xref: /original-bsd/sys/i386/stand/boot.c (revision e59fb703)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 char copyright[] =
13 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
14  All rights reserved.\n";
15 #endif /* not lint */
16 
17 #ifndef lint
18 static char sccsid[] = "@(#)boot.c	7.3 (Berkeley) 05/04/91";
19 #endif /* not lint */
20 
21 #include "param.h"
22 #include "reboot.h"
23 #include <a.out.h>
24 #include <setjmp.h>
25 #include "saio.h"
26 
27 /*
28  * Boot program... arguments from lower-level bootstrap determine
29  * whether boot stops to ask for system name and which device
30  * boot comes from.
31  */
32 
33 char line[100] = UNIX;
34 extern	int opendev, bootdev, cyloffset;
35 int	retry = 0;
36 extern jmp_buf  exception;
37 
38 main(howto, dev, off)
39 {
40 	int io;
41 
42 	if((dev&B_MAGICMASK) == B_DEVMAGIC) {
43 		bootdev = dev;
44 		cyloffset = off;
45 	} else	goto again;
46 
47 	if(_setjmp(exception)) {
48 		close(io);
49 		printf("- load aborted\n");
50 again:
51 		howto = RB_SINGLE|RB_ASKNAME;
52 		cyloffset = 0;
53 	}
54 
55 	for (;;) {
56 		if (howto & RB_ASKNAME) {
57 			char *cp;
58 
59 			printf("Boot: ");
60 			gets(line);
61 
62 			/* process additional flags if any */
63 			if(cp = (char *)index(line, ' ')) {
64 				howto = strtol (cp, 0, 0);
65 				*cp = '\0';
66 			}
67 			cyloffset = 0;
68 		} else
69 			printf("Boot: %s\n", line);
70 
71 		if (line[0] == 0) {
72 			strcpy(line, UNIX);
73 			printf("Boot: %s\n", line);
74 		}
75 
76 		io = open(line, 0);
77 		if (io >= 0) {
78 			copyunix(io, howto);
79 			goto again;
80 		} else if (++retry > 2)
81 			goto again;
82 	}
83 }
84 
85 /*ARGSUSED*/
86 copyunix(io, howto)
87 	register io;
88 {
89 	struct exec x;
90 	int i;
91 	char *addr,c;
92 
93 	i = read(io, (char *)&x, sizeof x);
94 	if (i != sizeof x ||
95 	    (x.a_magic != 0407 && x.a_magic != 0413 && x.a_magic != 0410)) {
96 		printf("Bad format\n");
97 		return;
98 	}
99 
100 	printf("%d", x.a_text);
101 	if (x.a_magic == 0413 && lseek(io, 0x400, 0) == -1)
102 		goto shread;
103 	if (read(io, (char *)0, x.a_text) != x.a_text)
104 		goto shread;
105 
106 	addr = (char *)x.a_text;
107 	if (x.a_magic == 0413 || x.a_magic == 0410)
108 		while ((int)addr & CLOFSET)
109 			*addr++ = 0;
110 	printf("+%d", x.a_data);
111 	if (read(io, addr, x.a_data) != x.a_data)
112 		goto shread;
113 
114 	addr += x.a_data;
115 	printf("+%d", x.a_bss);
116 	x.a_bss += 128*512;	/* slop */
117 	for (i = 0; i < x.a_bss; i++)
118 		*addr++ = 0;
119 
120 	/* mask high order bits corresponding to relocated system base */
121 	x.a_entry &= 0xfff00000;
122 	printf(" start 0x%x\n", x.a_entry);
123 
124 	if(c=scankbd())
125 		_longjmp(&exception,1);
126 
127 	i = (*((int (*)()) x.a_entry))(howto, opendev, 0, cyloffset);
128 
129 	if (i) printf("exit %d\n", i) ;
130 	return;
131 shread:
132 	printf("Short read\n");
133 	return;
134 }
135