api/api.c

   1 /*
   2  * (C) Copyright 2007 Semihalf
   3  *
   4  * Written by: Rafal Jaworowski <raj@semihalf.com>
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  *
  24  */
  25
  26 #include <config.h>
  27 #include <command.h>
  28 #include <common.h>
  29 #include <malloc.h>
  30 #include <environment.h>
  31 #include <linux/types.h>
  32 #include <api_public.h>
  33
  34 #include "api_private.h"
  35
  36 #define DEBUG
  37 #undef DEBUG
  38
  39 /* U-Boot routines needed */
  40 extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
  41
  42 /*****************************************************************************
  43  *
  44  * This is the API core.
  45  *
  46  * API_ functions are part of U-Boot code and constitute the lowest level
  47  * calls:
  48  *
  49  *  - they know what values they need as arguments
  50  *  - their direct return value pertains to the API_ "shell" itself (0 on
  51  *    success, some error code otherwise)
  52  *  - if the call returns a value it is buried within arguments
  53  *
  54  ****************************************************************************/
  55
  56 #ifdef DEBUG
  57 #define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
  58 #else
  59 #define debugf(fmt, args...)
  60 #endif
  61
  62 typedef int (*cfp_t)(va_list argp);
  63
  64 static int calls_no;
  65
  66 /*
  67  * pseudo signature:
  68  *
  69  * int API_getc(int *c)
  70  */
  71 static int API_getc(va_list ap)
  72 {
  73         int *c;
  74
  75         if ((c = (int *)va_arg(ap, u_int32_t)) == NULL)
  76                 return API_EINVAL;
  77
  78         *c = getc();
  79         return 0;
  80 }
  81
  82 /*
  83  * pseudo signature:
  84  *
  85  * int API_tstc(int *c)
  86  */
  87 static int API_tstc(va_list ap)
  88 {
  89         int *t;
  90
  91         if ((t = (int *)va_arg(ap, u_int32_t)) == NULL)
  92                 return API_EINVAL;
  93
  94         *t = tstc();
  95         return 0;
  96 }
  97
  98 /*
  99  * pseudo signature:
 100  *
 101  * int API_putc(char *ch)
 102  */
 103 static int API_putc(va_list ap)
 104 {
 105         char *c;
 106
 107         if ((c = (char *)va_arg(ap, u_int32_t)) == NULL)
 108                 return API_EINVAL;
 109
 110         putc(*c);
 111         return 0;
 112 }
 113
 114 /*
 115  * pseudo signature:
 116  *
 117  * int API_puts(char **s)
 118  */
 119 static int API_puts(va_list ap)
 120 {
 121         char *s;
 122
 123         if ((s = (char *)va_arg(ap, u_int32_t)) == NULL)
 124                 return API_EINVAL;
 125
 126         puts(s);
 127         return 0;
 128 }
 129
 130 /*
 131  * pseudo signature:
 132  *
 133  * int API_reset(void)
 134  */
 135 static int API_reset(va_list ap)
 136 {
 137         do_reset(NULL, 0, 0, NULL);
 138
 139         /* NOT REACHED */
 140         return 0;
 141 }
 142
 143 /*
 144  * pseudo signature:
 145  *
 146  * int API_get_sys_info(struct sys_info *si)
 147  *
 148  * fill out the sys_info struct containing selected parameters about the
 149  * machine
 150  */
 151 static int API_get_sys_info(va_list ap)
 152 {
 153         struct sys_info *si;
 154
 155         si = (struct sys_info *)va_arg(ap, u_int32_t);
 156         if (si == NULL)
 157                 return API_ENOMEM;
 158
 159         return (platform_sys_info(si)) ? 0 : API_ENODEV;
 160 }
 161
 162 /*
 163  * pseudo signature:
 164  *
 165  * int API_udelay(unsigned long *udelay)
 166  */
 167 static int API_udelay(va_list ap)
 168 {
 169         unsigned long *d;
 170
 171         if ((d = (unsigned long *)va_arg(ap, u_int32_t)) == NULL)
 172                 return API_EINVAL;
 173
 174         udelay(*d);
 175         return 0;
 176 }
 177
 178 /*
 179  * pseudo signature:
 180  *
 181  * int API_get_timer(unsigned long *current, unsigned long *base)
 182  */
 183 static int API_get_timer(va_list ap)
 184 {
 185         unsigned long *base, *cur;
 186
 187         cur = (unsigned long *)va_arg(ap, u_int32_t);
 188         if (cur == NULL)
 189                 return API_EINVAL;
 190
 191         base = (unsigned long *)va_arg(ap, u_int32_t);
 192         if (base == NULL)
 193                 return API_EINVAL;
 194
 195         *cur = get_timer(*base);
 196         return 0;
 197 }
 198
 199
 200 /*****************************************************************************
 201  *
 202  * pseudo signature:
 203  *
 204  * int API_dev_enum(struct device_info *)
 205  *
 206  *
 207  * cookies uniqely identify the previously enumerated device instance and
 208  * provide a hint for what to inspect in current enum iteration:
 209  *
 210  *   - net: &eth_device struct address from list pointed to by eth_devices
 211  *
 212  *   - storage: block_dev_desc_t struct address from &ide_dev_desc[n],
 213  *     &scsi_dev_desc[n] and similar tables
 214  *
 215  ****************************************************************************/
 216
 217 static int API_dev_enum(va_list ap)
 218 {
 219         struct device_info *di;
 220
 221         /* arg is ptr to the device_info struct we are going to fill out */
 222         di = (struct device_info *)va_arg(ap, u_int32_t);
 223         if (di == NULL)
 224                 return API_EINVAL;
 225
 226         if (di->cookie == NULL) {
 227                 /* start over - clean up enumeration */
 228                 dev_enum_reset();       /* XXX shouldn't the name contain 'stor'? */
 229                 debugf("RESTART ENUM\n");
 230
 231                 /* net device enumeration first */
 232                 if (dev_enum_net(di))
 233                         return 0;
 234         }
 235
 236         /*
 237          * The hidden assumption is there can only be one active network
 238          * device and it is identified upon enumeration (re)start, so there's
 239          * no point in trying to find network devices in other cases than the
 240          * (re)start and hence the 'next' device can only be storage
 241          */
 242         if (!dev_enum_storage(di))
 243                 /* make sure we mark there are no more devices */
 244                 di->cookie = NULL;
 245
 246         return 0;
 247 }
 248
 249
 250 static int API_dev_open(va_list ap)
 251 {
 252         struct device_info *di;
 253         int err = 0;
 254
 255         /* arg is ptr to the device_info struct */
 256         di = (struct device_info *)va_arg(ap, u_int32_t);
 257         if (di == NULL)
 258                 return API_EINVAL;
 259
 260         /* Allow only one consumer of the device at a time */
 261         if (di->state == DEV_STA_OPEN)
 262                 return API_EBUSY;
 263
 264         if (di->cookie == NULL)
 265                 return API_ENODEV;
 266
 267         if (di->type & DEV_TYP_STOR)
 268                 err = dev_open_stor(di->cookie);
 269
 270         else if (di->type & DEV_TYP_NET)
 271                 err = dev_open_net(di->cookie);
 272         else
 273                 err = API_ENODEV;
 274
 275         if (!err)
 276                 di->state = DEV_STA_OPEN;
 277
 278         return err;
 279 }
 280
 281
 282 static int API_dev_close(va_list ap)
 283 {
 284         struct device_info *di;
 285         int err = 0;
 286
 287         /* arg is ptr to the device_info struct */
 288         di = (struct device_info *)va_arg(ap, u_int32_t);
 289         if (di == NULL)
 290                 return API_EINVAL;
 291
 292         if (di->state == DEV_STA_CLOSED)
 293                 return 0;
 294
 295         if (di->cookie == NULL)
 296                 return API_ENODEV;
 297
 298         if (di->type & DEV_TYP_STOR)
 299                 err = dev_close_stor(di->cookie);
 300
 301         else if (di->type & DEV_TYP_NET)
 302                 err = dev_close_net(di->cookie);
 303         else
 304                 /*
 305                  * In case of unknown device we cannot change its state, so
 306                  * only return error code
 307                  */
 308                 err = API_ENODEV;
 309
 310         if (!err)
 311                 di->state = DEV_STA_CLOSED;
 312
 313         return err;
 314 }
 315
 316
 317 /*
 318  * Notice: this is for sending network packets only, as U-Boot does not
 319  * support writing to storage at the moment (12.2007)
 320  *
 321  * pseudo signature:
 322  *
 323  * int API_dev_write(
 324  *      struct device_info *di,
 325  *      void *buf,
 326  *      int *len
 327  * )
 328  *
 329  * buf: ptr to buffer from where to get the data to send
 330  *
 331  * len: length of packet to be sent (in bytes)
 332  *
 333  */
 334 static int API_dev_write(va_list ap)
 335 {
 336         struct device_info *di;
 337         void *buf;
 338         int *len;
 339         int err = 0;
 340
 341         /* 1. arg is ptr to the device_info struct */
 342         di = (struct device_info *)va_arg(ap, u_int32_t);
 343         if (di == NULL)
 344                 return API_EINVAL;
 345
 346         /* XXX should we check if device is open? i.e. the ->state ? */
 347
 348         if (di->cookie == NULL)
 349                 return API_ENODEV;
 350
 351         /* 2. arg is ptr to buffer from where to get data to write */
 352         buf = (void *)va_arg(ap, u_int32_t);
 353         if (buf == NULL)
 354                 return API_EINVAL;
 355
 356         /* 3. arg is length of buffer */
 357         len = (int *)va_arg(ap, u_int32_t);
 358         if (len == NULL)
 359                 return API_EINVAL;
 360         if (*len <= 0)
 361                 return API_EINVAL;
 362
 363         if (di->type & DEV_TYP_STOR)
 364                 /*
 365                  * write to storage is currently not supported by U-Boot:
 366                  * no storage device implements block_write() method
 367                  */
 368                 return API_ENODEV;
 369
 370         else if (di->type & DEV_TYP_NET)
 371                 err = dev_write_net(di->cookie, buf, *len);
 372         else
 373                 err = API_ENODEV;
 374
 375         return err;
 376 }
 377
 378
 379 /*
 380  * pseudo signature:
 381  *
 382  * int API_dev_read(
 383  *      struct device_info *di,
 384  *      void *buf,
 385  *      size_t *len,
 386  *      unsigned long *start
 387  *      size_t *act_len
 388  * )
 389  *
 390  * buf: ptr to buffer where to put the read data
 391  *
 392  * len: ptr to length to be read
 393  *      - network: len of packet to read (in bytes)
 394  *      - storage: # of blocks to read (can vary in size depending on define)
 395  *
 396  * start: ptr to start block (only used for storage devices, ignored for
 397  *        network)
 398  *
 399  * act_len: ptr to where to put the len actually read
 400  */
 401 static int API_dev_read(va_list ap)
 402 {
 403         struct device_info *di;
 404         void *buf;
 405         lbasize_t *len_stor, *act_len_stor;
 406         lbastart_t *start;
 407         int *len_net, *act_len_net;
 408
 409         /* 1. arg is ptr to the device_info struct */
 410         di = (struct device_info *)va_arg(ap, u_int32_t);
 411         if (di == NULL)
 412                 return API_EINVAL;
 413
 414         /* XXX should we check if device is open? i.e. the ->state ? */
 415
 416         if (di->cookie == NULL)
 417                 return API_ENODEV;
 418
 419         /* 2. arg is ptr to buffer from where to put the read data */
 420         buf = (void *)va_arg(ap, u_int32_t);
 421         if (buf == NULL)
 422                 return API_EINVAL;
 423
 424         if (di->type & DEV_TYP_STOR) {
 425                 /* 3. arg - ptr to var with # of blocks to read */
 426                 len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
 427                 if (!len_stor)
 428                         return API_EINVAL;
 429                 if (*len_stor <= 0)
 430                         return API_EINVAL;
 431
 432                 /* 4. arg - ptr to var with start block */
 433                 start = (lbastart_t *)va_arg(ap, u_int32_t);
 434
 435                 /* 5. arg - ptr to var where to put the len actually read */
 436                 act_len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
 437                 if (!act_len_stor)
 438                         return API_EINVAL;
 439
 440                 *act_len_stor = dev_read_stor(di->cookie, buf, *len_stor, *start);
 441
 442         } else if (di->type & DEV_TYP_NET) {
 443
 444                 /* 3. arg points to the var with length of packet to read */
 445                 len_net = (int *)va_arg(ap, u_int32_t);
 446                 if (!len_net)
 447                         return API_EINVAL;
 448                 if (*len_net <= 0)
 449                         return API_EINVAL;
 450
 451                 /* 4. - ptr to var where to put the len actually read */
 452                 act_len_net = (int *)va_arg(ap, u_int32_t);
 453                 if (!act_len_net)
 454                         return API_EINVAL;
 455
 456                 *act_len_net = dev_read_net(di->cookie, buf, *len_net);
 457
 458         } else
 459                 return API_ENODEV;
 460
 461         return 0;
 462 }
 463
 464
 465 /*
 466  * pseudo signature:
 467  *
 468  * int API_env_get(const char *name, char **value)
 469  *
 470  * name: ptr to name of env var
 471  */
 472 static int API_env_get(va_list ap)
 473 {
 474         char *name, **value;
 475
 476         if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
 477                 return API_EINVAL;
 478         if ((value = (char **)va_arg(ap, u_int32_t)) == NULL)
 479                 return API_EINVAL;
 480
 481         *value = getenv(name);
 482
 483         return 0;
 484 }
 485
 486 /*
 487  * pseudo signature:
 488  *
 489  * int API_env_set(const char *name, const char *value)
 490  *
 491  * name: ptr to name of env var
 492  *
 493  * value: ptr to value to be set
 494  */
 495 static int API_env_set(va_list ap)
 496 {
 497         char *name, *value;
 498
 499         if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
 500                 return API_EINVAL;
 501         if ((value = (char *)va_arg(ap, u_int32_t)) == NULL)
 502                 return API_EINVAL;
 503
 504         setenv(name, value);
 505
 506         return 0;
 507 }
 508
 509 /*
 510  * pseudo signature:
 511  *
 512  * int API_env_enum(const char *last, char **next)
 513  *
 514  * last: ptr to name of env var found in last iteration
 515  */
 516 static int API_env_enum(va_list ap)
 517 {
 518         int i, n;
 519         char *last, **next;
 520
 521         last = (char *)va_arg(ap, u_int32_t);
 522
 523         if ((next = (char **)va_arg(ap, u_int32_t)) == NULL)
 524                 return API_EINVAL;
 525
 526         if (last == NULL)
 527                 /* start over */
 528                 *next = ((char *)env_get_addr(0));
 529         else {
 530                 *next = last;
 531
 532                 for (i = 0; env_get_char(i) != '\0'; i = n + 1) {
 533                         for (n = i; env_get_char(n) != '\0'; ++n) {
 534                                 if (n >= CONFIG_ENV_SIZE) {
 535                                         /* XXX shouldn't we set *next = NULL?? */
 536                                         return 0;
 537                                 }
 538                         }
 539
 540                         if (envmatch((uchar *)last, i) < 0)
 541                                 continue;
 542
 543                         /* try to get next name */
 544                         i = n + 1;
 545                         if (env_get_char(i) == '\0') {
 546                                 /* no more left */
 547                                 *next = NULL;
 548                                 return 0;
 549                         }
 550
 551                         *next = ((char *)env_get_addr(i));
 552                         return 0;
 553                 }
 554         }
 555
 556         return 0;
 557 }
 558
 559 static cfp_t calls_table[API_MAXCALL] = { NULL, };
 560
 561 /*
 562  * The main syscall entry point - this is not reentrant, only one call is
 563  * serviced until finished.
 564  *
 565  * e.g. syscall(1, int *, u_int32_t, u_int32_t, u_int32_t, u_int32_t);
 566  *
 567  * call:        syscall number
 568  *
 569  * retval:      points to the return value placeholder, this is the place the
 570  *              syscall puts its return value, if NULL the caller does not
 571  *              expect a return value
 572  *
 573  * ...          syscall arguments (variable number)
 574  *
 575  * returns:     0 if the call not found, 1 if serviced
 576  */
 577 int syscall(int call, int *retval, ...)
 578 {
 579         va_list ap;
 580         int rv;
 581
 582         if (call < 0 || call >= calls_no) {
 583                 debugf("invalid call #%d\n", call);
 584                 return 0;
 585         }
 586
 587         if (calls_table[call] == NULL) {
 588                 debugf("syscall #%d does not have a handler\n", call);
 589                 return 0;
 590         }
 591
 592         va_start(ap, retval);
 593         rv = calls_table[call](ap);
 594         if (retval != NULL)
 595                 *retval = rv;
 596
 597         return 1;
 598 }
 599
 600 void api_init(void)
 601 {
 602         struct api_signature *sig = NULL;
 603
 604         /* TODO put this into linker set one day... */
 605         calls_table[API_RSVD] = NULL;
 606         calls_table[API_GETC] = &API_getc;
 607         calls_table[API_PUTC] = &API_putc;
 608         calls_table[API_TSTC] = &API_tstc;
 609         calls_table[API_PUTS] = &API_puts;
 610         calls_table[API_RESET] = &API_reset;
 611         calls_table[API_GET_SYS_INFO] = &API_get_sys_info;
 612         calls_table[API_UDELAY] = &API_udelay;
 613         calls_table[API_GET_TIMER] = &API_get_timer;
 614         calls_table[API_DEV_ENUM] = &API_dev_enum;
 615         calls_table[API_DEV_OPEN] = &API_dev_open;
 616         calls_table[API_DEV_CLOSE] = &API_dev_close;
 617         calls_table[API_DEV_READ] = &API_dev_read;
 618         calls_table[API_DEV_WRITE] = &API_dev_write;
 619         calls_table[API_ENV_GET] = &API_env_get;
 620         calls_table[API_ENV_SET] = &API_env_set;
 621         calls_table[API_ENV_ENUM] = &API_env_enum;
 622         calls_no = API_MAXCALL;
 623
 624         debugf("API initialized with %d calls\n", calls_no);
 625
 626         dev_stor_init();
 627
 628         /*
 629          * Produce the signature so the API consumers can find it
 630          */
 631         sig = malloc(sizeof(struct api_signature));
 632         if (sig == NULL) {
 633                 printf("API: could not allocate memory for the signature!\n");
 634                 return;
 635         }
 636
 637         debugf("API sig @ 0x%08x\n", sig);
 638         memcpy(sig->magic, API_SIG_MAGIC, 8);
 639         sig->version = API_SIG_VERSION;
 640         sig->syscall = &syscall;
 641         sig->checksum = 0;
 642         sig->checksum = crc32(0, (unsigned char *)sig,
 643                               sizeof(struct api_signature));
 644         debugf("syscall entry: 0x%08x\n", sig->syscall);
 645 }
 646
 647 void platform_set_mr(struct sys_info *si, unsigned long start, unsigned long size,
 648                         int flags)
 649 {
 650         int i;
 651
 652         if (!si->mr || !size || (flags == 0))
 653                 return;
 654
 655         /* find free slot */
 656         for (i = 0; i < si->mr_no; i++)
 657                 if (si->mr[i].flags == 0) {
 658                         /* insert new mem region */
 659                         si->mr[i].start = start;
 660                         si->mr[i].size = size;
 661                         si->mr[i].flags = flags;
 662                         return;
 663                 }
 664 }