Annotation of sys/arch/vax/boot/xxboot/start.S, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: start.S,v 1.2 2003/11/07 10:16:45 jmc Exp $ */
2: /* $NetBSD: start.S,v 1.1 2002/02/24 01:04:26 matt Exp $ */
3: /*
4: * Copyright (c) 1995 Ludd, University of Lule}, Sweden.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to Ludd by
8: * Bertram Barth.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed at Ludd, University of
21: * Lule}, Sweden and its contributors.
22: * 4. The name of the author may not be used to endorse or promote products
23: * derived from this software without specific prior written permission
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35: */
36:
37: /* All bugs are subject to removal without further notice */
38:
39:
40: #define _LOCORE
41:
42: #include "sys/disklabel.h"
43:
44: #include "../include/mtpr.h"
45: #include "../include/asm.h"
46:
47: _C_LABEL(_start):
48: _C_LABEL(start):
49: .globl _C_LABEL(start) # this is the symbolic name for the start
50: .globl _C_LABEL(_start) # of code to be relocated. We can use this
51: # to get the actual/real address (pc-rel)
52: # or to get the relocated address (abs).
53:
54: .org 0x00 # uVAX booted from TK50 starts here
55: brb from_0x00 # continue behind dispatch-block
56:
57: .org 0x02 # information used by uVAX-ROM
58: .byte 0xff # offset in words to identification area
59: .byte 1 # this byte must be 1
60: .word 0 # logical block number (word swapped)
61: .word 0 # of the secondary image
62:
63: .org 0x08 #
64: brb from_0x08 # skip ...
65:
66: .org 0x0C # 11/750 & 8200 starts here
67: movzbl $1,_C_LABEL(from)# We booted from "old" rom.
68: brw cont_750
69:
70:
71: from_0x00: # uVAX from TK50
72: brw start_uvax # all uVAXen continue there
73:
74: from_0x08: # Any machine from VMB
75: movzbl $4,_C_LABEL(from) # Booted from full VMB
76: brw start_vmb
77:
78: # the complete area reserved for label
79: # must be empty (i.e. filled with zeroes).
80: # disklabel(8) checks that before installing
81: # the bootblocks over existing label.
82:
83: .org LABELOFFSET
84: .globl _C_LABEL(romlabel)
85: _C_LABEL(romlabel):
86: .long 0
87:
88: .org LABELOFFSET + d_end_
89: start_vmb:
90: /*
91: * Read in block 1-15.
92: */
93: movl 52(r11), r7 # load iovec/bqo into %r7
94: addl3 (r7), r7, r6 # load qio into %r6
95: pushl r11 # base of rpb
96: pushl $0 # virtual-flag
97: pushl $33 # read-logical-block
98: pushl $1 # lbn to start reading
99: pushl $7680 # number of bytes to read
100: pushab start_uvax # buffer-address
101: calls $6, (r6) # call the qio-routine
102: brw start_uvax
103:
104: /*
105: * Parameter block for uVAX boot.
106: */
107: #define VOLINFO 0 /* 1=single-sided 81=double-sided volumes */
108: #define SISIZE 16 /* size in blocks of secondary image */
109: #define SILOAD 0 /* load offset (usually 0) from the default */
110: #define SIOFF 0x260 /* byte offset into secondary image */
111:
112: .org 0x1fe
113: .byte 0x18 # must be 0x18
114: .byte 0x00 # must be 0x00 (MBZ)
115: .byte 0x00 # any value
116: .byte 0xFF - (0x18 + 0x00 + 0x00)
117: /* 4th byte holds 1s' complement of sum of previous 3 bytes */
118:
119: .byte 0x00 # must be 0x00 (MBZ)
120: .byte VOLINFO
121: .byte 0x00 # any value
122: .byte 0x00 # any value
123:
124: .long SISIZE # size in blocks of secondary image
125: .long SILOAD # load offset (usually 0)
126: .long SIOFF # byte offset into secondary image
127: .long (SISIZE + SILOAD + SIOFF) # sum of previous 3
128:
129:
130: .align 2
131: .globl _C_LABEL(from)
132: _C_LABEL(from):
133: .long 0
134:
135: /*
136: * After bootblock (LBN0) has been loaded into the first page
137: * of good memory by 11/750's ROM-code (transfer address
138: * of bootblock-code is: base of good memory + 0x0C) registers
139: * are initialized as:
140: * R0: type of boot-device
141: * 0: Massbus device
142: * 1: RK06/RK07
143: * 2: RL02
144: * 17: UDA50
145: * 35: TK50
146: * 64: TU58
147: * R1: (UBA) address of UNIBUS I/O-page
148: * (MBA) address of boot device's adapter
149: * R2: (UBA) address of the boot device's CSR
150: * (MBA) controller number of boot device
151: * R6: address of driver subroutine in ROM
152: *
153: * cont_750 reads in LBN1-15 for further execution.
154: */
155: cont_750:
156: movl $_C_LABEL(start), sp # move stack to avoid clobbering the code
157: pushr $0x131 # save clobbered registers
158: clrl r4 # %r4 == # of blocks transferred
159: movab _C_LABEL(start),r5 # %r5 have base address for next transfer
160: pushl r5 # ...on stack also (Why?)
161: 1: incl r4 # increment block count
162: movl r4,r8 # LBN is in %r8 for rom routine
163: addl2 $0x200,r5 # Increase address for next read
164: cmpl $16,r4 # read 15 blocks?
165: beql 2f # Yep
166: movl r5,(sp) # move address to stack also
167: jsb (r6) # read 512 bytes
168: blbs r0,1b # jump if read succeeded
169: halt # otherwise die...
170: 2: tstl (sp)+ # remove boring arg from stack
171: popr $0x131 # restore clobbered registers
172: brw start_all # Ok, continue...
173:
174: /* uVAX main entry is at the start of the second disk block. This is
175: * needed for multi-arch CD booting where multiple architecture need
176: * to shove stuff in boot block 0.
177: */
178: .org 0x260 # uVAX booted from disk starts here
179:
180: start_uvax:
181: movzbl $2,_C_LABEL(from) # Booted from subset-VMB
182: brb start_all
183:
184: /*
185: * start_all: stack already at RELOC, we save registers, move ourself
186: * to RELOC and loads boot.
187: */
188: start_all:
189: movl $_C_LABEL(start), sp # move stack to a better
190: pushr $0x1fff # save all regs, used later.
191:
192: subl3 $_C_LABEL(start), $_C_LABEL(edata), r0
193: # get size of text+data (w/o bss)
194: moval _C_LABEL(start), r1 # get actual base-address of code
195: subl3 $_C_LABEL(start), $_C_LABEL(end), r2
196: # get complete size (incl. bss)
197: movl $_C_LABEL(start), r3 # get relocated base-address of code
198: movc5 r0, (r1), $0, r2, (r3) # copy code to new location
199:
200: movpsl -(sp)
201: movl $relocated, -(sp) # return-address on top of stack
202: rei # can be replaced with new address
203: relocated: # now relocation is done !!!
204: movl sp, _C_LABEL(bootregs)
205: calls $0, _C_LABEL(Xmain) # call Xmain (gcc workaround)which is
206: halt # not intended to return ...
207:
208: /*
209: * hoppabort() is called when jumping to the newly loaded program.
210: */
211: ENTRY(hoppabort, 0)
212: movl 4(ap),r6
213: movl _C_LABEL(rpb),r11
214: mnegl $1,ap # Hack to figure out boot device.
215: movpsl -(sp)
216: pushab 2(r6)
217: mnegl $1,_C_LABEL(vax_load_failure)
218: rei
219: # calls $0,(r6)
220: halt
221:
222: ENTRY(unit_init, R6|R7|R8|R9|R10|R11)
223: mfpr $17,r7 # Wanted bu KDB
224: movl 4(ap),r0 # init routine address
225: movl 8(ap),r9 # RPB in %r9
226: movl 12(ap),r1 # VMB argument list
227: callg (r1),(r0)
228: ret
229:
230: # A bunch of functions unwanted in boot blocks.
231: ENTRY(getchar, 0)
232: halt
233:
234: #ifndef USE_PRINTF
235: ENTRY(putchar, 0)
236: ret
237:
238: #endif
239:
240: ENTRY(panic, 0)
241: halt
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