xref: /openbmc/u-boot/api/api.c (revision ef64e782)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2007 Semihalf
4  *
5  * Written by: Rafal Jaworowski <raj@semihalf.com>
6  */
7 
8 #include <config.h>
9 #include <command.h>
10 #include <common.h>
11 #include <malloc.h>
12 #include <environment.h>
13 #include <linux/types.h>
14 #include <api_public.h>
15 
16 #include "api_private.h"
17 
18 #define DEBUG
19 #undef DEBUG
20 
21 /*****************************************************************************
22  *
23  * This is the API core.
24  *
25  * API_ functions are part of U-Boot code and constitute the lowest level
26  * calls:
27  *
28  *  - they know what values they need as arguments
29  *  - their direct return value pertains to the API_ "shell" itself (0 on
30  *    success, some error code otherwise)
31  *  - if the call returns a value it is buried within arguments
32  *
33  ****************************************************************************/
34 
35 #ifdef DEBUG
36 #define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
37 #else
38 #define debugf(fmt, args...)
39 #endif
40 
41 typedef	int (*cfp_t)(va_list argp);
42 
43 static int calls_no;
44 
45 /*
46  * pseudo signature:
47  *
48  * int API_getc(int *c)
49  */
50 static int API_getc(va_list ap)
51 {
52 	int *c;
53 
54 	if ((c = (int *)va_arg(ap, uintptr_t)) == NULL)
55 		return API_EINVAL;
56 
57 	*c = getc();
58 	return 0;
59 }
60 
61 /*
62  * pseudo signature:
63  *
64  * int API_tstc(int *c)
65  */
66 static int API_tstc(va_list ap)
67 {
68 	int *t;
69 
70 	if ((t = (int *)va_arg(ap, uintptr_t)) == NULL)
71 		return API_EINVAL;
72 
73 	*t = tstc();
74 	return 0;
75 }
76 
77 /*
78  * pseudo signature:
79  *
80  * int API_putc(char *ch)
81  */
82 static int API_putc(va_list ap)
83 {
84 	char *c;
85 
86 	if ((c = (char *)va_arg(ap, uintptr_t)) == NULL)
87 		return API_EINVAL;
88 
89 	putc(*c);
90 	return 0;
91 }
92 
93 /*
94  * pseudo signature:
95  *
96  * int API_puts(char **s)
97  */
98 static int API_puts(va_list ap)
99 {
100 	char *s;
101 
102 	if ((s = (char *)va_arg(ap, uintptr_t)) == NULL)
103 		return API_EINVAL;
104 
105 	puts(s);
106 	return 0;
107 }
108 
109 /*
110  * pseudo signature:
111  *
112  * int API_reset(void)
113  */
114 static int API_reset(va_list ap)
115 {
116 	do_reset(NULL, 0, 0, NULL);
117 
118 	/* NOT REACHED */
119 	return 0;
120 }
121 
122 /*
123  * pseudo signature:
124  *
125  * int API_get_sys_info(struct sys_info *si)
126  *
127  * fill out the sys_info struct containing selected parameters about the
128  * machine
129  */
130 static int API_get_sys_info(va_list ap)
131 {
132 	struct sys_info *si;
133 
134 	si = (struct sys_info *)va_arg(ap, uintptr_t);
135 	if (si == NULL)
136 		return API_ENOMEM;
137 
138 	return (platform_sys_info(si)) ? 0 : API_ENODEV;
139 }
140 
141 /*
142  * pseudo signature:
143  *
144  * int API_udelay(unsigned long *udelay)
145  */
146 static int API_udelay(va_list ap)
147 {
148 	unsigned long *d;
149 
150 	if ((d = (unsigned long *)va_arg(ap, unsigned long)) == NULL)
151 		return API_EINVAL;
152 
153 	udelay(*d);
154 	return 0;
155 }
156 
157 /*
158  * pseudo signature:
159  *
160  * int API_get_timer(unsigned long *current, unsigned long *base)
161  */
162 static int API_get_timer(va_list ap)
163 {
164 	unsigned long *base, *cur;
165 
166 	cur = (unsigned long *)va_arg(ap, unsigned long);
167 	if (cur == NULL)
168 		return API_EINVAL;
169 
170 	base = (unsigned long *)va_arg(ap, unsigned long);
171 	if (base == NULL)
172 		return API_EINVAL;
173 
174 	*cur = get_timer(*base);
175 	return 0;
176 }
177 
178 
179 /*****************************************************************************
180  *
181  * pseudo signature:
182  *
183  * int API_dev_enum(struct device_info *)
184  *
185  *
186  * cookies uniqely identify the previously enumerated device instance and
187  * provide a hint for what to inspect in current enum iteration:
188  *
189  *   - net: &eth_device struct address from list pointed to by eth_devices
190  *
191  *   - storage: struct blk_desc struct address from &ide_dev_desc[n],
192  *     &scsi_dev_desc[n] and similar tables
193  *
194  ****************************************************************************/
195 
196 static int API_dev_enum(va_list ap)
197 {
198 	struct device_info *di;
199 
200 	/* arg is ptr to the device_info struct we are going to fill out */
201 	di = (struct device_info *)va_arg(ap, uintptr_t);
202 	if (di == NULL)
203 		return API_EINVAL;
204 
205 	if (di->cookie == NULL) {
206 		/* start over - clean up enumeration */
207 		dev_enum_reset();	/* XXX shouldn't the name contain 'stor'? */
208 		debugf("RESTART ENUM\n");
209 
210 		/* net device enumeration first */
211 		if (dev_enum_net(di))
212 			return 0;
213 	}
214 
215 	/*
216 	 * The hidden assumption is there can only be one active network
217 	 * device and it is identified upon enumeration (re)start, so there's
218 	 * no point in trying to find network devices in other cases than the
219 	 * (re)start and hence the 'next' device can only be storage
220 	 */
221 	if (!dev_enum_storage(di))
222 		/* make sure we mark there are no more devices */
223 		di->cookie = NULL;
224 
225 	return 0;
226 }
227 
228 
229 static int API_dev_open(va_list ap)
230 {
231 	struct device_info *di;
232 	int err = 0;
233 
234 	/* arg is ptr to the device_info struct */
235 	di = (struct device_info *)va_arg(ap, uintptr_t);
236 	if (di == NULL)
237 		return API_EINVAL;
238 
239 	/* Allow only one consumer of the device at a time */
240 	if (di->state == DEV_STA_OPEN)
241 		return API_EBUSY;
242 
243 	if (di->cookie == NULL)
244 		return API_ENODEV;
245 
246 	if (di->type & DEV_TYP_STOR)
247 		err = dev_open_stor(di->cookie);
248 
249 	else if (di->type & DEV_TYP_NET)
250 		err = dev_open_net(di->cookie);
251 	else
252 		err = API_ENODEV;
253 
254 	if (!err)
255 		di->state = DEV_STA_OPEN;
256 
257 	return err;
258 }
259 
260 
261 static int API_dev_close(va_list ap)
262 {
263 	struct device_info *di;
264 	int err = 0;
265 
266 	/* arg is ptr to the device_info struct */
267 	di = (struct device_info *)va_arg(ap, uintptr_t);
268 	if (di == NULL)
269 		return API_EINVAL;
270 
271 	if (di->state == DEV_STA_CLOSED)
272 		return 0;
273 
274 	if (di->cookie == NULL)
275 		return API_ENODEV;
276 
277 	if (di->type & DEV_TYP_STOR)
278 		err = dev_close_stor(di->cookie);
279 
280 	else if (di->type & DEV_TYP_NET)
281 		err = dev_close_net(di->cookie);
282 	else
283 		/*
284 		 * In case of unknown device we cannot change its state, so
285 		 * only return error code
286 		 */
287 		err = API_ENODEV;
288 
289 	if (!err)
290 		di->state = DEV_STA_CLOSED;
291 
292 	return err;
293 }
294 
295 
296 /*
297  * Notice: this is for sending network packets only, as U-Boot does not
298  * support writing to storage at the moment (12.2007)
299  *
300  * pseudo signature:
301  *
302  * int API_dev_write(
303  *	struct device_info *di,
304  *	void *buf,
305  *	int *len
306  * )
307  *
308  * buf:	ptr to buffer from where to get the data to send
309  *
310  * len: length of packet to be sent (in bytes)
311  *
312  */
313 static int API_dev_write(va_list ap)
314 {
315 	struct device_info *di;
316 	void *buf;
317 	int *len;
318 	int err = 0;
319 
320 	/* 1. arg is ptr to the device_info struct */
321 	di = (struct device_info *)va_arg(ap, uintptr_t);
322 	if (di == NULL)
323 		return API_EINVAL;
324 
325 	/* XXX should we check if device is open? i.e. the ->state ? */
326 
327 	if (di->cookie == NULL)
328 		return API_ENODEV;
329 
330 	/* 2. arg is ptr to buffer from where to get data to write */
331 	buf = (void *)va_arg(ap, uintptr_t);
332 	if (buf == NULL)
333 		return API_EINVAL;
334 
335 	/* 3. arg is length of buffer */
336 	len = (int *)va_arg(ap, uintptr_t);
337 	if (len == NULL)
338 		return API_EINVAL;
339 	if (*len <= 0)
340 		return API_EINVAL;
341 
342 	if (di->type & DEV_TYP_STOR)
343 		/*
344 		 * write to storage is currently not supported by U-Boot:
345 		 * no storage device implements block_write() method
346 		 */
347 		return API_ENODEV;
348 
349 	else if (di->type & DEV_TYP_NET)
350 		err = dev_write_net(di->cookie, buf, *len);
351 	else
352 		err = API_ENODEV;
353 
354 	return err;
355 }
356 
357 
358 /*
359  * pseudo signature:
360  *
361  * int API_dev_read(
362  *	struct device_info *di,
363  *	void *buf,
364  *	size_t *len,
365  *	unsigned long *start
366  *	size_t *act_len
367  * )
368  *
369  * buf:	ptr to buffer where to put the read data
370  *
371  * len: ptr to length to be read
372  *      - network: len of packet to read (in bytes)
373  *      - storage: # of blocks to read (can vary in size depending on define)
374  *
375  * start: ptr to start block (only used for storage devices, ignored for
376  *        network)
377  *
378  * act_len: ptr to where to put the len actually read
379  */
380 static int API_dev_read(va_list ap)
381 {
382 	struct device_info *di;
383 	void *buf;
384 	lbasize_t *len_stor, *act_len_stor;
385 	lbastart_t *start;
386 	int *len_net, *act_len_net;
387 
388 	/* 1. arg is ptr to the device_info struct */
389 	di = (struct device_info *)va_arg(ap, uintptr_t);
390 	if (di == NULL)
391 		return API_EINVAL;
392 
393 	/* XXX should we check if device is open? i.e. the ->state ? */
394 
395 	if (di->cookie == NULL)
396 		return API_ENODEV;
397 
398 	/* 2. arg is ptr to buffer from where to put the read data */
399 	buf = (void *)va_arg(ap, uintptr_t);
400 	if (buf == NULL)
401 		return API_EINVAL;
402 
403 	if (di->type & DEV_TYP_STOR) {
404 		/* 3. arg - ptr to var with # of blocks to read */
405 		len_stor = (lbasize_t *)va_arg(ap, uintptr_t);
406 		if (!len_stor)
407 			return API_EINVAL;
408 		if (*len_stor <= 0)
409 			return API_EINVAL;
410 
411 		/* 4. arg - ptr to var with start block */
412 		start = (lbastart_t *)va_arg(ap, uintptr_t);
413 
414 		/* 5. arg - ptr to var where to put the len actually read */
415 		act_len_stor = (lbasize_t *)va_arg(ap, uintptr_t);
416 		if (!act_len_stor)
417 			return API_EINVAL;
418 
419 		*act_len_stor = dev_read_stor(di->cookie, buf, *len_stor, *start);
420 
421 	} else if (di->type & DEV_TYP_NET) {
422 
423 		/* 3. arg points to the var with length of packet to read */
424 		len_net = (int *)va_arg(ap, uintptr_t);
425 		if (!len_net)
426 			return API_EINVAL;
427 		if (*len_net <= 0)
428 			return API_EINVAL;
429 
430 		/* 4. - ptr to var where to put the len actually read */
431 		act_len_net = (int *)va_arg(ap, uintptr_t);
432 		if (!act_len_net)
433 			return API_EINVAL;
434 
435 		*act_len_net = dev_read_net(di->cookie, buf, *len_net);
436 
437 	} else
438 		return API_ENODEV;
439 
440 	return 0;
441 }
442 
443 
444 /*
445  * pseudo signature:
446  *
447  * int API_env_get(const char *name, char **value)
448  *
449  * name: ptr to name of env var
450  */
451 static int API_env_get(va_list ap)
452 {
453 	char *name, **value;
454 
455 	if ((name = (char *)va_arg(ap, uintptr_t)) == NULL)
456 		return API_EINVAL;
457 	if ((value = (char **)va_arg(ap, uintptr_t)) == NULL)
458 		return API_EINVAL;
459 
460 	*value = env_get(name);
461 
462 	return 0;
463 }
464 
465 /*
466  * pseudo signature:
467  *
468  * int API_env_set(const char *name, const char *value)
469  *
470  * name: ptr to name of env var
471  *
472  * value: ptr to value to be set
473  */
474 static int API_env_set(va_list ap)
475 {
476 	char *name, *value;
477 
478 	if ((name = (char *)va_arg(ap, uintptr_t)) == NULL)
479 		return API_EINVAL;
480 	if ((value = (char *)va_arg(ap, uintptr_t)) == NULL)
481 		return API_EINVAL;
482 
483 	env_set(name, value);
484 
485 	return 0;
486 }
487 
488 /*
489  * pseudo signature:
490  *
491  * int API_env_enum(const char *last, char **next)
492  *
493  * last: ptr to name of env var found in last iteration
494  */
495 static int API_env_enum(va_list ap)
496 {
497 	int i, buflen;
498 	char *last, **next, *s;
499 	ENTRY *match, search;
500 	static char *var;
501 
502 	last = (char *)va_arg(ap, unsigned long);
503 
504 	if ((next = (char **)va_arg(ap, uintptr_t)) == NULL)
505 		return API_EINVAL;
506 
507 	if (last == NULL) {
508 		var = NULL;
509 		i = 0;
510 	} else {
511 		var = strdup(last);
512 		s = strchr(var, '=');
513 		if (s != NULL)
514 			*s = 0;
515 		search.key = var;
516 		i = hsearch_r(search, FIND, &match, &env_htab, 0);
517 		if (i == 0) {
518 			i = API_EINVAL;
519 			goto done;
520 		}
521 	}
522 
523 	/* match the next entry after i */
524 	i = hmatch_r("", i, &match, &env_htab);
525 	if (i == 0)
526 		goto done;
527 	buflen = strlen(match->key) + strlen(match->data) + 2;
528 	var = realloc(var, buflen);
529 	snprintf(var, buflen, "%s=%s", match->key, match->data);
530 	*next = var;
531 	return 0;
532 
533 done:
534 	free(var);
535 	var = NULL;
536 	*next = NULL;
537 	return i;
538 }
539 
540 /*
541  * pseudo signature:
542  *
543  * int API_display_get_info(int type, struct display_info *di)
544  */
545 static int API_display_get_info(va_list ap)
546 {
547 	int type;
548 	struct display_info *di;
549 
550 	type = va_arg(ap, int);
551 	di = va_arg(ap, struct display_info *);
552 
553 	return display_get_info(type, di);
554 }
555 
556 /*
557  * pseudo signature:
558  *
559  * int API_display_draw_bitmap(ulong bitmap, int x, int y)
560  */
561 static int API_display_draw_bitmap(va_list ap)
562 {
563 	ulong bitmap;
564 	int x, y;
565 
566 	bitmap = va_arg(ap, ulong);
567 	x = va_arg(ap, int);
568 	y = va_arg(ap, int);
569 
570 	return display_draw_bitmap(bitmap, x, y);
571 }
572 
573 /*
574  * pseudo signature:
575  *
576  * void API_display_clear(void)
577  */
578 static int API_display_clear(va_list ap)
579 {
580 	display_clear();
581 	return 0;
582 }
583 
584 static cfp_t calls_table[API_MAXCALL] = { NULL, };
585 
586 /*
587  * The main syscall entry point - this is not reentrant, only one call is
588  * serviced until finished.
589  *
590  * e.g. syscall(1, int *, u_int32_t, u_int32_t, u_int32_t, u_int32_t);
591  *
592  * call:	syscall number
593  *
594  * retval:	points to the return value placeholder, this is the place the
595  *		syscall puts its return value, if NULL the caller does not
596  *		expect a return value
597  *
598  * ...		syscall arguments (variable number)
599  *
600  * returns:	0 if the call not found, 1 if serviced
601  */
602 int syscall(int call, int *retval, ...)
603 {
604 	va_list	ap;
605 	int rv;
606 
607 	if (call < 0 || call >= calls_no) {
608 		debugf("invalid call #%d\n", call);
609 		return 0;
610 	}
611 
612 	if (calls_table[call] == NULL) {
613 		debugf("syscall #%d does not have a handler\n", call);
614 		return 0;
615 	}
616 
617 	va_start(ap, retval);
618 	rv = calls_table[call](ap);
619 	if (retval != NULL)
620 		*retval = rv;
621 
622 	return 1;
623 }
624 
625 void api_init(void)
626 {
627 	struct api_signature *sig;
628 
629 	/* TODO put this into linker set one day... */
630 	calls_table[API_RSVD] = NULL;
631 	calls_table[API_GETC] = &API_getc;
632 	calls_table[API_PUTC] = &API_putc;
633 	calls_table[API_TSTC] = &API_tstc;
634 	calls_table[API_PUTS] = &API_puts;
635 	calls_table[API_RESET] = &API_reset;
636 	calls_table[API_GET_SYS_INFO] = &API_get_sys_info;
637 	calls_table[API_UDELAY] = &API_udelay;
638 	calls_table[API_GET_TIMER] = &API_get_timer;
639 	calls_table[API_DEV_ENUM] = &API_dev_enum;
640 	calls_table[API_DEV_OPEN] = &API_dev_open;
641 	calls_table[API_DEV_CLOSE] = &API_dev_close;
642 	calls_table[API_DEV_READ] = &API_dev_read;
643 	calls_table[API_DEV_WRITE] = &API_dev_write;
644 	calls_table[API_ENV_GET] = &API_env_get;
645 	calls_table[API_ENV_SET] = &API_env_set;
646 	calls_table[API_ENV_ENUM] = &API_env_enum;
647 	calls_table[API_DISPLAY_GET_INFO] = &API_display_get_info;
648 	calls_table[API_DISPLAY_DRAW_BITMAP] = &API_display_draw_bitmap;
649 	calls_table[API_DISPLAY_CLEAR] = &API_display_clear;
650 	calls_no = API_MAXCALL;
651 
652 	debugf("API initialized with %d calls\n", calls_no);
653 
654 	dev_stor_init();
655 
656 	/*
657 	 * Produce the signature so the API consumers can find it
658 	 */
659 	sig = malloc(sizeof(struct api_signature));
660 	if (sig == NULL) {
661 		printf("API: could not allocate memory for the signature!\n");
662 		return;
663 	}
664 
665 	env_set_hex("api_address", (unsigned long)sig);
666 	debugf("API sig @ 0x%lX\n", (unsigned long)sig);
667 	memcpy(sig->magic, API_SIG_MAGIC, 8);
668 	sig->version = API_SIG_VERSION;
669 	sig->syscall = &syscall;
670 	sig->checksum = 0;
671 	sig->checksum = crc32(0, (unsigned char *)sig,
672 			      sizeof(struct api_signature));
673 	debugf("syscall entry: 0x%lX\n", (unsigned long)sig->syscall);
674 }
675 
676 void platform_set_mr(struct sys_info *si, unsigned long start, unsigned long size,
677 			int flags)
678 {
679 	int i;
680 
681 	if (!si->mr || !size || (flags == 0))
682 		return;
683 
684 	/* find free slot */
685 	for (i = 0; i < si->mr_no; i++)
686 		if (si->mr[i].flags == 0) {
687 			/* insert new mem region */
688 			si->mr[i].start = start;
689 			si->mr[i].size = size;
690 			si->mr[i].flags = flags;
691 			return;
692 		}
693 }
694