3 ms·

Sorry about that! Any good alternatives?

cnvogel 13y ago
Instead of letting the C-compiler compile a huge array, you can use objcopy. objcopy -I binary -O elf32-littlearm -B arm /etc/passwd passwd.o cc -c -o testme.o testme.c cc testme.o passwd.o -o testme --- testme.c --- #include <unistd.h> #include <stdlib.h> #include <stdio.h> /* "address" of symbol _size is the size of the objcopied file */ extern void _binary__etc_passwd_size; /* ..._start is the first byte of data */ extern char _binary__etc_passwd_start; /* ..._end is the one following the last byte of data */ extern char _binary__etc_passwd_end; int main(int argc, char **argv) { /* "address" of the symbol ..._size is the size */ /* you could also do size = &..._end - &..._start; */ size_t size = &_binary__etc_passwd_size; printf("Dumping /etc/passwd, in memory @%p, size is %ld.\n", &_binary__etc_passwd_start, size); write(1,&_binary__etc_passwd_start,size); exit(0); } --- demo --- chris@raspberrypi ~/tmp/objcopy_to_carray $ ./testme Dumping /etc/passwd, in memory @0x106b0, size is 607. root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/bin/false daemon:x:2:2:daemon:/sbin:/bin/false mail:x:8:12:mail:/var/spool/mail:/bin/false (...remaining data omitted...) --- dumping headers of the passwd.o file --- chris@raspberrypi ~/tmp/objcopy_to_carray $ objdump -x passwd.o passwd.o: file format elf32-littlearm passwd.o architecture: arm, flags 0x00000010: HAS_SYMS start address 0x00000000 private flags = 0: [APCS-32] [FPA float format] Sections: Idx Name Size VMA LMA File off Algn 0 .data 0000025f 00000000 00000000 00000034 2**0 CONTENTS, ALLOC, LOAD, DATA SYMBOL TABLE: 00000000 l d .data 00000000 .data 00000000 g .data 00000000 _binary__etc_passwd_start 0000025f g .data 00000000 _binary__etc_passwd_end 0000025f g *ABS* 00000000 _binary__etc_passwd_size

Instead of letting the C-compiler compile a huge array, you can use objcopy. objcopy -I binary -O elf32-littlearm -B arm /etc/passwd passwd.o cc -c -o testme.o testme.c cc testme.o passwd.o -o testme --- testme.c --- #include <unistd.h> #include <stdlib.h> #include <stdio.h> /* "address" of symbol _size is the size of the objcopied file */ extern void _binary__etc_passwd_size; /* ..._start is the first byte of data */ extern char _binary__etc_passwd_start; /* ..._end is the one following the last byte of data */ extern char _binary__etc_passwd_end; int main(int argc, char **argv) { /* "address" of the symbol ..._size is the size */ /* you could also do size = &..._end - &..._start; */ size_t size = &_binary__etc_passwd_size; printf("Dumping /etc/passwd, in memory @%p, size is %ld.\n", &_binary__etc_passwd_start, size); write(1,&_binary__etc_passwd_start,size); exit(0); } --- demo --- chris@raspberrypi ~/tmp/objcopy_to_carray $ ./testme Dumping /etc/passwd, in memory @0x106b0, size is 607. root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/bin/false daemon:x:2:2:daemon:/sbin:/bin/false mail:x:8:12:mail:/var/spool/mail:/bin/false (...remaining data omitted...) --- dumping headers of the passwd.o file --- chris@raspberrypi ~/tmp/objcopy_to_carray $ objdump -x passwd.o passwd.o: file format elf32-littlearm passwd.o architecture: arm, flags 0x00000010: HAS_SYMS start address 0x00000000 private flags = 0: [APCS-32] [FPA float format] Sections: Idx Name Size VMA LMA File off Algn 0 .data 0000025f 00000000 00000000 00000034 2**0 CONTENTS, ALLOC, LOAD, DATA SYMBOL TABLE: 00000000 l d .data 00000000 .data 00000000 g .data 00000000 _binary__etc_passwd_start 0000025f g .data 00000000 _binary__etc_passwd_end 0000025f g *ABS* 00000000 _binary__etc_passwd_size