Initial version

code/bin/coff2flat.c

@@ -0,0 +1,126 @@
+/*
+ Copyright (c) 1992 The Regents of the University of California.
+ All rights reserved.  See copyright.h for copyright notice and limitation 
+ of liability and disclaimer of warranty provisions.
+ */
+
+/* This program reads in a COFF format file, and outputs a flat file --
+ * the flat file can then be copied directly to virtual memory and executed.
+ * In other words, the various pieces of the object code are loaded at 
+ * the appropriate offset in the flat file.
+ *
+ * Assumes coff file compiled with -N -T 0 to make sure it's not shared text.
+ */
+
+#define MAIN
+#include "copyright.h"
+#undef MAIN
+
+#include <filehdr.h>
+#include <aouthdr.h>
+#include <scnhdr.h>
+#include <reloc.h>
+#include <syms.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+
+/* NOTE -- once you have implemented large files, it's ok to make this bigger! */
+#define StackSize      		1024      /* in bytes */
+#define ReadStruct(f,s) 	Read(f,&s,sizeof(s))
+
+extern char *malloc();
+
+/* read and check for error */
+void Read(int fd, void *buf, int nBytes)
+{
+    if (read(fd, buf, nBytes) != nBytes) {
+	fprintf(stderr, "File is too short\n");
+	exit(1);
+    }
+}
+
+/* write and check for error */
+void Write(int fd, void *buf, int nBytes)
+{
+    if (write(fd, buf, nBytes) != nBytes) {
+	fprintf(stderr, "Unable to write file\n");
+	exit(1);
+    }
+}
+
+/* do the real work */
+main (int argc, char **argv)
+{
+    int fdIn, fdOut, numsections, i, top, tmp;
+    struct filehdr fileh;
+    struct aouthdr systemh;
+    struct scnhdr *sections;
+    char *buffer;
+
+    if (argc < 2) {
+	fprintf(stderr, "Usage: %s <coffFileName> <flatFileName>\n", argv[0]);
+	exit(1);
+    }
+    
+/* open the object file (input) */
+    fdIn = open(argv[1], O_RDONLY, 0);
+    if (fdIn == -1) {
+	perror(argv[1]);
+	exit(1);
+    }
+
+/* open the flat file (output) */
+    fdOut = open(argv[2], O_RDWR|O_CREAT|O_TRUNC, 0666);
+    if (fdIn == -1) {
+	perror(argv[2]);
+	exit(1);
+    }
+    
+/* Read in the file header and check the magic number. */
+    ReadStruct(fdIn,fileh);
+    if (fileh.f_magic != MIPSELMAGIC) {
+	fprintf(stderr, "File is not a MIPSEL COFF file\n");
+	exit(1);
+    }
+    
+/* Read in the system header and check the magic number */
+    ReadStruct(fdIn,systemh);
+    if (systemh.magic != OMAGIC) {
+	fprintf(stderr, "File is not a OMAGIC file\n");
+	exit(1);
+    }
+    
+/* Read in the section headers. */
+    numsections = fileh.f_nscns;
+    sections = (struct scnhdr *)malloc(fileh.f_nscns * sizeof(struct scnhdr));
+    Read(fdIn, sections, fileh.f_nscns * sizeof(struct scnhdr));
+
+ /* Copy the segments in */
+    printf("Loading %d sections:\n", fileh.f_nscns);
+    for (top = 0, i = 0; i < fileh.f_nscns; i++) {
+	printf("\t\"%s\", filepos 0x%x, mempos 0x%x, size 0x%x\n",
+	      sections[i].s_name, sections[i].s_scnptr,
+	      sections[i].s_paddr, sections[i].s_size);
+	if ((sections[i].s_paddr + sections[i].s_size) > top)
+	    top = sections[i].s_paddr + sections[i].s_size;
+	if (strcmp(sections[i].s_name, ".bss") && /* no need to copy if .bss */
+	    	strcmp(sections[i].s_name, ".sbss")) {
+	    lseek(fdIn, sections[i].s_scnptr, 0);
+	    buffer = malloc(sections[i].s_size);
+	    Read(fdIn, buffer, sections[i].s_size);
+	    Write(fdOut, buffer, sections[i].s_size);
+	    free(buffer);
+	}
+    }
+/* put a blank word at the end, so we know where the end is! */
+    printf("Adding stack of size: %d\n", StackSize);
+    lseek(fdOut, top + StackSize - 4, 0);
+    tmp = 0;
+    Write(fdOut, &tmp, 4);
+
+    close(fdIn);
+    close(fdOut);
+}