1 /*
2 * qobj.c - identify and parse a PowerPC object file
3 * forsyth@terzarima.net
4 */
5 #include <lib9.h>
6 #include <bio.h>
7 #include "mach.h"
8 #include "qc/q.out.h"
9 #include "obj.h"
10
11 typedef struct Addr Addr;
12 struct Addr
13 {
14 char type;
15 char sym;
16 char name;
17 };
18 static Addr addr(Biobuf*);
19 static char type2char(int);
20 static void skip(Biobuf*, int);
21
22 int
_isq(char * s)23 _isq(char *s)
24 {
25 return (s[0]&0377) == ANAME /* ANAME */
26 && (s[1]&0377) == ANAME>>8
27 && s[2] == D_FILE /* type */
28 && s[3] == 1 /* sym */
29 && s[4] == '<'; /* name of file */
30 }
31
32 int
_readq(Biobuf * bp,Prog * p)33 _readq(Biobuf *bp, Prog *p)
34 {
35 int as, n, c;
36 Addr a;
37
38 as = Bgetc(bp); /* as(low) */
39 if(as < 0)
40 return 0;
41 c = Bgetc(bp); /* as(high) */
42 if(c < 0)
43 return 0;
44 as |= ((c & 0xff) << 8);
45 p->kind = aNone;
46 p->sig = 0;
47 if(as == ANAME || as == ASIGNAME){
48 if(as == ASIGNAME){
49 Bread(bp, &p->sig, 4);
50 p->sig = beswal(p->sig);
51 }
52 p->kind = aName;
53 p->type = type2char(Bgetc(bp)); /* type */
54 p->sym = Bgetc(bp); /* sym */
55 n = 0;
56 for(;;) {
57 as = Bgetc(bp);
58 if(as < 0)
59 return 0;
60 n++;
61 if(as == 0)
62 break;
63 }
64 p->id = malloc(n);
65 if(p->id == 0)
66 return 0;
67 Bseek(bp, -n, 1);
68 if(Bread(bp, p->id, n) != n)
69 return 0;
70 return 1;
71 }
72 if(as == ATEXT)
73 p->kind = aText;
74 else if(as == AGLOBL)
75 p->kind = aData;
76 n = Bgetc(bp); /* reg and flag */
77 skip(bp, 4); /* lineno(4) */
78 a = addr(bp);
79 if(n & 0x40)
80 addr(bp);
81 addr(bp);
82 if(a.type != D_OREG || a.name != D_STATIC && a.name != D_EXTERN)
83 p->kind = aNone;
84 p->sym = a.sym;
85 return 1;
86 }
87
88 static Addr
addr(Biobuf * bp)89 addr(Biobuf *bp)
90 {
91 Addr a;
92 long off;
93
94 a.type = Bgetc(bp); /* a.type */
95 skip(bp,1); /* reg */
96 a.sym = Bgetc(bp); /* sym index */
97 a.name = Bgetc(bp); /* sym type */
98 switch(a.type){
99 default:
100 case D_NONE: case D_REG: case D_FREG: case D_CREG:
101 case D_FPSCR: case D_MSR: case D_SREG:
102 break;
103 case D_SPR:
104 case D_OREG:
105 case D_DCR:
106 case D_CONST:
107 case D_BRANCH:
108 off = Bgetc(bp);
109 off |= Bgetc(bp) << 8;
110 off |= Bgetc(bp) << 16;
111 off |= Bgetc(bp) << 24;
112 if(off < 0)
113 off = -off;
114 if(a.sym && (a.name==D_PARAM || a.name==D_AUTO))
115 _offset(a.sym, off);
116 break;
117 case D_SCONST:
118 skip(bp, NSNAME);
119 break;
120 case D_FCONST:
121 skip(bp, 8);
122 break;
123 }
124 return a;
125 }
126
127 static char
type2char(int t)128 type2char(int t)
129 {
130 switch(t){
131 case D_EXTERN: return 'U';
132 case D_STATIC: return 'b';
133 case D_AUTO: return 'a';
134 case D_PARAM: return 'p';
135 default: return UNKNOWN;
136 }
137 }
138
139 static void
skip(Biobuf * bp,int n)140 skip(Biobuf *bp, int n)
141 {
142 while (n-- > 0)
143 Bgetc(bp);
144 }
145