api.c 14.1 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007 Semihalf
 *
 * Written by: Rafal Jaworowski <raj@semihalf.com>
 */

#include <config.h>
#include <command.h>
#include <common.h>
#include <malloc.h>
#include <environment.h>
#include <linux/types.h>
#include <api_public.h>

#include "api_private.h"

#define DEBUG
#undef DEBUG

/*****************************************************************************
 *
 * This is the API core.
 *
 * API_ functions are part of U-Boot code and constitute the lowest level
 * calls:
 *
 *  - they know what values they need as arguments
 *  - their direct return value pertains to the API_ "shell" itself (0 on
 *    success, some error code otherwise)
 *  - if the call returns a value it is buried within arguments
 *
 ****************************************************************************/

#ifdef DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
#else
#define debugf(fmt, args...)
#endif

typedef	int (*cfp_t)(va_list argp);

static int calls_no;

/*
 * pseudo signature:
 *
 * int API_getc(int *c)
 */
static int API_getc(va_list ap)
{
	int *c;

	if ((c = (int *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	*c = getc();
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_tstc(int *c)
 */
static int API_tstc(va_list ap)
{
	int *t;

	if ((t = (int *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	*t = tstc();
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_putc(char *ch)
 */
static int API_putc(va_list ap)
{
	char *c;

	if ((c = (char *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	putc(*c);
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_puts(char **s)
 */
static int API_puts(va_list ap)
{
	char *s;

	if ((s = (char *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	puts(s);
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_reset(void)
 */
static int API_reset(va_list ap)
{
	do_reset(NULL, 0, 0, NULL);

	/* NOT REACHED */
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_get_sys_info(struct sys_info *si)
 *
 * fill out the sys_info struct containing selected parameters about the
 * machine
 */
static int API_get_sys_info(va_list ap)
{
	struct sys_info *si;

	si = (struct sys_info *)va_arg(ap, uintptr_t);
	if (si == NULL)
		return API_ENOMEM;

	return (platform_sys_info(si)) ? 0 : API_ENODEV;
}

/*
 * pseudo signature:
 *
 * int API_udelay(unsigned long *udelay)
 */
static int API_udelay(va_list ap)
{
	unsigned long *d;

	if ((d = (unsigned long *)va_arg(ap, unsigned long)) == NULL)
		return API_EINVAL;

	udelay(*d);
	return 0;
}

/*
 * pseudo signature:
 *
 * int API_get_timer(unsigned long *current, unsigned long *base)
 */
static int API_get_timer(va_list ap)
{
	unsigned long *base, *cur;

	cur = (unsigned long *)va_arg(ap, unsigned long);
	if (cur == NULL)
		return API_EINVAL;

	base = (unsigned long *)va_arg(ap, unsigned long);
	if (base == NULL)
		return API_EINVAL;

	*cur = get_timer(*base);
	return 0;
}


/*****************************************************************************
 *
 * pseudo signature:
 *
 * int API_dev_enum(struct device_info *)
 *
 *
 * cookies uniqely identify the previously enumerated device instance and
 * provide a hint for what to inspect in current enum iteration:
 *
 *   - net: &eth_device struct address from list pointed to by eth_devices
 *
 *   - storage: struct blk_desc struct address from &ide_dev_desc[n],
 *     &scsi_dev_desc[n] and similar tables
 *
 ****************************************************************************/

static int API_dev_enum(va_list ap)
{
	struct device_info *di;

	/* arg is ptr to the device_info struct we are going to fill out */
	di = (struct device_info *)va_arg(ap, uintptr_t);
	if (di == NULL)
		return API_EINVAL;

	if (di->cookie == NULL) {
		/* start over - clean up enumeration */
		dev_enum_reset();	/* XXX shouldn't the name contain 'stor'? */
		debugf("RESTART ENUM\n");

		/* net device enumeration first */
		if (dev_enum_net(di))
			return 0;
	}

	/*
	 * The hidden assumption is there can only be one active network
	 * device and it is identified upon enumeration (re)start, so there's
	 * no point in trying to find network devices in other cases than the
	 * (re)start and hence the 'next' device can only be storage
	 */
	if (!dev_enum_storage(di))
		/* make sure we mark there are no more devices */
		di->cookie = NULL;

	return 0;
}


static int API_dev_open(va_list ap)
{
	struct device_info *di;
	int err = 0;

	/* arg is ptr to the device_info struct */
	di = (struct device_info *)va_arg(ap, uintptr_t);
	if (di == NULL)
		return API_EINVAL;

	/* Allow only one consumer of the device at a time */
	if (di->state == DEV_STA_OPEN)
		return API_EBUSY;

	if (di->cookie == NULL)
		return API_ENODEV;

	if (di->type & DEV_TYP_STOR)
		err = dev_open_stor(di->cookie);

	else if (di->type & DEV_TYP_NET)
		err = dev_open_net(di->cookie);
	else
		err = API_ENODEV;

	if (!err)
		di->state = DEV_STA_OPEN;

	return err;
}


static int API_dev_close(va_list ap)
{
	struct device_info *di;
	int err = 0;

	/* arg is ptr to the device_info struct */
	di = (struct device_info *)va_arg(ap, uintptr_t);
	if (di == NULL)
		return API_EINVAL;

	if (di->state == DEV_STA_CLOSED)
		return 0;

	if (di->cookie == NULL)
		return API_ENODEV;

	if (di->type & DEV_TYP_STOR)
		err = dev_close_stor(di->cookie);

	else if (di->type & DEV_TYP_NET)
		err = dev_close_net(di->cookie);
	else
		/*
		 * In case of unknown device we cannot change its state, so
		 * only return error code
		 */
		err = API_ENODEV;

	if (!err)
		di->state = DEV_STA_CLOSED;

	return err;
}


/*
 * Notice: this is for sending network packets only, as U-Boot does not
 * support writing to storage at the moment (12.2007)
 *
 * pseudo signature:
 *
 * int API_dev_write(
 *	struct device_info *di,
 *	void *buf,
 *	int *len
 * )
 *
 * buf:	ptr to buffer from where to get the data to send
 *
 * len: length of packet to be sent (in bytes)
 *
 */
static int API_dev_write(va_list ap)
{
	struct device_info *di;
	void *buf;
	int *len;
	int err = 0;

	/* 1. arg is ptr to the device_info struct */
	di = (struct device_info *)va_arg(ap, uintptr_t);
	if (di == NULL)
		return API_EINVAL;

	/* XXX should we check if device is open? i.e. the ->state ? */

	if (di->cookie == NULL)
		return API_ENODEV;

	/* 2. arg is ptr to buffer from where to get data to write */
	buf = (void *)va_arg(ap, uintptr_t);
	if (buf == NULL)
		return API_EINVAL;

	/* 3. arg is length of buffer */
	len = (int *)va_arg(ap, uintptr_t);
	if (len == NULL)
		return API_EINVAL;
	if (*len <= 0)
		return API_EINVAL;

	if (di->type & DEV_TYP_STOR)
		/*
		 * write to storage is currently not supported by U-Boot:
		 * no storage device implements block_write() method
		 */
		return API_ENODEV;

	else if (di->type & DEV_TYP_NET)
		err = dev_write_net(di->cookie, buf, *len);
	else
		err = API_ENODEV;

	return err;
}


/*
 * pseudo signature:
 *
 * int API_dev_read(
 *	struct device_info *di,
 *	void *buf,
 *	size_t *len,
 *	unsigned long *start
 *	size_t *act_len
 * )
 *
 * buf:	ptr to buffer where to put the read data
 *
 * len: ptr to length to be read
 *      - network: len of packet to read (in bytes)
 *      - storage: # of blocks to read (can vary in size depending on define)
 *
 * start: ptr to start block (only used for storage devices, ignored for
 *        network)
 *
 * act_len: ptr to where to put the len actually read
 */
static int API_dev_read(va_list ap)
{
	struct device_info *di;
	void *buf;
	lbasize_t *len_stor, *act_len_stor;
	lbastart_t *start;
	int *len_net, *act_len_net;

	/* 1. arg is ptr to the device_info struct */
	di = (struct device_info *)va_arg(ap, uintptr_t);
	if (di == NULL)
		return API_EINVAL;

	/* XXX should we check if device is open? i.e. the ->state ? */

	if (di->cookie == NULL)
		return API_ENODEV;

	/* 2. arg is ptr to buffer from where to put the read data */
	buf = (void *)va_arg(ap, uintptr_t);
	if (buf == NULL)
		return API_EINVAL;

	if (di->type & DEV_TYP_STOR) {
		/* 3. arg - ptr to var with # of blocks to read */
		len_stor = (lbasize_t *)va_arg(ap, uintptr_t);
		if (!len_stor)
			return API_EINVAL;
		if (*len_stor <= 0)
			return API_EINVAL;

		/* 4. arg - ptr to var with start block */
		start = (lbastart_t *)va_arg(ap, uintptr_t);

		/* 5. arg - ptr to var where to put the len actually read */
		act_len_stor = (lbasize_t *)va_arg(ap, uintptr_t);
		if (!act_len_stor)
			return API_EINVAL;

		*act_len_stor = dev_read_stor(di->cookie, buf, *len_stor, *start);

	} else if (di->type & DEV_TYP_NET) {

		/* 3. arg points to the var with length of packet to read */
		len_net = (int *)va_arg(ap, uintptr_t);
		if (!len_net)
			return API_EINVAL;
		if (*len_net <= 0)
			return API_EINVAL;

		/* 4. - ptr to var where to put the len actually read */
		act_len_net = (int *)va_arg(ap, uintptr_t);
		if (!act_len_net)
			return API_EINVAL;

		*act_len_net = dev_read_net(di->cookie, buf, *len_net);

	} else
		return API_ENODEV;

	return 0;
}


/*
 * pseudo signature:
 *
 * int API_env_get(const char *name, char **value)
 *
 * name: ptr to name of env var
 */
static int API_env_get(va_list ap)
{
	char *name, **value;

	if ((name = (char *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;
	if ((value = (char **)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	*value = env_get(name);

	return 0;
}

/*
 * pseudo signature:
 *
 * int API_env_set(const char *name, const char *value)
 *
 * name: ptr to name of env var
 *
 * value: ptr to value to be set
 */
static int API_env_set(va_list ap)
{
	char *name, *value;

	if ((name = (char *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;
	if ((value = (char *)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	env_set(name, value);

	return 0;
}

/*
 * pseudo signature:
 *
 * int API_env_enum(const char *last, char **next)
 *
 * last: ptr to name of env var found in last iteration
 */
static int API_env_enum(va_list ap)
{
	int i, buflen;
	char *last, **next, *s;
	ENTRY *match, search;
	static char *var;

	last = (char *)va_arg(ap, unsigned long);

	if ((next = (char **)va_arg(ap, uintptr_t)) == NULL)
		return API_EINVAL;

	if (last == NULL) {
		var = NULL;
		i = 0;
	} else {
		var = strdup(last);
		s = strchr(var, '=');
		if (s != NULL)
			*s = 0;
		search.key = var;
		i = hsearch_r(search, FIND, &match, &env_htab, 0);
		if (i == 0) {
			i = API_EINVAL;
			goto done;
		}
	}

	/* match the next entry after i */
	i = hmatch_r("", i, &match, &env_htab);
	if (i == 0)
		goto done;
	buflen = strlen(match->key) + strlen(match->data) + 2;
	var = realloc(var, buflen);
	snprintf(var, buflen, "%s=%s", match->key, match->data);
	*next = var;
	return 0;

done:
	free(var);
	var = NULL;
	*next = NULL;
	return i;
}

/*
 * pseudo signature:
 *
 * int API_display_get_info(int type, struct display_info *di)
 */
static int API_display_get_info(va_list ap)
{
	int type;
	struct display_info *di;

	type = va_arg(ap, int);
	di = va_arg(ap, struct display_info *);

	return display_get_info(type, di);
}

/*
 * pseudo signature:
 *
 * int API_display_draw_bitmap(ulong bitmap, int x, int y)
 */
static int API_display_draw_bitmap(va_list ap)
{
	ulong bitmap;
	int x, y;

	bitmap = va_arg(ap, ulong);
	x = va_arg(ap, int);
	y = va_arg(ap, int);

	return display_draw_bitmap(bitmap, x, y);
}

/*
 * pseudo signature:
 *
 * void API_display_clear(void)
 */
static int API_display_clear(va_list ap)
{
	display_clear();
	return 0;
}

static cfp_t calls_table[API_MAXCALL] = { NULL, };

/*
 * The main syscall entry point - this is not reentrant, only one call is
 * serviced until finished.
 *
 * e.g. syscall(1, int *, u_int32_t, u_int32_t, u_int32_t, u_int32_t);
 *
 * call:	syscall number
 *
 * retval:	points to the return value placeholder, this is the place the
 *		syscall puts its return value, if NULL the caller does not
 *		expect a return value
 *
 * ...		syscall arguments (variable number)
 *
 * returns:	0 if the call not found, 1 if serviced
 */
int syscall(int call, int *retval, ...)
{
	va_list	ap;
	int rv;

	if (call < 0 || call >= calls_no) {
		debugf("invalid call #%d\n", call);
		return 0;
	}

	if (calls_table[call] == NULL) {
		debugf("syscall #%d does not have a handler\n", call);
		return 0;
	}

	va_start(ap, retval);
	rv = calls_table[call](ap);
	if (retval != NULL)
		*retval = rv;

	return 1;
}

void api_init(void)
{
	struct api_signature *sig;

	/* TODO put this into linker set one day... */
	calls_table[API_RSVD] = NULL;
	calls_table[API_GETC] = &API_getc;
	calls_table[API_PUTC] = &API_putc;
	calls_table[API_TSTC] = &API_tstc;
	calls_table[API_PUTS] = &API_puts;
	calls_table[API_RESET] = &API_reset;
	calls_table[API_GET_SYS_INFO] = &API_get_sys_info;
	calls_table[API_UDELAY] = &API_udelay;
	calls_table[API_GET_TIMER] = &API_get_timer;
	calls_table[API_DEV_ENUM] = &API_dev_enum;
	calls_table[API_DEV_OPEN] = &API_dev_open;
	calls_table[API_DEV_CLOSE] = &API_dev_close;
	calls_table[API_DEV_READ] = &API_dev_read;
	calls_table[API_DEV_WRITE] = &API_dev_write;
	calls_table[API_ENV_GET] = &API_env_get;
	calls_table[API_ENV_SET] = &API_env_set;
	calls_table[API_ENV_ENUM] = &API_env_enum;
	calls_table[API_DISPLAY_GET_INFO] = &API_display_get_info;
	calls_table[API_DISPLAY_DRAW_BITMAP] = &API_display_draw_bitmap;
	calls_table[API_DISPLAY_CLEAR] = &API_display_clear;
	calls_no = API_MAXCALL;

	debugf("API initialized with %d calls\n", calls_no);

	dev_stor_init();

	/*
	 * Produce the signature so the API consumers can find it
	 */
	sig = malloc(sizeof(struct api_signature));
	if (sig == NULL) {
		printf("API: could not allocate memory for the signature!\n");
		return;
	}

	env_set_hex("api_address", (unsigned long)sig);
	debugf("API sig @ 0x%lX\n", (unsigned long)sig);
	memcpy(sig->magic, API_SIG_MAGIC, 8);
	sig->version = API_SIG_VERSION;
	sig->syscall = &syscall;
	sig->checksum = 0;
	sig->checksum = crc32(0, (unsigned char *)sig,
			      sizeof(struct api_signature));
	debugf("syscall entry: 0x%lX\n", (unsigned long)sig->syscall);
}

void platform_set_mr(struct sys_info *si, unsigned long start, unsigned long size,
			int flags)
{
	int i;

	if (!si->mr || !size || (flags == 0))
		return;

	/* find free slot */
	for (i = 0; i < si->mr_no; i++)
		if (si->mr[i].flags == 0) {
			/* insert new mem region */
			si->mr[i].start = start;
			si->mr[i].size = size;
			si->mr[i].flags = flags;
			return;
		}
}