1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Operating System Interface
4  *
5  * This provides access to useful OS routines for the sandbox architecture.
6  * They are kept in a separate file so we can include system headers.
7  *
8  * Copyright (c) 2011 The Chromium OS Authors.
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  * @fd:		File descriptor as returned by os_open()
23  * @buf:	Buffer to place data
24  * @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 write() system call
31  *
32  * @fd:		File descriptor as returned by os_open()
33  * @buf:	Buffer containing data to write
34  * @count:	Number of bytes to write
35  * Return:	number of bytes written, or -1 on error
36  */
37 ssize_t os_write(int fd, const void *buf, size_t count);
38 
39 /**
40  * Access to the OS lseek() system call
41  *
42  * @fd:		File descriptor as returned by os_open()
43  * @offset:	File offset (based on whence)
44  * @whence:	Position offset is relative to (see below)
45  * Return:	new file offset
46  */
47 off_t os_lseek(int fd, off_t offset, int whence);
48 
49 /* Defines for "whence" in os_lseek() */
50 #define OS_SEEK_SET	0
51 #define OS_SEEK_CUR	1
52 #define OS_SEEK_END	2
53 
54 /**
55  * Access to the OS open() system call
56  *
57  * @pathname:	Pathname of file to open
58  * @flags:	Flags, like OS_O_RDONLY, OS_O_RDWR
59  * Return:	file descriptor, or -1 on error
60  */
61 int os_open(const char *pathname, int flags);
62 
63 #define OS_O_RDONLY	0
64 #define OS_O_WRONLY	1
65 #define OS_O_RDWR	2
66 #define OS_O_MASK	3	/* Mask for read/write flags */
67 #define OS_O_CREAT	0100
68 #define OS_O_TRUNC	01000
69 
70 /**
71  * os_close() - access to the OS close() system call
72  *
73  * @fd:		File descriptor to close
74  * Return:	0 on success, -1 on error
75  */
76 int os_close(int fd);
77 
78 /**
79  * os_unlink() - access to the OS unlink() system call
80  *
81  * @pathname:	Path of file to delete
82  * Return:	0 for success, other for error
83  */
84 int os_unlink(const char *pathname);
85 
86 /**
87  * os_exit() - access to the OS exit() system call
88  *
89  * This exits with the supplied return code, which should be 0 to indicate
90  * success.
91  *
92  * @exit_code:	exit code for U-Boot
93  */
94 void os_exit(int exit_code) __attribute__((noreturn));
95 
96 /**
97  * os_tty_raw() - put tty into raw mode to mimic serial console better
98  *
99  * @fd:		File descriptor of stdin (normally 0)
100  * @allow_sigs:	Allow Ctrl-C, Ctrl-Z to generate signals rather than
101  *		be handled by U-Boot
102  */
103 void os_tty_raw(int fd, bool allow_sigs);
104 
105 /**
106  * os_fs_restore() - restore the tty to its original mode
107  *
108  * Call this to restore the original terminal mode, after it has been changed
109  * by os_tty_raw(). This is an internal function.
110  */
111 void os_fd_restore(void);
112 
113 /**
114  * os_malloc() - aquires some memory from the underlying os.
115  *
116  * @length:	Number of bytes to be allocated
117  * Return:	Pointer to length bytes or NULL if @length is 0 or on error
118  */
119 void *os_malloc(size_t length);
120 
121 /**
122  * os_free() - free memory previous allocated with os_malloc()
123  *
124  * This returns the memory to the OS.
125  *
126  * @ptr:	Pointer to memory block to free. If this is NULL then this
127  *		function does nothing
128  */
129 void os_free(void *ptr);
130 
131 /**
132  * os_realloc() - reallocate memory
133  *
134  * This follows the semantics of realloc(), so can perform an os_malloc() or
135  * os_free() depending on @ptr and @length.
136  *
137  * @ptr:	pointer to previously allocated memory of NULL
138  * @length:	number of bytes to allocate
139  * Return:	pointer to reallocated memory or NULL if @length is 0
140  */
141 void *os_realloc(void *ptr, size_t length);
142 
143 /**
144  * os_usleep() - access to the usleep function of the os
145  *
146  * @usec:	time to sleep in micro seconds
147  */
148 void os_usleep(unsigned long usec);
149 
150 /**
151  * Gets a monotonic increasing number of nano seconds from the OS
152  *
153  * Return:	a monotonic increasing time scaled in nano seconds
154  */
155 uint64_t os_get_nsec(void);
156 
157 /**
158  * Parse arguments and update sandbox state.
159  *
160  * @state:	sandbox state to update
161  * @argc:	argument count
162  * @argv:	argument vector
163  * Return:
164  * *  0 if ok, and program should continue
165  * *  1 if ok, but program should stop
166  * * -1 on error: program should terminate
167  */
168 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
169 
170 /*
171  * enum os_dirent_t - type of directory entry
172  *
173  * Types of directory entry that we support. See also os_dirent_typename in
174  * the C file.
175  */
176 enum os_dirent_t {
177 	/**
178 	 * @OS_FILET_REG:	regular file
179 	 */
180 	OS_FILET_REG,
181 	/**
182 	 * @OS_FILET_LNK:	symbolic link
183 	 */
184 	OS_FILET_LNK,
185 	/**
186 	 * @OS_FILET_DIR:	directory
187 	 */
188 	OS_FILET_DIR,
189 	/**
190 	 * @OS_FILET_UNKNOWN:	something else
191 	 */
192 	OS_FILET_UNKNOWN,
193 	/**
194 	 * @OS_FILET_COUNT:	number of directory entry types
195 	 */
196 	OS_FILET_COUNT,
197 };
198 
199 /**
200  * struct os_dirent_node - directory node
201  *
202  * A directory entry node, containing information about a single dirent
203  *
204  */
205 struct os_dirent_node {
206 	/**
207 	 * @next:	pointer to next node, or NULL
208 	 */
209 	struct os_dirent_node *next;
210 	/**
211 	 * @size:	size of file in bytes
212 	 */
213 	ulong size;
214 	/**
215 	 * @type:	type of entry
216 	 */
217 	enum os_dirent_t type;
218 	/**
219 	 * @name:	name of entry
220 	 */
221 	char name[0];
222 };
223 
224 /**
225  * os_dirent_ls() - get a directory listing
226  *
227  * This allocates and returns a linked list containing the directory listing.
228  *
229  * @dirname:	directory to examine
230  * @headp:	on return pointer to head of linked list, or NULL if none
231  * Return:	0 if ok, -ve on error
232  */
233 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
234 
235 /**
236  * os_dirent_free() - free directory list
237  *
238  * This frees a linked list containing a directory listing.
239  *
240  * @node:	pointer to head of linked list
241  */
242 void os_dirent_free(struct os_dirent_node *node);
243 
244 /**
245  * os_dirent_get_typename() - get the name of a directory entry type
246  *
247  * @type:	type to check
248  * Return:
249  * string containing the name of that type,
250  * or "???" if none/invalid
251  */
252 const char *os_dirent_get_typename(enum os_dirent_t type);
253 
254 /**
255  * os_get_filesize() - get the size of a file
256  *
257  * @fname:	filename to check
258  * @size:	size of file is returned if no error
259  * Return:	0 on success or -1 if an error ocurred
260  */
261 int os_get_filesize(const char *fname, loff_t *size);
262 
263 /**
264  * os_putc() - write a character to the controlling OS terminal
265  *
266  * This bypasses the U-Boot console support and writes directly to the OS
267  * stdout file descriptor.
268  *
269  * @ch:		haracter to write
270  */
271 void os_putc(int ch);
272 
273 /**
274  * os_puts() - write a string to the controlling OS terminal
275  *
276  * This bypasses the U-Boot console support and writes directly to the OS
277  * stdout file descriptor.
278  *
279  * @str:	string to write (note that \n is not appended)
280  */
281 void os_puts(const char *str);
282 
283 /**
284  * os_write_ram_buf() - write the sandbox RAM buffer to a existing file
285  *
286  * @fname:	filename to write memory to (simple binary format)
287  * Return:	0 if OK, -ve on error
288  */
289 int os_write_ram_buf(const char *fname);
290 
291 /**
292  * os_read_ram_buf() - read the sandbox RAM buffer from an existing file
293  *
294  * @fname:	filename containing memory (simple binary format)
295  * Return:	0 if OK, -ve on error
296  */
297 int os_read_ram_buf(const char *fname);
298 
299 /**
300  * os_jump_to_image() - jump to a new executable image
301  *
302  * This uses exec() to run a new executable image, after putting it in a
303  * temporary file. The same arguments and environment are passed to this
304  * new image, with the addition of:
305  *
306  *	-j <filename>	Specifies the filename the image was written to. The
307  *			calling image may want to delete this at some point.
308  *	-m <filename>	Specifies the file containing the sandbox memory
309  *			(ram_buf) from this image, so that the new image can
310  *			have access to this. It also means that the original
311  *			memory filename passed to U-Boot will be left intact.
312  *
313  * @dest:	buffer containing executable image
314  * @size:	size of buffer
315  * Return:	0 if OK, -ve on error
316  */
317 int os_jump_to_image(const void *dest, int size);
318 
319 /**
320  * os_find_u_boot() - determine the path to U-Boot proper
321  *
322  * This function is intended to be called from within sandbox SPL. It uses
323  * a few heuristics to find U-Boot proper. Normally it is either in the same
324  * directory, or the directory above (since u-boot-spl is normally in an
325  * spl/ subdirectory when built).
326  *
327  * @fname:	place to put full path to U-Boot
328  * @maxlen:	maximum size of @fname
329  * @use_img:	select the 'u-boot.img' file instead of the 'u-boot' ELF file
330  * Return:	0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
331  */
332 int os_find_u_boot(char *fname, int maxlen, bool use_img);
333 
334 /**
335  * os_spl_to_uboot() - Run U-Boot proper
336  *
337  * When called from SPL, this runs U-Boot proper. The filename is obtained by
338  * calling os_find_u_boot().
339  *
340  * @fname:	full pathname to U-Boot executable
341  * Return:	0 if OK, -ve on error
342  */
343 int os_spl_to_uboot(const char *fname);
344 
345 /**
346  * os_localtime() - read the current system time
347  *
348  * This reads the current Local Time and places it into the provided
349  * structure.
350  *
351  * @rt:		place to put system time
352  */
353 void os_localtime(struct rtc_time *rt);
354 
355 /**
356  * os_abort() - raise SIGABRT to exit sandbox (e.g. to debugger)
357  */
358 void os_abort(void) __attribute__((noreturn));
359 
360 /**
361  * os_mprotect_allow() - Remove write-protection on a region of memory
362  *
363  * The start and length will be page-aligned before use.
364  *
365  * @start:	Region start
366  * @len:	Region length in bytes
367  * Return:	0 if OK, -1 on error from mprotect()
368  */
369 int os_mprotect_allow(void *start, size_t len);
370 
371 /**
372  * os_write_file() - write a file to the host filesystem
373  *
374  * This can be useful when debugging for writing data out of sandbox for
375  * inspection by external tools.
376  *
377  * @name:	File path to write to
378  * @buf:	Data to write
379  * @size:	Size of data to write
380  * Return:	0 if OK, -ve on error
381  */
382 int os_write_file(const char *name, const void *buf, int size);
383 
384 /**
385  * os_read_file() - Read a file from the host filesystem
386  *
387  * This can be useful when reading test data into sandbox for use by test
388  * routines. The data is allocated using os_malloc() and should be freed by
389  * the caller.
390  *
391  * @name:	File path to read from
392  * @bufp:	Returns buffer containing data read
393  * @sizep:	Returns size of data
394  * Return:	0 if OK, -ve on error
395  */
396 int os_read_file(const char *name, void **bufp, int *sizep);
397 
398 /*
399  * os_find_text_base() - Find the text section in this running process
400  *
401  * This tries to find the address of the text section in this running process.
402  * It can be useful to map the address of functions to the address listed in
403  * the u-boot.map file.
404  *
405  * Return:	address if found, else NULL
406  */
407 void *os_find_text_base(void);
408 
409 /**
410  * os_relaunch() - restart the sandbox
411  *
412  * This functions is used to implement the cold reboot of the sand box.
413  * @argv\[0] specifies the binary that is started while the calling process
414  * stops immediately. If the new binary cannot be started, the process is
415  * terminated and 1 is set as shell return code.
416  *
417  * The PID of the process stays the same. All file descriptors that have not
418  * been opened with O_CLOEXEC stay open including stdin, stdout, stderr.
419  *
420  * @argv:	NULL terminated list of command line parameters
421  */
422 void os_relaunch(char *argv[]);
423 
424 /**
425  * os_setup_signal_handlers() - setup signal handlers
426  *
427  * Install signal handlers for SIGBUS and SIGSEGV.
428  *
429  * Return:	0 for success
430  */
431 int os_setup_signal_handlers(void);
432 
433 /**
434  * os_signal_action() - handle a signal
435  *
436  * @sig:	signal
437  * @pc:		program counter
438  */
439 void os_signal_action(int sig, unsigned long pc);
440 
441 /**
442  * os_get_time_offset() - get time offset
443  *
444  * Get the time offset from environment variable UBOOT_SB_TIME_OFFSET.
445  *
446  * Return:	offset in seconds
447  */
448 long os_get_time_offset(void);
449 
450 /**
451  * os_set_time_offset() - set time offset
452  *
453  * Save the time offset in environment variable UBOOT_SB_TIME_OFFSET.
454  *
455  * @offset:	offset in seconds
456  */
457 void os_set_time_offset(long offset);
458 
459 #endif
460