arch/cris/arch-v10/kernel/head.S

   1 /* $Id: head.S,v 1.10 2005/06/20 05:12:54 starvik Exp $
   2  *
   3  * Head of the kernel - alter with care
   4  *
   5  * Copyright (C) 2000, 2001 Axis Communications AB
   6  *
   7  * Authors:     Bjorn Wesen (bjornw@axis.com)
   8  *
   9  * $Log: head.S,v $
  10  * Revision 1.10  2005/06/20 05:12:54  starvik
  11  * Remove unnecessary diff to kernel.org tree
  12  *
  13  * Revision 1.9  2004/12/13 12:21:51  starvik
  14  * Added I/O and DMA allocators from Linux 2.4
  15  *
  16  * Revision 1.8  2004/11/22 11:41:14  starvik
  17  * Kernel command line may be supplied to kernel. Not used by Axis but may
  18  * be used by customers.
  19  *
  20  * Revision 1.7  2004/05/14 07:58:01  starvik
  21  * Merge of changes from 2.4
  22  *
  23  * Revision 1.6  2003/04/28 05:31:46  starvik
  24  * Added section attributes
  25  *
  26  * Revision 1.5  2002/12/11 15:42:02  starvik
  27  * Extracted v10 (ETRAX 100LX) specific stuff from arch/cris/kernel/*.c
  28  *
  29  * Revision 1.4  2002/11/07 09:00:44  starvik
  30  * Names changed for init sections
  31  * init_task_union -> init_thread_union
  32  *
  33  * Revision 1.3  2002/02/05 15:38:23  bjornw
  34  * Oops.. non-CRAMFS_MAGIC should jump over the copying, not into it...
  35  *
  36  * Revision 1.2  2001/12/18 13:35:19  bjornw
  37  * Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15).
  38  *
  39  * Revision 1.43  2001/11/08 15:09:43  starvik
  40  * Only start MII clock if Ethernet is configured
  41  *
  42  * Revision 1.42  2001/11/08 14:37:34  starvik
  43  * Start MII clock early to make sure that it is running at tranceiver reset
  44  *
  45  * Revision 1.41  2001/10/29 14:55:58  pkj
  46  * Corrected pa$r0 to par0.
  47  *
  48  * Revision 1.40  2001/10/03 14:59:57  pkj
  49  * Added support for resetting the Bluetooth hardware.
  50  *
  51  * Revision 1.39  2001/10/01 14:45:03  bjornw
  52  * Removed underscores and added register prefixes
  53  *
  54  * Revision 1.38  2001/09/21 07:14:11  jonashg
  55  * Made root filesystem (cramfs) use mtdblock driver when booting from flash.
  56  *
  57  * Revision 1.37  2001/09/11 13:44:29  orjanf
  58  * Decouple usage of serial ports for debug and kgdb.
  59  *
  60  * Revision 1.36  2001/06/29 12:39:31  pkj
  61  * Added support for mirroring the first flash to just below the
  62  * second one, to make them look consecutive to cramfs.
  63  *
  64  * Revision 1.35  2001/06/25 14:07:00  hp
  65  *      Fix review comment.
  66  *      * head.S: Use IO_STATE, IO_FIELD and IO_MASK constructs instead of
  67  *      magic numbers.  Add comment that -traditional must not be used.
  68  *      * entry.S (SYMBOL_NAME): Change redefinition to use ## concatenation.
  69  *      Correct and update comment.
  70  *      * Makefile (.S.o): Don't use -traditional.  Add comment why the
  71  *      toplevel rule can't be used (now that there's a reason).
  72  *
  73  * Revision 1.34  2001/05/15 07:08:14  hp
  74  * Tweak "notice" to reflect that both r8 r9 are used
  75  *
  76  * Revision 1.33  2001/05/15 06:40:05  hp
  77  * Put bulk of code in .text.init, data in .data.init
  78  *
  79  * Revision 1.32  2001/05/15 06:18:56  hp
  80  * Execute review comment: s/bcc/bhs/g; s/bcs/blo/g
  81  *
  82  * Revision 1.31  2001/05/15 06:08:40  hp
  83  * Add sentence about autodetecting the bit31-MMU-bug
  84  *
  85  * Revision 1.30  2001/05/15 06:00:05  hp
  86  * Update comment: LOW_MAP is not forced on xsim anymore.
  87  *
  88  * Revision 1.29  2001/04/18 12:51:59  orjanf
  89  * * Reverted review change regarding the use of bcs/bcc.
  90  * * Removed non-working LED-clearing code.
  91  *
  92  * Revision 1.28  2001/04/17 13:58:39  orjanf
  93  * * Renamed CONFIG_KGDB to CONFIG_ETRAX_KGDB.
  94  *
  95  * Revision 1.27  2001/04/17 11:42:35  orjanf
  96  * Changed according to review:
  97  * * Added comment explaining memory map bug.
  98  * * Changed bcs and bcc to blo and bhs, respectively.
  99  * * Removed mentioning of Stallone and Olga boards.
 100  *
 101  * Revision 1.26  2001/04/06 12:31:07  jonashg
 102  * Check for cramfs in flash before RAM instead of RAM before flash.
 103  *
 104  * Revision 1.25  2001/04/04 06:23:53  starvik
 105  * Initialize DRAM if not already initialized
 106  *
 107  * Revision 1.24  2001/04/03 11:12:00  starvik
 108  * Removed dram init (done by rescue or etrax100boot
 109  * Corrected include
 110  *
 111  * Revision 1.23  2001/04/03 09:53:03  starvik
 112  * Include hw_settings.S
 113  *
 114  * Revision 1.22  2001/03/26 14:23:26  bjornw
 115  * Namechange of some config options
 116  *
 117  * Revision 1.21  2001/03/08 12:14:41  bjornw
 118  * * Config name for ETRAX IDE was renamed
 119  * * Removed G27 auto-setting when JULIETTE is chosen (need to make this
 120  *   a new config option later)
 121  *
 122  * Revision 1.20  2001/02/23 12:47:56  bjornw
 123  * MMU regs during LOW_MAP updated to reflect a newer reality
 124  *
 125  * Revision 1.19  2001/02/19 11:12:07  bjornw
 126  * Changed comment header format
 127  *
 128  * Revision 1.18  2001/02/15 07:25:38  starvik
 129  * Added support for synchronous serial ports
 130  *
 131  * Revision 1.17  2001/02/08 15:53:13  starvik
 132  * Last commit removed some important ifdefs
 133  *
 134  * Revision 1.16  2001/02/08 15:20:38  starvik
 135  * Include dram_init.S as inline
 136  *
 137  * Revision 1.15  2001/01/29 18:12:01  bjornw
 138  * Corrected some comments
 139  *
 140  * Revision 1.14  2001/01/29 13:11:29  starvik
 141  * Include dram_init.S (with DRAM/SDRAM initialization)
 142  *
 143  * Revision 1.13  2001/01/23 14:54:57  markusl
 144  * Updated for USB
 145  * i.e. added r_gen_config settings
 146  *
 147  * Revision 1.12  2001/01/19 16:16:29  perf
 148  * Added temporary mapping of 0x0c->0x0c to avoid flash loading confusion.
 149  * Renamed serial options from ETRAX100 to ETRAX.
 150  *
 151  * Revision 1.11  2001/01/16 16:31:38  bjornw
 152  * * Changed name and semantics of running_from_flash to romfs_in_flash,
 153  *   set by head.S to indicate to setup.c whether there is a cramfs image
 154  *   after the kernels BSS or not. Should work for all three boot-cases
 155  *   (DRAM with cramfs in DRAM, DRAM with cramfs in flash (compressed boot),
 156  *    and flash with cramfs in flash)
 157  *
 158  * Revision 1.10  2001/01/16 14:12:21  bjornw
 159  * * Check for cramfs start passed in r9 from the decompressor, if all other
 160  *   cramfs options fail (if we boot from DRAM but don't find a cramfs image
 161  *   after the kernel in DRAM, it is probably still in the flash)
 162  * * Check magic in cramfs detection when booting from flash directly
 163  *
 164  * Revision 1.9  2001/01/15 17:17:02  bjornw
 165  * * Corrected the code that detects the cramfs lengths
 166  * * Added a comment saying that the above does not work due to other
 167  *   reasons..
 168  *
 169  * Revision 1.8  2001/01/15 16:27:51  jonashg
 170  * Made boot after flashing work.
 171  * * end destination is __vmlinux_end in RAM.
 172  * * _romfs_start moved because of virtual memory.
 173  *
 174  * Revision 1.7  2000/11/21 13:55:29  bjornw
 175  * Use CONFIG_CRIS_LOW_MAP for the low VM map instead of explicit CPU type
 176  *
 177  * Revision 1.6  2000/10/06 12:36:55  bjornw
 178  * Forgot swapper_pg_dir when changing memory map..
 179  *
 180  * Revision 1.5  2000/10/04 16:49:30  bjornw
 181  * * Fixed memory mapping in LX
 182  * * Check for cramfs instead of romfs
 183  *
 184  */
 185
 186 #include <linux/config.h>
 187 #define ASSEMBLER_MACROS_ONLY
 188 /* The IO_* macros use the ## token concatenation operator, so
 189    -traditional must not be used when assembling this file.  */
 190 #include <asm/arch/sv_addr_ag.h>
 191
 192 #define CRAMFS_MAGIC 0x28cd3d45
 193 #define RAM_INIT_MAGIC 0x56902387
 194 #define COMMAND_LINE_MAGIC 0x87109563
 195
 196 #define START_ETHERNET_CLOCK IO_STATE(R_NETWORK_GEN_CONFIG, enable, on) |\
 197                              IO_STATE(R_NETWORK_GEN_CONFIG, phy, mii_clk)
 198
 199         ;; exported symbols
 200
 201         .globl  etrax_irv
 202         .globl  romfs_start
 203         .globl  romfs_length
 204         .globl  romfs_in_flash
 205         .globl  swapper_pg_dir
 206
 207         .text
 208
 209         ;; This is the entry point of the kernel. We are in supervisor mode.
 210         ;; 0x00000000 if Flash, 0x40004000 if DRAM
 211         ;; since etrax actually starts at address 2 when booting from flash, we
 212         ;; put a nop (2 bytes) here first so we dont accidentally skip the di
 213         ;;
 214         ;; NOTICE! The registers r8 and r9 are used as parameters carrying
 215         ;; information from the decompressor (if the kernel was compressed).
 216         ;; They should not be used in the code below until read.
 217
 218         nop
 219         di
 220
 221         ;; First setup the kseg_c mapping from where the kernel is linked
 222         ;; to 0x40000000 (where the actual DRAM resides) otherwise
 223         ;; we cannot do very much! See arch/cris/README.mm
 224         ;;
 225         ;; Notice that since we're potentially running at 0x00 or 0x40 right now,
 226         ;; we will get a fault as soon as we enable the MMU if we dont
 227         ;; temporarily map those segments linearily.
 228         ;;
 229         ;; Due to a bug in Etrax-100 LX version 1 we need to map the memory
 230         ;; slightly different.  The bug is that you can't remap bit 31 of
 231         ;; an address.  Though we can check the version register for
 232         ;; whether the bug is present, some constants would then have to
 233         ;; be variables, so we don't.  The drawback is that you can "only" map
 234         ;; 1G per process with CONFIG_CRIS_LOW_MAP.
 235
 236 #ifdef CONFIG_CRIS_LOW_MAP
 237         ; kseg mappings, temporary map of 0xc0->0x40
 238         move.d    IO_FIELD (R_MMU_KBASE_HI, base_c, 4)          \
 239                 | IO_FIELD (R_MMU_KBASE_HI, base_b, 0xb)        \
 240                 | IO_FIELD (R_MMU_KBASE_HI, base_9, 9)          \
 241                 | IO_FIELD (R_MMU_KBASE_HI, base_8, 8), $r0
 242         move.d  $r0, [R_MMU_KBASE_HI]
 243
 244         ; temporary map of 0x40->0x40 and 0x60->0x40
 245         move.d    IO_FIELD (R_MMU_KBASE_LO, base_6, 4)          \
 246                 | IO_FIELD (R_MMU_KBASE_LO, base_4, 4), $r0
 247         move.d  $r0, [R_MMU_KBASE_LO]
 248
 249         ; mmu enable, segs e,c,b,a,6,5,4,0 segment mapped
 250         move.d    IO_STATE (R_MMU_CONFIG, mmu_enable, enable)   \
 251                 | IO_STATE (R_MMU_CONFIG, inv_excp, enable)     \
 252                 | IO_STATE (R_MMU_CONFIG, acc_excp, enable)     \
 253                 | IO_STATE (R_MMU_CONFIG, we_excp, enable)      \
 254                 | IO_STATE (R_MMU_CONFIG, seg_f, page)          \
 255                 | IO_STATE (R_MMU_CONFIG, seg_e, seg)           \
 256                 | IO_STATE (R_MMU_CONFIG, seg_d, page)          \
 257                 | IO_STATE (R_MMU_CONFIG, seg_c, seg)           \
 258                 | IO_STATE (R_MMU_CONFIG, seg_b, seg)           \
 259                 | IO_STATE (R_MMU_CONFIG, seg_a, seg)           \
 260                 | IO_STATE (R_MMU_CONFIG, seg_9, page)          \
 261                 | IO_STATE (R_MMU_CONFIG, seg_8, page)          \
 262                 | IO_STATE (R_MMU_CONFIG, seg_7, page)          \
 263                 | IO_STATE (R_MMU_CONFIG, seg_6, seg)           \
 264                 | IO_STATE (R_MMU_CONFIG, seg_5, seg)           \
 265                 | IO_STATE (R_MMU_CONFIG, seg_4, seg)           \
 266                 | IO_STATE (R_MMU_CONFIG, seg_3, page)          \
 267                 | IO_STATE (R_MMU_CONFIG, seg_2, page)          \
 268                 | IO_STATE (R_MMU_CONFIG, seg_1, page)          \
 269                 | IO_STATE (R_MMU_CONFIG, seg_0, seg), $r0
 270         move.d  $r0, [R_MMU_CONFIG]
 271 #else
 272         ; kseg mappings
 273         move.d    IO_FIELD (R_MMU_KBASE_HI, base_e, 8)          \
 274                 | IO_FIELD (R_MMU_KBASE_HI, base_c, 4)          \
 275                 | IO_FIELD (R_MMU_KBASE_HI, base_b, 0xb), $r0
 276         move.d  $r0, [R_MMU_KBASE_HI]
 277
 278         ; temporary map of 0x40->0x40 and 0x00->0x00
 279         move.d    IO_FIELD (R_MMU_KBASE_LO, base_4, 4), $r0
 280         move.d  $r0, [R_MMU_KBASE_LO]
 281
 282         ; mmu enable, segs f,e,c,b,4,0 segment mapped
 283         move.d    IO_STATE (R_MMU_CONFIG, mmu_enable, enable)   \
 284                 | IO_STATE (R_MMU_CONFIG, inv_excp, enable)     \
 285                 | IO_STATE (R_MMU_CONFIG, acc_excp, enable)     \
 286                 | IO_STATE (R_MMU_CONFIG, we_excp, enable)      \
 287                 | IO_STATE (R_MMU_CONFIG, seg_f, seg)           \
 288                 | IO_STATE (R_MMU_CONFIG, seg_e, seg)           \
 289                 | IO_STATE (R_MMU_CONFIG, seg_d, page)          \
 290                 | IO_STATE (R_MMU_CONFIG, seg_c, seg)           \
 291                 | IO_STATE (R_MMU_CONFIG, seg_b, seg)           \
 292                 | IO_STATE (R_MMU_CONFIG, seg_a, page)          \
 293                 | IO_STATE (R_MMU_CONFIG, seg_9, page)          \
 294                 | IO_STATE (R_MMU_CONFIG, seg_8, page)          \
 295                 | IO_STATE (R_MMU_CONFIG, seg_7, page)          \
 296                 | IO_STATE (R_MMU_CONFIG, seg_6, page)          \
 297                 | IO_STATE (R_MMU_CONFIG, seg_5, page)          \
 298                 | IO_STATE (R_MMU_CONFIG, seg_4, seg)           \
 299                 | IO_STATE (R_MMU_CONFIG, seg_3, page)          \
 300                 | IO_STATE (R_MMU_CONFIG, seg_2, page)          \
 301                 | IO_STATE (R_MMU_CONFIG, seg_1, page)          \
 302                 | IO_STATE (R_MMU_CONFIG, seg_0, seg), $r0
 303         move.d  $r0, [R_MMU_CONFIG]
 304 #endif
 305
 306         ;; Now we need to sort out the segments and their locations in RAM or
 307         ;; Flash. The image in the Flash (or in DRAM) consists of 3 pieces:
 308         ;; 1) kernel text, 2) kernel data, 3) ROM filesystem image
 309         ;; But the linker has linked the kernel to expect this layout in
 310         ;; DRAM memory:
 311         ;; 1) kernel text, 2) kernel data, 3) kernel BSS
 312         ;; (the location of the ROM filesystem is determined by the krom driver)
 313         ;; If we boot this from Flash, we want to keep the ROM filesystem in
 314         ;; the flash, we want to copy the text and need to copy the data to DRAM.
 315         ;; But if we boot from DRAM, we need to move the ROMFS image
 316         ;; from its position after kernel data, to after kernel BSS, BEFORE the
 317         ;; kernel starts using the BSS area (since its "overlayed" with the ROMFS)
 318         ;;
 319         ;; In both cases, we start in un-cached mode, and need to jump into a
 320         ;; cached PC after we're done fiddling around with the segments.
 321         ;;
 322         ;; arch/etrax100/etrax100.ld sets some symbols that define the start
 323         ;; and end of each segment.
 324
 325         ;; Check if we start from DRAM or FLASH by testing PC
 326
 327         move.d  $pc,$r0
 328         and.d   0x7fffffff,$r0  ; get rid of the non-cache bit
 329         cmp.d   0x10000,$r0     ; arbitrary... just something above this code
 330         blo     _inflash0
 331         nop
 332
 333         jump    _inram          ; enter cached ram
 334
 335         ;; Jumpgate for branches.
 336 _inflash0:
 337         jump    _inflash
 338
 339         ;; Put this in a suitable section where we can reclaim storage
 340         ;; after init.
 341         .section ".init.text", "ax"
 342 _inflash:
 343 #ifdef CONFIG_ETRAX_ETHERNET
 344         ;; Start MII clock to make sure it is running when tranceiver is reset
 345         move.d START_ETHERNET_CLOCK, $r0
 346         move.d $r0, [R_NETWORK_GEN_CONFIG]
 347 #endif
 348
 349         ;; Set up waitstates etc according to kernel configuration.
 350 #ifndef CONFIG_SVINTO_SIM
 351         move.d   CONFIG_ETRAX_DEF_R_WAITSTATES, $r0
 352         move.d   $r0, [R_WAITSTATES]
 353
 354         move.d   CONFIG_ETRAX_DEF_R_BUS_CONFIG, $r0
 355         move.d   $r0, [R_BUS_CONFIG]
 356 #endif
 357
 358         ;; We need to initialze DRAM registers before we start using the DRAM
 359
 360         cmp.d   RAM_INIT_MAGIC, $r8     ; Already initialized?
 361         beq     _dram_init_finished
 362         nop
 363
 364 #include "../lib/dram_init.S"
 365
 366 _dram_init_finished:
 367         ;; Copy text+data to DRAM
 368         ;; This is fragile - the calculation of r4 as the image size depends
 369         ;; on that the labels below actually are the first and last positions
 370         ;; in the linker-script.
 371         ;;
 372         ;; Then the locating of the cramfs image depends on the aforementioned
 373         ;; image being located in the flash at 0. This is most often not true,
 374         ;; thus the following does not work (normally there is a rescue-block
 375         ;; between the physical start of the flash and the flash-image start,
 376         ;; and when run with compression, the kernel is actually unpacked to
 377         ;; DRAM and we never get here in the first place :))
 378
 379         moveq   0, $r0                  ; source
 380         move.d  text_start, $r1         ; destination
 381         move.d  __vmlinux_end, $r2      ; end destination
 382         move.d  $r2, $r4
 383         sub.d   $r1, $r4                ; r4=__vmlinux_end in flash, used below
 384 1:      move.w  [$r0+], $r3
 385         move.w  $r3, [$r1+]
 386         cmp.d   $r2, $r1
 387         blo     1b
 388         nop
 389
 390         ;; We keep the cramfs in the flash.
 391         ;; There might be none, but that does not matter because
 392         ;; we don't do anything than read some bytes here.
 393
 394         moveq   0, $r0
 395         move.d  $r0, [romfs_length] ; default if there is no cramfs
 396
 397         move.d  [$r4], $r0      ; cramfs_super.magic
 398         cmp.d   CRAMFS_MAGIC, $r0
 399         bne     1f
 400         nop
 401         move.d  [$r4 + 4], $r0  ; cramfs_super.size
 402         move.d  $r0, [romfs_length]
 403 #ifdef CONFIG_CRIS_LOW_MAP
 404         add.d   0x50000000, $r4 ; add flash start in virtual memory (cached)
 405 #else
 406         add.d   0xf0000000, $r4 ; add flash start in virtual memory (cached)
 407 #endif
 408         move.d  $r4, [romfs_start]
 409 1:
 410         moveq   1, $r0
 411         move.d  $r0, [romfs_in_flash]
 412
 413         jump    _start_it       ; enter code, cached this time
 414
 415 _inram:
 416         ;; Move the ROM fs to after BSS end. This assumes that the cramfs
 417         ;; second longword contains the length of the cramfs
 418
 419         moveq   0, $r0
 420         move.d  $r0, [romfs_length] ; default if there is no cramfs
 421
 422         ;; The kernel could have been unpacked to DRAM by the loader, but
 423         ;; the cramfs image could still be in the Flash directly after the
 424         ;; compressed kernel image. The loader passes the address of the
 425         ;; byte succeeding the last compressed byte in the flash in the
 426         ;; register r9 when starting the kernel. Check if r9 points to a
 427         ;; decent cramfs image!
 428         ;; (Notice that if this is not booted from the loader, r9 will be
 429         ;;  garbage but we do sanity checks on it, the chance that it points
 430         ;;  to a cramfs magic is small.. )
 431
 432         cmp.d   0x0ffffff8, $r9
 433         bhs     _no_romfs_in_flash      ; r9 points outside the flash area
 434         nop
 435         move.d  [$r9], $r0      ; cramfs_super.magic
 436         cmp.d   CRAMFS_MAGIC, $r0
 437         bne     _no_romfs_in_flash
 438         nop
 439         move.d  [$r9+4], $r0    ; cramfs_super.length
 440         move.d  $r0, [romfs_length]
 441 #ifdef CONFIG_CRIS_LOW_MAP
 442         add.d   0x50000000, $r9 ; add flash start in virtual memory (cached)
 443 #else
 444         add.d   0xf0000000, $r9 ; add flash start in virtual memory (cached)
 445 #endif
 446         move.d  $r9, [romfs_start]
 447
 448         moveq   1, $r0
 449         move.d  $r0, [romfs_in_flash]
 450
 451         jump    _start_it       ; enter code, cached this time
 452
 453 _no_romfs_in_flash:
 454
 455         ;; Check if there is a cramfs (magic value).
 456         ;; Notice that we check for cramfs magic value - which is
 457         ;; the "rom fs" we'll possibly use in 2.4 if not JFFS (which does
 458         ;; not need this mechanism anyway)
 459
 460         move.d  __vmlinux_end, $r0; the image will be after the vmlinux end address
 461         move.d  [$r0], $r1      ; cramfs assumes same endian on host/target
 462         cmp.d   CRAMFS_MAGIC, $r1; magic value in cramfs superblock
 463         bne     2f
 464         nop
 465
 466         ;; Ok. What is its size ?
 467
 468         move.d  [$r0 + 4], $r2  ; cramfs_super.size (again, no need to swapwb)
 469
 470         ;; We want to copy it to the end of the BSS
 471
 472         move.d  _end, $r1
 473
 474         ;; Remember values so cramfs and setup can find this info
 475
 476         move.d  $r1, [romfs_start]      ; new romfs location
 477         move.d  $r2, [romfs_length]
 478
 479         ;; We need to copy it backwards, since they can be overlapping
 480
 481         add.d   $r2, $r0
 482         add.d   $r2, $r1
 483
 484         ;; Go ahead. Make my loop.
 485
 486         lsrq    1, $r2          ; size is in bytes, we copy words
 487
 488 1:      move.w  [$r0=$r0-2],$r3
 489         move.w  $r3,[$r1=$r1-2]
 490         subq    1, $r2
 491         bne     1b
 492         nop
 493
 494 2:
 495         ;; Dont worry that the BSS is tainted. It will be cleared later.
 496
 497         moveq   0, $r0
 498         move.d  $r0, [romfs_in_flash]
 499
 500         jump    _start_it       ; better skip the additional cramfs check below
 501
 502 _start_it:
 503
 504         ;; Check if kernel command line is supplied
 505         cmp.d   COMMAND_LINE_MAGIC, $r10
 506         bne     no_command_line
 507         nop
 508
 509         move.d  256, $r13
 510         move.d  cris_command_line, $r10
 511         or.d    0x80000000, $r11 ; Make it virtual
 512 1:
 513         move.b  [$r11+], $r12
 514         move.b  $r12, [$r10+]
 515         subq    1, $r13
 516         bne     1b
 517         nop
 518
 519 no_command_line:
 520
 521         ;; the kernel stack is overlayed with the task structure for each
 522         ;; task. thus the initial kernel stack is in the same page as the
 523         ;; init_task (but starts in the top of the page, size 8192)
 524         move.d  init_thread_union + 8192, $sp
 525         move.d  ibr_start,$r0   ; this symbol is set by the linker script
 526         move    $r0,$ibr
 527         move.d  $r0,[etrax_irv] ; set the interrupt base register and pointer
 528
 529         ;; Clear BSS region, from _bss_start to _end
 530
 531         move.d  __bss_start, $r0
 532         move.d  _end, $r1
 533 1:      clear.d [$r0+]
 534         cmp.d   $r1, $r0
 535         blo     1b
 536         nop
 537
 538 #ifdef CONFIG_BLK_DEV_ETRAXIDE
 539         ;; disable ATA before enabling it in genconfig below
 540         moveq   0,$r0
 541         move.d  $r0,[R_ATA_CTRL_DATA]
 542         move.d  $r0,[R_ATA_TRANSFER_CNT]
 543         move.d  $r0,[R_ATA_CONFIG]
 544 #if 0
 545         move.d  R_PORT_G_DATA, $r1
 546         move.d  $r0, [$r1]; assert ATA bus-reset
 547         nop
 548         nop
 549         nop
 550         nop
 551         nop
 552         nop
 553         move.d  0x08000000,$r0
 554         move.d  $r0,[$r1]
 555 #endif
 556 #endif
 557
 558 #ifdef CONFIG_JULIETTE
 559         ;; configure external DMA channel 0 before enabling it in genconfig
 560
 561         moveq   0,$r0
 562         move.d  $r0,[R_EXT_DMA_0_ADDR]
 563         ; cnt enable, word size, output, stop, size 0
 564         move.d    IO_STATE (R_EXT_DMA_0_CMD, cnt, enable)       \
 565                 | IO_STATE (R_EXT_DMA_0_CMD, rqpol, ahigh)      \
 566                 | IO_STATE (R_EXT_DMA_0_CMD, apol, ahigh)       \
 567                 | IO_STATE (R_EXT_DMA_0_CMD, rq_ack, burst)     \
 568                 | IO_STATE (R_EXT_DMA_0_CMD, wid, word)         \
 569                 | IO_STATE (R_EXT_DMA_0_CMD, dir, output)       \
 570                 | IO_STATE (R_EXT_DMA_0_CMD, run, stop)         \
 571                 | IO_FIELD (R_EXT_DMA_0_CMD, trf_count, 0),$r0
 572         move.d  $r0,[R_EXT_DMA_0_CMD]
 573
 574         ;; reset dma4 and wait for completion
 575
 576         moveq   IO_STATE (R_DMA_CH4_CMD, cmd, reset),$r0
 577         move.b  $r0,[R_DMA_CH4_CMD]
 578 1:      move.b  [R_DMA_CH4_CMD],$r0
 579         and.b   IO_MASK (R_DMA_CH4_CMD, cmd),$r0
 580         cmp.b   IO_STATE (R_DMA_CH4_CMD, cmd, reset),$r0
 581         beq     1b
 582         nop
 583
 584         ;; reset dma5 and wait for completion
 585
 586         moveq   IO_STATE (R_DMA_CH5_CMD, cmd, reset),$r0
 587         move.b  $r0,[R_DMA_CH5_CMD]
 588 1:      move.b  [R_DMA_CH5_CMD],$r0
 589         and.b   IO_MASK (R_DMA_CH5_CMD, cmd),$r0
 590         cmp.b   IO_STATE (R_DMA_CH5_CMD, cmd, reset),$r0
 591         beq     1b
 592         nop
 593 #endif
 594
 595         ;; Etrax product HW genconfig setup
 596
 597         moveq   0,$r0
 598
 599         ;; Init interfaces (disable them).
 600         or.d      IO_STATE (R_GEN_CONFIG, scsi0, disable) \
 601                 | IO_STATE (R_GEN_CONFIG, ata, disable) \
 602                 | IO_STATE (R_GEN_CONFIG, par0, disable) \
 603                 | IO_STATE (R_GEN_CONFIG, ser2, disable) \
 604                 | IO_STATE (R_GEN_CONFIG, mio, disable) \
 605                 | IO_STATE (R_GEN_CONFIG, scsi1, disable) \
 606                 | IO_STATE (R_GEN_CONFIG, scsi0w, disable) \
 607                 | IO_STATE (R_GEN_CONFIG, par1, disable) \
 608                 | IO_STATE (R_GEN_CONFIG, ser3, disable) \
 609                 | IO_STATE (R_GEN_CONFIG, mio_w, disable) \
 610                 | IO_STATE (R_GEN_CONFIG, usb1, disable) \
 611                 | IO_STATE (R_GEN_CONFIG, usb2, disable) \
 612                 | IO_STATE (R_GEN_CONFIG, par_w, disable),$r0
 613
 614         ;; Init DMA channel muxing (set to unused clients).
 615         or.d      IO_STATE (R_GEN_CONFIG, dma2, ata)    \
 616                 | IO_STATE (R_GEN_CONFIG, dma3, ata) \
 617                 | IO_STATE (R_GEN_CONFIG, dma4, scsi1) \
 618                 | IO_STATE (R_GEN_CONFIG, dma5, scsi1) \
 619                 | IO_STATE (R_GEN_CONFIG, dma6, unused) \
 620                 | IO_STATE (R_GEN_CONFIG, dma7, unused) \
 621                 | IO_STATE (R_GEN_CONFIG, dma8, usb) \
 622                 | IO_STATE (R_GEN_CONFIG, dma9, usb),$r0
 623
 624
 625 #if defined(CONFIG_ETRAX_DEF_R_PORT_G0_DIR_OUT)
 626         or.d      IO_STATE (R_GEN_CONFIG, g0dir, out),$r0
 627 #endif
 628
 629 #if defined(CONFIG_ETRAX_DEF_R_PORT_G8_15_DIR_OUT)
 630         or.d      IO_STATE (R_GEN_CONFIG, g8_15dir, out),$r0
 631 #endif
 632 #if defined(CONFIG_ETRAX_DEF_R_PORT_G16_23_DIR_OUT)
 633        or.d      IO_STATE (R_GEN_CONFIG, g16_23dir, out),$r0
 634 #endif
 635
 636 #if defined(CONFIG_ETRAX_DEF_R_PORT_G24_DIR_OUT)
 637        or.d      IO_STATE (R_GEN_CONFIG, g24dir, out),$r0
 638 #endif
 639
 640         move.d  $r0,[genconfig_shadow] ; init a shadow register of R_GEN_CONFIG
 641
 642 #ifndef CONFIG_SVINTO_SIM
 643         move.d  $r0,[R_GEN_CONFIG]
 644
 645 #if 0
 646         moveq   4,$r0
 647         move.b  $r0,[R_DMA_CH6_CMD]     ; reset (ser0 dma out)
 648         move.b  $r0,[R_DMA_CH7_CMD]     ; reset (ser0 dma in)
 649 1:      move.b  [R_DMA_CH6_CMD],$r0     ; wait for reset cycle to finish
 650         and.b   7,$r0
 651         cmp.b   4,$r0
 652         beq     1b
 653         nop
 654 1:      move.b  [R_DMA_CH7_CMD],$r0     ; wait for reset cycle to finish
 655         and.b   7,$r0
 656         cmp.b   4,$r0
 657         beq     1b
 658         nop
 659 #endif
 660
 661         moveq   IO_STATE (R_DMA_CH8_CMD, cmd, reset),$r0
 662         move.b  $r0,[R_DMA_CH8_CMD]     ; reset (ser1 dma out)
 663         move.b  $r0,[R_DMA_CH9_CMD]     ; reset (ser1 dma in)
 664 1:      move.b  [R_DMA_CH8_CMD],$r0     ; wait for reset cycle to finish
 665         andq    IO_MASK (R_DMA_CH8_CMD, cmd),$r0
 666         cmpq    IO_STATE (R_DMA_CH8_CMD, cmd, reset),$r0
 667         beq     1b
 668         nop
 669 1:      move.b  [R_DMA_CH9_CMD],$r0     ; wait for reset cycle to finish
 670         andq    IO_MASK (R_DMA_CH9_CMD, cmd),$r0
 671         cmpq    IO_STATE (R_DMA_CH9_CMD, cmd, reset),$r0
 672         beq     1b
 673         nop
 674
 675         ;; setup port PA and PB default initial directions and data
 676         ;; including their shadow registers
 677
 678         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DIR,$r0
 679 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_PA7)
 680         or.b    IO_STATE (R_PORT_PA_DIR, dir7, output),$r0
 681 #endif
 682         move.b  $r0,[port_pa_dir_shadow]
 683         move.b  $r0,[R_PORT_PA_DIR]
 684         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DATA,$r0
 685 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_PA7)
 686 #if defined(CONFIG_BLUETOOTH_RESET_ACTIVE_HIGH)
 687         and.b   ~(1 << 7),$r0
 688 #else
 689         or.b    (1 << 7),$r0
 690 #endif
 691 #endif
 692         move.b  $r0,[port_pa_data_shadow]
 693         move.b  $r0,[R_PORT_PA_DATA]
 694
 695         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_CONFIG,$r0
 696         move.b  $r0,[port_pb_config_shadow]
 697         move.b  $r0,[R_PORT_PB_CONFIG]
 698         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DIR,$r0
 699 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_PB5)
 700         or.b    IO_STATE (R_PORT_PB_DIR, dir5, output),$r0
 701 #endif
 702         move.b  $r0,[port_pb_dir_shadow]
 703         move.b  $r0,[R_PORT_PB_DIR]
 704         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DATA,$r0
 705 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_PB5)
 706 #if defined(CONFIG_BLUETOOTH_RESET_ACTIVE_HIGH)
 707         and.b   ~(1 << 5),$r0
 708 #else
 709         or.b    (1 << 5),$r0
 710 #endif
 711 #endif
 712         move.b  $r0,[port_pb_data_shadow]
 713         move.b  $r0,[R_PORT_PB_DATA]
 714
 715         moveq   0, $r0
 716         move.d  $r0,[port_pb_i2c_shadow]
 717         move.d  $r0, [R_PORT_PB_I2C]
 718
 719         moveq   0,$r0
 720 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_G10)
 721 #if defined(CONFIG_BLUETOOTH_RESET_ACTIVE_HIGH)
 722         and.d   ~(1 << 10),$r0
 723 #else
 724         or.d    (1 << 10),$r0
 725 #endif
 726 #endif
 727 #if defined(CONFIG_BLUETOOTH) && defined(CONFIG_BLUETOOTH_RESET_G11)
 728 #if defined(CONFIG_BLUETOOTH_RESET_ACTIVE_HIGH)
 729         and.d   ~(1 << 11),$r0
 730 #else
 731         or.d    (1 << 11),$r0
 732 #endif
 733 #endif
 734         move.d  $r0,[port_g_data_shadow]
 735         move.d  $r0,[R_PORT_G_DATA]
 736
 737         ;; setup the serial port 0 at 115200 baud for debug purposes
 738
 739         moveq     IO_STATE (R_SERIAL0_XOFF, tx_stop, enable)            \
 740                 | IO_STATE (R_SERIAL0_XOFF, auto_xoff, disable)         \
 741                 | IO_FIELD (R_SERIAL0_XOFF, xoff_char, 0),$r0
 742         move.d  $r0,[R_SERIAL0_XOFF]
 743
 744         ; 115.2kbaud for both transmit and receive
 745         move.b    IO_STATE (R_SERIAL0_BAUD, tr_baud, c115k2Hz)          \
 746                 | IO_STATE (R_SERIAL0_BAUD, rec_baud, c115k2Hz),$r0
 747         move.b  $r0,[R_SERIAL0_BAUD]
 748
 749         ; Set up and enable the serial0 receiver.
 750         move.b    IO_STATE (R_SERIAL0_REC_CTRL, dma_err, stop)          \
 751                 | IO_STATE (R_SERIAL0_REC_CTRL, rec_enable, enable)     \
 752                 | IO_STATE (R_SERIAL0_REC_CTRL, rts_, active)           \
 753                 | IO_STATE (R_SERIAL0_REC_CTRL, sampling, middle)       \
 754                 | IO_STATE (R_SERIAL0_REC_CTRL, rec_stick_par, normal)  \
 755                 | IO_STATE (R_SERIAL0_REC_CTRL, rec_par, even)          \
 756                 | IO_STATE (R_SERIAL0_REC_CTRL, rec_par_en, disable)    \
 757                 | IO_STATE (R_SERIAL0_REC_CTRL, rec_bitnr, rec_8bit),$r0
 758         move.b  $r0,[R_SERIAL0_REC_CTRL]
 759
 760         ; Set up and enable the serial0 transmitter.
 761         move.b    IO_FIELD (R_SERIAL0_TR_CTRL, txd, 0)                  \
 762                 | IO_STATE (R_SERIAL0_TR_CTRL, tr_enable, enable)       \
 763                 | IO_STATE (R_SERIAL0_TR_CTRL, auto_cts, disabled)      \
 764                 | IO_STATE (R_SERIAL0_TR_CTRL, stop_bits, one_bit)      \
 765                 | IO_STATE (R_SERIAL0_TR_CTRL, tr_stick_par, normal)    \
 766                 | IO_STATE (R_SERIAL0_TR_CTRL, tr_par, even)            \
 767                 | IO_STATE (R_SERIAL0_TR_CTRL, tr_par_en, disable)      \
 768                 | IO_STATE (R_SERIAL0_TR_CTRL, tr_bitnr, tr_8bit),$r0
 769         move.b  $r0,[R_SERIAL0_TR_CTRL]
 770
 771         ;; setup the serial port 1 at 115200 baud for debug purposes
 772
 773         moveq     IO_STATE (R_SERIAL1_XOFF, tx_stop, enable)            \
 774                 | IO_STATE (R_SERIAL1_XOFF, auto_xoff, disable)         \
 775                 | IO_FIELD (R_SERIAL1_XOFF, xoff_char, 0),$r0
 776         move.d  $r0,[R_SERIAL1_XOFF]
 777
 778         ; 115.2kbaud for both transmit and receive
 779         move.b    IO_STATE (R_SERIAL1_BAUD, tr_baud, c115k2Hz)          \
 780                 | IO_STATE (R_SERIAL1_BAUD, rec_baud, c115k2Hz),$r0
 781         move.b  $r0,[R_SERIAL1_BAUD]
 782
 783         ; Set up and enable the serial1 receiver.
 784         move.b    IO_STATE (R_SERIAL1_REC_CTRL, dma_err, stop)          \
 785                 | IO_STATE (R_SERIAL1_REC_CTRL, rec_enable, enable)     \
 786                 | IO_STATE (R_SERIAL1_REC_CTRL, rts_, active)           \
 787                 | IO_STATE (R_SERIAL1_REC_CTRL, sampling, middle)       \
 788                 | IO_STATE (R_SERIAL1_REC_CTRL, rec_stick_par, normal)  \
 789                 | IO_STATE (R_SERIAL1_REC_CTRL, rec_par, even)          \
 790                 | IO_STATE (R_SERIAL1_REC_CTRL, rec_par_en, disable)    \
 791                 | IO_STATE (R_SERIAL1_REC_CTRL, rec_bitnr, rec_8bit),$r0
 792         move.b  $r0,[R_SERIAL1_REC_CTRL]
 793
 794         ; Set up and enable the serial1 transmitter.
 795         move.b    IO_FIELD (R_SERIAL1_TR_CTRL, txd, 0)                  \
 796                 | IO_STATE (R_SERIAL1_TR_CTRL, tr_enable, enable)       \
 797                 | IO_STATE (R_SERIAL1_TR_CTRL, auto_cts, disabled)      \
 798                 | IO_STATE (R_SERIAL1_TR_CTRL, stop_bits, one_bit)      \
 799                 | IO_STATE (R_SERIAL1_TR_CTRL, tr_stick_par, normal)    \
 800                 | IO_STATE (R_SERIAL1_TR_CTRL, tr_par, even)            \
 801                 | IO_STATE (R_SERIAL1_TR_CTRL, tr_par_en, disable)      \
 802                 | IO_STATE (R_SERIAL1_TR_CTRL, tr_bitnr, tr_8bit),$r0
 803         move.b  $r0,[R_SERIAL1_TR_CTRL]
 804
 805
 806 #ifdef CONFIG_ETRAX_SERIAL_PORT3
 807         ;; setup the serial port 3 at 115200 baud for debug purposes
 808
 809         moveq     IO_STATE (R_SERIAL3_XOFF, tx_stop, enable)            \
 810                 | IO_STATE (R_SERIAL3_XOFF, auto_xoff, disable)         \
 811                 | IO_FIELD (R_SERIAL3_XOFF, xoff_char, 0),$r0
 812         move.d  $r0,[R_SERIAL3_XOFF]
 813
 814         ; 115.2kbaud for both transmit and receive
 815         move.b    IO_STATE (R_SERIAL3_BAUD, tr_baud, c115k2Hz)          \
 816                 | IO_STATE (R_SERIAL3_BAUD, rec_baud, c115k2Hz),$r0
 817         move.b  $r0,[R_SERIAL3_BAUD]
 818
 819         ; Set up and enable the serial3 receiver.
 820         move.b    IO_STATE (R_SERIAL3_REC_CTRL, dma_err, stop)          \
 821                 | IO_STATE (R_SERIAL3_REC_CTRL, rec_enable, enable)     \
 822                 | IO_STATE (R_SERIAL3_REC_CTRL, rts_, active)           \
 823                 | IO_STATE (R_SERIAL3_REC_CTRL, sampling, middle)       \
 824                 | IO_STATE (R_SERIAL3_REC_CTRL, rec_stick_par, normal)  \
 825                 | IO_STATE (R_SERIAL3_REC_CTRL, rec_par, even)          \
 826                 | IO_STATE (R_SERIAL3_REC_CTRL, rec_par_en, disable)    \
 827                 | IO_STATE (R_SERIAL3_REC_CTRL, rec_bitnr, rec_8bit),$r0
 828         move.b  $r0,[R_SERIAL3_REC_CTRL]
 829
 830         ; Set up and enable the serial3 transmitter.
 831         move.b    IO_FIELD (R_SERIAL3_TR_CTRL, txd, 0)                  \
 832                 | IO_STATE (R_SERIAL3_TR_CTRL, tr_enable, enable)       \
 833                 | IO_STATE (R_SERIAL3_TR_CTRL, auto_cts, disabled)      \
 834                 | IO_STATE (R_SERIAL3_TR_CTRL, stop_bits, one_bit)      \
 835                 | IO_STATE (R_SERIAL3_TR_CTRL, tr_stick_par, normal)    \
 836                 | IO_STATE (R_SERIAL3_TR_CTRL, tr_par, even)            \
 837                 | IO_STATE (R_SERIAL3_TR_CTRL, tr_par_en, disable)      \
 838                 | IO_STATE (R_SERIAL3_TR_CTRL, tr_bitnr, tr_8bit),$r0
 839         move.b  $r0,[R_SERIAL3_TR_CTRL]
 840 #endif
 841
 842 #endif /* CONFIG_SVINTO_SIM */
 843
 844         jump    start_kernel    ; jump into the C-function start_kernel in init/main.c
 845
 846         .data
 847 etrax_irv:
 848         .dword  0
 849 romfs_start:
 850         .dword  0
 851 romfs_length:
 852         .dword  0
 853 romfs_in_flash:
 854         .dword  0
 855
 856         ;; put some special pages at the beginning of the kernel aligned
 857         ;; to page boundaries - the kernel cannot start until after this
 858
 859 #ifdef CONFIG_CRIS_LOW_MAP
 860 swapper_pg_dir = 0x60002000
 861 #else
 862 swapper_pg_dir = 0xc0002000
 863 #endif
 864
 865         .section ".init.data", "aw"
 866 #include "../lib/hw_settings.S"