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      1 /*	$NetBSD: virtex_start.S,v 1.9 2018/07/15 05:16:42 maxv Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2006 Jachym Holecek
      5  * All rights reserved.
      6  *
      7  * Written for DFC Design, s.r.o.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  *
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  *
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * This file is based on startup code of Walnut and Explora boards.
     34  */
     35 
     36 #include "opt_ddb.h"
     37 #include "opt_lockdebug.h"
     38 #include "opt_modular.h"
     39 #include "opt_multiprocessor.h"
     40 #include "opt_ppcarch.h"
     41 #include "opt_ppcparam.h"
     42 #include "opt_virtex.h"
     43 #include "assym.h"
     44 #include "ksyms.h"
     45 
     46 #include <sys/syscall.h>
     47 
     48 #include <machine/param.h>
     49 #include <machine/psl.h>
     50 #include <machine/trap.h>
     51 #include <machine/asm.h>
     52 
     53 #include <powerpc/spr.h>
     54 #include <powerpc/ibm4xx/spr.h>
     55 #include <powerpc/ibm4xx/dcr4xx.h>
     56 
     57 
     58 /* N megabytes. */
     59 #define MB(n) 				((n)*1024*1024)
     60 
     61 /* Set bit (beginning with MSB) for each 128MB of RAM. */
     62 #define PHYSMEM_REGIONS_MASK 		~((1 << (32 - MB(PHYSMEM)/MB(128))) - 1)
     63 
     64 /* For kvm_mkdb, supposed to mark the start of kernel text. */
     65 	.text
     66 	.globl	_C_LABEL(kernel_text)
     67 _C_LABEL(kernel_text):
     68 
     69 /* Startup entry. This must be the first thing in the text segment! */
     70 	.text
     71 	.globl	__start
     72 __start:
     73 	/* Disable MMU/exceptions */
     74 	lis	%r0, 0
     75 	mtmsr	%r0
     76 
     77 	/* Disable timers */
     78 	lis 	%r0, 0
     79 	mttcr 	%r0
     80 
     81 	sync
     82 	isync
     83 
     84 	/* Disable caches */
     85 	mtdccr 	%r0
     86 	mticcr	%r0
     87 	sync
     88 	isync
     89 
     90 	/* Invalidate I$, operands ignored on the 405 */
     91 	li 	%r0,0 			/* just in case... */
     92 	iccci 	%r0,%r0
     93 
     94 	/* Invalidate D$, hardcoded for 16KB size, 32B line */
     95 	li      %r7,256 		/* # of congruence classes */
     96 	mtctr   %r7
     97 	li      %r6,0
     98 1:
     99 	dccci   %r0,%r6 		/* invalidates both ways */
    100 	addi    %r6,%r6,32
    101 	bdnz    1b
    102 
    103         /*
    104          * Errata 213: 	Incorrect data may be flushed from the data cache.
    105          * Cores: 	PPC405D5X1, PPC405D5X2
    106          * Workaround: 	#1, CCR0 modification sequence #2
    107          * Note: 	Meaning of bits we need to set is undocumented.
    108          */
    109 	sync
    110         mfccr0  %r0
    111         oris    %r0,%r0,0x50000000@h
    112         mtccr0  %r0
    113 	isync
    114 
    115 	/*
    116 	 * Errata  58: 	Load string instructions may write incorrect
    117 	 * 		data into the last GPR targeted in operation.
    118 	 * Cores: 	PPC405GP
    119 	 * Workaround: 	set OCM0_DSCNTL[DSEN]=0 and OCM0_DSCNTL[DOF]=0
    120 	 */
    121 	mtdcr   DCR_OCM0_DSCNTL,%r0    /* Disable Data access to OCM */
    122 
    123 #if 0
    124 	/* Allow cacheing for whole RAM. */
    125 	lis	%r0,PHYSMEM_REGIONS_MASK@ha
    126 	ori 	%r0,%r0,PHYSMEM_REGIONS_MASK@l
    127 #else
    128 #ifndef PPC_4XX_NOCACHE
    129 	/* Allow cacheing for only the first 1GB of RAM */
    130 	lis 	%r0,0xff00
    131 	mtdccr	%r0
    132 	mticcr	%r0
    133 #endif /* PPC_4XX_NOCACHE */
    134 #endif
    135 
    136 	/* Invalidate all TLB entries */
    137 	tlbia
    138 	sync
    139 	isync
    140 
    141 	/* Set kernel MMU context, we'll enable MMU in initppc() */
    142 	li	%r0,KERNEL_PID
    143 	mtpid	%r0
    144 	sync
    145 	isync
    146 
    147 	/* Setup endkernel argument for initppc() and INIT_CPUINFO */
    148 	lis	%r4,_C_LABEL(end)@h
    149 	ori 	%r4,%r4,_C_LABEL(end)@l
    150 
    151 	/* Clear .bss segment */
    152 	lis 	%r7,_C_LABEL(edata)-4@h
    153 	ori 	%r7,%r7,_C_LABEL(edata)-4@l
    154 	li 	%r3,0
    155 2: 	stwu    %r3,4(%r7)
    156 	cmpw    %r7,%r4
    157 	bne+    2b
    158 
    159 #if NKSYMS || defined(DDB) || defined(MODULAR)
    160 	/* We don't have a symbol table, so set startsym = endsym = end */
    161 	lis	%r7,_C_LABEL(startsym)@ha
    162 	ori 	%r7,%r7,_C_LABEL(startsym)@l
    163 	stw	%r4,0(%r7)
    164 	lis	%r7,_C_LABEL(endsym)@ha
    165 	ori 	%r7,%r7,_C_LABEL(endsym)@l
    166 	stw	%r4,0(%r7)
    167 #endif
    168 
    169 	/* INIT_CPUINFO will 'addi', so clean up. */
    170 	lis 	%r1,0
    171 
    172 	INIT_CPUINFO(4,1,9,0)
    173 
    174 	/* startkernel argument for initppc */
    175 	lis	%r3,__start@h
    176 	addi	%r3,%r3,__start@l
    177 
    178 	bl	_C_LABEL(initppc)
    179 	bl	_C_LABEL(main)
    180 
    181 loop: 	/* UNREACHED */
    182 	b	loop
    183 
    184 #include <powerpc/ibm4xx/4xx_locore.S>
    185