feat(bin/readcoff): display symtab

bin/ld/main.c

@@ -5,11 +5,13 @@
 static char *prg_name;
 static char *outfile = "a.out";
 
-typedef struct section
+typedef struct {
-{
 	
 } Section;
 
+typedef struct {
+
+} Object;
 
 static void
 usage(int retcode)
@@ -45,7 +47,7 @@ main(int argc, char **argv)
 	FILHDR fhdr;
 	SCNHDR shdr;
 	uint8_t *buffer;
-    SYM entry;
+    SYMENT entry;
 	RELOC reloc;
 	int idx;
 
@@ -108,7 +110,7 @@ main(int argc, char **argv)
 
 	for (idx = 0; idx < fhdr.f_nsyms; idx++)
 	{
-		fread(&entry, 1, SYMSZ, fp);
+		fread(&entry, 1, SYMESZ, fp);
 		printf("name: %c%c%c%c%c%c%c%c\n", entry.n_name[0], entry.n_name[1],entry.n_name[2],entry.n_name[3],entry.n_name[4],entry.n_name[5],entry.n_name[6],entry.n_name[7]);
 		printf("\tvalue: %d\n", entry.n_value);
 		printf("\tscnum: %hd\n", entry.n_scnum);

bin/readcoff/main.c

@@ -2,6 +2,7 @@
 #include <stdio.h>
 #include <time.h>
 #include <string.h>
+#include <assert.h>
 #ifndef __stupidos__
 # include <libgen.h>
 #endif
@@ -29,9 +30,9 @@ static const char *mach = NULL;
 
 /* */
 static int display_header = 0;
-static int display_program_header = 0;
+static int display_optional_header = 0;
 static int display_sections = 0;
-
+static int display_symbol_table = 0;
 
 static void
 usage(int retval)
@@ -64,6 +65,7 @@ main(int argc, char **argv)
 	FILHDR file_header;
 	AOUTHDR aout_header;
 	SCNHDR section_header;
+	SYMENT sym_entry;
 	char name[9];
 	char *type;
 	FILE *fp;
@@ -82,7 +84,8 @@ main(int argc, char **argv)
 		{
 			case 'a':
 				display_header = 1;
-				display_program_header = 1;
+				display_optional_header = 1;
+				display_symbol_table = 1;
 				display_sections = 1;
 				break;
 			case 'H':
@@ -169,6 +172,23 @@ main(int argc, char **argv)
 			printf("[%2d] %-8s  %-8s  %08X  %08X\n", idx, name, type, section_header.s_vaddr, section_header.s_scnptr);
 			printf("     %08X\n", section_header.s_size);
 		}
+		printf("\n");
+	}
+
+	if (display_symbol_table)
+	{
+		printf("Symbol table contains %d entries:\n", file_header.f_nsyms);
+		printf("  Num:    Value  Type Name\n");
+		assert(sizeof(SYMENT) == SYMESZ);
+		for (idx = 0; idx <= file_header.f_nsyms; idx++)
+		{
+			fseek(fp, file_header.f_symptr + (SYMESZ * idx), SEEK_SET);
+			fread(&sym_entry, 1, SYMESZ, fp);
+			memset(name, 0, 9);
+			memcpy(name, sym_entry.n_name, 8);
+			printf("  %d:    %08x  %hd %s\n", idx, sym_entry.n_value, sym_entry.n_type, name);
+		}
+
 	}
 
 	return (EXIT_SUCCESS);

docs/COFF.txt

@@ -79,3 +79,4 @@ About: Usefull links
 - <https://wiki.osdev.org/COFF>
 - <http://www.delorie.com/djgpp/doc/coff/filhdr.html>
 - <Official Microsoft COFF Specification (2016) at https://web.archive.org/web/20230703150217/https%3A%2F%2Fdownload.microsoft.com%2Fdownload%2F9%2Fc%2F5%2F9c5b2167-8017-4bae-9fde-d599bac8184a%2Fpecoff_v83.docx>
+- <UNIX System V/386 Release 3.2 Programmer's Guide, Volume II at http://bitsavers.org/pdf/att/unix/System_V_386_Release_3.2/UNIX_System_V_386_Release_3.2_Programmers_Guide_Vol2_1989.pdf>

include/coff.h

@@ -16,7 +16,30 @@ typedef struct filehdr
 
 # define FILHSZ sizeof(FILHDR)
 
-# define F_MACH_I386 0x014c
+# define F_MACH_UNKNOWN   0x0
+# define F_MACH_AM33      0x1d3
+# define F_MACH_AMD64     0x8664
+# define F_MACH_ARM       0x1c0
+# define F_MACH_ARMNT     0x1c4
+# define F_MACH_EBC       0xebc
+# define F_MACH_I386      0x14c
+# define F_MACH_IA64      0x200
+# define F_MACH_M32R      0x9041
+# define F_MACH_MIPS16    0x266
+# define F_MACH_MIPSFPU   0x366
+# define F_MACH_MIPSFPU16 0x466
+# define F_MACH_POWERPC   0x1f0
+# define F_MACH_POWERPCFP 0x1f1
+# define F_MACH_R4000     0x166
+# define F_MACH_RISCV32   0x5032
+# define F_MACH_RISCV64   0x5064
+# define F_MACH_RISCV128  0x5128
+# define F_MACH_SH3       0x1a2
+# define F_MACH_SH3DSP    0x1a3
+# define F_MACH_SH4       0x1a6
+# define F_MACH_SH5       0x1a8
+# define F_MACH_THUMB     0x1c2
+# define F_MACH_WCEMIPSV2 0x169
 
 # define F_RELFLG   0x0001
 # define F_EXEC     0x0002
@@ -82,11 +105,12 @@ typedef struct reloc
 } __attribute__((packed)) RELOC;
 # define RELSZ 10
 
-# define R_ABS     0x000
+# define R_ABS     0
-# define R_DIR16   0x001
+# define R_DIR16   01
-# define R_REL16   0x002
+# define R_REL16   02
-# define R_DIR32   0x006
+# define R_DIR32   06
-# define R_PCRLONG 0x024
+# define R_SEG12   011
+# define R_PCRLONG 024
 
 typedef struct lineno
 {
@@ -99,22 +123,132 @@ typedef struct lineno
 } __attribute__((packed)) LINENO;
 # define LINESZ 6
 
-typedef struct sym
-{
-	uint8_t n_name[8];
-	int32_t n_value;
-	int16_t n_scnum;
-	uint16_t n_type;
-	uint8_t n_sclass;
-	uint8_t n_numaux;
-} __attribute__((packed)) SYM;
-# define SYMSZ 18
-
 # define N_UNDEF (0x0)
 # define N_ABS   (-0x1)
 # define N_DEBUG (-0x2)
 
-# define C_EXT  0x2
+# define C_EFCN    -1   /* physical end of a function */
-# define C_STAT 0x3
+# define C_NULL    0
+# define C_AUTO    1
+# define C_EXT     2  /* external symbol */
+# define C_STAT    3  /* static */
+# define C_REG     4  /* register var */
+# define C_EXTDEF  5  /* external definition */
+# define C_LABEL   6
+# define C_ULABEL  7  /* undefined label */
+# define C_MOS     8  /* member of struct */
+# define C_ARG     9
+# define C_STRTAG  10 /* struct tag */
+# define C_MOU     11 /* member of union */
+# define C_UNTAG   12 /* union tag */
+# define C_TPDEF   13 /* typedef */
+# define C_USTATIC 14
+# define C_ENTAG   15
+# define C_MOE     16
+# define C_REGPARM 17
+# define C_FIELD   18
+# define C_BLOCK   100
+# define C_FCN     101
+# define C_EOS     102
+# define C_FILE    103
+# define C_LINE    104
+# define C_ALIAS   105
+# define C_HIDDEN  106
+
+# define T_NULL   0
+# define T_ARG    1
+# define T_CHAR   2
+# define T_SHORT  3
+# define T_INT    4
+# define T_LONG   5
+# define T_FLOAT  6
+# define T_DOUBLE 7
+# define T_STRUCT 8
+# define T_UNION  9
+# define T_ENUM   10
+# define T_MOE    11
+# define T_UCHAR  12
+# define T_USHORT 13
+# define T_UINT   14
+# define T_ULONG  15
+
+# define DT_NON 0
+# define DT_PTR 1
+# define DT_FCN 2
+# define DT_ARY 3
+
+typedef struct syment
+{
+	union
+	{
+		char _n_name[8]; /* symbol name */
+		struct
+		{
+			int32_t _n_zeroes; /* symbol name */
+			int32_t _n_offset; /* loc in str table */
+		} _n_n;
+		uint32_t _n_nptr[2];
+	} _n;
+	uint32_t n_value;
+	int16_t n_scnum;
+	uint16_t n_type;
+	int8_t n_sclass;
+	int8_t n_numaux;
+} __attribute__((packed)) SYMENT;
+
+# define SYMESZ 18
+
+# define n_name   _n._n_name
+# define n_zeroes _n._n_n._n_zeroes
+# define n_offset _n._n_n._n_offset
+# define n_nptr  _n._n_nptr[1]
+
+typedef union auxent
+{
+	struct 
+	{
+		int32_t x_tagndx;
+		union
+		{
+			struct
+			{
+				uint16_t x_lnno;
+				uint16_t x_size;
+			} x_lnsz;
+			int32_t x_fsize;
+		} x_misc;
+		union
+		{
+			struct
+			{
+				int32_t x_lnnoptr;
+				int32_t x_endndx;
+			} x_fcn;
+			struct 
+			{
+				uint16_t x_dimen[4];
+			} x_ary;
+		} x_fcnary;
+		uint16_t x_tvndx;
+	} x_sym;
+	struct
+	{
+		char x_fname[14];
+	} x_file;
+	struct
+	{
+		int32_t x_scnlen;
+		uint16_t x_nreloc;
+		uint16_t x_nlinno;
+	} x_scn;
+	struct
+	{
+		int32_t x_tvfill;
+		uint16_t x_tvlen;
+		uint16_t x_tvran[2];
+	} x_tv;
+} AUXENT;
+
+# define AUXESZ 18
 
 #endif /* !COFF_H */