1/* $NetBSD: srt0.s,v 1.1 2007/12/17 19:09:54 garbled Exp $ */ 2 3/* 4 * Copyright (C) 1996-1999 Cort Dougan (cort@fsmlasb.com). 5 * Copyright (C) 1996-1999 Gary Thomas (gdt@osf.org). 6 * Copyright (C) 1996-1999 Paul Mackeras (paulus@linuxcare.com). 7 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by TooLs GmbH. 20 * 4. The name of TooLs GmbH may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35#define MSR_IP (1<<6) 36 37#define HID0_DCI (1<<10) 38#define HID0_ICFI (1<<11) 39#define HID0_DCE (1<<14) 40#define HID0_ICE (1<<15) 41 42/* when we start, the IPLCB pointer is in r3, and the extended one is in r4 */ 43 44 .text 45 46 .globl _start 47_start: 48 bl start 49start: 50 mr 11,3 /* save the IPLCB pointer in r11 */ 51 mr 12,4 /* save the extended IPLCB in r12 */ 52 li 3,MSR_IP /* Establish default MSR value */ 53 mtmsr 3 54 isync 55 56 mflr 7 57 bl flush_icache 58 mfspr 3,1008 59 lis 4,~(HID0_ICE|HID0_DCE)@h 60 ori 4,4,~(HID0_ICE|HID0_DCE)@l 61 andc 3,3,4 62 mtspr 1008,3 63 mtlr 7 64 65/* We aren't passed our loadaddr, so leave it alone */ 66#if 0 67/* 68 * check if we need to relocate ourselves to the link addr or were we 69 * loaded there to begin with -- Cort 70 */ 71 lis 4,_start@h 72 ori 4,4,_start@l 73 mflr 3 74 subi 3,3,4 /* we get the nip, not the ip of the branch */ 75 mr 8,3 76 cmpw 3,4 77 bne relocate 78 b start_ldr 79 80/* 81 * no matter where we're loaded, move ourselves to -Ttext address 82 */ 83relocate: 84 lis 4,_start@h 85 ori 4,4,_start@l 86 lis 5,end@h 87 ori 5,5,end@l 88 addi 5,5,3 /* Round up - just in case */ 89 sub 5,5,4 /* Compute # longwords to move */ 90 srwi 5,5,2 91 mtctr 5 92 subi 3,3,4 /* Set up for loop */ 93 subi 4,4,4 942: 95 lwzu 5,4(3) 96 stwu 5,4(4) 97 bdnz 2b 98 lis 3,start_ldr@h 99 ori 3,3,start_ldr@l 100 mtlr 3 /* Easiest way to do an absolute jump */ 101 blr 102#endif 103 104start_ldr: 105 mr 9,1 /* Save old stack pointer */ 106 lis 1,.stack@h 107 ori 1,1,.stack@l 108 addi 1,1,4096 109 li 2,0x000F 110 andc 1,1,2 111 mr 3,11 /* arg1: IPLCB pointer */ 112 mr 4,12 /* arg2: IPLCB extended block pointer */ 113 bl boot 114hang: 115 b hang 116 117/* 118 * Execute 119 * run(startsym, endsym, args, bootinfo, entry) 120 */ 121 .globl run 122run: 123 mtctr 7 /* Entry point */ 124 bctr 125 126/* 127 * Flush instruction cache 128 */ 129 .globl flush_icache 130flush_icache: 131 mflr 5 132 bl flush_dcache 133 mfspr 4,1008 134 li 4,0 135 ori 4,4,HID0_ICE|HID0_ICFI 136 or 3,3,4 137 mtspr 1008,3 138 andc 3,3,4 139 ori 3,3,HID0_ICE 140 mtspr 1008,3 141 mtlr 5 142 blr 143 144/* 145 * Flush data cache 146 */ 147 .globl flush_dcache 148flush_dcache: 149 lis 3,0x1000@h 150 ori 3,3,0x1000@l 151 li 4,1024 152 mtctr 4 1531: 154 lwz 4,0(3) 155 addi 3,3,32 156 bdnz 1b 157 blr 158 159#if 0 160/* 161 * write LEDS 162 */ 163 164 .globl led 165led: 166 mfmsr 5 /* save MSR to r5 */ 167 lis 7,0xffff 168 ori 7,7,~(MSR_DR) 169 and 6,5,7 170 mtmsr 6 171 isync 172 173#endif 174/* 175 * local stack 176 */ 177 .comm .stack,8192,4 178