xref: /plan9/sys/src/libmach/9obj.c (revision 47ad917500b8a90d491f36a7d58aefb5241656ee)
1 /*
2  * 9obj.c - identify and parse a PowerPC-64 object file
3  *	forsyth@terzarima.net
4  */
5 #include <u.h>
6 #include <libc.h>
7 #include <bio.h>
8 #include <mach.h>
9 #include "9c/9.out.h"
10 #include "obj.h"
11 
12 typedef struct Addr	Addr;
13 struct Addr
14 {
15 	char	type;
16 	char	sym;
17 	char	name;
18 };
19 static Addr addr(Biobuf*);
20 static char type2char(int);
21 static void skip(Biobuf*, int);
22 
23 int
_is9(char * s)24 _is9(char *s)
25 {
26 	return  (s[0]&0377) == ANAME			/* ANAME */
27 		&& (s[1]&0377) == ANAME>>8
28 		&& s[2] == D_FILE			/* type */
29 		&& s[3] == 1				/* sym */
30 		&& s[4] == '<';				/* name of file */
31 }
32 
33 int
_read9(Biobuf * bp,Prog * p)34 _read9(Biobuf *bp, Prog *p)
35 {
36 	int as, n, c;
37 	Addr a;
38 
39 	as = Bgetc(bp);					/* as(low) */
40 	if(as < 0)
41 		return 0;
42 	c = Bgetc(bp);					/* as(high) */
43 	if(c < 0)
44 		return 0;
45 	as |= ((c & 0xff) << 8);
46 	p->kind = aNone;
47 	p->sig = 0;
48 	if(as == ANAME || as == ASIGNAME){
49 		if(as == ASIGNAME){
50 			Bread(bp, &p->sig, 4);
51 			p->sig = beswal(p->sig);
52 		}
53 		p->kind = aName;
54 		p->type = type2char(Bgetc(bp));		/* type */
55 		p->sym = Bgetc(bp);			/* sym */
56 		n = 0;
57 		for(;;) {
58 			as = Bgetc(bp);
59 			if(as < 0)
60 				return 0;
61 			n++;
62 			if(as == 0)
63 				break;
64 		}
65 		p->id = malloc(n);
66 		if(p->id == 0)
67 			return 0;
68 		Bseek(bp, -n, 1);
69 		if(Bread(bp, p->id, n) != n)
70 			return 0;
71 		return 1;
72 	}
73 	if(as == ATEXT)
74 		p->kind = aText;
75 	else if(as == AGLOBL)
76 		p->kind = aData;
77 	n = Bgetc(bp);					/* reg and flag */
78 	skip(bp, 4);					/* lineno(4) */
79 	a = addr(bp);
80 	if(n & 0x40)
81 		addr(bp);
82 	addr(bp);
83 	if(a.type != D_OREG || a.name != D_STATIC && a.name != D_EXTERN)
84 		p->kind = aNone;
85 	p->sym = a.sym;
86 	return 1;
87 }
88 
89 static Addr
addr(Biobuf * bp)90 addr(Biobuf *bp)
91 {
92 	Addr a;
93 	vlong off;
94 	long l;
95 
96 	a.type = Bgetc(bp);				/* a.type */
97 	skip(bp,1);					/* reg */
98 	a.sym = Bgetc(bp);				/* sym index */
99 	a.name = Bgetc(bp);				/* sym type */
100 	switch(a.type){
101 	default:
102 	case D_NONE: case D_REG: case D_FREG: case D_CREG:
103 	case D_FPSCR: case D_MSR:
104 		break;
105 	case D_SPR:
106 	case D_OREG:
107 	case D_CONST:
108 	case D_BRANCH:
109 	case D_DCONST:
110 	case D_DCR:
111 		l = Bgetc(bp);
112 		l |= Bgetc(bp) << 8;
113 		l |= Bgetc(bp) << 16;
114 		l |= Bgetc(bp) << 24;
115 		off = l;
116 		if(a.type == D_DCONST){
117 			l = Bgetc(bp);
118 			l |= Bgetc(bp) << 8;
119 			l |= Bgetc(bp) << 16;
120 			l |= Bgetc(bp) << 24;
121 			off = ((vlong)l << 32) | (off & 0xFFFFFFFF);
122 			a.type = D_CONST;		/* perhaps */
123 		}
124 		if(off < 0)
125 			off = -off;
126 		if(a.sym && (a.name==D_PARAM || a.name==D_AUTO))
127 			_offset(a.sym, off);
128 		break;
129 	case D_SCONST:
130 		skip(bp, NSNAME);
131 		break;
132 	case D_FCONST:
133 		skip(bp, 8);
134 		break;
135 	}
136 	return a;
137 }
138 
139 static char
type2char(int t)140 type2char(int t)
141 {
142 	switch(t){
143 	case D_EXTERN:		return 'U';
144 	case D_STATIC:		return 'b';
145 	case D_AUTO:		return 'a';
146 	case D_PARAM:		return 'p';
147 	default:		return UNKNOWN;
148 	}
149 }
150 
151 static void
skip(Biobuf * bp,int n)152 skip(Biobuf *bp, int n)
153 {
154 	while (n-- > 0)
155 		Bgetc(bp);
156 }
157