arch/arm/cpu/arm_intcm/start.S

   1 /*
   2  *  armboot - Startup Code for ARM926EJS CPU-core
   3  *
   4  *  Copyright (c) 2003  Texas Instruments
   5  *
   6  *  ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
   7  *
   8  *  Copyright (c) 2001  Marius Gröger <mag@sysgo.de>
   9  *  Copyright (c) 2002  Alex Züpke <azu@sysgo.de>
  10  *  Copyright (c) 2002  Gary Jennejohn <garyj@denx.de>
  11  *  Copyright (c) 2003  Richard Woodruff <r-woodruff2@ti.com>
  12  *  Copyright (c) 2003  Kshitij <kshitij@ti.com>
  13  *
  14  * See file CREDITS for list of people who contributed to this
  15  * project.
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License as
  19  * published by the Free Software Foundation; either version 2 of
  20  * the License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  30  * MA 02111-1307 USA
  31  */
  32
  33
  34 #include <config.h>
  35 #include <version.h>
  36
  37 /*
  38  *************************************************************************
  39  *
  40  * Jump vector table
  41  *
  42  *************************************************************************
  43  */
  44
  45 .globl _start
  46 _start:
  47         b       reset
  48         ldr     pc, _undefined_instruction
  49         ldr     pc, _software_interrupt
  50         ldr     pc, _prefetch_abort
  51         ldr     pc, _data_abort
  52         ldr     pc, _not_used
  53         ldr     pc, _irq
  54         ldr     pc, _fiq
  55
  56 _undefined_instruction:
  57         .word undefined_instruction
  58 _software_interrupt:
  59         .word software_interrupt
  60 _prefetch_abort:
  61         .word prefetch_abort
  62 _data_abort:
  63         .word data_abort
  64 _not_used:
  65         .word not_used
  66 _irq:
  67         .word irq
  68 _fiq:
  69         .word fiq
  70
  71         .balignl 16,0xdeadbeef
  72
  73 /*
  74  *************************************************************************
  75  *
  76  * Startup Code (reset vector)
  77  *
  78  * do important init only if we don't start from memory!
  79  * setup memory and board specific bits prior to relocation.
  80  * relocate armboot to ram
  81  * setup stack
  82  *
  83  *************************************************************************
  84  */
  85
  86 .globl _TEXT_BASE
  87 _TEXT_BASE:
  88         .word   TEXT_BASE /* address of _start in the linked image */
  89
  90 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
  91 .globl _armboot_start
  92 _armboot_start:
  93         .word _start
  94 #endif
  95
  96 /*
  97  * These are defined in the board-specific linker script.
  98  */
  99 .globl _bss_start
 100 _bss_start:
 101         .word __bss_start
 102
 103 .globl _bss_end
 104 _bss_end:
 105         .word _end
 106
 107 #ifdef CONFIG_USE_IRQ
 108 /* IRQ stack memory (calculated at run-time) */
 109 .globl IRQ_STACK_START
 110 IRQ_STACK_START:
 111         .word   0x0badc0de
 112
 113 /* IRQ stack memory (calculated at run-time) */
 114 .globl FIQ_STACK_START
 115 FIQ_STACK_START:
 116         .word 0x0badc0de
 117 #endif
 118
 119 #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
 120 /* IRQ stack memory (calculated at run-time) + 8 bytes */
 121 .globl IRQ_STACK_START_IN
 122 IRQ_STACK_START_IN:
 123         .word   0x0badc0de
 124
 125 .globl _datarel_start
 126 _datarel_start:
 127         .word __datarel_start
 128
 129 .globl _datarelrolocal_start
 130 _datarelrolocal_start:
 131         .word __datarelrolocal_start
 132
 133 .globl _datarellocal_start
 134 _datarellocal_start:
 135         .word __datarellocal_start
 136
 137 .globl _datarelro_start
 138 _datarelro_start:
 139         .word __datarelro_start
 140
 141 .globl _got_start
 142 _got_start:
 143         .word __got_start
 144
 145 .globl _got_end
 146 _got_end:
 147         .word __got_end
 148
 149 /*
 150  * the actual reset code
 151  */
 152
 153 reset:
 154         /*
 155          * set the cpu to SVC32 mode
 156          */
 157         mrs     r0,cpsr
 158         bic     r0,r0,#0x1f
 159         orr     r0,r0,#0xd3
 160         msr     cpsr,r0
 161
 162         /*
 163          * we do sys-critical inits only at reboot,
 164          * not when booting from ram!
 165          */
 166 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 167         bl      cpu_init_crit
 168 #endif
 169
 170 /* Set stackpointer in internal RAM to call board_init_f */
 171 call_board_init_f:
 172         ldr     sp, =(CONFIG_SYS_INIT_SP_ADDR)
 173         ldr     r0,=0x00000000
 174         bl      board_init_f
 175
 176 /*------------------------------------------------------------------------------*/
 177
 178 /*
 179  * void relocate_code (addr_sp, gd, addr_moni)
 180  *
 181  * This "function" does not return, instead it continues in RAM
 182  * after relocating the monitor code.
 183  *
 184  */
 185         .globl  relocate_code
 186 relocate_code:
 187         mov     r4, r0  /* save addr_sp */
 188         mov     r5, r1  /* save addr of gd */
 189         mov     r6, r2  /* save addr of destination */
 190         mov     r7, r2  /* save addr of destination */
 191
 192         /* Set up the stack                                                 */
 193 stack_setup:
 194         mov     sp, r4
 195
 196         adr     r0, _start
 197         ldr     r2, _TEXT_BASE
 198         ldr     r3, _bss_start
 199         sub     r2, r3, r2              /* r2 <- size of armboot            */
 200         add     r2, r0, r2              /* r2 <- source end address         */
 201         cmp     r0, r6
 202         beq     clear_bss
 203
 204 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
 205 copy_loop:
 206         ldmia   r0!, {r9-r10}           /* copy from source address [r0]    */
 207         stmia   r6!, {r9-r10}           /* copy to   target address [r1]    */
 208         cmp     r0, r2                  /* until source end addreee [r2]    */
 209         ble     copy_loop
 210
 211 #ifndef CONFIG_PRELOADER
 212         /* fix got entries */
 213         ldr     r1, _TEXT_BASE          /* Text base */
 214         mov     r0, r7                  /* reloc addr */
 215         ldr     r2, _got_start          /* addr in Flash */
 216         ldr     r3, _got_end            /* addr in Flash */
 217         sub     r3, r3, r1
 218         add     r3, r3, r0
 219         sub     r2, r2, r1
 220         add     r2, r2, r0
 221
 222 fixloop:
 223         ldr     r4, [r2]
 224         sub     r4, r4, r1
 225         add     r4, r4, r0
 226         str     r4, [r2]
 227         add     r2, r2, #4
 228         cmp     r2, r3
 229         bne     fixloop
 230 #endif
 231 #endif  /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
 232
 233 clear_bss:
 234 #ifndef CONFIG_PRELOADER
 235         ldr     r0, _bss_start
 236         ldr     r1, _bss_end
 237         ldr     r3, _TEXT_BASE          /* Text base */
 238         mov     r4, r7                  /* reloc addr */
 239         sub     r0, r0, r3
 240         add     r0, r0, r4
 241         sub     r1, r1, r3
 242         add     r1, r1, r4
 243         mov     r2, #0x00000000         /* clear                            */
 244
 245 clbss_l:str     r2, [r0]                /* clear loop...                    */
 246         add     r0, r0, #4
 247         cmp     r0, r1
 248         bne     clbss_l
 249
 250         bl coloured_LED_init
 251         bl red_LED_on
 252 #endif
 253
 254 /*
 255  * We are done. Do not return, instead branch to second part of board
 256  * initialization, now running from RAM.
 257  */
 258         ldr     r0, _TEXT_BASE
 259         ldr     r2, _board_init_r
 260         sub     r2, r2, r0
 261         add     r2, r2, r7      /* position from board_init_r in RAM */
 262         /* setup parameters for board_init_r */
 263         mov     r0, r5          /* gd_t */
 264         mov     r1, r7          /* dest_addr */
 265         /* jump to it ... */
 266         mov     lr, r2
 267         mov     pc, lr
 268
 269 _board_init_r: .word board_init_r
 270
 271 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 272
 273 /*
 274  * the actual reset code
 275  */
 276 .globl reset
 277 reset:
 278         /*
 279          * set the cpu to SVC32 mode
 280          */
 281         mrs     r0,cpsr
 282         bic     r0,r0,#0x1f
 283         orr     r0,r0,#0xd3
 284         msr     cpsr,r0
 285
 286         /*
 287          * we do sys-critical inits only at reboot,
 288          * not when booting from ram!
 289          */
 290 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 291         bl      cpu_init_crit
 292 #endif
 293
 294 relocate:                               /* relocate U-Boot to RAM           */
 295         adr     r0, _start              /* pc relative  address of label    */
 296         ldr     r1, _TEXT_BASE          /* linked image address of label    */
 297         cmp     r0, r1                  /* test if we run from flash or RAM */
 298         beq     stack_setup             /* ifeq we are in the RAM copy      */
 299
 300         ldr     r2, _armboot_start
 301         ldr     r3, _bss_start
 302         sub     r2, r3, r2              /* r2 <- size of armboot            */
 303         add     r2, r0, r2              /* r2 <- source end address         */
 304
 305 copy_loop:
 306         ldmia   r0!, {r3-r10}           /* copy from source address [r0]    */
 307         stmia   r1!, {r3-r10}           /* copy to   target address [r1]    */
 308         cmp     r0, r2                  /* until source end addreee [r2]    */
 309         ble     copy_loop
 310
 311         /* Set up the stack                                                 */
 312 stack_setup:
 313         ldr     r0, _TEXT_BASE          /* upper 128 KiB: relocated uboot   */
 314         sub     r0, r0, #CONFIG_SYS_MALLOC_LEN  /* malloc area                      */
 315         sub     r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo                        */
 316 #ifdef CONFIG_USE_IRQ
 317         sub     r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
 318 #endif
 319         sub     sp, r0, #12             /* leave 3 words for abort-stack    */
 320         bic     sp, sp, #7              /* 8-byte alignment for ABI compliance */
 321
 322 clear_bss:
 323         ldr     r0, _bss_start          /* find start of bss segment        */
 324         ldr     r1, _bss_end            /* stop here                        */
 325         mov     r2, #0x00000000         /* clear                            */
 326
 327 clbss_l:str     r2, [r0]                /* clear loop...                    */
 328         add     r0, r0, #4
 329         cmp     r0, r1
 330         ble     clbss_l
 331
 332         ldr     pc, _start_armboot
 333
 334 _start_armboot:
 335         .word start_armboot
 336
 337 #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 338
 339 /*
 340  *************************************************************************
 341  *
 342  * CPU_init_critical registers
 343  *
 344  * setup important registers
 345  * setup memory timing
 346  *
 347  *************************************************************************
 348  */
 349
 350 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 351 cpu_init_crit:
 352         /*  arm_int_generic assumes the ARM boot monitor, or user software,
 353          * has initialized the platform
 354          */
 355         mov     pc, lr          /* back to my caller */
 356 #endif
 357 /*
 358  *************************************************************************
 359  *
 360  * Interrupt handling
 361  *
 362  *************************************************************************
 363  */
 364
 365 @
 366 @ IRQ stack frame.
 367 @
 368 #define S_FRAME_SIZE    72
 369
 370 #define S_OLD_R0        68
 371 #define S_PSR           64
 372 #define S_PC            60
 373 #define S_LR            56
 374 #define S_SP            52
 375
 376 #define S_IP            48
 377 #define S_FP            44
 378 #define S_R10           40
 379 #define S_R9            36
 380 #define S_R8            32
 381 #define S_R7            28
 382 #define S_R6            24
 383 #define S_R5            20
 384 #define S_R4            16
 385 #define S_R3            12
 386 #define S_R2            8
 387 #define S_R1            4
 388 #define S_R0            0
 389
 390 #define MODE_SVC 0x13
 391 #define I_BIT    0x80
 392
 393 /*
 394  * use bad_save_user_regs for abort/prefetch/undef/swi ...
 395  * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
 396  */
 397
 398         .macro  bad_save_user_regs
 399         @ carve out a frame on current user stack
 400         sub     sp, sp, #S_FRAME_SIZE
 401         stmia   sp, {r0 - r12}  @ Save user registers (now in svc mode) r0-r12
 402
 403 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
 404         ldr     r2, _armboot_start
 405         sub     r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
 406         sub     r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8)  @ set base 2 words into abort stack
 407 #else
 408         ldr     r2, IRQ_STACK_START_IN
 409 #endif
 410         @ get values for "aborted" pc and cpsr (into parm regs)
 411         ldmia   r2, {r2 - r3}
 412         add     r0, sp, #S_FRAME_SIZE           @ grab pointer to old stack
 413         add     r5, sp, #S_SP
 414         mov     r1, lr
 415         stmia   r5, {r0 - r3}   @ save sp_SVC, lr_SVC, pc, cpsr
 416         mov     r0, sp          @ save current stack into r0 (param register)
 417         .endm
 418
 419         .macro  irq_save_user_regs
 420         sub     sp, sp, #S_FRAME_SIZE
 421         stmia   sp, {r0 - r12}                  @ Calling r0-r12
 422         @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
 423         add     r8, sp, #S_PC
 424         stmdb   r8, {sp, lr}^           @ Calling SP, LR
 425         str     lr, [r8, #0]            @ Save calling PC
 426         mrs     r6, spsr
 427         str     r6, [r8, #4]            @ Save CPSR
 428         str     r0, [r8, #8]            @ Save OLD_R0
 429         mov     r0, sp
 430         .endm
 431
 432         .macro  irq_restore_user_regs
 433         ldmia   sp, {r0 - lr}^                  @ Calling r0 - lr
 434         mov     r0, r0
 435         ldr     lr, [sp, #S_PC]                 @ Get PC
 436         add     sp, sp, #S_FRAME_SIZE
 437         subs    pc, lr, #4              @ return & move spsr_svc into cpsr
 438         .endm
 439
 440         .macro get_bad_stack
 441 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
 442         ldr     r13, _armboot_start             @ setup our mode stack
 443         sub     r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
 444         sub     r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
 445 #else
 446         ldr     r13, IRQ_STACK_START_IN         @ setup our mode stack
 447 #endif
 448
 449         str     lr, [r13]       @ save caller lr in position 0 of saved stack
 450         mrs     lr, spsr        @ get the spsr
 451         str     lr, [r13, #4]   @ save spsr in position 1 of saved stack
 452         mov     r13, #MODE_SVC  @ prepare SVC-Mode
 453         @ msr   spsr_c, r13
 454         msr     spsr, r13       @ switch modes, make sure moves will execute
 455         mov     lr, pc          @ capture return pc
 456         movs    pc, lr          @ jump to next instruction & switch modes.
 457         .endm
 458
 459         .macro get_irq_stack                    @ setup IRQ stack
 460         ldr     sp, IRQ_STACK_START
 461         .endm
 462
 463         .macro get_fiq_stack                    @ setup FIQ stack
 464         ldr     sp, FIQ_STACK_START
 465         .endm
 466
 467 /*
 468  * exception handlers
 469  */
 470         .align  5
 471 .globl undefined_instruction
 472 undefined_instruction:
 473         get_bad_stack
 474         bad_save_user_regs
 475         bl      do_undefined_instruction
 476
 477         .align  5
 478 .globl software_interrupt
 479 software_interrupt:
 480         get_bad_stack
 481         bad_save_user_regs
 482         bl      do_software_interrupt
 483
 484         .align  5
 485 .globl prefetch_abort
 486 prefetch_abort:
 487         get_bad_stack
 488         bad_save_user_regs
 489         bl      do_prefetch_abort
 490
 491         .align  5
 492 .globl data_abort
 493 data_abort:
 494         get_bad_stack
 495         bad_save_user_regs
 496         bl      do_data_abort
 497
 498         .align  5
 499 .globl not_used
 500 not_used:
 501         get_bad_stack
 502         bad_save_user_regs
 503         bl      do_not_used
 504
 505 #ifdef CONFIG_USE_IRQ
 506         .align  5
 507 .globl irq
 508 irq:
 509         get_irq_stack
 510         irq_save_user_regs
 511         bl      do_irq
 512         irq_restore_user_regs
 513
 514         .align  5
 515 .globl fiq
 516 fiq:
 517         get_fiq_stack
 518         /* someone ought to write a more effiction fiq_save_user_regs */
 519         irq_save_user_regs
 520         bl      do_fiq
 521         irq_restore_user_regs
 522
 523 #else
 524
 525         .align  5
 526 .globl irq
 527 irq:
 528         get_bad_stack
 529         bad_save_user_regs
 530         bl      do_irq
 531
 532         .align  5
 533 .globl fiq
 534 fiq:
 535         get_bad_stack
 536         bad_save_user_regs
 537         bl      do_fiq
 538
 539 #endif