start.S revision 1.3
1 /* $NetBSD: start.S,v 1.3 2005/10/21 21:10:45 he Exp $ */ 2 /* 3 * Copyright (c) 1995 Ludd, University of Lule}, Sweden. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Ludd by 7 * Bertram Barth. 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 at Ludd, University of 20 * Lule}, Sweden and its contributors. 21 * 4. The name of the author may not be used to endorse or promote products 22 * derived from this software without specific prior written permission 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* All bugs are subject to removal without further notice */ 37 38 39 #define _LOCORE 40 41 #define OMIT_DKTYPENUMS 42 #define OMIT_FSTYPENUMS 43 #include "sys/disklabel.h" 44 45 #include "../include/mtpr.h" 46 #include "../include/asm.h" 47 48 _C_LABEL(_start): 49 _C_LABEL(start): 50 .globl _C_LABEL(start) # this is the symbolic name for the start 51 .globl _C_LABEL(_start) # of code to be relocated. We can use this 52 # to get the actual/real address (pc-rel) 53 # or to get the relocated address (abs). 54 55 .org 0x00 # uVAX booted from TK50 starts here 56 brb from_0x00 # continue behind dispatch-block 57 58 .org 0x02 # information used by uVAX-ROM 59 .byte 0xcf # offset in words to identification area 60 .byte 1 # this byte must be 1 61 .word 0 # logical block number (word swapped) 62 .word 0 # of the secondary image 63 64 .org 0x08 # 65 brb from_0x08 # skip ... 66 67 .org 0x0C # 11/750 & 8200 starts here 68 movzbl $1,_C_LABEL(from)# We booted from "old" rom. 69 brw cont_750 70 71 72 from_0x00: # uVAX from TK50 73 brw start_uvax # all uVAXen continue there 74 75 from_0x08: # Any machine from VMB 76 movzbl $4,_C_LABEL(from) # Booted from full VMB 77 brw start_vmb 78 79 # the complete area reserved for label 80 # must be empty (i.e. filled with zeroes). 81 # disklabel(8) checks that before installing 82 # the bootblocks over existing label. 83 84 .org LABELOFFSET 85 .globl _C_LABEL(romlabel) 86 _C_LABEL(romlabel): 87 .long 0 88 89 .org LABELOFFSET + d_end_ 90 start_vmb: 91 /* 92 * Read in block 1-15. 93 */ 94 movl 52(%r11), %r7 # load iovec/bqo into %r7 95 addl3 (%r7), %r7, %r6 # load qio into %r6 96 pushl %r11 # base of rpb 97 pushl $0 # virtual-flag 98 pushl $33 # read-logical-block 99 pushl $1 # lbn to start reading 100 pushl $7680 # number of bytes to read 101 pushab start_uvax # buffer-address 102 calls $6, (%r6) # call the qio-routine 103 brw start_uvax 104 105 /* 106 * Parameter block for uVAX boot. 107 */ 108 #define VOLINFO 0 /* 1=single-sided 81=double-sided volumes */ 109 #define SISIZE 16 /* size in blocks of secondary image */ 110 #define SILOAD 0 /* load offset (usually 0) from the default */ 111 #define SIOFF 0x200 /* byte offset into secondary image */ 112 113 .org 0x19e 114 .byte 0x18 # must be 0x18 115 .byte 0x00 # must be 0x00 (MBZ) 116 .byte 0x00 # any value 117 .byte 0xFF - (0x18 + 0x00 + 0x00) 118 /* 4th byte holds 1s' complement of sum of previous 3 bytes */ 119 120 .byte 0x00 # must be 0x00 (MBZ) 121 .byte VOLINFO 122 .byte 0x00 # any value 123 .byte 0x00 # any value 124 125 .long SISIZE # size in blocks of secondary image 126 .long SILOAD # load offset (usually 0) 127 .long SIOFF # byte offset into secondary image 128 .long (SISIZE + SILOAD + SIOFF) # sum of previous 3 129 130 131 .align 2 132 .globl _C_LABEL(from) 133 _C_LABEL(from): 134 .long 0 135 136 /* 137 * After bootblock (LBN0) has been loaded into the first page 138 * of good memory by 11/750's ROM-code (transfer address 139 * of bootblock-code is: base of good memory + 0x0C) registers 140 * are initialized as: 141 * R0: type of boot-device 142 * 0: Massbus device 143 * 1: RK06/RK07 144 * 2: RL02 145 * 17: UDA50 146 * 35: TK50 147 * 64: TU58 148 * R1: (UBA) address of UNIBUS I/O-page 149 * (MBA) address of boot device's adapter 150 * R2: (UBA) address of the boot device's CSR 151 * (MBA) controller number of boot device 152 * R6: address of driver subroutine in ROM 153 * 154 * cont_750 reads in LBN1-15 for further execution. 155 */ 156 cont_750: 157 movl $_C_LABEL(start), %sp # move stack to avoid clobbering the code 158 pushr $0x131 # save clobbered registers 159 clrl %r4 # %r4 == # of blocks transferred 160 movab _C_LABEL(start),%r5 # %r5 have base address for next transfer 161 pushl %r5 # ...on stack also (Why?) 162 1: incl %r4 # increment block count 163 movl %r4,%r8 # LBN is in %r8 for rom routine 164 addl2 $0x200,%r5 # Increase address for next read 165 cmpl $16,%r4 # read 15 blocks? 166 beql 2f # Yep 167 movl %r5,(%sp) # move address to stack also 168 jsb (%r6) # read 512 bytes 169 blbs %r0,1b # jump if read succeeded 170 halt # otherwise die... 171 2: tstl (%sp)+ # remove boring arg from stack 172 popr $0x131 # restore clobbered registers 173 brw start_all # Ok, continue... 174 175 /* uVAX main entry is at the start of the second disk block. This is 176 * needed for multi-arch CD booting where multiple architecture need 177 * to shove stuff in boot block 0. 178 */ 179 .org 0x200 # uVAX booted from disk starts here 180 181 start_uvax: 182 movzbl $2,_C_LABEL(from) # Booted from subset-VMB 183 brb start_all 184 185 /* 186 * start_all: stack already at RELOC, we save registers, move ourself 187 * to RELOC and loads boot. 188 */ 189 start_all: 190 movl $_C_LABEL(start), %sp # move stack to a better 191 pushr $0x1fff # save all regs, used later. 192 193 subl3 $_C_LABEL(start), $_C_LABEL(edata), %r0 194 # get size of text+data (w/o bss) 195 moval _C_LABEL(start), %r1 # get actual base-address of code 196 subl3 $_C_LABEL(start), $_C_LABEL(end), %r2 197 # get complete size (incl. bss) 198 movl $_C_LABEL(start), %r3 # get relocated base-address of code 199 movc5 %r0, (%r1), $0, %r2, (%r3) # copy code to new location 200 201 movpsl -(%sp) 202 movl $relocated, -(%sp) # return-address on top of stack 203 rei # can be replaced with new address 204 relocated: # now relocation is done !!! 205 movl %sp, _C_LABEL(bootregs) 206 calls $0, _C_LABEL(Xmain) # call Xmain (gcc workaround)which is 207 halt # not intended to return ... 208 209 /* 210 * hoppabort() is called when jumping to the newly loaded program. 211 */ 212 ENTRY(hoppabort, 0) 213 movl 4(%ap),%r6 214 movl _C_LABEL(rpb),%r11 215 mnegl $1,%ap # Hack to figure out boot device. 216 movpsl -(%sp) 217 pushab 2(%r6) 218 mnegl $1,_C_LABEL(vax_load_failure) 219 rei 220 # calls $0,(%r6) 221 halt 222 223 ENTRY(unit_init, R6|R7|R8|R9|R10|R11) 224 mfpr $17,%r7 # Wanted bu KDB 225 movl 4(%ap),%r0 # init routine address 226 movl 8(%ap),%r9 # RPB in %r9 227 movl 12(%ap),%r1 # VMB argument list 228 callg (%r1),(%r0) 229 ret 230 231 # A bunch of functions unwanted in boot blocks. 232 ENTRY(getchar, 0) 233 halt 234 235 #ifndef USE_PRINTF 236 ENTRY(putchar, 0) 237 ret 238 239 ENTRY(printf, 0) 240 ret 241 #endif 242 243 ENTRY(panic, 0) 244 halt 245
Indexes created Mon Sep 29 18:09:42 GMT 2025