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  * os_printf() - print directly to OS console
21  *
22  * @format: format string
23  */
24 int os_printf(const char *format, ...);
25 
26 /**
27  * Access to the OS read() system call
28  *
29  * @fd:		File descriptor as returned by os_open()
30  * @buf:	Buffer to place data
31  * @count:	Number of bytes to read
32  * Return:	number of bytes read, or -1 on error
33  */
34 ssize_t os_read(int fd, void *buf, size_t count);
35 
36 /**
37  * Access to the OS write() system call
38  *
39  * @fd:		File descriptor as returned by os_open()
40  * @buf:	Buffer containing data to write
41  * @count:	Number of bytes to write
42  * Return:	number of bytes written, or -1 on error
43  */
44 ssize_t os_write(int fd, const void *buf, size_t count);
45 
46 /**
47  * Access to the OS lseek() system call
48  *
49  * @fd:		File descriptor as returned by os_open()
50  * @offset:	File offset (based on whence)
51  * @whence:	Position offset is relative to (see below)
52  * Return:	new file offset
53  */
54 off_t os_lseek(int fd, off_t offset, int whence);
55 
56 /* Defines for "whence" in os_lseek() */
57 #define OS_SEEK_SET	0
58 #define OS_SEEK_CUR	1
59 #define OS_SEEK_END	2
60 
61 /**
62  * os_filesize() - Calculate the size of a file
63  *
64  * @fd:		File descriptor as returned by os_open()
65  * Return:	file size or negative error code
66  */
67 off_t os_filesize(int fd);
68 
69 /**
70  * Access to the OS open() system call
71  *
72  * @pathname:	Pathname of file to open
73  * @flags:	Flags, like OS_O_RDONLY, OS_O_RDWR
74  * Return:	file descriptor, or -1 on error
75  */
76 int os_open(const char *pathname, int flags);
77 
78 #define OS_O_RDONLY	0
79 #define OS_O_WRONLY	1
80 #define OS_O_RDWR	2
81 #define OS_O_MASK	3	/* Mask for read/write flags */
82 #define OS_O_CREAT	0100
83 #define OS_O_TRUNC	01000
84 
85 /**
86  * os_close() - access to the OS close() system call
87  *
88  * @fd:		File descriptor to close
89  * Return:	0 on success, -1 on error
90  */
91 int os_close(int fd);
92 
93 /**
94  * os_unlink() - access to the OS unlink() system call
95  *
96  * @pathname:	Path of file to delete
97  * Return:	0 for success, other for error
98  */
99 int os_unlink(const char *pathname);
100 
101 /**
102  * os_exit() - access to the OS exit() system call
103  *
104  * This exits with the supplied return code, which should be 0 to indicate
105  * success.
106  *
107  * @exit_code:	exit code for U-Boot
108  */
109 void os_exit(int exit_code) __attribute__((noreturn));
110 
111 /**
112  * os_alarm() - access to the OS alarm() system call
113  *
114  * @seconds: number of seconds before the signal is sent
115  * Returns: number of seconds remaining until any previously scheduled alarm was
116  * due to be delivered; 0 if there was no previously scheduled alarm
117  */
118 unsigned int os_alarm(unsigned int seconds);
119 
120 /**
121  * os_set_alarm_handler() - set handler for SIGALRM
122  *
123  * @handler:   The handler function. Pass NULL for SIG_DFL.
124  */
125 void os_set_alarm_handler(void (*handler)(int));
126 
127 /**
128  * os_raise_sigalrm() - do raise(SIGALRM)
129  */
130 void os_raise_sigalrm(void);
131 
132 /**
133  * os_tty_raw() - put tty into raw mode to mimic serial console better
134  *
135  * @fd:		File descriptor of stdin (normally 0)
136  * @allow_sigs:	Allow Ctrl-C, Ctrl-Z to generate signals rather than
137  *		be handled by U-Boot
138  */
139 void os_tty_raw(int fd, bool allow_sigs);
140 
141 /**
142  * os_fs_restore() - restore the tty to its original mode
143  *
144  * Call this to restore the original terminal mode, after it has been changed
145  * by os_tty_raw(). This is an internal function.
146  */
147 void os_fd_restore(void);
148 
149 /**
150  * os_malloc() - aquires some memory from the underlying os.
151  *
152  * @length:	Number of bytes to be allocated
153  * Return:	Pointer to length bytes or NULL if @length is 0 or on error
154  */
155 void *os_malloc(size_t length);
156 
157 /**
158  * os_free() - free memory previous allocated with os_malloc()
159  *
160  * This returns the memory to the OS.
161  *
162  * @ptr:	Pointer to memory block to free. If this is NULL then this
163  *		function does nothing
164  */
165 void os_free(void *ptr);
166 
167 /**
168  * os_realloc() - reallocate memory
169  *
170  * This follows the semantics of realloc(), so can perform an os_malloc() or
171  * os_free() depending on @ptr and @length.
172  *
173  * @ptr:	pointer to previously allocated memory of NULL
174  * @length:	number of bytes to allocate
175  * Return:	pointer to reallocated memory or NULL if @length is 0
176  */
177 void *os_realloc(void *ptr, size_t length);
178 
179 /**
180  * os_usleep() - access to the usleep function of the os
181  *
182  * @usec:	time to sleep in micro seconds
183  */
184 void os_usleep(unsigned long usec);
185 
186 /**
187  * Gets a monotonic increasing number of nano seconds from the OS
188  *
189  * Return:	a monotonic increasing time scaled in nano seconds
190  */
191 uint64_t os_get_nsec(void);
192 
193 /**
194  * Parse arguments and update sandbox state.
195  *
196  * @state:	sandbox state to update
197  * @argc:	argument count
198  * @argv:	argument vector
199  * Return:
200  * *  0 if ok, and program should continue
201  * *  1 if ok, but program should stop
202  * * -1 on error: program should terminate
203  */
204 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
205 
206 /*
207  * enum os_dirent_t - type of directory entry
208  *
209  * Types of directory entry that we support. See also os_dirent_typename in
210  * the C file.
211  */
212 enum os_dirent_t {
213 	/**
214 	 * @OS_FILET_REG:	regular file
215 	 */
216 	OS_FILET_REG,
217 	/**
218 	 * @OS_FILET_LNK:	symbolic link
219 	 */
220 	OS_FILET_LNK,
221 	/**
222 	 * @OS_FILET_DIR:	directory
223 	 */
224 	OS_FILET_DIR,
225 	/**
226 	 * @OS_FILET_UNKNOWN:	something else
227 	 */
228 	OS_FILET_UNKNOWN,
229 	/**
230 	 * @OS_FILET_COUNT:	number of directory entry types
231 	 */
232 	OS_FILET_COUNT,
233 };
234 
235 /**
236  * struct os_dirent_node - directory node
237  *
238  * A directory entry node, containing information about a single dirent
239  *
240  */
241 struct os_dirent_node {
242 	/**
243 	 * @next:	pointer to next node, or NULL
244 	 */
245 	struct os_dirent_node *next;
246 	/**
247 	 * @size:	size of file in bytes
248 	 */
249 	ulong size;
250 	/**
251 	 * @type:	type of entry
252 	 */
253 	enum os_dirent_t type;
254 	/**
255 	 * @name:	name of entry
256 	 */
257 	char name[0];
258 };
259 
260 /**
261  * os_dirent_ls() - get a directory listing
262  *
263  * This allocates and returns a linked list containing the directory listing.
264  *
265  * @dirname:	directory to examine
266  * @headp:	on return pointer to head of linked list, or NULL if none
267  * Return:	0 if ok, -ve on error
268  */
269 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
270 
271 /**
272  * os_dirent_free() - free directory list
273  *
274  * This frees a linked list containing a directory listing.
275  *
276  * @node:	pointer to head of linked list
277  */
278 void os_dirent_free(struct os_dirent_node *node);
279 
280 /**
281  * os_dirent_get_typename() - get the name of a directory entry type
282  *
283  * @type:	type to check
284  * Return:
285  * string containing the name of that type,
286  * or "???" if none/invalid
287  */
288 const char *os_dirent_get_typename(enum os_dirent_t type);
289 
290 /**
291  * os_get_filesize() - get the size of a file
292  *
293  * @fname:	filename to check
294  * @size:	size of file is returned if no error
295  * Return:	0 on success or -1 if an error ocurred
296  */
297 int os_get_filesize(const char *fname, long long *size);
298 
299 /**
300  * os_putc() - write a character to the controlling OS terminal
301  *
302  * This bypasses the U-Boot console support and writes directly to the OS
303  * stdout file descriptor.
304  *
305  * @ch:		haracter to write
306  */
307 void os_putc(int ch);
308 
309 /**
310  * os_puts() - write a string to the controlling OS terminal
311  *
312  * This bypasses the U-Boot console support and writes directly to the OS
313  * stdout file descriptor.
314  *
315  * @str:	string to write (note that \n is not appended)
316  */
317 void os_puts(const char *str);
318 
319 /**
320  * os_flush() - flush controlling OS terminal
321  *
322  * This bypasses the U-Boot console support and flushes directly the OS
323  * stdout file descriptor.
324  */
325 void os_flush(void);
326 
327 /**
328  * os_write_ram_buf() - write the sandbox RAM buffer to a existing file
329  *
330  * @fname:	filename to write memory to (simple binary format)
331  * Return:	0 if OK, -ve on error
332  */
333 int os_write_ram_buf(const char *fname);
334 
335 /**
336  * os_read_ram_buf() - read the sandbox RAM buffer from an existing file
337  *
338  * @fname:	filename containing memory (simple binary format)
339  * Return:	0 if OK, -ve on error
340  */
341 int os_read_ram_buf(const char *fname);
342 
343 /**
344  * os_jump_to_image() - jump to a new executable image
345  *
346  * This uses exec() to run a new executable image, after putting it in a
347  * temporary file. The same arguments and environment are passed to this
348  * new image, with the addition of:
349  *
350  *	-j <filename>	Specifies the filename the image was written to. The
351  *			calling image may want to delete this at some point.
352  *	-m <filename>	Specifies the file containing the sandbox memory
353  *			(ram_buf) from this image, so that the new image can
354  *			have access to this. It also means that the original
355  *			memory filename passed to U-Boot will be left intact.
356  *
357  * @dest:	buffer containing executable image
358  * @size:	size of buffer
359  * Return:	0 if OK, -ve on error
360  */
361 int os_jump_to_image(const void *dest, int size);
362 
363 /**
364  * os_find_u_boot() - determine the path to U-Boot proper
365  *
366  * This function is intended to be called from within sandbox SPL. It uses
367  * a few heuristics to find U-Boot proper. Normally it is either in the same
368  * directory, or the directory above (since u-boot-spl is normally in an
369  * spl/ subdirectory when built).
370  *
371  * @fname:	place to put full path to U-Boot
372  * @maxlen:	maximum size of @fname
373  * @use_img:	select the 'u-boot.img' file instead of the 'u-boot' ELF file
374  * @cur_prefix:	prefix of current executable, e.g. "spl" or "tpl"
375  * @next_prefix: prefix of executable to find, e.g. "spl" or ""
376  * Return:	0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
377  */
378 int os_find_u_boot(char *fname, int maxlen, bool use_img,
379 		   const char *cur_prefix, const char *next_prefix);
380 
381 /**
382  * os_spl_to_uboot() - Run U-Boot proper
383  *
384  * When called from SPL, this runs U-Boot proper. The filename is obtained by
385  * calling os_find_u_boot().
386  *
387  * @fname:	full pathname to U-Boot executable
388  * Return:	0 if OK, -ve on error
389  */
390 int os_spl_to_uboot(const char *fname);
391 
392 /**
393  * os_localtime() - read the current system time
394  *
395  * This reads the current Local Time and places it into the provided
396  * structure.
397  *
398  * @rt:		place to put system time
399  */
400 void os_localtime(struct rtc_time *rt);
401 
402 /**
403  * os_abort() - raise SIGABRT to exit sandbox (e.g. to debugger)
404  */
405 void os_abort(void) __attribute__((noreturn));
406 
407 /**
408  * os_mprotect_allow() - Remove write-protection on a region of memory
409  *
410  * The start and length will be page-aligned before use.
411  *
412  * @start:	Region start
413  * @len:	Region length in bytes
414  * Return:	0 if OK, -1 on error from mprotect()
415  */
416 int os_mprotect_allow(void *start, size_t len);
417 
418 /**
419  * os_write_file() - write a file to the host filesystem
420  *
421  * This can be useful when debugging for writing data out of sandbox for
422  * inspection by external tools.
423  *
424  * @name:	File path to write to
425  * @buf:	Data to write
426  * @size:	Size of data to write
427  * Return:	0 if OK, -ve on error
428  */
429 int os_write_file(const char *name, const void *buf, int size);
430 
431 /**
432  * os_read_file() - Read a file from the host filesystem
433  *
434  * This can be useful when reading test data into sandbox for use by test
435  * routines. The data is allocated using os_malloc() and should be freed by
436  * the caller.
437  *
438  * @name:	File path to read from
439  * @bufp:	Returns buffer containing data read
440  * @sizep:	Returns size of data
441  * Return:	0 if OK, -ve on error
442  */
443 int os_read_file(const char *name, void **bufp, int *sizep);
444 
445 /**
446  * os_map_file() - Map a file from the host filesystem into memory
447  *
448  * This can be useful when to provide a backing store for an emulated device
449  *
450  * @pathname:	File pathname to map
451  * @os_flags:	Flags, like OS_O_RDONLY, OS_O_RDWR
452  * @bufp:	Returns buffer containing the file
453  * @sizep:	Returns size of data
454  * Return:	0 if OK, -ve on error
455  */
456 int os_map_file(const char *pathname, int os_flags, void **bufp, int *sizep);
457 
458 /**
459  * os_unmap() - Unmap a file previously mapped
460  *
461  * @buf: Mapped address
462  * @size: Size in bytes
463  * Return:	0 if OK, -ve on error
464  */
465 int os_unmap(void *buf, int size);
466 
467 /*
468  * os_find_text_base() - Find the text section in this running process
469  *
470  * This tries to find the address of the text section in this running process.
471  * It can be useful to map the address of functions to the address listed in
472  * the u-boot.map file.
473  *
474  * Return:	address if found, else NULL
475  */
476 void *os_find_text_base(void);
477 
478 /**
479  * os_relaunch() - restart the sandbox
480  *
481  * This functions is used to implement the cold reboot of the sand box.
482  * @argv\[0] specifies the binary that is started while the calling process
483  * stops immediately. If the new binary cannot be started, the process is
484  * terminated and 1 is set as shell return code.
485  *
486  * The PID of the process stays the same. All file descriptors that have not
487  * been opened with O_CLOEXEC stay open including stdin, stdout, stderr.
488  *
489  * @argv:	NULL terminated list of command line parameters
490  */
491 void os_relaunch(char *argv[]);
492 
493 /**
494  * os_setup_signal_handlers() - setup signal handlers
495  *
496  * Install signal handlers for SIGBUS and SIGSEGV.
497  *
498  * Return:	0 for success
499  */
500 int os_setup_signal_handlers(void);
501 
502 /**
503  * os_signal_action() - handle a signal
504  *
505  * @sig:	signal
506  * @pc:		program counter
507  */
508 void os_signal_action(int sig, unsigned long pc);
509 
510 /**
511  * os_get_time_offset() - get time offset
512  *
513  * Get the time offset from environment variable UBOOT_SB_TIME_OFFSET.
514  *
515  * Return:	offset in seconds
516  */
517 long os_get_time_offset(void);
518 
519 /**
520  * os_set_time_offset() - set time offset
521  *
522  * Save the time offset in environment variable UBOOT_SB_TIME_OFFSET.
523  *
524  * @offset:	offset in seconds
525  */
526 void os_set_time_offset(long offset);
527 
528 #endif
529