This program to compress a kernel with. You loose all the symbols, so

usability is limited.  Very useful on fixit floppies &c.

Obtained from:	Linux via 386BSD

usr.bin/kzip/Makefile

@@ -0,0 +1,9 @@
+#	$Id$
+
+PROG=	kzip
+NOMAN=	toobad
+
+# Where we load the compressed stuff to uncompress it
+CFLAGS+= -DKZBASE=\"0x300000\"
+
+.include <bsd.prog.mk>

usr.bin/kzip/kzip.c

@@ -0,0 +1,254 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (C) 1993  Hannu Savolainen
+ * Ported to 386bsd by Serge Vakulenko
+ * based on tools/build.c by Linus Torvalds
+ * $Id$
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/file.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <a.out.h>
+#include <string.h>
+
+int
+main(int argc, char **argv)
+{
+	pid_t Pext, Pgzip, Ppiggy, Pld;
+	int pipe1[2], pipe2[2];
+	int status,fdi,fdo;
+	char obj[BUFSIZ];
+	char out[BUFSIZ];
+
+	if(argc != 2) {
+		fprintf(stderr,"usage:\n\t%s kernel\n",argv[0]);
+		return 2;
+	}
+
+	strcpy(obj,argv[1]); strcat(obj,".o");
+	strcpy(out,argv[1]); strcat(out,".kz");
+
+	fdi = open(argv[1],O_RDONLY);
+	if(fdi<0) {
+		perror(argv[1]);
+		return 2;
+	}
+	fdo = open(obj,O_WRONLY|O_TRUNC|O_CREAT,0666);
+	if(fdo<0) {
+		perror(obj);
+		return 2;
+	}
+	
+	if (pipe(pipe1) < 0) { perror("pipe()"); return 1; }
+
+	if (pipe(pipe2) < 0) { perror("pipe()"); return 1; }
+
+	Pext = fork();
+	if (Pext < 0) { perror("fork()"); return 1; }
+	if (!Pext) {
+		dup2(fdi,0);
+		dup2(pipe1[1],1);
+		close(pipe1[0]); close(pipe1[1]);
+		close(pipe2[0]); close(pipe2[1]);
+		close(fdi); close(fdo);
+		extract(argv[1]);
+		exit(0);
+	}
+
+	Pgzip = fork();
+	if (Pgzip < 0) { perror("fork()"); return 1; }
+	if (!Pgzip) {
+		dup2(pipe1[0],0);
+		dup2(pipe2[1],1);
+		close(pipe1[0]); close(pipe1[1]);
+		close(pipe2[0]); close(pipe2[1]);
+		close(fdi); close(fdo);
+		execlp("gzip", "gzip", "-9", "-n", 0);
+		exit (0);
+	}
+
+	Ppiggy = fork();
+	if (Ppiggy < 0) { perror("fork()"); return 1; }
+	if (!Ppiggy) {
+		dup2(pipe2[0],0);
+		dup2(fdo,1);
+		close(pipe1[0]); close(pipe1[1]);
+		close(pipe2[0]); close(pipe2[1]);
+		close(fdi); close(fdo);
+		piggyback(obj);
+		exit(0);
+	}
+
+	close(pipe1[0]); close(pipe1[1]);
+	close(pipe2[0]); close(pipe2[1]);
+	close(fdi); close(fdo);
+
+	if (waitpid(Pext, &status,0) < 0) 
+		{ perror("waitpid(Pextract)"); return 1; }
+
+	if(status) {
+		fprintf(stderr,"extract returned %x\n",status);
+		return 3;
+	}
+
+	if (waitpid(Pgzip, &status,0) < 0) 
+		{ perror("waitpid(Pgzip)"); return 1; }
+	
+	if(status) {
+		fprintf(stderr,"gzip returned %x\n",status);
+		return 3;
+	}
+
+	if (waitpid(Ppiggy, &status,0) < 0) 
+		{ perror("waitpid(Ppiggy)"); return 1; }
+
+	if(status) {
+		fprintf(stderr,"piggyback returned %x\n",status);
+		return 3;
+	}
+
+	Pld = fork();
+	if (Pld < 0) { perror("fork()"); return 1; }
+	if (!Pld) {
+		execlp("ld",
+			"ld",
+			"-Bstatic",
+			"-Z",
+			"-T",
+			KZBASE,
+			"-o",
+			out,
+			"/usr/lib/kzip.o",
+			obj,
+			0);
+		exit(2);
+	}
+
+	if (waitpid(Pld, &status,0) < 0) 
+		{ perror("waitpid(Pld)"); return 1; }
+
+	if(status) {
+		fprintf(stderr,"ld returned %x\n",status);
+		return 3;
+	}
+
+	unlink(obj);
+	exit(0);
+}
+
+int 
+extract (char *file)
+{
+	int sz;
+	char buf[BUFSIZ];
+	struct exec hdr;
+
+	if (read (0, (char *)&hdr, sizeof(hdr)) != sizeof(hdr)) {
+		perror(file);
+		exit(2);
+	}
+	if (hdr.a_magic != ZMAGIC) {
+		fprintf(stderr,"Bad magic in file %s, probably not a kernel\n",
+			file);
+		exit(2);
+	}
+	if (lseek (0, N_TXTOFF(hdr), 0) < 0) {
+		perror(file);
+		exit(2);
+	}
+
+	sz = N_SYMOFF (hdr) - N_TXTOFF (hdr);
+
+	while (sz) {
+		int l, n;
+
+		l = sz;
+		if (l > sizeof(buf))
+			l = sizeof(buf);
+
+		n = read (0, buf, l);
+		if (n != l) {
+			if (n == -1) 
+				perror (file);
+			else
+				fprintf (stderr, "Unexpected EOF\n");
+
+			exit(1);
+		}
+
+		write (1, buf, l);
+		sz -= l;
+	}
+	exit(0);
+}
+
+
+char string_names[] = {"_input_data\0_input_len\0"};
+
+struct nlist var_names[2] = {                           /* Symbol table */
+	{ { (char*)  4 }, N_EXT|N_TEXT, 0, 0, 0 },      /* _input_data  */
+	{ { (char*) 16 }, N_EXT|N_TEXT, 0, 0, 0 },      /* _input_len */
+};
+
+int 
+piggyback(char *file)
+{
+	int n, len;
+	struct exec hdr;                        /* object header */
+	char image[1024*1024];                   /* kernel image buffer */
+
+	len = 0;
+	while ((n = read (0, &image[len], sizeof(image)-len+1)) > 0)
+	      len += n;
+
+	if (n < 0) {
+		perror ("stdin");
+		exit (1);
+	}
+
+	if (len >= sizeof(image)) {
+		fprintf (stderr,"Input too large\n");
+		exit (1);
+	}
+
+	/*
+	 *      Output object header
+	 */
+	memset(&hdr,0,sizeof hdr);
+	hdr.a_magic = OMAGIC;
+	hdr.a_text = len + sizeof(long);
+	hdr.a_syms = sizeof(var_names);
+	write (1, (char *)&hdr, sizeof(hdr));
+
+	/*
+	 *      Output text segment (compressed system & len)
+	 */
+	write (1, image, len);
+	write (1, (char *)&len, sizeof(len));
+
+	/*
+	 *      Output symbol table
+	 */
+	var_names[1].n_value = len;
+	write (1, (char *)&var_names, sizeof(var_names));
+
+	/*
+	 *      Output string table
+	 */
+	len = sizeof(string_names) + sizeof(len);
+	write (1, (char *)&len, sizeof(len));
+	write (1, string_names, sizeof(string_names));
+
+	return (0);
+}