--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/objdump.c	Sat Jan 24 02:34:25 2009 +0000
@@ -0,0 +1,303 @@
+/*
+objdump.c
+Copyright © 2009 William Astle
+
+This file is part of LWLINK
+
+LWLINK is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+A standalone program to dump an object file in a text form to stdout
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "util.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+void read_lwobj16v0(unsigned char *filedata, long filesize);
+
+/*
+The logic of reading the entire file into memory is simple. All the symbol
+names in the file are NUL terminated strings and can be used directly without
+making additional copies.
+*/
+int main(int argc, char **argv)
+{
+	int i;
+	long size;
+	FILE *f;
+	long bread;
+	unsigned char *filedata;
+	
+	if (argc != 2)
+	{
+		fprintf(stderr, "Must specify exactly one input file.\n");
+		exit(1);
+	}
+
+	f = fopen(argv[1], "rb");
+	if (!f)
+	{
+		fprintf(stderr, "Can't open file %s:", argv[1]);
+		perror("");
+		exit(1);
+	}
+	fseek(f, 0, SEEK_END);
+	size = ftell(f);
+	rewind(f);
+		
+	filedata = lw_malloc(size);
+		
+	bread = fread(filedata, 1, size, f);
+	if (bread < size)
+	{
+		fprintf(stderr, "Short read on file %s (%ld/%ld):", argv[1], bread, size);
+		perror("");
+		exit(1);
+	}
+			
+	fclose(f);
+		
+	if (!memcmp(filedata, "LWOBJ16", 8))
+	{
+		// read v0 LWOBJ16 file
+		read_lwobj16v0(filedata, size);
+	}
+	else
+	{
+		fprintf(stderr, "%s: unknown file format\n", argv[1]);
+		exit(1);
+	}
+	exit(0);
+}
+
+// this macro is used to bail out if we run off the end of the file data
+// while parsing - it keeps the code below cleaner
+#define NEXTBYTE()	do { cc++; if (cc > filesize) { fprintf(stderr, "***invalid file format\n"); exit(1); } } while (0)
+// this macro is used to refer to the current byte in the stream
+#define CURBYTE()	(filedata[cc < filesize ? cc : filesize - 1])
+// this one will leave the input pointer past the trailing NUL
+#define CURSTR()	read_lwobj16v0_str(&cc, &filedata, filesize)
+unsigned char *read_lwobj16v0_str(long *cc1, unsigned char **filedata1, long filesize)
+{
+	int cc = *cc1;
+	unsigned char *filedata = *filedata1;
+	unsigned char *fp;
+	fp = &CURBYTE();
+	while (CURBYTE())
+		NEXTBYTE();
+	NEXTBYTE();
+	*cc1 = cc;
+	*filedata1 = filedata;
+	return fp;
+}
+// the function below can be switched to dealing with data coming from a
+// source other than an in-memory byte pool by adjusting the input data
+// in "fn" and the above two macros
+void read_lwobj16v0(unsigned char *filedata, long filesize)
+{
+	unsigned char *fp;
+	long cc;
+	int val;
+	int bss;
+
+	static char *opernames[] = {
+		"?",
+		"PLUS",
+		"MINUS",
+		"TIMES",
+		"DIVIDE",
+		"MOD",
+		"INTDIV",
+		"BWAND",
+		"BWOR",
+		"BWXOR",
+		"AND",
+		"OR",
+		"NEG",
+		"COM"
+	};
+	static const int numopers = 13;
+		
+	// start reading *after* the magic number
+	cc = 8;
+	
+	while (1)
+	{
+		bss = 0;
+		
+		// bail out if no more sections
+		if (!(CURBYTE()))
+			break;
+		
+		fp = CURSTR();
+		
+		printf("SECTION %s\n", fp);
+		
+		// read flags
+		while (CURBYTE())
+		{
+			switch (CURBYTE())
+			{
+			case 0x01:
+				printf("    FLAG: BSS\n");
+				bss = 1;
+				break;
+
+			default:
+				printf("    FLAG: %02X (unknown)\n", CURBYTE());
+				break;
+			}
+			NEXTBYTE();
+		}
+		// skip NUL terminating flags
+		NEXTBYTE();
+		
+		printf("    Local symbols:\n");
+		// now parse the local symbol table
+		while (CURBYTE())
+		{
+			fp = CURSTR();
+
+			// fp is the symbol name
+			val = (CURBYTE()) << 8;
+			NEXTBYTE();
+			val |= (CURBYTE());
+			NEXTBYTE();
+			// val is now the symbol value
+			
+			printf("        %s=%04X\n", fp, val);
+			
+		}
+		// skip terminating NUL
+		NEXTBYTE();
+
+		printf("    Exported symbols\n");
+				
+		// now parse the exported symbol table
+		while (CURBYTE())
+		{
+			fp = CURSTR();
+
+			// fp is the symbol name
+			val = (CURBYTE()) << 8;
+			NEXTBYTE();
+			val |= (CURBYTE());
+			NEXTBYTE();
+			// val is now the symbol value
+			
+			printf("        %s=%04X\n", fp, val);
+		}
+		// skip terminating NUL
+		NEXTBYTE();
+		
+		// now parse the incomplete references and make a list of
+		// external references that need resolution
+		printf("    Incomplete references\n");
+		while (CURBYTE())
+		{
+			printf("        (");
+			// parse the expression
+			while (CURBYTE())
+			{
+				int tt = CURBYTE();
+				NEXTBYTE();
+				switch (tt)
+				{
+				case 0x01:
+					// 16 bit integer
+					tt = CURBYTE() << 8;
+					NEXTBYTE();
+					tt |= CURBYTE();
+					NEXTBYTE();
+					// normalize for negatives...
+					if (tt > 0x7fff)
+						tt -= 0x10000;
+					printf(" I16=%d", tt);
+					break;
+				
+				case 0x02:
+					// external symbol reference
+					printf(" ES=%s", CURSTR());
+					break;
+					
+				case 0x03:
+					// internal symbol reference
+					printf(" IS=%s", CURSTR());
+					break;
+				
+				case 0x04:
+					// operator
+					if (CURBYTE() > 0 && CURBYTE() <= numopers)
+						printf(" OP=%s", opernames[CURBYTE()]);
+					else
+						printf(" OP=?");
+					NEXTBYTE();
+					break;
+
+				case 0x05:
+					// section base reference (NULL internal reference is
+					// the section base address
+					printf(" SB");
+					break;
+					
+				default:
+					printf(" ERR");
+				}
+			}
+			// skip the NUL
+			NEXTBYTE();
+			
+			// fetch the offset
+			val = CURBYTE() << 8;
+			NEXTBYTE();
+			val |= CURBYTE() & 0xff;
+			NEXTBYTE();
+			printf(" ) @ %04X\n", val);
+		}
+		// skip the NUL terminating the relocations
+		NEXTBYTE();
+				
+		// now set code location and size and verify that the file
+		// contains data going to the end of the code (if !SECTION_BSS)
+		val = CURBYTE() << 8;
+		NEXTBYTE();
+		val |= CURBYTE();
+		NEXTBYTE();
+		
+		printf("    CODE %04X bytes", val);
+		
+		// skip the code if we're not in a BSS section
+		if (!bss)
+		{
+			int i;
+			for (i = 0; i < val; i++)
+			{
+				if (! (i % 16))
+				{
+					printf("\n    %04X ", i);
+				}
+				printf("%02X", CURBYTE());
+				NEXTBYTE();
+			}
+		}
+		printf("\n");
+	}
+}