diff options
Diffstat (limited to 'gdb/a.out.encap.h')
| -rw-r--r-- | gdb/a.out.encap.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/gdb/a.out.encap.h b/gdb/a.out.encap.h new file mode 100644 index 0000000..8885455 --- /dev/null +++ b/gdb/a.out.encap.h @@ -0,0 +1,112 @@ +/* + * another try at encapsulating bsd object files in coff + * by Pace Willisson 12/9/88 + * + * This time, we will only use the coff headers to tell the kernel + * how to exec the file. Therefore, the only fields that need to + * be filled in are the scnptr and vaddr for the text and data + * sections, and the vaddr for the bss. As far as coff is concerned, + * there is no symbol table, relocation, or line numbers. + * + * A normal bsd header (struct exec) is placed after the coff headers, + * and before the real text. I defined a the new fields 'a_machtype' + * and a_flags. If a_machtype is M_386, and a_flags & A_ENCAP is + * true, then the bsd header is preceeded by a coff header. Macros + * like N_TXTOFF and N_TXTADDR use this field to find the bsd header. + * + * The only problem is to track down the bsd exec header. The + * macros HEADER_OFFSET, etc do this. Look at nm.c, dis.c, etc + * for examples. + */ + +#include "a.out.gnu.h" + +#define N_FLAGS_COFF_ENCAPSULATE 0x20 /* coff header precedes bsd header */ + +/* Describe the COFF header used for encapsulation. */ + +struct coffheader +{ + /* filehdr */ + unsigned short f_magic; + unsigned short f_nscns; + long f_timdat; + long f_symptr; + long f_nsyms; + unsigned short f_opthdr; + unsigned short f_flags; + /* aouthdr */ + short magic; + short vstamp; + long tsize; + long dsize; + long bsize; + long entry; + long text_start; + long data_start; + struct coffscn + { + char s_name[8]; + long s_paddr; + long s_vaddr; + long s_size; + long s_scnptr; + long s_relptr; + long s_lnnoptr; + unsigned short s_nreloc; + unsigned short s_nlnno; + long s_flags; + } scns[3]; +}; + +/* Describe some of the parameters of the encapsulation, + including how to find the encapsulated BSD header. */ + +#ifdef i386 +#define COFF_MAGIC 0514 /* I386MAGIC */ +#endif + +#if defined(i386) +short __header_offset_temp; +#define HEADER_OFFSET(f) \ + (__header_offset_temp = 0, \ + fread ((char *)&__header_offset_temp, sizeof (short), 1, (f)), \ + fseek ((f), -sizeof (short), 1), \ + __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0) + +#define HEADER_OFFSET_FD(fd) \ + (__header_offset_temp = 0, \ + read ((fd), (char *)&__header_offset_temp, sizeof (short)), \ + lseek ((fd), -sizeof (short), 1), \ + __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0) + + +#else +#define HEADER_OFFSET(f) 0 +#define HEADER_OFFSET_FD(fd) 0 +#endif + +#define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1)) +#define HEADER_SEEK_FD(fd) (lseek ((fd), HEADER_OFFSET_FD((fd)), 1)) + + +/* Describe the characteristics of the BSD header + that appears inside the encapsulation. */ + +#undef _N_HDROFF +#undef N_TXTADDR +#undef N_DATADDR + +#define _N_HDROFF(x) ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ + sizeof (struct coffheader) : 0) + +/* Address of text segment in memory after it is loaded. */ +#define N_TXTADDR(x) \ + ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ + sizeof (struct coffheader) + sizeof (struct exec) : 0) + +#define SEGMENT_SIZE 0x400000 +#define N_DATADDR(x) \ + ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ + (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))) : \ + (N_TXTADDR(x)+(x).a_text)) |