Add support for creating a.out output files in addition to ELF.

This allows booting from compressed binaries using older bootstraps.

Thanks to: dwmalone

usr.sbin/kgzip/Makefile

@@ -3,7 +3,7 @@
 MAINTAINER=	rnordier
 
 PROG=	kgzip
-SRCS=	kgzip.c elfhdr.c kgzcmp.c kgzld.c xio.c
+SRCS=	kgzip.c aouthdr.c elfhdr.c kgzcmp.c kgzld.c xio.c
 MAN8=	kgzip.8
 CFLAGS+=-pedantic \
 	-W -Wall -Waggregate-return -Wbad-function-cast -Wcast-align \

usr.sbin/kgzip/aouthdr.c

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2000 Robert Nordier
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <stddef.h>
+#include "aouthdr.h"
+
+#define KGZ_FIX_NSIZE	0	/* Run-time fixup */
+
+const struct kgz_aouthdr0 aouthdr0 = {
+    /* a.out header */
+    {
+	MID_I386 << 020 | OMAGIC,			/* a_midmag */
+	0,						/* a_text */
+	sizeof(struct kgz_hdr) + KGZ_FIX_NSIZE, 	/* a_data */
+	0,						/* a_bss */
+	sizeof(struct nlist) * KGZ__STNUM,		/* a_syms */
+	0,						/* a_entry */
+	0,						/* a_trsize */
+	0						/* a_drsize */
+    }
+};
+
+const struct kgz_aouthdr1 aouthdr1 = {
+    /* Symbol table */
+    {
+	{
+	    {
+		(char *)offsetof(struct kgz__strtab,
+				 kgz)			/* n_un */
+	    },
+	    N_DATA | N_EXT,				/* n_type */
+	    AUX_OBJECT, 				/* n_other */
+	    0,						/* n_desc */
+	    0						/* n_value */
+	},
+	{
+	    {
+		(char *)offsetof(struct kgz__strtab,
+				 kgz_ndata)		/* n_un */
+	    },
+	    N_DATA | N_EXT,				/* n_type */
+	    AUX_OBJECT, 				/* n_other */
+	    0,						/* n_desc */
+	    sizeof(struct kgz_hdr)			/* n_value */
+	}
+    },
+    /* String table */
+    {
+	sizeof(struct kgz__strtab),			/* length */
+	KGZ__STR_KGZ,					/* kgz */
+	KGZ__STR_KGZ_NDATA				/* kgz_ndata */
+    }
+};

usr.sbin/kgzip/aouthdr.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2000 Robert Nordier
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <a.out.h>
+#include "kgz.h"
+
+/* Relocatable header: part 0 */
+struct kgz_aouthdr0 {
+    struct exec a;
+};
+
+/* Symbol table entries */
+#define KGZ__STNUM		2
+
+/* Symbol table strings */
+#define KGZ__STR_KGZ		"_kgz"
+#define KGZ__STR_KGZ_NDATA	"_kgz_ndata"
+
+/* String table */
+struct kgz__strtab {
+    unsigned long length;
+    char kgz[sizeof(KGZ__STR_KGZ)];
+    char kgz_ndata[sizeof(KGZ__STR_KGZ_NDATA)];
+};
+
+/* Relocatable header: part 1 */
+struct kgz_aouthdr1 {
+    struct nlist st[KGZ__STNUM];
+    struct kgz__strtab strtab;
+};
+
+extern const struct kgz_aouthdr0 aouthdr0;
+extern const struct kgz_aouthdr1 aouthdr1;

usr.sbin/kgzip/kgzcmp.c

@@ -39,16 +39,12 @@
 #include <a.out.h>
 #include <elf.h>
 
+#include "aouthdr.h"
 #include "elfhdr.h"
 #include "kgzip.h"
 
-#define KGZOFF (sizeof(struct kgz_elfhdr) + sizeof(struct kgz_hdr))
-
-#define F_AOUT	1		/* Input format: a.out */
-#define F_ELF	2		/* Input format: ELF32 */
-
 static void mk_data(const struct iodesc *i, const struct iodesc *,
-		    struct kgz_hdr *);
+		    struct kgz_hdr *, size_t);
 static int ld_elf(const struct iodesc *, const struct iodesc *,
 		  struct kgz_hdr *, const Elf32_Ehdr *);
 static int ld_aout(const struct iodesc *, const struct iodesc *,
@@ -61,7 +57,6 @@ void
 kgzcmp(struct kgz_hdr *kh, const char *f1, const char *f2)
 {
     struct iodesc idi, ido;
-    struct kgz_elfhdr ehdr;
 
     if ((idi.fd = open(idi.fname = f1, O_RDONLY)) == -1)
 	err(1, "%s", idi.fname);
@@ -72,15 +67,31 @@ kgzcmp(struct kgz_hdr *kh, const char *f1, const char *f2)
     kh->ident[1] = KGZ_ID1;
     kh->ident[2] = KGZ_ID2;
     kh->ident[3] = KGZ_ID3;
-    xseek(&ido, KGZOFF);
-    mk_data(&idi, &ido, kh);
+    mk_data(&idi, &ido, kh,
+	    (format == F_AOUT ? sizeof(struct kgz_aouthdr0) :
+				sizeof(struct kgz_elfhdr)) +
+	     sizeof(struct kgz_hdr));
     kh->dload &= 0xffffff;
     kh->entry &= 0xffffff;
-    xseek(&ido, 0);
-    ehdr = elfhdr;
-    ehdr.st[KGZ_ST_KGZ_NDATA].st_size = kh->nsize;
-    ehdr.sh[KGZ_SH_DATA].sh_size += kh->nsize;
-    xwrite(&ido, &ehdr, sizeof(ehdr));
+    if (format == F_AOUT) {
+	struct kgz_aouthdr0 ahdr0 = aouthdr0;
+	struct kgz_aouthdr1 ahdr1 = aouthdr1;
+	unsigned x = (sizeof(struct kgz_hdr) + kh->nsize) & (16 - 1);
+	if (x) {
+	    x = 16 - x;
+	    xzero(&ido, x);
+	}
+	xwrite(&ido, &ahdr1, sizeof(ahdr1));
+	ahdr0.a.a_data += kh->nsize + x;
+	xseek(&ido, 0);
+	xwrite(&ido, &ahdr0, sizeof(ahdr0));
+    } else {
+	struct kgz_elfhdr ehdr = elfhdr;
+	ehdr.st[KGZ_ST_KGZ_NDATA].st_size = kh->nsize;
+	ehdr.sh[KGZ_SH_DATA].sh_size += kh->nsize;
+	xseek(&ido, 0);
+	xwrite(&ido, &ehdr, sizeof(ehdr));
+    }
     xwrite(&ido, kh, sizeof(*kh));
     xclose(&ido);
     xclose(&idi);
@@ -91,7 +102,7 @@ kgzcmp(struct kgz_hdr *kh, const char *f1, const char *f2)
  */
 static void
 mk_data(const struct iodesc * idi, const struct iodesc * ido,
-	struct kgz_hdr * kh)
+	struct kgz_hdr * kh, size_t off)
 {
     union {
 	struct exec ex;
@@ -112,6 +123,7 @@ mk_data(const struct iodesc * idi, const struct iodesc * ido,
 	fmt = F_AOUT;
     if (!fmt)
 	errx(1, "%s: Format not supported", idi->fname);
+    xseek(ido, off);
     if (pipe(fd))
 	err(1, NULL);
     switch (pid = fork()) {
@@ -143,7 +155,7 @@ mk_data(const struct iodesc * idi, const struct iodesc * ido,
 	errx(1, "%s: Invalid format", idi->fname);
     if (fstat(ido->fd, &sb))
 	err(1, "%s", ido->fname);
-    kh->nsize = sb.st_size - KGZOFF;
+    kh->nsize = sb.st_size - off;
 }
 
 /*

usr.sbin/kgzip/kgzip.8

@@ -33,6 +33,7 @@
 .Sh SYNOPSIS
 .Nm kgzip
 .Op Fl cv
+.Op Fl f Ar format
 .Op Fl l Ar loader
 .Op Fl o Ar output
 .Ar file
@@ -57,8 +58,7 @@ an executable suitable for booting with either the second- or
 third-level bootstraps.
 .El
 .Pp
-Supported input formats are ELF and a.out ZMAGIC; the output format
-is always ELF.	Only 32-bit objects are supported.
+Supported object formats are 32-bit ELF and a.out ZMAGIC.
 .Pp
 If the
 .Ar file
@@ -73,6 +73,16 @@ The options are:
 Omit the link phase.
 .It Fl v
 Display object file information.
+.It Fl f Ar format
+Use
+.Ar format
+as the output format, where
+.Ar format
+is
+.Sq aout
+or
+.Sq elf .
+The default format is ELF.
 .It Fl l Ar loader
 Link
 .Ar loader
@@ -113,8 +123,8 @@ The default loader
 .Sh SEE ALSO
 .Xr gzip 1 ,
 .Xr ld 1 ,
-.Xr elf 5 ,
 .Xr a.out 5 ,
+.Xr elf 5 ,
 .Xr boot 8 ,
 .Xr loader 8
 .Sh DIAGNOSTICS

usr.sbin/kgzip/kgzip.c

@@ -49,6 +49,7 @@ static const char rcsid[] =
 #define SFX_MAX 	5	/* Size of larger filename suffix */
 
 const char *loader = "/usr/lib/kgzldr.o";  /* Default loader */
+int format;			/* Output format */
 
 char *tname;			/* Name of temporary file */
 
@@ -70,11 +71,11 @@ main(int argc, char *argv[])
 
     tmpdir = getenv("TMPDIR");
     if (asprintf(&tname, "%s/kgzXXXXXXXXXX", tmpdir == NULL ? _PATH_TMP : tmpdir) == -1)
-        errx(1, "Out of memory");
+	errx(1, "Out of memory");
 
     output = NULL;
     cflag = vflag = 0;
-    while ((c = getopt(argc, argv, "cvl:o:")) != -1)
+    while ((c = getopt(argc, argv, "cvf:l:o:")) != -1)
 	switch (c) {
 	case 'c':
 	    cflag = 1;
@@ -82,6 +83,14 @@ main(int argc, char *argv[])
 	case 'v':
 	    vflag = 1;
 	    break;
+	case 'f':
+	    if (!strcmp(optarg, "aout"))
+		format = F_AOUT;
+	    else if (!strcmp(optarg, "elf"))
+		format = F_ELF;
+	    else
+		errx(1, "%s: Unknown format", optarg);
+	    break;
 	case 'l':
 	    loader = optarg;
 	    break;
@@ -98,8 +107,11 @@ main(int argc, char *argv[])
     atexit(cleanup);
     mk_fn(cflag, *argv, output, fn);
     memset(&kh, 0, sizeof(kh));
-    if (fn[FN_SRC])
+    if (fn[FN_SRC]) {
+	if (!format)
+	    format = F_ELF;
 	kgzcmp(&kh, fn[FN_SRC], fn[FN_OBJ]);
+    }
     if (!cflag)
 	kgzld(&kh, fn[FN_OBJ], fn[FN_KGZ]);
     if (vflag)
@@ -159,6 +171,6 @@ static void
 usage(void)
 {
     fprintf(stderr,
-	    "usage: kgzip [-cv] [-l file] [-o filename] file\n");
+      "usage: kgzip [-cv] [-f format] [-l file] [-o filename] file\n");
     exit(1);
 }

usr.sbin/kgzip/kgzip.h

@@ -28,6 +28,9 @@
 
 #include "kgz.h"
 
+#define F_AOUT	1		/* Format: a.out */
+#define F_ELF	2		/* Format: ELF32 */
+
 /* Used by I/O routines */
 struct iodesc {
     const char *fname;		/* File name */
@@ -35,6 +38,7 @@ struct iodesc {
 };
 
 extern const char *loader;	/* Default loader */
+extern int format;		/* Output format */
 
 void kgzcmp(struct kgz_hdr *, const char *, const char *);
 void kgzld(struct kgz_hdr *, const char *, const char *);

usr.sbin/kgzip/kgzld.c

@@ -36,11 +36,10 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "aouthdr.h"
 #include "elfhdr.h"
 #include "kgzip.h"
 
-#define KGZOFF sizeof(struct kgz_elfhdr)
-
 #define align(x, y) (((x) + (y) - 1) & ~((y) - 1))
 
 /*
@@ -58,7 +57,23 @@ kgzld(struct kgz_hdr * kh, const char *f1, const char *f2)
     if (strcmp(kh->ident, "KGZ")) {
 	if ((idi.fd = open(idi.fname = f1, O_RDONLY)) == -1)
 	    err(1, "%s", idi.fname);
-	n = xread(&idi, kh, sizeof(*kh), KGZOFF);
+	if (!format) {
+	    union {
+		struct exec ex;
+		Elf32_Ehdr ee;
+	    } hdr;
+	    n = xread(&idi, &hdr, sizeof(hdr), 0);
+	    if (n >= sizeof(hdr.ee) && IS_ELF(hdr.ee))
+		format = F_ELF;
+	    else if (n >= sizeof(hdr.ex) &&
+		     N_GETMAGIC(hdr.ex) == OMAGIC)
+		format = F_AOUT;
+	    if (!format)
+		errx(1, "%s: Format not supported", idi.fname);
+	}
+	n = xread(&idi, kh, sizeof(*kh),
+		  format == F_AOUT ? sizeof(struct kgz_aouthdr0)
+				   : sizeof(struct kgz_elfhdr));
 	xclose(&idi);
 	if (n != sizeof(*kh) || strcmp(kh->ident, "KGZ"))
 	    errx(1, "%s: Invalid format", idi.fname);
@@ -68,7 +83,12 @@ kgzld(struct kgz_hdr * kh, const char *f1, const char *f2)
     case -1:
 	err(1, NULL);
     case 0:
-	execlp("ld", "ld", "-Ttext", addr, "-o", f2, loader, f1, NULL);
+	if (format == F_AOUT)
+	    execlp("ld", "ld", "-aout", "-Z", "-T", addr, "-o", f2,
+		   loader, f1, NULL);
+	else
+	    execlp("ld", "ld", "-Ttext", addr, "-o", f2, loader, f1,
+		   NULL);
 	warn(NULL);
 	_exit(1);
     default: