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Root/branches/xZenu/src/util/dyldsymboltool.c

Source at commit 1406 created 12 years 10 months ago.
By meklort, Revert drivers.c so that kexts are only loaded when OSBundleRequired is set and that value is not safe mode. Added some comments about it too.
1/*␊
2 * Copyright (c) 2010 Evan Lojewski. All rights reserved.␊
3 *␉␊
4 *␉dyldsymboltool␊
5 *␊
6 *␉␉Generates a dylib file for the dyld implimentation in chameleon␊
7 *␉to load and link. This is used to import the boot symbols into the␊
8 *␉module system. ␊
9 */␊
10␊
11#include <stdio.h>␊
12#include <stdlib.h>␊
13#include <mach/mach.h>␊
14#include <sys/file.h>␊
15#include <mach-o/loader.h>␊
16#include <mach-o/nlist.h>␊
17␊
18␊
19#define DYLIB_NAME "Symbols"␊
20#define VOID_SYMBOL "_load_all_modules"␊
21#define START_SYMBOL "start"␊
22␊
23typedef struct symbols_dylib␊
24{␊
25␉struct mach_header␉␉header;␊
26␉struct dylib_command␉dylib_info;␊
27␉char␉␉␉␉␉module_name[sizeof(DYLIB_NAME)];␉␊
28␉struct symtab_command␉symtab;␊
29} symbols_dylib_t;␊
30␊
31␊
32typedef struct symbolList_t␊
33{␊
34␉char*␉␉␉␉␉name;␊
35␉uint32_t␉␉␉␉addr;␊
36␉int␉␉␉␉␉␉pos;␊
37␉struct symbolList_t*␉next;␊
38} symbolList_t;␊
39␊
40␊
41int num_symbols(symbolList_t* list);␊
42int string_size(symbolList_t* list);␊
43void add_symbol(symbolList_t** list, char* name, uint32_t addr);␊
44␊
45␊
46int main(int argc, char *argv[])␊
47{␊
48␉if(argc < 3) ␊
49␉{␊
50␉␉fprintf(stderr, "usage: dyldsymboltool obj1 [obj2 ...] outfile\n");␊
51␊
52␉␉exit(-1);␊
53␉}␊
54␊
55␉␊
56␊
57␉symbols_dylib_t dylib;␊
58␉symbolList_t*␉symbols = NULL;␊
59␊
60␉uint32_t start_addr = 0;␊
61␉␊
62␉␊
63␉␊
64␉␊
65 int i;␊
66␉for(i = 1; i < argc-1; i++)␊
67 {␊
68 char line[256];␊
69 char* command = malloc(strlen(argv[1]) + sizeof("nm -g "));␊
70 FILE *fpipe;␊
71␊
72 // Parse boot.sys (arg1) to get symtab␊
73 sprintf(command, "nm -g %s", argv[i]);␉// TODO: read boot.sym directly, no need for nm␊
74 ␊
75 if ( !(fpipe = (FILE*)popen(command,"r")) )␊
76 { // If fpipe is NULL␊
77 perror("Problems with pipe");␊
78 exit(1);␊
79 }␊
80 ␊
81 ␊
82 while ( fgets( line, sizeof line, fpipe))␊
83 {␊
84 if((strlen(line) < strlen(argv[i]) ||␊
85 strncmp(line, argv[i], strlen(argv[i])) != 0)␊
86 && line[0] != ' ')␊
87 {␊
88 uint32_t address = 0;␊
89 char* addr = strtok(line, " ");␊
90 strtok(NULL, " ");␊
91 char* name = strtok(NULL, " ");␊
92 name[strlen(name)-1] = 0;␉// remove newline␊
93 sscanf(addr, "%x", &address);␊
94 if(strcmp(name, VOID_SYMBOL) == 0) start_addr = address;␊
95 add_symbol(&symbols, name, address);␊
96 }␊
97 } ␊
98 ␊
99 pclose(fpipe);␊
100 ␊
101 free(command);␊
102 }␊
103 ␊
104 ␊
105␉␊
106␉if(start_addr == 0)␊
107␉{␊
108␉␉fprintf(stderr, "Unable to locate Symbol.dylib start function\n");␊
109 ␊
110 //exit(1);␊
111␉}␊
112 else␊
113 {␊
114 add_symbol(&symbols, START_SYMBOL, start_addr);␊
115␉}␊
116␉␊
117␉/* Header command info */␊
118␉dylib.header.ncmds = 2;␊
119␉dylib.header.sizeofcmds = sizeof(dylib) - sizeof(struct mach_header);// + dylib.symtab.nsyms * sizeof(struct nlist) + dylib.symtab.strsize;␊
120␉␊
121␉dylib.header.magic = MH_MAGIC;␊
122␉// TODO: make configurable *or* read from orig file␊
123␉dylib.header.cputype = CPU_TYPE_X86;␊
124␉dylib.header.cpusubtype = /*CPUSUBTYPE_I386*/ 3;␊
125␉dylib.header.filetype = MH_DYLIB;␊
126␉dylib.header.flags = MH_NOUNDEFS | MH_DYLDLINK | MH_NO_REEXPORTED_DYLIBS;␊
127␉␉␊
128␉/* Load Commands - dylib id */␊
129␉dylib.dylib_info.cmd = LC_ID_DYLIB;␊
130␉dylib.dylib_info.cmdsize = sizeof(struct dylib_command) + sizeof(dylib.module_name);␉// todo: verify␊
131␉dylib.dylib_info.dylib.name.offset = sizeof(struct dylib_command);␊
132␉dylib.dylib_info.dylib.timestamp = 0;␉// TODO: populate with time␊
133␉dylib.dylib_info.dylib.current_version = 0;␉␉␉// TODO␊
134␉dylib.dylib_info.dylib.compatibility_version = 0;␉// TODO␊
135␉␊
136␉␊
137␉//int offset = dylib.dylib_info.cmdsize%4 ? 4 - (dylib.dylib_info.cmdsize % 4) : 0;␊
138␉//dylib.dylib_info.cmdsize += offset;␊
139␉//dylib.header.sizeofcmds += offset;␊
140␉␊
141␉sprintf(dylib.module_name, "%s", DYLIB_NAME);␊
142␉␊
143␉/* Load Commands - Symtable */␊
144␉dylib.symtab.cmd = LC_SYMTAB;␊
145␉dylib.symtab.symoff = sizeof(dylib);␉␊
146␉dylib.symtab.nsyms = num_symbols(symbols);␊
147␉dylib.symtab.stroff = sizeof(dylib) + dylib.symtab.nsyms * sizeof(struct nlist);␊
148␉dylib.symtab.strsize = string_size(symbols);␊
149␉dylib.symtab.cmdsize = sizeof(struct symtab_command);␊
150␉␊
151␉␊
152 ␊
153␉FILE* outfile = fopen(argv[argc-1], "w");␊
154␉fwrite(&dylib,␉sizeof(dylib)␉/* Sizeof header + module name */␊
155␉␉␉␉␉, 1, outfile);␊
156␉␊
157␉char* symtab = malloc(dylib.symtab.stroff + dylib.symtab.strsize - sizeof(dylib) + 1); // Add extra 1 for last symbol␊
158␉memset(symtab, 0, dylib.symtab.nsyms * sizeof(struct nlist) + dylib.symtab.strsize + 1);␊
159␉char* orig = symtab;␊
160␉␊
161␉//symtab += offset;␊
162␉␊
163␉␊
164␉while(symbols)␊
165␉{␊
166␉␉␊
167␉␉((struct nlist*)symtab)->n_un.n_strx = symbols->pos;␊
168␉␉((struct nlist*)symtab)->n_type = 0xF;␉// TODO: read from boot.sys␊
169␉␉((struct nlist*)symtab)->n_sect = 0;␊
170␉␉((struct nlist*)symtab)->n_desc = REFERENCE_FLAG_DEFINED;␊
171␉␉((struct nlist*)symtab)->n_value = (uint32_t)symbols->addr;␊
172␉␉symtab+= sizeof(struct nlist);␊
173␉␉␊
174␉␉strcpy(orig + dylib.symtab.stroff - sizeof(dylib) + symbols->pos, symbols->name);␊
175␊
176␉␉symbols = symbols->next;␊
177␉}␊
178␊
179␉fwrite(orig,␉ ␊
180␉␉␉␉␉dylib.symtab.stroff␉+␉␉␉␉␉// Sizeof symbol nlists ␊
181␉␉␉␉␉dylib.symtab.strsize - sizeof(dylib) + 1␉// sizeof symbol strings␊
182␉␉␉␉␉, 1, outfile);␊
183␊
184␉␊
185␉fclose(outfile);␊
186␉␊
187␉exit(0);␊
188}␊
189␊
190int num_symbols(symbolList_t* list)␊
191{␊
192␉int retVal = 0;␊
193␉while(list)␊
194␉{␊
195␉␉retVal++;␊
196␉␉list = list->next;␊
197␉}␊
198␉return retVal;␊
199}␊
200␊
201int string_size(symbolList_t* list)␊
202{␊
203␉int retVal = 0;␊
204␉while(list)␊
205␉{␊
206␉␉retVal += strlen(list->name)+1;␊
207␉␉list = list->next;␊
208␉}␊
209␉return retVal;␊
210␉␊
211}␊
212␊
213void add_symbol(symbolList_t** list, char* name, uint32_t addr)␊
214{␊
215␉symbolList_t* entry = malloc(sizeof(symbolList_t));␊
216␉entry->next = (*list);␊
217␉␊
218␉if(*list) entry->pos = (*list)->pos + strlen((*list)->name) + 1;␊
219␉else entry->pos = 1;␊
220␉*list = entry;␊
221␉␊
222␉entry->addr = addr;␊
223␉entry->name = malloc(strlen(name)+1);␊
224␉strcpy(entry->name, name);␊
225}␊
226

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