srt0.S revision 1.2
1 /* $NetBSD: srt0.S,v 1.2 1997/03/10 08:00:47 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: Utah $Hdr: srt0.c 1.18 92/12/21$ 41 * 42 * @(#)srt0.c 8.1 (Berkeley) 6/10/93 43 */ 44 45 /* 46 * Startup code for standalone system 47 */ 48 49 .globl begin 50 .globl _end 51 .globl _edata 52 .globl _main 53 .globl _configure 54 .globl __rtt 55 .globl _bootdev,_howto,_lowram,_machineid 56 .globl _internalhpib 57 58 STACK = 0xfffff000 | below the ROM page 59 BOOTTYPE = 0xfffffdc0 60 LOWRAM = 0xfffffdce 61 SYSFLAG = 0xfffffed2 | system flags 62 MSUS = 0xfffffedc | MSUS (?) structure 63 VECTORS = 0xfffffee0 | beginning of jump vectors 64 NMIRESET = 0xffffff9c | reset vector 65 BUSERR = 0xfffffffc 66 MAXADDR = 0xfffff000 67 NBPG = 4096 68 MMUCMD = 0x005f400c | MMU command/status register 69 70 .data 71 _bootdev: 72 .long 0 73 _howto: 74 .long 0 75 _lowram: 76 .long 0 77 _machineid: 78 .long 0 79 80 .text 81 begin: 82 movl #STACK,sp 83 moveq #47,d0 | # of vectors - 1 84 movl #VECTORS+2,a0 | addr part of first vector 85 vecloop: 86 movl #trap,a0@ | make it direct to trap 87 addql #6,a0 | move to next vector addr 88 dbf d0,vecloop | go til done 89 movl #NMIRESET,a0 | NMI keyboard reset addr 90 movl #nmi,a0@ | catch in reset routine 91 /* 92 * Determine our CPU type and look for internal HP-IB 93 * (really only care about detecting 320 (no DIO-II) right now). 94 */ 95 lea _machineid,a0 96 movl #0x808,d0 97 movc d0,cacr | clear and disable on-chip cache(s) 98 movl #0x200,d0 | data freeze bit 99 movc d0,cacr | only exists on 68030 100 movc cacr,d0 | read it back 101 tstl d0 | zero? 102 jeq not68030 | yes, we have 68020/68040 103 movl #0x808,d0 104 movc d0,cacr | clear data freeze bit again 105 106 movl #0x80,MMUCMD | set magic cookie 107 movl MMUCMD,d0 | read it back 108 btst #7,d0 | cookie still on? 109 jeq not370 | no, 360 or 375 110 movl #4,a0@ | consider a 370 for now 111 movl #0,MMUCMD | clear magic cookie 112 movl MMUCMD,d0 | read it back 113 btst #7,d0 | still on? 114 jeq ihpibcheck | no, a 370 115 movl #5,a0@ | yes, must be a 340 116 jra ihpibcheck 117 not370: 118 movl #3,a0@ | type is at least a 360 119 movl #0,MMUCMD | clear magic cookie2 120 movl MMUCMD,d0 | read it back 121 btst #16,d0 | still on? 122 jeq ihpibcheck | no, a 360 123 movl #6,a0@ | yes, must be a 345/375/400 124 jra ihpibcheck 125 not68030: 126 bset #31,d0 | data cache enable bit 127 movc d0,cacr | only exists on 68040 128 movc cacr,d0 | read it back 129 tstl d0 | zero? 130 beq is68020 | yes, we have 68020 131 moveq #0,d0 | now turn it back off 132 movec d0,cacr | before we access any data 133 .long 0x4e7b0004 | movc d0,itt0 134 .long 0x4e7b0005 | movc d0,itt1 135 .long 0x4e7b0006 | movc d0,dtt0 136 .long 0x4e7b0007 | movc d0,dtt1 137 .word 0xf4d8 | cinva bc 138 movl MMUCMD,d0 | get MMU register 139 lsrl #8,d0 | get apparent ID 140 cmpb #6,d0 | id == 6? 141 jeq is33mhz | yes, we have a 433s 142 movl #7,a0@ | no, we have a 380/425t 143 jra ihpibcheck 144 is33mhz: 145 movl #8,a0@ | 433s (XXX 425s returns same ID, ugh!) 146 jra ihpibcheck 147 is68020: 148 movl #1,a0@ | consider a 330 for now 149 movl #1,MMUCMD | a 68020, write HP MMU location 150 movl MMUCMD,d0 | read it back 151 btst #0,d0 | zero? 152 jeq ihpibcheck | yes, a 330 153 movl #0,a0@ | no, consider a 320 for now 154 movl #0x80,MMUCMD | set magic cookie 155 movl MMUCMD,d0 | read it back 156 btst #7,d0 | cookie still on? 157 jeq ihpibcheck | no, just a 320 158 movl #2,a0@ | yes, a 350 159 ihpibcheck: 160 movl #0,MMUCMD | make sure MMU is off 161 btst #5,SYSFLAG | do we have an internal HP-IB? 162 jeq boottype | yes, continue 163 clrl _internalhpib | no, clear the internal address 164 /* 165 * If this is a reboot, extract howto/bootdev stored by kernel 166 */ 167 boottype: 168 cmpw #12,BOOTTYPE | is this a reboot (REQ_REBOOT)? 169 jne notreboot | no, skip 170 lea MAXADDR,a0 | find last page 171 movl a0@+,d7 | and extract howto, bootdev 172 movl a0@+,d6 | from where doboot() left them 173 jra boot1 174 /* 175 * At this point we do not know which logical device the MSUS select 176 * code refers to so we cannot construct bootdev. So we just punt 177 * and let configure() construct it. 178 */ 179 notreboot: 180 moveq #0,d6 | make sure bootdev is invalid 181 cmpw #18,BOOTTYPE | does the user want to interact? 182 jeq askme | yes, go to it 183 moveq #0,d7 | default to RB_AUTOBOOT 184 jra boot1 185 askme: 186 moveq #3,d7 | default to RB_SINGLE|RB_ASKNAME 187 boot1: 188 movl d6,_bootdev | save bootdev and howto 189 movl d7,_howto | globally so all can access 190 movl LOWRAM,d0 | read lowram value from bootrom 191 /* 192 * Must preserve the scratch area for the BOOT ROM. 193 * Round up to the next 8k boundary. 194 */ 195 addl #((2*NBPG)-1),d0 196 andl #-(2*NBPG),d0 197 movl d0,_lowram | stash that value 198 start: 199 movl #_edata,a2 | start of BSS 200 movl #_end,a3 | end 201 clr: 202 clrb a2@+ | clear BSS 203 cmpl a2,a3 | done? 204 bne clr | no, keep going 205 jsr _configure | configure critical devices 206 jsr _main | lets go 207 __rtt: 208 movl #3,_howto | restarts get RB_SINGLE|RB_ASKNAME 209 jmp start 210 211 /* 212 * probe a location and see if it causes a bus error 213 */ 214 .globl _badaddr 215 _badaddr: 216 movl BUSERR,__bsave | save ROM bus error handler address 217 movl sp,__ssave | and current stack pointer 218 movl #catchbad,BUSERR| plug in our handler 219 movl sp@(4),a0 | address to probe 220 movw a0@,d1 | do it 221 movl __bsave,BUSERR | if we got here, it did not fault 222 clrl d0 | return that this was not a bad addr 223 rts 224 225 catchbad: 226 movl __bsave,BUSERR | got a bus error, so restore old handler 227 movl __ssave,sp | manually restore stack 228 moveq #1,d0 | indicate that we got a fault 229 rts | return to caller of badaddr() 230 231 __bsave: 232 .long 0 233 __ssave: 234 .long 0 235 236 .globl _trap 237 trap: 238 moveml #0xFFFF,sp@- | save registers 239 movl sp,sp@- | push pointer to frame 240 jsr _trap | call C routine to deal with it 241 tstl d0 242 jeq Lstop 243 addql #4,sp 244 moveml sp@+,#0x7FFF 245 addql #8,sp 246 rte 247 Lstop: 248 stop #0x2700 | stop cold 249 250 nmi: 251 movw #18,BOOTTYPE | mark as system switch 252 jsr _kbdnmi | clear the interrupt 253 jra begin | start over 254 255 .globl _call_req_reboot 256 _call_req_reboot: 257 jmp 0x1A4 | call ROM reboot function 258 rts | XXX: just in case? 259 260 #ifdef ROMPRF 261 .globl _romout 262 _romout: 263 movl sp@(4),d0 | line number 264 movl sp@(8),a0 | string 265 jsr 0x150 | do it 266 rts 267 #endif 268
Indexes created Tue Sep 30 20:09:53 GMT 2025