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
16struct rtc_time;
17struct sandbox_state;
18
19/**
20 * os_printf() - print directly to OS console
21 *
22 * @format: format string
23 */
24int 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 */
34ssize_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 */
44ssize_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 */
54off_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 */
67off_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 */
76int 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 */
91int 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 */
99int os_unlink(const char *pathname);
100
101/** os_persistent_fname() - Find the path to a test file
102 *
103 * @buf: Buffer to hold path
104 * @maxsize: Maximum size of buffer
105 * @fname: Leaf filename to find
106 * Returns: 0 on success, -ENOENT if file is not found, -ENOSPC if the buffer is
107 * too small
108 */
109int os_persistent_file(char *buf, int maxsize, const char *fname);
110
111/**
112 * os_mktemp() - Create a temporary file
113 * @fname: The template to use for the file name. This must end with 6 Xs. It
114 *         will be modified to the opened filename on success.
115 * @size: The size of the file
116 *
117 * Create a temporary file using @fname as a template, unlink it, and truncate
118 * it to @size.
119 *
120 * Return: A file descriptor, or negative errno on error
121 */
122int os_mktemp(char *fname, off_t size);
123
124/**
125 * os_exit() - access to the OS exit() system call
126 *
127 * This exits with the supplied return code, which should be 0 to indicate
128 * success.
129 *
130 * @exit_code:	exit code for U-Boot
131 */
132void os_exit(int exit_code) __attribute__((noreturn));
133
134/**
135 * os_alarm() - access to the OS alarm() system call
136 *
137 * @seconds: number of seconds before the signal is sent
138 * Returns: number of seconds remaining until any previously scheduled alarm was
139 * due to be delivered; 0 if there was no previously scheduled alarm
140 */
141unsigned int os_alarm(unsigned int seconds);
142
143/**
144 * os_set_alarm_handler() - set handler for SIGALRM
145 *
146 * @handler:   The handler function. Pass NULL for SIG_DFL.
147 */
148void os_set_alarm_handler(void (*handler)(int));
149
150/**
151 * os_raise_sigalrm() - do raise(SIGALRM)
152 */
153void os_raise_sigalrm(void);
154
155/**
156 * os_tty_raw() - put tty into raw mode to mimic serial console better
157 *
158 * @fd:		File descriptor of stdin (normally 0)
159 * @allow_sigs:	Allow Ctrl-C, Ctrl-Z to generate signals rather than
160 *		be handled by U-Boot
161 */
162void os_tty_raw(int fd, bool allow_sigs);
163
164/**
165 * os_fs_restore() - restore the tty to its original mode
166 *
167 * Call this to restore the original terminal mode, after it has been changed
168 * by os_tty_raw(). This is an internal function.
169 */
170void os_fd_restore(void);
171
172/**
173 * os_malloc() - aquires some memory from the underlying os.
174 *
175 * @length:	Number of bytes to be allocated
176 * Return:	Pointer to length bytes or NULL if @length is 0 or on error
177 */
178void *os_malloc(size_t length);
179
180/**
181 * os_free() - free memory previous allocated with os_malloc()
182 *
183 * This returns the memory to the OS.
184 *
185 * @ptr:	Pointer to memory block to free. If this is NULL then this
186 *		function does nothing
187 */
188void os_free(void *ptr);
189
190/**
191 * os_realloc() - reallocate memory
192 *
193 * This follows the semantics of realloc(), so can perform an os_malloc() or
194 * os_free() depending on @ptr and @length.
195 *
196 * @ptr:	pointer to previously allocated memory of NULL
197 * @length:	number of bytes to allocate
198 * Return:	pointer to reallocated memory or NULL if @length is 0
199 */
200void *os_realloc(void *ptr, size_t length);
201
202/**
203 * os_usleep() - access to the usleep function of the os
204 *
205 * @usec:	time to sleep in micro seconds
206 */
207void os_usleep(unsigned long usec);
208
209/**
210 * Gets a monotonic increasing number of nano seconds from the OS
211 *
212 * Return:	a monotonic increasing time scaled in nano seconds
213 */
214uint64_t os_get_nsec(void);
215
216/**
217 * Parse arguments and update sandbox state.
218 *
219 * @state:	sandbox state to update
220 * @argc:	argument count
221 * @argv:	argument vector
222 * Return:
223 * *  0 if ok, and program should continue
224 * *  1 if ok, but program should stop
225 * * -1 on error: program should terminate
226 */
227int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
228
229/*
230 * enum os_dirent_t - type of directory entry
231 *
232 * Types of directory entry that we support. See also os_dirent_typename in
233 * the C file.
234 */
235enum os_dirent_t {
236	/**
237	 * @OS_FILET_REG:	regular file
238	 */
239	OS_FILET_REG,
240	/**
241	 * @OS_FILET_LNK:	symbolic link
242	 */
243	OS_FILET_LNK,
244	/**
245	 * @OS_FILET_DIR:	directory
246	 */
247	OS_FILET_DIR,
248	/**
249	 * @OS_FILET_UNKNOWN:	something else
250	 */
251	OS_FILET_UNKNOWN,
252	/**
253	 * @OS_FILET_COUNT:	number of directory entry types
254	 */
255	OS_FILET_COUNT,
256};
257
258/**
259 * struct os_dirent_node - directory node
260 *
261 * A directory entry node, containing information about a single dirent
262 *
263 */
264struct os_dirent_node {
265	/**
266	 * @next:	pointer to next node, or NULL
267	 */
268	struct os_dirent_node *next;
269	/**
270	 * @size:	size of file in bytes
271	 */
272	ulong size;
273	/**
274	 * @type:	type of entry
275	 */
276	enum os_dirent_t type;
277	/**
278	 * @name:	name of entry
279	 */
280	char name[0];
281};
282
283/**
284 * os_dirent_ls() - get a directory listing
285 *
286 * This allocates and returns a linked list containing the directory listing.
287 *
288 * @dirname:	directory to examine
289 * @headp:	on return pointer to head of linked list, or NULL if none
290 * Return:	0 if ok, -ve on error
291 */
292int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
293
294/**
295 * os_dirent_free() - free directory list
296 *
297 * This frees a linked list containing a directory listing.
298 *
299 * @node:	pointer to head of linked list
300 */
301void os_dirent_free(struct os_dirent_node *node);
302
303/**
304 * os_dirent_get_typename() - get the name of a directory entry type
305 *
306 * @type:	type to check
307 * Return:
308 * string containing the name of that type,
309 * or "???" if none/invalid
310 */
311const char *os_dirent_get_typename(enum os_dirent_t type);
312
313/**
314 * os_get_filesize() - get the size of a file
315 *
316 * @fname:	filename to check
317 * @size:	size of file is returned if no error
318 * Return:	0 on success or -1 if an error ocurred
319 */
320int os_get_filesize(const char *fname, long long *size);
321
322/**
323 * os_putc() - write a character to the controlling OS terminal
324 *
325 * This bypasses the U-Boot console support and writes directly to the OS
326 * stdout file descriptor.
327 *
328 * @ch:		haracter to write
329 */
330void os_putc(int ch);
331
332/**
333 * os_puts() - write a string to the controlling OS terminal
334 *
335 * This bypasses the U-Boot console support and writes directly to the OS
336 * stdout file descriptor.
337 *
338 * @str:	string to write (note that \n is not appended)
339 */
340void os_puts(const char *str);
341
342/**
343 * os_flush() - flush controlling OS terminal
344 *
345 * This bypasses the U-Boot console support and flushes directly the OS
346 * stdout file descriptor.
347 */
348void os_flush(void);
349
350/**
351 * os_write_ram_buf() - write the sandbox RAM buffer to a existing file
352 *
353 * @fname:	filename to write memory to (simple binary format)
354 * Return:	0 if OK, -ve on error
355 */
356int os_write_ram_buf(const char *fname);
357
358/**
359 * os_read_ram_buf() - read the sandbox RAM buffer from an existing file
360 *
361 * @fname:	filename containing memory (simple binary format)
362 * Return:	0 if OK, -ve on error
363 */
364int os_read_ram_buf(const char *fname);
365
366/**
367 * os_jump_to_image() - jump to a new executable image
368 *
369 * This uses exec() to run a new executable image, after putting it in a
370 * temporary file. The same arguments and environment are passed to this
371 * new image, with the addition of:
372 *
373 *	-j <filename>	Specifies the filename the image was written to. The
374 *			calling image may want to delete this at some point.
375 *	-m <filename>	Specifies the file containing the sandbox memory
376 *			(ram_buf) from this image, so that the new image can
377 *			have access to this. It also means that the original
378 *			memory filename passed to U-Boot will be left intact.
379 *
380 * @dest:	buffer containing executable image
381 * @size:	size of buffer
382 * Return:	0 if OK, -ve on error
383 */
384int os_jump_to_image(const void *dest, int size);
385
386/**
387 * os_find_u_boot() - determine the path to U-Boot proper
388 *
389 * This function is intended to be called from within sandbox SPL. It uses
390 * a few heuristics to find U-Boot proper. Normally it is either in the same
391 * directory, or the directory above (since u-boot-spl is normally in an
392 * spl/ subdirectory when built).
393 *
394 * @fname:	place to put full path to U-Boot
395 * @maxlen:	maximum size of @fname
396 * @use_img:	select the 'u-boot.img' file instead of the 'u-boot' ELF file
397 * @cur_prefix:	prefix of current executable, e.g. "spl" or "tpl"
398 * @next_prefix: prefix of executable to find, e.g. "spl" or ""
399 * Return:	0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
400 */
401int os_find_u_boot(char *fname, int maxlen, bool use_img,
402		   const char *cur_prefix, const char *next_prefix);
403
404/**
405 * os_spl_to_uboot() - Run U-Boot proper
406 *
407 * When called from SPL, this runs U-Boot proper. The filename is obtained by
408 * calling os_find_u_boot().
409 *
410 * @fname:	full pathname to U-Boot executable
411 * Return:	0 if OK, -ve on error
412 */
413int os_spl_to_uboot(const char *fname);
414
415/**
416 * os_localtime() - read the current system time
417 *
418 * This reads the current Local Time and places it into the provided
419 * structure.
420 *
421 * @rt:		place to put system time
422 */
423void os_localtime(struct rtc_time *rt);
424
425/**
426 * os_abort() - raise SIGABRT to exit sandbox (e.g. to debugger)
427 */
428void os_abort(void) __attribute__((noreturn));
429
430/**
431 * os_mprotect_allow() - Remove write-protection on a region of memory
432 *
433 * The start and length will be page-aligned before use.
434 *
435 * @start:	Region start
436 * @len:	Region length in bytes
437 * Return:	0 if OK, -1 on error from mprotect()
438 */
439int os_mprotect_allow(void *start, size_t len);
440
441/**
442 * os_write_file() - write a file to the host filesystem
443 *
444 * This can be useful when debugging for writing data out of sandbox for
445 * inspection by external tools.
446 *
447 * @name:	File path to write to
448 * @buf:	Data to write
449 * @size:	Size of data to write
450 * Return:	0 if OK, -ve on error
451 */
452int os_write_file(const char *name, const void *buf, int size);
453
454/**
455 * os_read_file() - Read a file from the host filesystem
456 *
457 * This can be useful when reading test data into sandbox for use by test
458 * routines. The data is allocated using os_malloc() and should be freed by
459 * the caller.
460 *
461 * @name:	File path to read from
462 * @bufp:	Returns buffer containing data read
463 * @sizep:	Returns size of data
464 * Return:	0 if OK, -ve on error
465 */
466int os_read_file(const char *name, void **bufp, int *sizep);
467
468/**
469 * os_map_file() - Map a file from the host filesystem into memory
470 *
471 * This can be useful when to provide a backing store for an emulated device
472 *
473 * @pathname:	File pathname to map
474 * @os_flags:	Flags, like OS_O_RDONLY, OS_O_RDWR
475 * @bufp:	Returns buffer containing the file
476 * @sizep:	Returns size of data
477 * Return:	0 if OK, -ve on error
478 */
479int os_map_file(const char *pathname, int os_flags, void **bufp, int *sizep);
480
481/**
482 * os_unmap() - Unmap a file previously mapped
483 *
484 * @buf: Mapped address
485 * @size: Size in bytes
486 * Return:	0 if OK, -ve on error
487 */
488int os_unmap(void *buf, int size);
489
490/*
491 * os_find_text_base() - Find the text section in this running process
492 *
493 * This tries to find the address of the text section in this running process.
494 * It can be useful to map the address of functions to the address listed in
495 * the u-boot.map file.
496 *
497 * Return:	address if found, else NULL
498 */
499void *os_find_text_base(void);
500
501/**
502 * os_relaunch() - restart the sandbox
503 *
504 * This functions is used to implement the cold reboot of the sand box.
505 * @argv\[0] specifies the binary that is started while the calling process
506 * stops immediately. If the new binary cannot be started, the process is
507 * terminated and 1 is set as shell return code.
508 *
509 * The PID of the process stays the same. All file descriptors that have not
510 * been opened with O_CLOEXEC stay open including stdin, stdout, stderr.
511 *
512 * @argv:	NULL terminated list of command line parameters
513 */
514void os_relaunch(char *argv[]);
515
516/**
517 * os_setup_signal_handlers() - setup signal handlers
518 *
519 * Install signal handlers for SIGBUS and SIGSEGV.
520 *
521 * Return:	0 for success
522 */
523int os_setup_signal_handlers(void);
524
525/**
526 * os_signal_action() - handle a signal
527 *
528 * @sig:	signal
529 * @pc:		program counter
530 */
531void os_signal_action(int sig, unsigned long pc);
532
533/**
534 * os_get_time_offset() - get time offset
535 *
536 * Get the time offset from environment variable UBOOT_SB_TIME_OFFSET.
537 *
538 * Return:	offset in seconds
539 */
540long os_get_time_offset(void);
541
542/**
543 * os_set_time_offset() - set time offset
544 *
545 * Save the time offset in environment variable UBOOT_SB_TIME_OFFSET.
546 *
547 * @offset:	offset in seconds
548 */
549void os_set_time_offset(long offset);
550
551#endif
552