the U-Boot console support and writes directly to the OS
257  * stdout file descriptor.
258  *
259  * @param str	String to write (note that \n is not appended)
260  */
261 void os_puts(const char *str);
262 
263 /**
264  * Write the sandbox RAM buffer to a existing file
265  *
266  * @param fname		Filename to write memory to (simple binary format)
267  * @return 0 if OK, -ve on error
268  */
269 int os_write_ram_buf(const char *fname);
270 
271 /**
272  * Read the sandbox RAM buffer from an existing file
273  *
274  * @param fname		Filename containing memory (simple binary format)
275  * @return 0 if OK, -ve on error
276  */
277 int os_read_ram_buf(const char *fname);
278 
279 /**
280  * Jump to a new executable image
281  *
282  * This uses exec() to run a new executable image, after putting it in a
283  * temporary file. The same arguments and environment are passed to this
284  * new image, with the addition of:
285  *
286  *	-j <filename>	Specifies the filename the image was written to. The
287  *			calling image may want to delete this at some point.
288  *	-m <filename>	Specifies the file containing the sandbox memory
289  *			(ram_buf) from this image, so that the new image can
290  *			have access to this. It also means that the original
291  *			memory filename passed to U-Boot will be left intact.
292  *
293  * @param dest		Buffer containing executable image
294  * @param size		Size of buffer
295  */
296 int os_jump_to_image(const void *dest, int size);
297 
298 /**
299  * os_find_u_boot() - Determine the path to U-Boot proper
300  *
301  * This function is intended to be called from within sandbox SPL. It uses
302  * a few heuristics to find U-Boot proper. Normally it is either in the same
303  * directory, or the directory above (since u-boot-spl is normally in an
304  * spl/ subdirectory when built).
305  *
306  * @fname:	Place to put full path to U-Boot
307  * @maxlen:	Maximum size of @fname
308  * @return 0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
309  */
310 int os_find_u_boot(char *fname, int maxlen);
311 
312 /**
313  * os_spl_to_uboot() - Run U-Boot proper
314  *
315  * When called from SPL, this runs U-Boot proper. The filename is obtained by
316  * calling os_find_u_boot().
317  *
318  * @fname:	Full pathname to U-Boot executable
319  * @return 0 if OK, -ve on error
320  */
321 int os_spl_to_uboot(const char *fname);
322 
323 /**
324  * Read the current system time
325  *
326  * This reads the current Local Time and places it into the provided
327  * structure.
328  *
329  * @param rt		Place to put system time
330  */
331 void os_localtime(struct rtc_time *rt);
332 
333 #endif
334