(Part #2, after the Internet link broke totally yesterday.)

This is the long-threatened ISO 9660 CD-ROM bootstrap code.

This work has been sponsored by Plutotech International, Inc (who paid
the initial work), and interface business GmbH (where i did most of
the work).  A big thanks also goes to Bruce Evans, for his continuing
help and answering my stupid questions.

The code is basically functioning, with the following caveats:

. Rock Ridge attributes are not yet supported.
. Only SCSI CD-ROMs are supported, since i fail to see any possibility
  to determine the drive type using BIOS functions.  (Even for hard disks,
  this determination is done by a big hack only.)
. El Torito specifies a lot of crap and useless misfeatures, but crucial
  things like the ability to figure out the CD TOC have been ``forgotten''.
  Thus, if you wanna boot a multisession CD, you need to know at which CD
  block your session starts, and need to speciffy it using the @ clause.

. None of the CD-ROM controllers i've seen so far implements the full
  El Torito specification at all.  Adaptec is probably the closest, but
  they miss on non-emulation booting (which would be the most logical
  choice for us).  Thus, the current code bloats the 7.5 KB boot code
  up to 1.44 MB, in order to fake a `floppy' image.

  If you wanna use it, specify this file as the boot image on the
  command-line of the mksiosfs command (option -b).

  Caveat emptor: some versions of the Adaptec BIOS might even fail to
  access the CD-ROM at all, using the BIOS functions.  I think i've
  notice this for ver 1.26, the code has been tested with ver 1.23.

The boot string is as follows:

        [@sess-start] [filename] [-flags]

sess-start      Extend # where the last session starts, measured in
                CD-ROM blocks.

filename        As usual, but the input is case-insensitive by now
                (since we  don't grok RR anyway).

flags           As usual, but -C (use CDROM root f/s) is default, so
                specifying -C will decactivate this option (which is
                probably not what you want :).

A lot of cleanup work is probably required, and some of the files
could/should be merged back to biosboot, perhaps made conditional on
some #ifdef.  The malloc implementation that comes with cdboot might
also be useful for kzipboot.  (I needed a malloc() since the root dir
ain't fixed in size on a CD.)

I've been testing all this with a 2.2-STABLE as the base for biosboot.
I don't expect too many surprises, although i know the biosboot stuff
has been changed a lot in -current lately.  I'm sure Bruce will
comment on all this here anyway. :-)

1 files changed, 179 insertions, 0 deletions

diff --git a/sys/i386/boot/cdboot/malloc.c b/sys/i386/boot/cdboot/malloc.c
new file mode 100644
index 0000000..2b8486d
--- /dev/null
+++ b/sys/i386/boot/cdboot/malloc.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright © 1997 Pluto Technologies International, Inc.  Boulder CO
+ * Copyright © 1997 interface business GmbH, Dresden.
+ *	All rights reserved.
+ *
+ * This code was written by Jörg Wunsch, Dresden.
+ * Direct comments to <joerg_wunsch@interface-business.de>.
+ *
+ * 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.
+ *
+ * $Id$
+ */
+
+/*
+ * Simple memory allocator for the bootstrap loader.  Probably suffers
+ * a lot from fragmentation.
+ */
+
+#include "boot.h"
+
+#include <stddef.h>
+
+/* ``Nobody will ever need more than 640 KB of RAM.'' :-) */
+#define MAXBRK (640 * 1024 * 1024)
+
+/* allocation unit */
+#define NCHUNKS 2048
+
+struct chunk
+{
+	struct chunk *next;
+	size_t len;
+};
+
+static void *brkval;
+static struct chunk *freelist;
+
+void *
+malloc(size_t len)
+{
+	struct chunk *p, *q, *oldp;
+	size_t nelems;
+
+	nelems = (len + sizeof(struct chunk) - 1) / sizeof(struct chunk) + 1;
+
+	/*
+	 * First, see if we can satisfy the request from the freelist.
+	 */
+	for (p = freelist, oldp = 0;
+	     p && p != (struct chunk *)brkval;
+	     oldp = p, p = p->next) {
+		if (p->len > nelems) {
+			/* chunk is larger, shorten, and return the tail */
+			p->len -= nelems;
+			q = p + p->len;
+			q->next = 0;
+			q->len = nelems;
+			q++;
+			return (void *)q;
+		}
+		if (p->len == nelems) {
+			/* exact match, remove from freelist */
+			if (oldp == 0)
+				freelist = p->next;
+			else
+				oldp->next = p->next;
+			p->next = 0;
+			p++;
+			return (void *)p;
+		}
+	}
+	/*
+	 * Nothing found on freelist, try obtaining more space.
+	 */
+	if (brkval == 0)
+		brkval = &end;
+	q = p = (struct chunk *)brkval;
+	if ((int)(p + NCHUNKS) > MAXBRK)
+		return 0;
+
+	p += NCHUNKS;
+	brkval = p;
+
+	q->next = p;
+	q->len = NCHUNKS;
+
+	if (oldp == 0)
+		freelist = q;
+	else {
+		if (oldp + oldp->len == q) {
+			/* extend last chunk */
+			oldp->len += NCHUNKS;
+			oldp->next = p;
+		} else
+			oldp->next = q;
+	}
+
+	return malloc(len);
+}
+
+void
+free(void *ptr)
+{
+	struct chunk *p, *q, *oldp;
+
+	if (ptr == 0)
+		return;
+
+	q = (struct chunk *)ptr;
+	q--;
+	if (q->next != 0) {
+		printf("malloc error: botched ptr to free()\n");
+		return;
+	}
+
+	/*
+	 * Walk the freelist, and insert in the correct sequence.
+	 */
+	for (p = freelist, oldp = 0;
+	     p && p != (struct chunk *)brkval;
+	     oldp = p, p = p->next) {
+		if ((unsigned)p > (unsigned)q) {
+			if (q + q->len == p) {
+				/* aggregate with next chunk */
+				q->len += p->len;
+				q->next = p->next;
+				p = p->next;
+			}
+			if (oldp) {
+				if (oldp + oldp->len == q) {
+				/* aggregate with previous chunk */
+					oldp->len += q->len;
+					oldp->next = p;
+				} else {
+				/* insert into chain */
+					q->next = p;
+					oldp->next = q;
+				}
+				return;
+			}
+			q->next = p;
+			freelist = q;
+		}
+	}
+	if (oldp) {
+		/* we are topmost */
+		if (oldp + oldp->len == q) {
+			/* aggregate with previous chunk */
+			oldp->len += q->len;
+			oldp->next = p;
+		} else {
+			oldp->next = q;
+			q->next = p;
+		}
+		return;
+	}
+	/* we are alone on the freelist */
+	freelist = q;
+}
+