2 * Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
3 * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
4 * Copyright (C) 2000,2001,2002 Wolfgang Denk <wd@denx.de>
6 * See file CREDITS for list of people who contributed to this
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.
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.
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,
24 /*------------------------------------------------------------------------------+ */
26 /* This source code has been made available to you by IBM on an AS-IS */
27 /* basis. Anyone receiving this source is licensed under IBM */
28 /* copyrights to use it in any way he or she deems fit, including */
29 /* copying it, modifying it, compiling it, and redistributing it either */
30 /* with or without modifications. No license under IBM patents or */
31 /* patent applications is to be implied by the copyright license. */
33 /* Any user of this software should understand that IBM cannot provide */
34 /* technical support for this software and will not be responsible for */
35 /* any consequences resulting from the use of this software. */
37 /* Any person who transfers this source code or any derivative work */
38 /* must include the IBM copyright notice, this paragraph, and the */
39 /* preceding two paragraphs in the transferred software. */
41 /* COPYRIGHT I B M CORPORATION 1995 */
42 /* LICENSED MATERIAL - PROGRAM PROPERTY OF I B M */
43 /*------------------------------------------------------------------------------- */
45 /* U-Boot - Startup Code for AMCC 4xx PowerPC based Embedded Boards
48 * The processor starts at 0xfffffffc and the code is executed
50 * in memory, but as long we don't jump around before relocating.
51 * board_init lies at a quite high address and when the cpu has
52 * jumped there, everything is ok.
53 * This works because the cpu gives the FLASH (CS0) the whole
54 * address space at startup, and board_init lies as a echo of
55 * the flash somewhere up there in the memorymap.
57 * board_init will change CS0 to be positioned at the correct
58 * address and (s)dram will be positioned at address 0
65 #define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
67 #include <ppc_asm.tmpl>
70 #include <asm/cache.h>
73 #ifndef CONFIG_IDENT_STRING
74 #define CONFIG_IDENT_STRING ""
77 #ifdef CFG_INIT_DCACHE_CS
78 # if (CFG_INIT_DCACHE_CS == 0)
82 # if (CFG_INIT_DCACHE_CS == 1)
86 # if (CFG_INIT_DCACHE_CS == 2)
90 # if (CFG_INIT_DCACHE_CS == 3)
94 # if (CFG_INIT_DCACHE_CS == 4)
98 # if (CFG_INIT_DCACHE_CS == 5)
102 # if (CFG_INIT_DCACHE_CS == 6)
106 # if (CFG_INIT_DCACHE_CS == 7)
110 #endif /* CFG_INIT_DCACHE_CS */
112 /* We don't want the MMU yet.
115 #define MSR_KERNEL ( MSR_ME ) /* Machine Check */
118 .extern ext_bus_cntlr_init
122 * Set up GOT: Global Offset Table
124 * Use r14 to access the GOT
127 GOT_ENTRY(_GOT2_TABLE_)
128 GOT_ENTRY(_FIXUP_TABLE_)
131 GOT_ENTRY(_start_of_vectors)
132 GOT_ENTRY(_end_of_vectors)
133 GOT_ENTRY(transfer_to_handler)
135 GOT_ENTRY(__init_end)
137 GOT_ENTRY(__bss_start)
141 * 440 Startup -- on reset only the top 4k of the effective
142 * address space is mapped in by an entry in the instruction
143 * and data shadow TLB. The .bootpg section is located in the
144 * top 4k & does only what's necessary to map in the the rest
145 * of the boot rom. Once the boot rom is mapped in we can
146 * proceed with normal startup.
148 * NOTE: CS0 only covers the top 2MB of the effective address
152 #if defined(CONFIG_440)
153 .section .bootpg,"ax"
156 /**************************************************************************/
158 /*----------------------------------------------------------------+
159 | Core bug fix. Clear the esr
160 +-----------------------------------------------------------------*/
163 /*----------------------------------------------------------------*/
164 /* Clear and set up some registers. */
165 /*----------------------------------------------------------------*/
166 iccci r0,r0 /* NOTE: operands not used for 440 */
167 dccci r0,r0 /* NOTE: operands not used for 440 */
174 #if defined(CONFIG_440GX) || defined(CONFIG_440SP) || defined(CONFIG_440SPE) /* NOTE: 440GX adds machine check status regs */
180 /*----------------------------------------------------------------*/
181 /* Initialize debug */
182 /*----------------------------------------------------------------*/
195 mtspr dbsr,r1 /* Clear all valid bits */
197 /*----------------------------------------------------------------*/
199 /*----------------------------------------------------------------*/
200 /* Disable store gathering & broadcast, guarantee inst/data
201 * cache block touch, force load/store alignment
202 * (see errata 1.12: 440_33)
204 lis r1,0x0030 /* store gathering & broadcast disable */
205 ori r1,r1,0x6000 /* cache touch */
208 #if defined (CONFIG_440SPE)
209 /*----------------------------------------------------------------+
210 | Initialize Core Configuration Reg1.
211 | a. ICDPEI: Record even parity. Normal operation.
212 | b. ICTPEI: Record even parity. Normal operation.
213 | c. DCTPEI: Record even parity. Normal operation.
214 | d. DCDPEI: Record even parity. Normal operation.
215 | e. DCUPEI: Record even parity. Normal operation.
216 | f. DCMPEI: Record even parity. Normal operation.
217 | g. FCOM: Normal operation
218 | h. MMUPEI: Record even parity. Normal operation.
219 | i. FFF: Flush only as much data as necessary.
220 | j. TCS: Timebase increments from externally supplied clock
221 +-----------------------------------------------------------------*/
226 /*----------------------------------------------------------------+
227 | Reset the timebase.
228 | The previous write to CCR1 sets the timebase source.
229 +-----------------------------------------------------------------*/
235 /*----------------------------------------------------------------*/
236 /* Setup interrupt vectors */
237 /*----------------------------------------------------------------*/
238 mtspr ivpr,r0 /* Vectors start at 0x0000_0000 */
240 mtspr ivor0,r1 /* Critical input */
242 mtspr ivor1,r1 /* Machine check */
244 mtspr ivor2,r1 /* Data storage */
246 mtspr ivor3,r1 /* Instruction storage */
248 mtspr ivor4,r1 /* External interrupt */
250 mtspr ivor5,r1 /* Alignment */
252 mtspr ivor6,r1 /* Program check */
254 mtspr ivor7,r1 /* Floating point unavailable */
256 mtspr ivor8,r1 /* System call */
258 mtspr ivor10,r1 /* Decrementer (PIT for 440) */
260 mtspr ivor13,r1 /* Data TLB error */
262 mtspr ivor14,r1 /* Instr TLB error */
264 mtspr ivor15,r1 /* Debug */
266 /*----------------------------------------------------------------*/
267 /* Configure cache regions */
268 /*----------------------------------------------------------------*/
286 /*----------------------------------------------------------------*/
287 /* Cache victim limits */
288 /*----------------------------------------------------------------*/
289 /* floors 0, ceiling max to use the entire cache -- nothing locked
296 /*----------------------------------------------------------------+
297 |Initialize MMUCR[STID] = 0.
298 +-----------------------------------------------------------------*/
305 /*----------------------------------------------------------------*/
306 /* Clear all TLB entries -- TID = 0, TS = 0 */
307 /*----------------------------------------------------------------*/
309 li r1,0x003f /* 64 TLB entries */
311 rsttlb: tlbwe r0,r1,0x0000 /* Invalidate all entries (V=0)*/
317 /*----------------------------------------------------------------*/
318 /* TLB entry setup -- step thru tlbtab */
319 /*----------------------------------------------------------------*/
320 bl tlbtab /* Get tlbtab pointer */
322 li r1,0x003f /* 64 TLB entries max */
329 beq 2f /* 0 marks end */
332 tlbwe r0,r4,0 /* TLB Word 0 */
333 tlbwe r1,r4,1 /* TLB Word 1 */
334 tlbwe r2,r4,2 /* TLB Word 2 */
335 addi r4,r4,1 /* Next TLB */
338 /*----------------------------------------------------------------*/
339 /* Continue from 'normal' start */
340 /*----------------------------------------------------------------*/
345 mtspr srr1,r0 /* Keep things disabled for now */
349 #endif /* CONFIG_440 */
352 * r3 - 1st arg to board_init(): IMMP pointer
353 * r4 - 2nd arg to board_init(): boot flag
356 .long 0x27051956 /* U-Boot Magic Number */
357 .globl version_string
359 .ascii U_BOOT_VERSION
360 .ascii " (", __DATE__, " - ", __TIME__, ")"
361 .ascii CONFIG_IDENT_STRING, "\0"
364 * Maybe this should be moved somewhere else because the current
365 * location (0x100) is where the CriticalInput Execption should be.
367 . = EXC_OFF_SYS_RESET
371 /*****************************************************************************/
372 #if defined(CONFIG_440)
374 /*----------------------------------------------------------------*/
375 /* Clear and set up some registers. */
376 /*----------------------------------------------------------------*/
379 mtspr dec,r0 /* prevent dec exceptions */
380 mtspr tbl,r0 /* prevent fit & wdt exceptions */
382 mtspr tsr,r1 /* clear all timer exception status */
383 mtspr tcr,r0 /* disable all */
384 mtspr esr,r0 /* clear exception syndrome register */
385 mtxer r0 /* clear integer exception register */
386 #if !defined(CONFIG_440GX) && !defined(CONFIG_440SPE)
387 lis r1,0x0002 /* set CE bit (Critical Exceptions) */
388 ori r1,r1,0x1000 /* set ME bit (Machine Exceptions) */
389 mtmsr r1 /* change MSR */
390 #elif !defined(CONFIG_440EP) && !defined(CONFIG_440GR)
392 b __440gx_msr_continue
395 lis r1, 0x0002 /* set CE bit (Critical Exceptions) */
396 ori r1,r1,0x1000 /* set ME bit (Machine Exceptions) */
401 __440gx_msr_continue:
404 /*----------------------------------------------------------------*/
405 /* Debug setup -- some (not very good) ice's need an event*/
406 /* to establish control :-( Define CFG_INIT_DBCR to the dbsr */
407 /* value you need in this case 0x8cff 0000 should do the trick */
408 /*----------------------------------------------------------------*/
409 #if defined(CFG_INIT_DBCR)
412 mtspr dbsr,r1 /* Clear all status bits */
413 lis r0,CFG_INIT_DBCR@h
414 ori r0,r0,CFG_INIT_DBCR@l
419 /*----------------------------------------------------------------*/
420 /* Setup the internal SRAM */
421 /*----------------------------------------------------------------*/
423 #if defined(CONFIG_440EP) || defined(CONFIG_440GR)
424 /* Clear Dcache to use as RAM */
425 addis r3,r0,CFG_INIT_RAM_ADDR@h
426 ori r3,r3,CFG_INIT_RAM_ADDR@l
427 addis r4,r0,CFG_INIT_RAM_END@h
428 ori r4,r4,CFG_INIT_RAM_END@l
429 rlwinm. r5,r4,0,27,31
440 #if defined (CONFIG_440GX) || defined(CONFIG_440SP) || defined(CONFIG_440SPE)
441 mtdcr l2_cache_cfg,r0 /* Ensure L2 Cache is off */
443 mtdcr isram0_sb1cr,r0 /* Disable bank 1 */
448 and r1,r1,r2 /* Disable parity check */
451 andis. r1,r1,r2 /* Disable pwr mgmt */
454 lis r1,0x8000 /* BAS = 8000_0000 */
455 #if defined(CONFIG_440GX) || defined(CONFIG_440SP)
456 ori r1,r1,0x0980 /* first 64k */
457 mtdcr isram0_sb0cr,r1
459 ori r1,r1,0x0980 /* second 64k */
460 mtdcr isram0_sb1cr,r1
462 ori r1,r1, 0x0980 /* third 64k */
463 mtdcr isram0_sb2cr,r1
465 ori r1,r1, 0x0980 /* fourth 64k */
466 mtdcr isram0_sb3cr,r1
467 #elif defined(CONFIG_440SPE)
468 lis r1,0x0000 /* BAS = 0000_0000 */
469 ori r1,r1,0x0984 /* first 64k */
470 mtdcr isram0_sb0cr,r1
472 ori r1,r1,0x0984 /* second 64k */
473 mtdcr isram0_sb1cr,r1
475 ori r1,r1, 0x0984 /* third 64k */
476 mtdcr isram0_sb2cr,r1
478 ori r1,r1, 0x0984 /* fourth 64k */
479 mtdcr isram0_sb3cr,r1
481 ori r1,r1,0x0380 /* 8k rw */
482 mtdcr isram0_sb0cr,r1
486 /*----------------------------------------------------------------*/
487 /* Setup the stack in internal SRAM */
488 /*----------------------------------------------------------------*/
489 lis r1,CFG_INIT_RAM_ADDR@h
490 ori r1,r1,CFG_INIT_SP_OFFSET@l
493 stwu r0,-4(r1) /* Terminate call chain */
495 stwu r1,-8(r1) /* Save back chain and move SP */
496 lis r0,RESET_VECTOR@h /* Address of reset vector */
497 ori r0,r0, RESET_VECTOR@l
498 stwu r1,-8(r1) /* Save back chain and move SP */
499 stw r0,+12(r1) /* Save return addr (underflow vect) */
503 bl cpu_init_f /* run low-level CPU init code (from Flash) */
506 #endif /* CONFIG_440 */
508 /*****************************************************************************/
510 /*----------------------------------------------------------------------- */
511 /* Set up some machine state registers. */
512 /*----------------------------------------------------------------------- */
513 addi r0,r0,0x0000 /* initialize r0 to zero */
514 mtspr esr,r0 /* clear Exception Syndrome Reg */
515 mttcr r0 /* timer control register */
516 mtexier r0 /* disable all interrupts */
517 addi r4,r0,0x1000 /* set ME bit (Machine Exceptions) */
518 oris r4,r4,0x2 /* set CE bit (Critical Exceptions) */
519 mtmsr r4 /* change MSR */
520 addis r4,r0,0xFFFF /* set r4 to 0xFFFFFFFF (status in the */
521 ori r4,r4,0xFFFF /* dbsr is cleared by setting bits to 1) */
522 mtdbsr r4 /* clear/reset the dbsr */
523 mtexisr r4 /* clear all pending interrupts */
525 mtexier r4 /* enable critical exceptions */
526 addis r4,r0,0x0000 /* assume 403GCX - enable core clk */
527 ori r4,r4,0x4020 /* dbling (no harm done on GA and GC */
528 mtiocr r4 /* since bit not used) & DRC to latch */
529 /* data bus on rising edge of CAS */
530 /*----------------------------------------------------------------------- */
532 /*----------------------------------------------------------------------- */
534 /*----------------------------------------------------------------------- */
535 /* Invalidate i-cache and d-cache TAG arrays. */
536 /*----------------------------------------------------------------------- */
537 addi r3,0,1024 /* 1/4 of I-cache size, half of D-cache */
538 addi r4,0,1024 /* 1/4 of I-cache */
543 addic. r3,r3,-16 /* move back one cache line */
544 bne ..cloop /* loop back to do rest until r3 = 0 */
547 /* initialize IOP480 so it can read 1 MB code area for SRAM spaces */
548 /* this requires enabling MA[17..0], by default only MA[12..0] are enabled. */
551 /* first copy IOP480 register base address into r3 */
552 addis r3,0,0x5000 /* IOP480 register base address hi */
553 /* ori r3,r3,0x0000 / IOP480 register base address lo */
556 /* use r4 as the working variable */
557 /* turn on CS3 (LOCCTL.7) */
558 lwz r4,0x84(r3) /* LOCTL is at offset 0x84 */
559 andi. r4,r4,0xff7f /* make bit 7 = 0 -- CS3 mode */
560 stw r4,0x84(r3) /* LOCTL is at offset 0x84 */
563 #ifdef CONFIG_DASA_SIM
564 /* use r4 as the working variable */
565 /* turn on MA17 (LOCCTL.7) */
566 lwz r4,0x84(r3) /* LOCTL is at offset 0x84 */
567 ori r4,r4,0x80 /* make bit 7 = 1 -- MA17 mode */
568 stw r4,0x84(r3) /* LOCTL is at offset 0x84 */
571 /* turn on MA16..13 (LCS0BRD.12 = 0) */
572 lwz r4,0x100(r3) /* LCS0BRD is at offset 0x100 */
573 andi. r4,r4,0xefff /* make bit 12 = 0 */
574 stw r4,0x100(r3) /* LCS0BRD is at offset 0x100 */
576 /* make sure above stores all comlete before going on */
579 /* last thing, set local init status done bit (DEVINIT.31) */
580 lwz r4,0x80(r3) /* DEVINIT is at offset 0x80 */
581 oris r4,r4,0x8000 /* make bit 31 = 1 */
582 stw r4,0x80(r3) /* DEVINIT is at offset 0x80 */
584 /* clear all pending interrupts and disable all interrupts */
585 li r4,-1 /* set p1 to 0xffffffff */
586 stw r4,0x1b0(r3) /* clear all pending interrupts */
587 stw r4,0x1b8(r3) /* clear all pending interrupts */
588 li r4,0 /* set r4 to 0 */
589 stw r4,0x1b4(r3) /* disable all interrupts */
590 stw r4,0x1bc(r3) /* disable all interrupts */
592 /* make sure above stores all comlete before going on */
595 /*----------------------------------------------------------------------- */
596 /* Enable two 128MB cachable regions. */
597 /*----------------------------------------------------------------------- */
600 mticcr r1 /* instruction cache */
604 mtdccr r1 /* data cache */
606 addis r1,r0,CFG_INIT_RAM_ADDR@h
607 ori r1,r1,CFG_INIT_SP_OFFSET /* set up the stack to SDRAM */
608 li r0, 0 /* Make room for stack frame header and */
609 stwu r0, -4(r1) /* clear final stack frame so that */
610 stwu r0, -4(r1) /* stack backtraces terminate cleanly */
612 GET_GOT /* initialize GOT access */
614 bl board_init_f /* run first part of init code (from Flash) */
616 #endif /* CONFIG_IOP480 */
618 /*****************************************************************************/
619 #if defined(CONFIG_405GP) || defined(CONFIG_405CR) || defined(CONFIG_405) || defined(CONFIG_405EP)
620 /*----------------------------------------------------------------------- */
621 /* Clear and set up some registers. */
622 /*----------------------------------------------------------------------- */
626 mtesr r4 /* clear Exception Syndrome Reg */
627 mttcr r4 /* clear Timer Control Reg */
628 mtxer r4 /* clear Fixed-Point Exception Reg */
629 mtevpr r4 /* clear Exception Vector Prefix Reg */
630 addi r4,r0,0x1000 /* set ME bit (Machine Exceptions) */
631 oris r4,r4,0x0002 /* set CE bit (Critical Exceptions) */
632 mtmsr r4 /* change MSR */
633 addi r4,r0,(0xFFFF-0x10000) /* set r4 to 0xFFFFFFFF (status in the */
634 /* dbsr is cleared by setting bits to 1) */
635 mtdbsr r4 /* clear/reset the dbsr */
637 /*----------------------------------------------------------------------- */
638 /* Invalidate I and D caches. Enable I cache for defined memory regions */
639 /* to speed things up. Leave the D cache disabled for now. It will be */
640 /* enabled/left disabled later based on user selected menu options. */
641 /* Be aware that the I cache may be disabled later based on the menu */
642 /* options as well. See miscLib/main.c. */
643 /*----------------------------------------------------------------------- */
647 /*----------------------------------------------------------------------- */
648 /* Enable two 128MB cachable regions. */
649 /*----------------------------------------------------------------------- */
652 mticcr r4 /* instruction cache */
657 mtdccr r4 /* data cache */
659 #if !(defined(CFG_EBC_PB0AP) && defined(CFG_EBC_PB0CR))
660 /*----------------------------------------------------------------------- */
661 /* Tune the speed and size for flash CS0 */
662 /*----------------------------------------------------------------------- */
663 bl ext_bus_cntlr_init
666 #if defined(CONFIG_405EP)
667 /*----------------------------------------------------------------------- */
668 /* DMA Status, clear to come up clean */
669 /*----------------------------------------------------------------------- */
670 addis r3,r0, 0xFFFF /* Clear all existing DMA status */
674 bl ppc405ep_init /* do ppc405ep specific init */
675 #endif /* CONFIG_405EP */
677 #if defined(CFG_OCM_DATA_ADDR) && defined(CFG_OCM_DATA_SIZE)
678 /********************************************************************
679 * Setup OCM - On Chip Memory
680 *******************************************************************/
684 mfdcr r3, ocmiscntl /* get instr-side IRAM config */
685 mfdcr r4, ocmdscntl /* get data-side IRAM config */
686 and r3, r3, r0 /* disable data-side IRAM */
687 and r4, r4, r0 /* disable data-side IRAM */
688 mtdcr ocmiscntl, r3 /* set instr-side IRAM config */
689 mtdcr ocmdscntl, r4 /* set data-side IRAM config */
692 addis r3, 0, CFG_OCM_DATA_ADDR@h /* OCM location */
694 addis r4, 0, 0xC000 /* OCM data area enabled */
699 /*----------------------------------------------------------------------- */
700 /* Setup temporary stack in DCACHE or OCM if needed for SDRAM SPD. */
701 /*----------------------------------------------------------------------- */
702 #ifdef CFG_INIT_DCACHE_CS
703 /*----------------------------------------------------------------------- */
704 /* Memory Bank x (nothingness) initialization 1GB+64MEG */
705 /* used as temporary stack pointer for stage0 */
706 /*----------------------------------------------------------------------- */
719 /* turn on data chache for this region */
723 /* set stack pointer and clear stack to known value */
725 lis r1,CFG_INIT_RAM_ADDR@h
726 ori r1,r1,CFG_INIT_SP_OFFSET@l
728 li r4,2048 /* we store 2048 words to stack */
731 lis r2,CFG_INIT_RAM_ADDR@h /* we also clear data area */
732 ori r2,r2,CFG_INIT_RAM_END@l /* so cant copy value from r1 */
734 lis r4,0xdead /* we store 0xdeaddead in the stack */
741 li r0, 0 /* Make room for stack frame header and */
742 stwu r0, -4(r1) /* clear final stack frame so that */
743 stwu r0, -4(r1) /* stack backtraces terminate cleanly */
745 * Set up a dummy frame to store reset vector as return address.
746 * this causes stack underflow to reset board.
748 stwu r1, -8(r1) /* Save back chain and move SP */
749 addis r0, 0, RESET_VECTOR@h /* Address of reset vector */
750 ori r0, r0, RESET_VECTOR@l
751 stwu r1, -8(r1) /* Save back chain and move SP */
752 stw r0, +12(r1) /* Save return addr (underflow vect) */
754 #elif defined(CFG_TEMP_STACK_OCM) && \
755 (defined(CFG_OCM_DATA_ADDR) && defined(CFG_OCM_DATA_SIZE))
760 /* Set up Stack at top of OCM */
761 lis r1, (CFG_INIT_RAM_ADDR + CFG_INIT_SP_OFFSET)@h
762 ori r1, r1, (CFG_INIT_RAM_ADDR + CFG_INIT_SP_OFFSET)@l
764 /* Set up a zeroized stack frame so that backtrace works right */
770 * Set up a dummy frame to store reset vector as return address.
771 * this causes stack underflow to reset board.
773 stwu r1, -8(r1) /* Save back chain and move SP */
774 lis r0, RESET_VECTOR@h /* Address of reset vector */
775 ori r0, r0, RESET_VECTOR@l
776 stwu r1, -8(r1) /* Save back chain and move SP */
777 stw r0, +12(r1) /* Save return addr (underflow vect) */
778 #endif /* CFG_INIT_DCACHE_CS */
780 /*----------------------------------------------------------------------- */
781 /* Initialize SDRAM Controller */
782 /*----------------------------------------------------------------------- */
786 * Setup temporary stack pointer only for boards
787 * that do not use SDRAM SPD I2C stuff since it
788 * is already initialized to use DCACHE or OCM
791 #if !(defined(CFG_INIT_DCACHE_CS) || defined(CFG_TEMP_STACK_OCM))
792 lis r1, CFG_INIT_RAM_ADDR@h
793 ori r1,r1,CFG_INIT_SP_OFFSET /* set up the stack in SDRAM */
795 li r0, 0 /* Make room for stack frame header and */
796 stwu r0, -4(r1) /* clear final stack frame so that */
797 stwu r0, -4(r1) /* stack backtraces terminate cleanly */
799 * Set up a dummy frame to store reset vector as return address.
800 * this causes stack underflow to reset board.
802 stwu r1, -8(r1) /* Save back chain and move SP */
803 lis r0, RESET_VECTOR@h /* Address of reset vector */
804 ori r0, r0, RESET_VECTOR@l
805 stwu r1, -8(r1) /* Save back chain and move SP */
806 stw r0, +12(r1) /* Save return addr (underflow vect) */
807 #endif /* !(CFG_INIT_DCACHE_CS || !CFG_TEM_STACK_OCM) */
809 GET_GOT /* initialize GOT access */
811 bl cpu_init_f /* run low-level CPU init code (from Flash) */
814 bl board_init_f /* run first part of init code (from Flash) */
816 #endif /* CONFIG_405GP || CONFIG_405CR || CONFIG_405 || CONFIG_405EP */
817 /*----------------------------------------------------------------------- */
820 /*****************************************************************************/
821 .globl _start_of_vectors
825 /*TODO Fixup _start above so we can do this*/
826 /* Critical input. */
827 CRIT_EXCEPTION(0x100, CritcalInput, CritcalInputException)
831 CRIT_EXCEPTION(0x200, MachineCheck, MachineCheckException)
833 /* Data Storage exception. */
834 STD_EXCEPTION(0x300, DataStorage, UnknownException)
836 /* Instruction Storage exception. */
837 STD_EXCEPTION(0x400, InstStorage, UnknownException)
839 /* External Interrupt exception. */
840 STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt)
842 /* Alignment exception. */
850 addi r3,r1,STACK_FRAME_OVERHEAD
852 rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
853 lwz r6,GOT(transfer_to_handler)
857 .long AlignmentException - _start + EXC_OFF_SYS_RESET
858 .long int_return - _start + EXC_OFF_SYS_RESET
860 /* Program check exception */
864 addi r3,r1,STACK_FRAME_OVERHEAD
866 rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
867 lwz r6,GOT(transfer_to_handler)
871 .long ProgramCheckException - _start + EXC_OFF_SYS_RESET
872 .long int_return - _start + EXC_OFF_SYS_RESET
874 /* No FPU on MPC8xx. This exception is not supposed to happen.
876 STD_EXCEPTION(0x800, FPUnavailable, UnknownException)
878 /* I guess we could implement decrementer, and may have
879 * to someday for timekeeping.
881 STD_EXCEPTION(0x900, Decrementer, timer_interrupt)
882 STD_EXCEPTION(0xa00, Trap_0a, UnknownException)
883 STD_EXCEPTION(0xb00, Trap_0b, UnknownException)
884 STD_EXCEPTION(0xc00, SystemCall, UnknownException)
885 STD_EXCEPTION(0xd00, SingleStep, UnknownException)
887 STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
888 STD_EXCEPTION(0xf00, Trap_0f, UnknownException)
890 /* On the MPC8xx, this is a software emulation interrupt. It occurs
891 * for all unimplemented and illegal instructions.
893 STD_EXCEPTION(0x1000, PIT, PITException)
895 STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException)
896 STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException)
897 STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException)
898 STD_EXCEPTION(0x1400, DataTLBError, UnknownException)
900 STD_EXCEPTION(0x1500, Reserved5, UnknownException)
901 STD_EXCEPTION(0x1600, Reserved6, UnknownException)
902 STD_EXCEPTION(0x1700, Reserved7, UnknownException)
903 STD_EXCEPTION(0x1800, Reserved8, UnknownException)
904 STD_EXCEPTION(0x1900, Reserved9, UnknownException)
905 STD_EXCEPTION(0x1a00, ReservedA, UnknownException)
906 STD_EXCEPTION(0x1b00, ReservedB, UnknownException)
908 STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException)
909 STD_EXCEPTION(0x1d00, InstructionBreakpoint, UnknownException)
910 STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException)
911 STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException)
913 CRIT_EXCEPTION(0x2000, DebugBreakpoint, DebugException )
915 .globl _end_of_vectors
922 * This code finishes saving the registers to the exception frame
923 * and jumps to the appropriate handler for the exception.
924 * Register r21 is pointer into trap frame, r1 has new stack pointer.
926 .globl transfer_to_handler
938 mfspr r23,SPRG3 /* if from user, fix up tss.regs */
940 addi r24,r1,STACK_FRAME_OVERHEAD
942 2: addi r2,r23,-TSS /* set r2 to current */
946 andi. r24,r23,0x3f00 /* get vector offset */
950 mtspr SPRG2,r22 /* r1 is now kernel sp */
952 addi r24,r2,TASK_STRUCT_SIZE /* check for kernel stack overflow */
956 bgt stack_ovf /* if r2 < r1 < r2+TASK_STRUCT_SIZE */
958 lwz r24,0(r23) /* virtual address of handler */
959 lwz r23,4(r23) /* where to go when done */
964 rfi /* jump to handler, enable MMU */
967 mfmsr r28 /* Disable interrupts */
971 SYNC /* Some chip revs need this... */
986 lwz r2,_NIP(r1) /* Restore environment */
997 mfmsr r28 /* Disable interrupts */
1001 SYNC /* Some chip revs need this... */
1016 lwz r2,_NIP(r1) /* Restore environment */
1018 mtspr 990,r2 /* SRR2 */
1019 mtspr 991,r0 /* SRR3 */
1029 iccci r0,r0 /* for 405, iccci invalidates the */
1030 blr /* entire I cache */
1033 addi r6,0,0x0000 /* clear GPR 6 */
1034 /* Do loop for # of dcache congruence classes. */
1035 lis r7, (CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2)@ha /* TBS for large sized cache */
1036 ori r7, r7, (CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2)@l
1037 /* NOTE: dccci invalidates both */
1038 mtctr r7 /* ways in the D cache */
1040 dccci 0,r6 /* invalidate line */
1041 addi r6,r6, CFG_CACHELINE_SIZE /* bump to next line */
1046 addis r9,r0,0x0002 /* set mask for EE and CE msr bits */
1048 mfmsr r12 /* save msr */
1050 mtmsr r9 /* disable EE and CE */
1051 addi r10,r0,0x0001 /* enable data cache for unused memory */
1052 mfdccr r9 /* region 0xF8000000-0xFFFFFFFF via */
1053 or r10,r10,r9 /* bit 31 in dccr */
1056 /* do loop for # of congruence classes. */
1057 lis r10,(CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2)@ha /* TBS: for large cache sizes */
1058 ori r10,r10,(CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2)@l
1059 lis r11,(CFG_DCACHE_SIZE / 2)@ha /* D cache set size - 2 way sets */
1060 ori r11,r11,(CFG_DCACHE_SIZE / 2)@l /* D cache set size - 2 way sets */
1062 addi r10,r0,(0xE000-0x10000) /* start at 0xFFFFE000 */
1063 add r11,r10,r11 /* add to get to other side of cache line */
1064 ..flush_dcache_loop:
1065 lwz r3,0(r10) /* least recently used side */
1066 lwz r3,0(r11) /* the other side */
1067 dccci r0,r11 /* invalidate both sides */
1068 addi r10,r10,CFG_CACHELINE_SIZE /* bump to next line */
1069 addi r11,r11,CFG_CACHELINE_SIZE /* bump to next line */
1070 bdnz ..flush_dcache_loop
1071 sync /* allow memory access to complete */
1072 mtdccr r9 /* restore dccr */
1073 mtmsr r12 /* restore msr */
1076 .globl icache_enable
1079 bl invalidate_icache
1082 addis r3,r0, 0x8000 /* set bit 0 */
1086 .globl icache_disable
1088 addis r3,r0, 0x0000 /* clear bit 0 */
1093 .globl icache_status
1096 srwi r3, r3, 31 /* >>31 => select bit 0 */
1099 .globl dcache_enable
1102 bl invalidate_dcache
1105 addis r3,r0, 0x8000 /* set bit 0 */
1109 .globl dcache_disable
1114 addis r3,r0, 0x0000 /* clear bit 0 */
1118 .globl dcache_status
1121 srwi r3, r3, 31 /* >>31 => select bit 0 */
1129 #if !defined(CONFIG_440)
1141 /*------------------------------------------------------------------------------- */
1143 /* Description: Input 8 bits */
1144 /*------------------------------------------------------------------------------- */
1150 /*------------------------------------------------------------------------------- */
1151 /* Function: out8 */
1152 /* Description: Output 8 bits */
1153 /*------------------------------------------------------------------------------- */
1159 /*------------------------------------------------------------------------------- */
1160 /* Function: out16 */
1161 /* Description: Output 16 bits */
1162 /*------------------------------------------------------------------------------- */
1168 /*------------------------------------------------------------------------------- */
1169 /* Function: out16r */
1170 /* Description: Byte reverse and output 16 bits */
1171 /*------------------------------------------------------------------------------- */
1177 /*------------------------------------------------------------------------------- */
1178 /* Function: out32 */
1179 /* Description: Output 32 bits */
1180 /*------------------------------------------------------------------------------- */
1186 /*------------------------------------------------------------------------------- */
1187 /* Function: out32r */
1188 /* Description: Byte reverse and output 32 bits */
1189 /*------------------------------------------------------------------------------- */
1195 /*------------------------------------------------------------------------------- */
1196 /* Function: in16 */
1197 /* Description: Input 16 bits */
1198 /*------------------------------------------------------------------------------- */
1204 /*------------------------------------------------------------------------------- */
1205 /* Function: in16r */
1206 /* Description: Input 16 bits and byte reverse */
1207 /*------------------------------------------------------------------------------- */
1213 /*------------------------------------------------------------------------------- */
1214 /* Function: in32 */
1215 /* Description: Input 32 bits */
1216 /*------------------------------------------------------------------------------- */
1222 /*------------------------------------------------------------------------------- */
1223 /* Function: in32r */
1224 /* Description: Input 32 bits and byte reverse */
1225 /*------------------------------------------------------------------------------- */
1231 /*------------------------------------------------------------------------------- */
1232 /* Function: ppcDcbf */
1233 /* Description: Data Cache block flush */
1234 /* Input: r3 = effective address */
1236 /*------------------------------------------------------------------------------- */
1242 /*------------------------------------------------------------------------------- */
1243 /* Function: ppcDcbi */
1244 /* Description: Data Cache block Invalidate */
1245 /* Input: r3 = effective address */
1247 /*------------------------------------------------------------------------------- */
1253 /*------------------------------------------------------------------------------- */
1254 /* Function: ppcSync */
1255 /* Description: Processor Synchronize */
1258 /*------------------------------------------------------------------------------- */
1264 /*------------------------------------------------------------------------------*/
1267 * void relocate_code (addr_sp, gd, addr_moni)
1269 * This "function" does not return, instead it continues in RAM
1270 * after relocating the monitor code.
1274 * r5 = length in bytes
1275 * r6 = cachelinesize
1277 .globl relocate_code
1279 #if defined(CONFIG_440EP) || defined(CONFIG_440GR) || defined(CONFIG_440SPE)
1280 dccci 0,0 /* Invalidate data cache, now no longer our stack */
1282 addi r1,r0,0x0000 /* TLB entry #0 */
1283 tlbre r0,r1,0x0002 /* Read contents */
1284 ori r0,r0,0x0c00 /* Or in the inhibit, write through bit */
1285 tlbwe r0,r1,0x0002 /* Save it out */
1288 mr r1, r3 /* Set new stack pointer */
1289 mr r9, r4 /* Save copy of Init Data pointer */
1290 mr r10, r5 /* Save copy of Destination Address */
1292 mr r3, r5 /* Destination Address */
1293 lis r4, CFG_MONITOR_BASE@h /* Source Address */
1294 ori r4, r4, CFG_MONITOR_BASE@l
1295 lwz r5, GOT(__init_end)
1297 li r6, CFG_CACHELINE_SIZE /* Cache Line Size */
1302 * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address
1308 /* First our own GOT */
1310 /* the the one used by the C code */
1320 beq cr1,4f /* In place copy is not necessary */
1321 beq 7f /* Protect against 0 count */
1340 * Now flush the cache: note that we must start from a cache aligned
1341 * address. Otherwise we might miss one cache line.
1345 beq 7f /* Always flush prefetch queue in any case */
1353 sync /* Wait for all dcbst to complete on bus */
1359 7: sync /* Wait for all icbi to complete on bus */
1363 * We are done. Do not return, instead branch to second part of board
1364 * initialization, now running from RAM.
1367 addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET
1369 blr /* NEVER RETURNS! */
1374 * Relocation Function, r14 point to got2+0x8000
1376 * Adjust got2 pointers, no need to check for 0, this code
1377 * already puts a few entries in the table.
1379 li r0,__got2_entries@sectoff@l
1380 la r3,GOT(_GOT2_TABLE_)
1381 lwz r11,GOT(_GOT2_TABLE_)
1391 * Now adjust the fixups and the pointers to the fixups
1392 * in case we need to move ourselves again.
1394 2: li r0,__fixup_entries@sectoff@l
1395 lwz r3,GOT(_FIXUP_TABLE_)
1409 * Now clear BSS segment
1411 lwz r3,GOT(__bss_start)
1425 mr r3, r9 /* Init Data pointer */
1426 mr r4, r10 /* Destination Address */
1430 * Copy exception vector code to low memory
1433 * r7: source address, r8: end address, r9: target address
1438 lwz r8, GOT(_end_of_vectors)
1440 li r9, 0x100 /* reset vector always at 0x100 */
1443 bgelr /* return if r7>=r8 - just in case */
1445 mflr r4 /* save link register */
1455 * relocate `hdlr' and `int_return' entries
1457 li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET
1458 li r8, Alignment - _start + EXC_OFF_SYS_RESET
1461 addi r7, r7, 0x100 /* next exception vector */
1465 li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET
1468 li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET
1471 li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET
1472 li r8, SystemCall - _start + EXC_OFF_SYS_RESET
1475 addi r7, r7, 0x100 /* next exception vector */
1479 li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET
1480 li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET
1483 addi r7, r7, 0x100 /* next exception vector */
1487 mtlr r4 /* restore link register */
1491 * Function: relocate entries for one exception vector
1494 lwz r0, 0(r7) /* hdlr ... */
1495 add r0, r0, r3 /* ... += dest_addr */
1498 lwz r0, 4(r7) /* int_return ... */
1499 add r0, r0, r3 /* ... += dest_addr */
1505 /**************************************************************************/
1506 /* PPC405EP specific stuff */
1507 /**************************************************************************/
1511 #ifdef CONFIG_BUBINGA
1513 * Initialize EBC chip selects 1 & 4 and GPIO pins (for alternate
1514 * function) to support FPGA and NVRAM accesses below.
1517 lis r3,GPIO0_OSRH@h /* config GPIO output select */
1518 ori r3,r3,GPIO0_OSRH@l
1519 lis r4,CFG_GPIO0_OSRH@h
1520 ori r4,r4,CFG_GPIO0_OSRH@l
1523 ori r3,r3,GPIO0_OSRL@l
1524 lis r4,CFG_GPIO0_OSRL@h
1525 ori r4,r4,CFG_GPIO0_OSRL@l
1528 lis r3,GPIO0_ISR1H@h /* config GPIO input select */
1529 ori r3,r3,GPIO0_ISR1H@l
1530 lis r4,CFG_GPIO0_ISR1H@h
1531 ori r4,r4,CFG_GPIO0_ISR1H@l
1533 lis r3,GPIO0_ISR1L@h
1534 ori r3,r3,GPIO0_ISR1L@l
1535 lis r4,CFG_GPIO0_ISR1L@h
1536 ori r4,r4,CFG_GPIO0_ISR1L@l
1539 lis r3,GPIO0_TSRH@h /* config GPIO three-state select */
1540 ori r3,r3,GPIO0_TSRH@l
1541 lis r4,CFG_GPIO0_TSRH@h
1542 ori r4,r4,CFG_GPIO0_TSRH@l
1545 ori r3,r3,GPIO0_TSRL@l
1546 lis r4,CFG_GPIO0_TSRL@h
1547 ori r4,r4,CFG_GPIO0_TSRL@l
1550 lis r3,GPIO0_TCR@h /* config GPIO driver output enables */
1551 ori r3,r3,GPIO0_TCR@l
1552 lis r4,CFG_GPIO0_TCR@h
1553 ori r4,r4,CFG_GPIO0_TCR@l
1556 li r3,pb1ap /* program EBC bank 1 for RTC access */
1558 lis r3,CFG_EBC_PB1AP@h
1559 ori r3,r3,CFG_EBC_PB1AP@l
1563 lis r3,CFG_EBC_PB1CR@h
1564 ori r3,r3,CFG_EBC_PB1CR@l
1567 li r3,pb1ap /* program EBC bank 1 for RTC access */
1569 lis r3,CFG_EBC_PB1AP@h
1570 ori r3,r3,CFG_EBC_PB1AP@l
1574 lis r3,CFG_EBC_PB1CR@h
1575 ori r3,r3,CFG_EBC_PB1CR@l
1578 li r3,pb4ap /* program EBC bank 4 for FPGA access */
1580 lis r3,CFG_EBC_PB4AP@h
1581 ori r3,r3,CFG_EBC_PB4AP@l
1585 lis r3,CFG_EBC_PB4CR@h
1586 ori r3,r3,CFG_EBC_PB4CR@l
1590 addi r3,0,CPC0_PCI_HOST_CFG_EN
1591 #ifdef CONFIG_BUBINGA
1593 !-----------------------------------------------------------------------
1594 ! Check FPGA for PCI internal/external arbitration
1595 ! If board is set to internal arbitration, update cpc0_pci
1596 !-----------------------------------------------------------------------
1598 addis r5,r0,FPGA_REG1@h /* set offset for FPGA_REG1 */
1599 ori r5,r5,FPGA_REG1@l
1600 lbz r5,0x0(r5) /* read to get PCI arb selection */
1601 andi. r6,r5,FPGA_REG1_PCI_INT_ARB /* using internal arbiter ?*/
1602 beq ..pci_cfg_set /* if not set, then bypass reg write*/
1604 ori r3,r3,CPC0_PCI_ARBIT_EN
1606 mtdcr CPC0_PCI, r3 /* Enable internal arbiter*/
1609 !-----------------------------------------------------------------------
1610 ! Check to see if chip is in bypass mode.
1611 ! If so, write stored CPC0_PLLMR0 and CPC0_PLLMR1 values and perform a
1612 ! CPU reset Otherwise, skip this step and keep going.
1613 ! Note: Running BIOS in bypass mode is not supported since PLB speed
1614 ! will not be fast enough for the SDRAM (min 66MHz)
1615 !-----------------------------------------------------------------------
1617 mfdcr r5, CPC0_PLLMR1
1618 rlwinm r4,r5,1,0x1 /* get system clock source (SSCS) */
1621 beq pll_done /* if SSCS =b'1' then PLL has */
1622 /* already been set */
1623 /* and CPU has been reset */
1624 /* so skip to next section */
1626 #ifdef CONFIG_BUBINGA
1628 !-----------------------------------------------------------------------
1629 ! Read NVRAM to get value to write in PLLMR.
1630 ! If value has not been correctly saved, write default value
1631 ! Default config values (assuming on-board 33MHz SYS_CLK) are above.
1632 ! See CPU_DEFAULT_200 and CPU_DEFAULT_266 above.
1634 ! WARNING: This code assumes the first three words in the nvram_t
1635 ! structure in openbios.h. Changing the beginning of
1636 ! the structure will break this code.
1638 !-----------------------------------------------------------------------
1640 addis r3,0,NVRAM_BASE@h
1641 addi r3,r3,NVRAM_BASE@l
1644 addis r5,0,NVRVFY1@h
1645 addi r5,r5,NVRVFY1@l
1646 cmp cr0,0,r4,r5 /* Compare 1st NVRAM Magic number*/
1650 addis r5,0,NVRVFY2@h
1651 addi r5,r5,NVRVFY2@l
1652 cmp cr0,0,r4,r5 /* Compare 2 NVRAM Magic number */
1654 addi r3,r3,8 /* Skip over conf_size */
1655 lwz r4, 4(r3) /* Load PLLMR1 value from NVRAM */
1656 lwz r3, 0(r3) /* Load PLLMR0 value from NVRAM */
1657 rlwinm r5,r4,1,0x1 /* get system clock source (SSCS) */
1658 cmpi cr0,0,r5,1 /* See if PLL is locked */
1661 #endif /* CONFIG_BUBINGA */
1663 addis r3,0,PLLMR0_DEFAULT@h /* PLLMR0 default value */
1664 ori r3,r3,PLLMR0_DEFAULT@l /* */
1665 addis r4,0,PLLMR1_DEFAULT@h /* PLLMR1 default value */
1666 ori r4,r4,PLLMR1_DEFAULT@l /* */
1668 b pll_write /* Write the CPC0_PLLMR with new value */
1672 !-----------------------------------------------------------------------
1673 ! Clear Soft Reset Register
1674 ! This is needed to enable PCI if not booting from serial EPROM
1675 !-----------------------------------------------------------------------
1685 blr /* return to main code */
1688 !-----------------------------------------------------------------------------
1689 ! Function: pll_write
1690 ! Description: Updates the value of the CPC0_PLLMR according to CMOS27E documentation
1692 ! 1. Pll is first disabled (de-activated by putting in bypass mode)
1694 ! 3. Clock dividers are set while PLL is held in reset and bypassed
1695 ! 4. PLL Reset is cleared
1696 ! 5. Wait 100us for PLL to lock
1697 ! 6. A core reset is performed
1698 ! Input: r3 = Value to write to CPC0_PLLMR0
1699 ! Input: r4 = Value to write to CPC0_PLLMR1
1701 !-----------------------------------------------------------------------------
1706 ori r5,r5,0x0101 /* Stop the UART clocks */
1707 mtdcr CPC0_UCR,r5 /* Before changing PLL */
1709 mfdcr r5, CPC0_PLLMR1
1710 rlwinm r5,r5,0,0x7FFFFFFF /* Disable PLL */
1711 mtdcr CPC0_PLLMR1,r5
1712 oris r5,r5,0x4000 /* Set PLL Reset */
1713 mtdcr CPC0_PLLMR1,r5
1715 mtdcr CPC0_PLLMR0,r3 /* Set clock dividers */
1716 rlwinm r5,r4,0,0x3FFFFFFF /* Reset & Bypass new PLL dividers */
1717 oris r5,r5,0x4000 /* Set PLL Reset */
1718 mtdcr CPC0_PLLMR1,r5 /* Set clock dividers */
1719 rlwinm r5,r5,0,0xBFFFFFFF /* Clear PLL Reset */
1720 mtdcr CPC0_PLLMR1,r5
1723 ! Wait min of 100us for PLL to lock.
1724 ! See CMOS 27E databook for more info.
1725 ! At 200MHz, that means waiting 20,000 instructions
1727 addi r3,0,20000 /* 2000 = 0x4e20 */
1732 oris r5,r5,0x8000 /* Enable PLL */
1733 mtdcr CPC0_PLLMR1,r5 /* Engage */
1736 * Reset CPU to guarantee timings are OK
1737 * Not sure if this is needed...
1740 mtspr dbcr0,r3 /* This will cause a CPU core reset, and */
1741 /* execution will continue from the poweron */
1742 /* vector of 0xfffffffc */
1743 #endif /* CONFIG_405EP */