arch/nds32/cpu/n1213/start.S

   1 /*
   2  *      Andesboot - Startup Code for Whitiger core
   3  *
   4  *      Copyright (C) 2006      Andes Technology Corporation
   5  *      Copyright (C) 2006      Shawn Lin <nobuhiro@andestech.com>
   6  *      Copyright (C) 2011      Macpaul Lin <macpaul@andestech.com>
   7  *                              Greentime Hu <greentime@andestech.com>
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 .pic
  13
  14 #include <asm-offsets.h>
  15 #include <config.h>
  16 #include <common.h>
  17 #include <asm/macro.h>
  18
  19 /*
  20  * Jump vector table for EVIC mode
  21  */
  22 #define ENA_DCAC                2UL
  23 #define DIS_DCAC                ~ENA_DCAC
  24 #define ICAC_MEM_KBF_ISET       (0x07)          ! I Cache sets per way
  25 #define ICAC_MEM_KBF_IWAY       (0x07<<3)       ! I cache ways
  26 #define ICAC_MEM_KBF_ISZ        (0x07<<6)       ! I cache line size
  27 #define DCAC_MEM_KBF_DSET       (0x07)          ! D Cache sets per way
  28 #define DCAC_MEM_KBF_DWAY       (0x07<<3)       ! D cache ways
  29 #define DCAC_MEM_KBF_DSZ        (0x07<<6)       ! D cache line size
  30
  31 #define PSW                     $ir0
  32 #define EIT_INTR_PSW            $ir1            ! interruption $PSW
  33 #define EIT_PREV_IPSW           $ir2            ! previous $IPSW
  34 #define EIT_IVB                 $ir3            ! intr vector base address
  35 #define EIT_EVA                 $ir4            ! MMU related Exception VA reg
  36 #define EIT_PREV_EVA            $ir5            ! previous $eva
  37 #define EIT_ITYPE               $ir6            ! interruption type
  38 #define EIT_PREV_ITYPE          $ir7            ! prev intr type
  39 #define EIT_MACH_ERR            $ir8            ! machine error log
  40 #define EIT_INTR_PC             $ir9            ! Interruption PC
  41 #define EIT_PREV_IPC            $ir10           ! previous $IPC
  42 #define EIT_OVL_INTR_PC         $ir11           ! overflow interruption PC
  43 #define EIT_PREV_P0             $ir12           ! prev $P0
  44 #define EIT_PREV_P1             $ir13           ! prev $p1
  45 #define CR_ICAC_MEM             $cr1            ! I-cache/memory config reg
  46 #define CR_DCAC_MEM             $cr2            ! D-cache/memory config reg
  47 #define MR_CAC_CTL              $mr8
  48
  49 .globl _start
  50
  51 _start: j       reset
  52         j       tlb_fill
  53         j       tlb_not_present
  54         j       tlb_misc
  55         j       tlb_vlpt_miss
  56         j       machine_error
  57         j       debug
  58         j       general_exception
  59         j       syscall
  60         j       internal_interrupt              ! H0I
  61         j       internal_interrupt              ! H1I
  62         j       internal_interrupt              ! H2I
  63         j       internal_interrupt              ! H3I
  64         j       internal_interrupt              ! H4I
  65         j       internal_interrupt              ! H5I
  66         j       software_interrupt              ! S0I
  67
  68         .balign 16
  69
  70 /*
  71  * Andesboot Startup Code (reset vector)
  72  *
  73  *      1.      bootstrap
  74  *              1.1 reset - start of u-boot
  75  *              1.2 to superuser mode - as is when reset
  76  *              1.4 Do lowlevel_init
  77  *                      - (this will jump out to lowlevel_init.S in SoC)
  78  *                      - (lowlevel_init)
  79  *              1.3 Turn off watchdog timer
  80  *                      - (this will jump out to watchdog.S in SoC)
  81  *                      - (turnoff_watchdog)
  82  *      2.      Do critical init when reboot (not from mem)
  83  *      3.      Relocate andesboot to ram
  84  *      4.      Setup stack
  85  *      5.      Jump to second stage (board_init_r)
  86  */
  87
  88 /* Note: TEXT_BASE is defined by the (board-dependent) linker script */
  89 .globl _TEXT_BASE
  90 _TEXT_BASE:
  91         .word   CONFIG_SYS_TEXT_BASE
  92
  93 /* IRQ stack memory (calculated at run-time) + 8 bytes */
  94 .globl IRQ_STACK_START_IN
  95 IRQ_STACK_START_IN:
  96         .word 0x0badc0de
  97
  98 /*
  99  * The bootstrap code of nds32 core
 100  */
 101
 102 reset:
 103
 104 /*
 105  *  gp = ~0            for burn mode
 106  *     = ~load_address for load mode
 107  */
 108 reset_gp:
 109         .relax_hint 0
 110         sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
 111         .relax_hint 0
 112         ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
 113         add5.pc $gp
 114
 115 set_ivb:
 116         li      $r0, 0x0
 117
 118         /* turn on BTB */
 119         mtsr    $r0, $misc_ctl
 120         /* set IVIC, vector size: 4 bytes, base: 0x0 */
 121         mtsr    $r0, $ivb
 122
 123 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 124         jal     lowlevel_init
 125 /*
 126  *  gp = ~VMA          for burn mode
 127  *     = ~load_address for load mode
 128  */
 129 update_gp:
 130         .relax_hint 0
 131         sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
 132         .relax_hint 0
 133         ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
 134         add5.pc $gp
 135 #endif
 136
 137 /*
 138  *  do critical initializations first (shall be in short time)
 139  *  do self_relocation ASAP.
 140  */
 141
 142 /*
 143  * Set the N1213 (Whitiger) core to superuser mode
 144  * According to spec, it is already when reset
 145  */
 146 #ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
 147         jal     turnoff_watchdog
 148 #endif
 149
 150 /*
 151  * Do CPU critical regs init only at reboot,
 152  * not when booting from ram
 153  */
 154 #ifdef CONFIG_INIT_CRITICAL
 155         jal     cpu_init_crit           ! Do CPU critical regs init
 156 #endif
 157
 158 /*
 159  * Set stackpointer in internal RAM to call board_init_f
 160  * $sp must be 8-byte alignment for ABI compliance.
 161  */
 162 call_board_init_f:
 163         li              $sp, CONFIG_SYS_INIT_SP_ADDR
 164         li              $r10, GD_SIZE   /* get GD size */
 165         sub             $sp, $sp, $r10  /* GD start addr */
 166         move    $r10, $sp
 167         li              $r0, 0x00000000
 168
 169 #ifdef __PIC__
 170 #ifdef __NDS32_N1213_43U1H__
 171 /* __NDS32_N1213_43U1H__ implies NDS32 V0 ISA */
 172         la      $r15, board_init_f      ! store function address into $r15
 173 #endif
 174 #endif
 175         j       board_init_f            ! jump to board_init_f() in lib/board.c
 176
 177 /*
 178  * void relocate_code (addr_sp, gd, addr_moni)
 179  *
 180  * This "function" does not return, instead it continues in RAM
 181  * after relocating the monitor code.
 182  *
 183  */
 184
 185 /*
 186  *  gp = ~RAM_SIZE - TEXT_SIZE for burn/load mode
 187  */
 188
 189 .globl  relocate_code
 190 relocate_code:
 191         move    $r4, $r0                /* save addr_sp */
 192         move    $r5, $r1                /* save addr of gd */
 193         move    $r6, $r2                /* save addr of destination */
 194
 195 /* Set up the stack */
 196 stack_setup:
 197         move    $sp, $r4
 198
 199         la      $r0, _start@GOTOFF
 200         beq     $r0, $r6, clear_bss     /* skip relocation */
 201
 202         la       $r1, _end@GOTOFF
 203         move $r2, $r6                   /* r2 <- scratch for copy_loop */
 204
 205 copy_loop:
 206         lwi.p   $r7, [$r0], #4
 207         swi.p   $r7, [$r2], #4
 208         blt     $r0, $r1, copy_loop
 209
 210 /*
 211  * fix relocations related issues
 212  */
 213 fix_relocations:
 214         l.w     $r0, _TEXT_BASE@GOTOFF  /* r0 <- Text base */
 215         sub     $r9, $r6, $r0                   /* r9 <- relocation offset */
 216
 217         la  $r7, __rel_dyn_start@GOTOFF
 218         add     $r7, $r7, $r9           /* r2 <- rel __got_start in RAM */
 219         la  $r8, __rel_dyn_end@GOTOFF
 220         add     $r8, $r8, $r9           /* r2 <- rel __got_start in RAM */
 221         li  $r3, #0x2a /* R_NDS32_RELATIVE */
 222 1:
 223         lmw.bim $r0, [$r7], $r2 /* r0,r1,r2 <- adr,type,addend */
 224         bne $r1, $r3, 2f
 225
 226         add $r0, $r0, $r9
 227         add $r2, $r2, $r9
 228         sw  $r2, [$r0]
 229 2:
 230         blt $r7, $r8, 1b
 231
 232 clear_bss:
 233         la      $r0, __bss_start@GOTOFF /* r0 <- rel __bss_start in FLASH */
 234         add     $r0, $r0, $r9           /* r0 <- rel __bss_start in FLASH */
 235         la      $r1, __bss_end@GOTOFF           /* r1 <- rel __bss_end in RAM */
 236         add     $r1, $r1, $r9           /* r0 <- rel __bss_end in RAM */
 237         li      $r2, 0x00000000         /* clear */
 238
 239 clbss_l:
 240         sw      $r2, [$r0]              /* clear loop... */
 241         addi    $r0, $r0, #4
 242         bne     $r0, $r1, clbss_l
 243
 244 /*
 245  * We are done. Do not return, instead branch to second part of board
 246  * initialization, now running from RAM.
 247  */
 248 call_board_init_r:
 249         la      $r0, board_init_r@GOTOFF
 250         move    $lp, $r0                /* offset of board_init_r() */
 251         add     $lp, $lp, $r9           /* real address of board_init_r() */
 252         /* setup parameters for board_init_r */
 253         move    $r0, $r5                /* gd_t */
 254         move    $r1, $r6                /* dest_addr */
 255
 256 #ifdef __PIC__
 257 #ifdef __NDS32_N1213_43U1H__            /* NDS32 V0 ISA */
 258         move    $r15, $lp               /* store function address into $r15 */
 259 #endif
 260 #endif
 261
 262         /* jump to it ... */
 263         jr      $lp                     /* jump to board_init_r() */
 264
 265 /*
 266  * Initialize CPU critical registers
 267  *
 268  *      1.      Setup control registers
 269  *              1.1 Mask all IRQs
 270  *              1.2 Flush cache and TLB
 271  *              1.3 Disable MMU and cache
 272  *      2.      Setup memory timing
 273  */
 274
 275 cpu_init_crit:
 276
 277         move    $r0, $lp                /* push ra */
 278
 279         /* Disable Interrupts by clear GIE in $PSW reg */
 280         setgie.d
 281
 282         /* Flush caches and TLB */
 283         /* Invalidate caches */
 284         jal     invalidate_icac
 285         jal     invalidate_dcac
 286
 287         /* Flush TLB */
 288         mfsr    $p0, $MMU_CFG
 289         andi    $p0, $p0, 0x3                   ! MMPS
 290         li      $p1, 0x2                        ! TLB MMU
 291         bne     $p0, $p1, 1f
 292         tlbop   flushall                        ! Flush TLB
 293
 294 1:
 295         ! Disable MMU, Dcache
 296         ! Whitiger is MMU disabled when reset
 297         ! Disable the D$
 298         mfsr    $p0, MR_CAC_CTL                 ! Get the $CACHE_CTL reg
 299         li      $p1, DIS_DCAC
 300         and     $p0, $p0, $p1                   ! Set DC_EN bit
 301         mtsr    $p0, MR_CAC_CTL                 ! write back the $CACHE_CTL reg
 302         isb
 303
 304         move    $lp, $r0
 305 2:
 306         ret
 307
 308 /*
 309  * Invalidate I$
 310  */
 311 invalidate_icac:
 312         ! read $cr1(I CAC/MEM cfg. reg.) configuration
 313         mfsr    $t0, CR_ICAC_MEM
 314
 315         ! Get the ISZ field
 316         andi    $p0, $t0, ICAC_MEM_KBF_ISZ
 317
 318         ! if $p0=0, then no I CAC existed
 319         beqz    $p0, end_flush_icache
 320
 321         ! get $p0 the index of I$ block
 322         srli    $p0, $p0, 6
 323
 324         ! $t1= bit width of I cache line size(ISZ)
 325         addi    $t1, $p0, 2
 326
 327         li      $t4, 1
 328         sll     $t5, $t4, $t1                   ! get $t5 cache line size
 329         andi    $p1, $t0, ICAC_MEM_KBF_ISET     ! get the ISET field
 330         addi    $t2, $p1, 6                     ! $t2= bit width of ISET
 331         andi    $p1, $t0, ICAC_MEM_KBF_IWAY     ! get bitfield of Iway
 332         srli    $p1, $p1, 3
 333         addi    $p1, $p1, 1                     ! then $p1 is I way number
 334         add     $t3, $t2, $t1                   ! SHIFT
 335         sll     $p1, $p1, $t3                   ! GET the total cache size
 336 ICAC_LOOP:
 337         sub     $p1, $p1, $t5
 338         cctl    $p1, L1I_IX_INVAL
 339         bnez    $p1, ICAC_LOOP
 340 end_flush_icache:
 341         ret
 342
 343 /*
 344  * Invalidate D$
 345  */
 346 invalidate_dcac:
 347         ! read $cr2(D CAC/MEM cfg. reg.) configuration
 348         mfsr    $t0, CR_DCAC_MEM
 349
 350         ! Get the DSZ field
 351         andi    $p0, $t0, DCAC_MEM_KBF_DSZ
 352
 353         ! if $p0=0, then no D CAC existed
 354         beqz    $p0, end_flush_dcache
 355
 356         ! get $p0 the index of D$ block
 357         srli    $p0, $p0, 6
 358
 359         ! $t1= bit width of D cache line size(DSZ)
 360         addi    $t1, $p0, 2
 361
 362         li      $t4, 1
 363         sll     $t5, $t4, $t1                   ! get $t5 cache line size
 364         andi    $p1, $t0, DCAC_MEM_KBF_DSET     ! get the DSET field
 365         addi    $t2, $p1, 6                     ! $t2= bit width of DSET
 366         andi    $p1, $t0, DCAC_MEM_KBF_DWAY     ! get bitfield of D way
 367         srli    $p1, $p1, 3
 368         addi    $p1, $p1, 1                     ! then $p1 is D way number
 369         add     $t3, $t2, $t1                   ! SHIFT
 370         sll     $p1, $p1, $t3                   ! GET the total cache size
 371 DCAC_LOOP:
 372         sub     $p1, $p1, $t5
 373         cctl    $p1, L1D_IX_INVAL
 374         bnez    $p1, DCAC_LOOP
 375 end_flush_dcache:
 376         ret
 377
 378 /*
 379  * Interrupt handling
 380  */
 381
 382 /*
 383  * exception handlers
 384  */
 385         .align  5
 386
 387 .macro  SAVE_ALL
 388         ! FIXME: Other way to get PC?
 389         ! FIXME: Update according to the newest spec!!
 390 1:
 391         li       $r28, 1
 392         push $r28
 393         mfsr $r28, PSW                  ! $PSW
 394         push $r28
 395         mfsr $r28, EIT_EVA              ! $ir1 $EVA
 396         push $r28
 397         mfsr $r28, EIT_ITYPE            ! $ir2 $ITYPE
 398         push $r28
 399         mfsr $r28, EIT_MACH_ERR         ! $ir3 Mach Error
 400         push $r28
 401         mfsr $r28, EIT_INTR_PSW         ! $ir5 $IPSW
 402         push $r28
 403         mfsr $r28, EIT_PREV_IPSW        ! $ir6 prev $IPSW
 404         push $r28
 405         mfsr $r28, EIT_PREV_EVA         ! $ir7 prev $EVA
 406         push $r28
 407         mfsr $r28, EIT_PREV_ITYPE       ! $ir8 prev $ITYPE
 408         push $r28
 409         mfsr $r28, EIT_INTR_PC          ! $ir9 Interruption PC
 410         push $r28
 411         mfsr $r28, EIT_PREV_IPC         ! $ir10 prev INTR_PC
 412         push $r28
 413         mfsr $r28, EIT_OVL_INTR_PC      ! $ir11 Overflowed INTR_PC
 414         push $r28
 415         mfusr $r28, $d1.lo
 416         push $r28
 417         mfusr $r28, $d1.hi
 418         push $r28
 419         mfusr $r28, $d0.lo
 420         push $r28
 421         mfusr $r28, $d0.hi
 422         push $r28
 423         pushm $r0, $r30         ! store $sp-$r31, ra-$r30, $gp-$r29, $r28-$fp
 424         addi    $sp, $sp, -4    ! make room for implicit pt_regs parameters
 425 .endm
 426
 427         .align  5
 428 tlb_fill:
 429         SAVE_ALL
 430         move    $r0, $sp                        ! To get the kernel stack
 431         li      $r1, 1                          ! Determine interruption type
 432         bal     do_interruption
 433
 434         .align  5
 435 tlb_not_present:
 436         SAVE_ALL
 437         move    $r0, $sp                        ! To get the kernel stack
 438         li      $r1, 2                          ! Determine interruption type
 439         bal     do_interruption
 440
 441         .align  5
 442 tlb_misc:
 443         SAVE_ALL
 444         move    $r0, $sp                        ! To get the kernel stack
 445         li      $r1, 3                          ! Determine interruption type
 446         bal     do_interruption
 447
 448         .align  5
 449 tlb_vlpt_miss:
 450         SAVE_ALL
 451         move    $r0, $sp                        ! To get the kernel stack
 452         li      $r1, 4                          ! Determine interruption type
 453         bal     do_interruption
 454
 455         .align  5
 456 machine_error:
 457         SAVE_ALL
 458         move    $r0, $sp                        ! To get the kernel stack
 459         li      $r1, 5                          ! Determine interruption type
 460         bal     do_interruption
 461
 462         .align  5
 463 debug:
 464         SAVE_ALL
 465         move    $r0, $sp                        ! To get the kernel stack
 466         li      $r1, 6                          ! Determine interruption type
 467         bal     do_interruption
 468
 469         .align  5
 470 general_exception:
 471         SAVE_ALL
 472         move    $r0, $sp                        ! To get the kernel stack
 473         li      $r1, 7                          ! Determine interruption type
 474         bal     do_interruption
 475
 476         .align  5
 477 syscall:
 478         SAVE_ALL
 479         move    $r0, $sp                        ! To get the kernel stack
 480         li      $r1, 8                          ! Determine interruption type
 481         bal     do_interruption
 482
 483         .align  5
 484 internal_interrupt:
 485         SAVE_ALL
 486         move    $r0, $sp                        ! To get the kernel stack
 487         li      $r1, 9                          ! Determine interruption type
 488         bal     do_interruption
 489
 490         .align  5
 491 software_interrupt:
 492         SAVE_ALL
 493         move    $r0, $sp                        ! To get the kernel stack
 494         li      $r1, 10                         ! Determine interruption type
 495         bal     do_interruption
 496
 497         .align  5
 498
 499 /*
 500  * void reset_cpu(ulong addr);
 501  * $r0: input address to jump to
 502  */
 503 .globl reset_cpu
 504 reset_cpu:
 505 /* No need to disable MMU because we never enable it */
 506
 507         bal     invalidate_icac
 508         bal     invalidate_dcac
 509         mfsr    $p0, $MMU_CFG
 510         andi    $p0, $p0, 0x3                   ! MMPS
 511         li      $p1, 0x2                        ! TLB MMU
 512         bne     $p0, $p1, 1f
 513         tlbop   flushall                        ! Flush TLB
 514 1:
 515         mfsr    $p0, MR_CAC_CTL                 ! Get the $CACHE_CTL reg
 516         li      $p1, DIS_DCAC
 517         and     $p0, $p0, $p1                   ! Clear the DC_EN bit
 518         mtsr    $p0, MR_CAC_CTL                 ! Write back the $CACHE_CTL reg
 519         br      $r0                             ! Jump to the input address