Enter cdboot, a CD-specific second-stage bootrap.

Testing krw@ and todd@, thanks.

assistance, testing and ok weingart@

9 files changed, 630 insertions, 18 deletions

diff --git a/sys/arch/i386/include/biosvar.h b/sys/arch/i386/include/biosvar.h
index 7e4d98933b4..e6cfe1a57c6 100644
--- a/sys/arch/i386/include/biosvar.h
+++ b/sys/arch/i386/include/biosvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: biosvar.h,v 1.43 2004/06/13 21:49:16 niklas Exp $	*/
+/*	$OpenBSD: biosvar.h,v 1.44 2004/06/23 00:21:49 tom Exp $	*/
 
 /*
  * Copyright (c) 1997-1999 Michael Shalayeff
@@ -158,6 +158,7 @@ typedef struct _bios_diskinfo {
 #define BDI_INVALID	0x00000001	/* I/O error during checksumming */
 #define BDI_GOODLABEL	0x00000002	/* Had SCSI or ST506/ESDI disklabel */
 #define BDI_BADLABEL	0x00000004	/* Had another disklabel */
+#define BDI_EL_TORITO	0x00000008	/* 2,048-byte sectors */
 #define BDI_PICKED	0x80000000	/* kernel-only: cksum matched */
 
 } bios_diskinfo_t;
diff --git a/sys/arch/i386/stand/cdboot/Makefile b/sys/arch/i386/stand/cdboot/Makefile
new file mode 100644
index 00000000000..3adc18677f7
--- /dev/null
+++ b/sys/arch/i386/stand/cdboot/Makefile
@@ -0,0 +1,46 @@
+#	$OpenBSD: Makefile,v 1.1 2004/06/23 00:21:49 tom Exp $
+
+.include "${.CURDIR}/../Makefile.inc"
+
+MAN=	cdboot.8
+
+.if ${MACHINE} == "i386"
+PROG=	cdboot
+LD?=	ld
+SIZE?=	size
+LDFLAGS+=-nostdlib -Bstatic
+INSTALL_STRIP=
+
+LDFLAGS+=-Ttext $(LINKADDR) -N -x -noinhibit-exec
+CLEANFILES+=	crt0.o
+SRCS=	srt0.S
+
+SRCS+=	boot.c cmd.c vars.c bootarg.c conf.c
+S	=${.CURDIR}/../../../..
+SADIR=	${.CURDIR}/..
+
+LDADD=	${LIBSA} ${LIBZ}
+DPADD=	${LIBSA} ${LIBZ}
+
+.PATH:	${S}/stand/boot
+
+${PROG}: $(OBJS) $(DPADD)
+	$(LD) $(LDFLAGS) -o ${PROG} $(OBJS) $(LDADD)
+	@$(SIZE) ${PROG}
+	@if [ -x ${.OBJDIR}/${PROG} ]; then \
+		objcopy -O binary ${PROG} ${.OBJDIR}/.tmp;\
+		mv -f ${.OBJDIR}/.tmp ${.OBJDIR}/${PROG}; \
+		ls -l ${.OBJDIR}/${PROG}; \
+	fi
+
+.else
+NOPROG=
+.endif
+
+.include <bsd.prog.mk>
+
+CPPFLAGS+=-DBOOTMAGIC=$(BOOTMAGIC) ${DEBUGFLAGS}
+CPPFLAGS+=-DLINKADDR=${LINKADDR}
+CFLAGS+=${SACFLAGS} -D__INTERNAL_LIBSA_CREAD
+#AFLAGS+=-Wa,-R
+# AFLAGS+=-Wa,-a
diff --git a/sys/arch/i386/stand/cdboot/cdboot.8 b/sys/arch/i386/stand/cdboot/cdboot.8
new file mode 100644
index 00000000000..1cad9712be3
--- /dev/null
+++ b/sys/arch/i386/stand/cdboot/cdboot.8
@@ -0,0 +1,96 @@
+.\"	$OpenBSD: cdboot.8,v 1.1 2004/06/23 00:21:49 tom Exp $
+.\" Copyright (c) 2004 Tom Cosgrove
+.\" Copyright (c) 2003 Matthias Drochner
+.\" Copyright (c) 1999 Doug White
+.\" 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+.\"
+.Dd June 13, 2004
+.Dt CDBOOT 8 i386
+.Os
+.Sh NAME
+.Nm cdboot
+.Nd
+i386-specific second-stage CD-specific bootstrap
+.Sh DESCRIPTION
+.Nm
+is a modified version of the i386 second-stage bootstrap program,
+.Xr boot 8 ,
+configured to be run by the
+.Ox
+El Torito CD-ROM boot sector
+.Pa cdbr .
+.Nm
+will look for an
+.Pa /etc/boot.conf
+configuration
+file on the CD-ROM.
+If it finds one, it processes the commands within it.
+.Pp
+.Nm
+then sits in a loop,
+processing commands given by the user.
+It accepts all the commands accepted by
+.Xr boot 8 .
+.Pp
+If no commands are given for a short time,
+.Nm
+will then attempt to load an
+.Ox
+kernel
+.Pa /bsd
+from the CD.
+It may be told to boot an alternative kernel,
+either by commands in the
+.Pa boot.conf
+file,
+or by commands typed by the user at the
+.Ic boot>
+prompt.
+.Sh FILES
+.Bl -tag -width /usr/mdec/cdbootxx -compact
+.It Pa /usr/mdec/cdboot
+CD-specific second-stage bootstrap
+.It Pa /etc/boot.conf
+.Nm
+configuration file (read from CD)
+.El
+.Sh EXAMPLES
+Boot the install kernel:
+.Pp
+.Dl boot> bsd.rd
+.Sh SEE ALSO
+.Xr boot 8 ,
+.Xr boot_i386 8
+.Rs
+.%T "El Torito" Bootable CD-ROM Format Specification
+.%N Version 1.0
+.%D January 25, 1995
+.%A Curtis E. Stevens, Phoenix Technologies
+.%A Stan Merkin, IBM
+.Re
+.Sh HISTORY
+The
+.Nm
+command first appeared in
+.Ox 3.6 .
diff --git a/sys/arch/i386/stand/cdboot/conf.c b/sys/arch/i386/stand/cdboot/conf.c
new file mode 100644
index 00000000000..d51dd50e1e9
--- /dev/null
+++ b/sys/arch/i386/stand/cdboot/conf.c
@@ -0,0 +1,107 @@
+/*	$OpenBSD: conf.c,v 1.1 2004/06/23 00:21:49 tom Exp $	*/
+
+/*
+ * Copyright (c) 2004 Tom Cosgrove
+ * Copyright (c) 1996 Michael Shalayeff
+ * 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 ``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 REGENTS OR CONTRIBUTORS 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.
+ */
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <libsa.h>
+#include <lib/libsa/ufs.h>
+#include <lib/libsa/cd9660.h>
+#ifdef notdef
+#include <lib/libsa/fat.h>
+#include <lib/libsa/nfs.h>
+#include <lib/libsa/tftp.h>
+#include <lib/libsa/netif.h>
+#endif
+#include <lib/libsa/unixdev.h>
+#include <biosdev.h>
+#include <dev/cons.h>
+#include "debug.h"
+
+const char version[] = "1.00";
+int	debug = 1;
+
+#undef _TEST
+
+
+void (*sa_cleanup)(void) = NULL;
+
+
+void (*i386_probe1[])(void) = {
+	ps2probe, gateA20on, debug_init, cninit, apmprobe,
+	pciprobe, /* smpprobe, */ memprobe
+};
+void (*i386_probe2[])(void) = {
+	diskprobe, cdprobe
+};
+
+struct i386_boot_probes probe_list[] = {
+	{ "probing", i386_probe1, NENTS(i386_probe1) },
+	{ "disk",    i386_probe2, NENTS(i386_probe2) },
+};
+int nibprobes = NENTS(probe_list);
+
+struct fs_ops file_system[] = {
+	{ ufs_open,    ufs_close,    ufs_read,    ufs_write,    ufs_seek,
+	  ufs_stat,    ufs_readdir    },
+	{ cd9660_open, cd9660_close, cd9660_read, cd9660_write, cd9660_seek,
+	  cd9660_stat, cd9660_readdir },
+#ifdef notdef
+	{ tftp_open,   tftp_close,   tftp_read,   tftp_write,   tftp_seek,
+	  tftp_stat,   tftp_readdir   },
+	{ nfs_open,    nfs_close,    nfs_read,    nfs_write,    nfs_seek,
+	  nfs_stat,    nfs_readdir    },
+	{ fat_open,    fat_close,    fat_read,    fat_write,    fat_seek,
+	  fat_stat,    fat_readdir    },
+#endif
+#ifdef _TEST
+	{ null_open,   null_close,   null_read,   null_write,   null_seek,
+	  null_stat,   null_readdir   }
+#endif
+};
+int nfsys = NENTS(file_system);
+
+struct devsw	devsw[] = {
+#ifdef _TEST
+	{ "UNIX", unixstrategy, unixopen, unixclose, unixioctl },
+#else
+	{ "BIOS", biosstrategy, biosopen, biosclose, biosioctl },
+#endif
+};
+int ndevs = NENTS(devsw);
+
+struct consdev constab[] = {
+#ifdef _TEST
+	{ unix_probe, unix_init, unix_getc, unix_putc },
+#else
+	{ pc_probe, pc_init, pc_getc, pc_putc },
+	{ com_probe, com_init, com_getc, com_putc },
+#endif
+	{ NULL }
+};
+struct consdev *cn_tab = constab;
diff --git a/sys/arch/i386/stand/cdboot/srt0.S b/sys/arch/i386/stand/cdboot/srt0.S
new file mode 100644
index 00000000000..261191b1e9f
--- /dev/null
+++ b/sys/arch/i386/stand/cdboot/srt0.S
@@ -0,0 +1,243 @@
+/*	$OpenBSD: srt0.S,v 1.1 2004/06/23 00:21:49 tom Exp $	*/
+
+/*
+ * Copyright (c) 1997 Michael Shalayeff
+ * 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 ``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 REGENTS OR CONTRIBUTORS 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.
+ *
+ */
+#include <machine/asm.h>
+#include <assym.h>
+
+#define BOOTSTACK 0xfffc
+
+	.globl	_C_LABEL(end)
+	.globl	_C_LABEL(edata)
+	.globl	_C_LABEL(boot)
+	.globl	_C_LABEL(_rtt)
+	.globl	_C_LABEL(bios_bootdev)
+	.globl	_ASM_LABEL(pmm_init)
+	.globl	Gdtr
+
+	.text
+	.code16
+	.globl	_start
+_start:
+#ifdef DEBUG
+	movl	$0xb80a0, %ebx
+	addr32 movl $0x07420742, (%ebx)
+#endif
+
+/* Clobbers %ax, maybe more */
+#define	putc(c)		movb	$c, %al;	call	Lchr
+
+	/*
+	 * We operate as a no emulation boot image, as defined by the
+	 * El Torito Bootable CD-ROM Format Specification v1.0.  We use
+	 * a load segment of 0x07C0 (physical load address of 0x7C00).
+	 * Like the standard /boot, we are linked to run at 0x40120
+	 * (load address 0x40000), so we relocate to there.
+	 *
+	 * From 0x7C00 to 0x40000 is 0x38400 (230400) bytes, so don't
+	 * have to worry about an overlapping copy until cdboot is
+	 * over 225 KB.
+	 *
+	 * Note that there are other reasons to be worried if
+	 * sizeof(/boot) > 64 KB.  So currently we copy a maximum of 64 KB.
+	 *
+	 * Our cdbr CD-ROM boot sector passes us the drive number to use
+	 * in %dl.
+	 */
+#define CDBOOTADDR	0x7c00		/* Address where BIOS loads up */
+	xorw	%ax, %ax
+	movw	%ax, %ss		/* CPU disables interrupts till... */
+	movl	$CDBOOTADDR-4, %esp	/* after this instruction */
+
+	movw	$(CDBOOTADDR >> 4), %ax
+	movw	%ax, %ds
+	xorw	%si, %si		/* Where we're coming from */
+
+	movw	$(LINKADDR >> 4), %ax
+	movw	%ax, %es		/* Set %es = 0x4000 */
+	xorw	%di, %di		/* Where we're going to */
+
+	movl	$_C_LABEL(end), %ecx
+	subl	$_C_LABEL(_start), %ecx	/* How big are we? */
+
+	cld
+	rep; movsb			/* Copy into place */
+
+	jmpl	$(LINKADDR >> 4), $(relocated-_start)	/* Now relocate */
+
+relocated:
+	/*
+	 * In 16-bit mode, we have segment registers == 0x4012, and
+	 * offsets work from here, with offset(_start) == 0.
+	 *
+	 * In 32-bit mode, we have a flat memory model, where
+	 * offset(_start) == 0x40120.  This is how we're linked.
+	 *
+	 * Now transition to protected mode.
+	 *
+	 * First, initialise the global descriptor table.
+	 */
+	cli
+	push	%cs
+	pop	%ds
+	addr32 data32 lgdt (Gdtr - LINKADDR)
+
+	movl	%cr0, %eax
+	orl	$CR0_PE, %eax
+	data32 movl %eax, %cr0
+	data32 ljmp $8, $1f		/* Seg sel 0x08 is flat 32-bit code */
+1:
+	.code32
+	movl	$0x10, %eax		/* Seg sel 0x10 is flat 32-bit data */
+	mov	%ax, %ds
+	mov	%ax, %es
+	mov	%ax, %fs
+	mov	%ax, %gs
+	mov	%ax, %ss
+	movl	$BOOTSTACK, %esp
+#ifdef DEBUG
+	movl	$0xb8000, %ebx
+	movl	$0x07420742, (%ebx)
+#endif
+
+	movzbl	%dl, %eax
+	orl	$0x100, %eax		/* Indicate that it's a cd device */
+	pushl	%eax			/* boot() takes this as a parameter */
+
+	/* Set up an interrupt descriptor table for protected mode. */
+	call	_ASM_LABEL(pmm_init)
+#ifdef DEBUG
+	movl	$0xb80a4, %ebx
+	movl	$0x07520752, (%ebx)
+#endif
+
+	/* Zero .bss */
+	xorl	%eax, %eax
+	movl	$_C_LABEL(end), %ecx
+	subl	$_C_LABEL(edata), %ecx
+	movl	$_C_LABEL(edata), %edi
+	cld
+	rep;	stosb
+
+	/* Set our program name ("CDBOOT", not "BOOT"). */
+	movl	$cd_progname, %eax
+	movl	%eax, progname
+
+	/* Put the boot device number into the globals that need it */
+	popl	%eax			/* Get this back from the stack */
+	pushl	%eax			/* boot() takes this as a parameter */
+	movl	%eax, _C_LABEL(bios_bootdev)
+	movl	%eax, _C_LABEL(bios_cddev)
+
+	/*
+	 * Now call "main()".
+	 *
+	 * We run in flat 32-bit protected mode, with no address mapping.
+	 */
+#ifdef DEBUG
+	movl	$0xb8004, %ebx
+	movl	$0x07410741, (%ebx)
+#endif
+	call	_C_LABEL(boot)
+
+	/* boot() should not return.  If it does, reset computer. */
+	jmp	_C_LABEL(_rtt)
+
+ENTRY(debugchar)
+	pushl	%ebx
+	movl	8(%esp), %ebx
+	addl	%ebx, %ebx
+	addl	$0xb8000, %ebx
+
+	xorl	%eax, %eax
+	movb	12(%esp), %al
+	
+	andl	$0xfffffffe, %ebx
+	movb	%al, (%ebx)
+	popl	%ebx
+	ret
+
+	.code16
+
+/*
+ * Display ASCIZ string at %si.  Trashes %si.
+ */
+Lstr:
+	pushw	%ax
+	cld
+1:
+	lodsb			/* %al = *%si++ */
+	testb	%al, %al
+	jz	1f
+	call    Lchr
+	jmp	1b
+1:	popw	%ax
+	ret
+
+/*
+ * Write out value in %ax in hex
+ */
+hex_word:
+	pushw	%ax
+	mov	%ah, %al
+	call	hex_byte
+	popw	%ax
+	/* fall thru */
+/*
+ * Write out value in %al in hex
+ */
+hex_byte:
+	pushw	%ax
+	shrb	$4, %al
+	call	hex_nibble
+	popw	%ax
+	/* fall thru */
+
+/* Write out nibble in %al */
+hex_nibble:
+	and	$0x0F, %al
+	add	$'0', %al
+	cmpb	$'9', %al
+	jbe	Lchr
+	addb	$'A'-'9'-1, %al
+	/* fall thru to Lchr */
+/*
+ *	Lchr: write the character in %al to console
+ */
+Lchr:
+	pushw	%bx
+	movb	$0x0e, %ah
+	xorw	%bx, %bx
+	incw	%bx		/* movw $0x01, %bx */
+	int	$0x10
+	popw	%bx
+	ret
+
+cd_progname:
+	.asciz	"CDBOOT"
+
+	.end
diff --git a/sys/arch/i386/stand/libsa/biosdev.c b/sys/arch/i386/stand/libsa/biosdev.c
index 4ad9aaa1f15..84a0387e1d4 100644
--- a/sys/arch/i386/stand/libsa/biosdev.c
+++ b/sys/arch/i386/stand/libsa/biosdev.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: biosdev.c,v 1.68 2004/03/09 19:12:12 tom Exp $	*/
+/*	$OpenBSD: biosdev.c,v 1.69 2004/06/23 00:21:49 tom Exp $	*/
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -34,6 +34,7 @@
 #include <machine/tss.h>
 #include <machine/biosvar.h>
 #include <lib/libsa/saerrno.h>
+#include <isofs/cd9660/iso.h>
 #include "disk.h"
 #include "debug.h"
 #include "libsa.h"
@@ -47,6 +48,7 @@ static int EDD_rw (int, int, u_int64_t, u_int32_t, void *);
 
 extern int debug;
 int bios_bootdev;
+int bios_cddev = -1;		/* Set by srt0 if coming from CD */
 
 #if 0
 struct biosdisk {
@@ -241,17 +243,35 @@ biosd_io(int rw, bios_diskinfo_t *bd, daddr_t off, int nsect, void *buf)
 	int dev = bd->bios_number;
 	int j, error;
 	void *bb;
+	int bbsize = nsect * DEV_BSIZE;
+
+	if (bd->flags & BDI_EL_TORITO) {	/* It's a CD device */
+		dev &= 0xff;			/* Mask out this flag bit */
 
-	/* use a bounce buffer to not cross 64k DMA boundary */
-	if ((((u_int32_t)buf) & ~0xffff) !=
-	    (((u_int32_t)buf + nsect * DEV_BSIZE) & ~0xffff)) {
+		/*
+		 * sys/lib/libsa/cd9600.c converts 2,048-byte CD sectors
+		 * to DEV_BSIZE blocks before calling the device strategy
+		 * routine.  However, the El Torito spec says that the
+		 * BIOS will work in 2,048-byte sectors.  So shift back.
+		 */
+		off >>= (ISO_DEFAULT_BLOCK_SHIFT - DEV_BSHIFT);
+		nsect >>= (ISO_DEFAULT_BLOCK_SHIFT - DEV_BSHIFT);
+	}
+
+	/*
+	 * Use a bounce buffer to not cross 64k DMA boundary, and to
+	 * not access above 1 MB.
+	 */
+	if (((((u_int32_t)buf) & ~0xffff) !=
+	    (((u_int32_t)buf + bbsize) & ~0xffff)) ||
+	    (((u_int32_t)buf) > 0x100000)) {
 		/*
 		 * XXX we believe that all the io is buffered
 		 * by fs routines, so no big reads anyway
 		 */
-		bb = alloca(nsect * DEV_BSIZE);
+		bb = alloca(bbsize);
 		if (rw != F_READ)
-			bcopy(buf, bb, nsect * DEV_BSIZE);
+			bcopy(buf, bb, bbsize);
 	} else
 		bb = buf;
 
@@ -302,7 +322,7 @@ biosd_io(int rw, bios_diskinfo_t *bd, daddr_t off, int nsect, void *buf)
 	}
 
 	if (bb != buf && rw == F_READ)
-		bcopy(bb, buf, nsect * DEV_BSIZE);
+		bcopy(bb, buf, bbsize);
 
 #ifdef BIOS_DEBUG
 	if (debug) {
@@ -442,6 +462,9 @@ biosopen(struct open_file *f, ...)
 		break;
 	case 2:  /* fd */
 		break;
+	case 6:  /* cd */
+		biosdev = bios_bootdev & 0xff;
+		break;
 	default:
 		return ENXIO;
 	}
diff --git a/sys/arch/i386/stand/libsa/dev_i386.c b/sys/arch/i386/stand/libsa/dev_i386.c
index 45afe2243c7..4db4b1e0b6f 100644
--- a/sys/arch/i386/stand/libsa/dev_i386.c
+++ b/sys/arch/i386/stand/libsa/dev_i386.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dev_i386.c,v 1.28 2004/03/09 19:12:12 tom Exp $	*/
+/*	$OpenBSD: dev_i386.c,v 1.29 2004/06/23 00:21:49 tom Exp $	*/
 
 /*
  * Copyright (c) 1996-1999 Michael Shalayeff
@@ -97,12 +97,18 @@ devboot(dev_t bootdev, char *p)
 	*p++ = '/';
 	*p++ = 'r';
 #endif
-	if (bootdev & 0x80)
-		*p++ = 'h';
-	else
-		*p++ = 'f';
-	*p++ = 'd';
-	*p++ = '0' + (bootdev & 0x7f);
+	if (bootdev & 0x100) {
+		*p++ = 'c';
+		*p++ = 'd';
+		*p++ = '0';
+	} else {
+		if (bootdev & 0x80)
+			*p++ = 'h';
+		else
+			*p++ = 'f';
+		*p++ = 'd';
+		*p++ = '0' + (bootdev & 0x7f);
+	}
 	*p++ = 'a';
 	*p = '\0';
 }
diff --git a/sys/arch/i386/stand/libsa/diskprobe.c b/sys/arch/i386/stand/libsa/diskprobe.c
index 27cc00c7d47..838117b6a7c 100644
--- a/sys/arch/i386/stand/libsa/diskprobe.c
+++ b/sys/arch/i386/stand/libsa/diskprobe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: diskprobe.c,v 1.26 2004/03/19 13:48:18 tom Exp $	*/
+/*	$OpenBSD: diskprobe.c,v 1.27 2004/06/23 00:21:49 tom Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -53,6 +53,8 @@ struct disklist_lh disklist;
 struct diskinfo *bootdev_dip;
 
 extern int debug;
+extern int bios_bootdev;
+extern int bios_cddev;
 
 /* Probe for all BIOS floppies */
 static void
@@ -205,6 +207,84 @@ diskprobe(void)
 }
 
 
+void
+cdprobe(void)
+{
+	struct diskinfo *dip;
+	int cddev = bios_cddev & 0xff;
+
+	/* Another BIOS boot device... */
+
+	if (bios_cddev == -1)			/* Not been set, so don't use */
+		return;
+
+	dip = alloc(sizeof(struct diskinfo));
+	bzero(dip, sizeof(*dip));
+
+#if 0
+	if (bios_getdiskinfo(cddev, &dip->bios_info)) {
+		printf(" <!cd0>");	/* XXX */
+		free(dip, 0);
+		return;
+	}
+#endif
+
+	printf(" cd0");
+
+	dip->bios_info.bios_number = cddev;
+	dip->bios_info.bios_edd = 1;		/* Use the LBA calls */
+	dip->bios_info.flags |= BDI_GOODLABEL | BDI_EL_TORITO;
+	dip->bios_info.checksum = 0;		 /* just in case */
+	dip->bios_info.bsd_dev =
+	    MAKEBOOTDEV(0, 0, 0, 0xff, RAW_PART);
+
+	/* Create an imaginary disk label */
+	dip->disklabel.d_secsize = 2048;
+	dip->disklabel.d_ntracks = 1;
+	dip->disklabel.d_nsectors = 100;
+	dip->disklabel.d_ncylinders = 1;
+	dip->disklabel.d_secpercyl = dip->disklabel.d_ntracks *
+	    dip->disklabel.d_nsectors;
+	if (dip->disklabel.d_secpercyl == 0) {
+		dip->disklabel.d_secpercyl = 100;
+		/* as long as it's not 0, since readdisklabel divides by it */
+	}
+
+	strncpy(dip->disklabel.d_typename, "ATAPI CD-ROM",
+	    sizeof(dip->disklabel.d_typename));
+	dip->disklabel.d_type = DTYPE_ATAPI;
+
+	strncpy(dip->disklabel.d_packname, "fictitious",
+	    sizeof(dip->disklabel.d_packname));
+	dip->disklabel.d_secperunit = 100;
+	dip->disklabel.d_rpm = 300;
+	dip->disklabel.d_interleave = 1;
+	dip->disklabel.d_flags = D_REMOVABLE;
+
+	dip->disklabel.d_bbsize = 2048;
+	dip->disklabel.d_sbsize = 2048;
+
+	dip->disklabel.d_magic = DISKMAGIC;
+	dip->disklabel.d_magic2 = DISKMAGIC;
+	dip->disklabel.d_checksum = dkcksum(&dip->disklabel);
+
+	/* 'a' partition covering the "whole" disk */
+	dip->disklabel.d_partitions[0].p_offset = 0;
+	dip->disklabel.d_partitions[0].p_size = 100;
+	dip->disklabel.d_partitions[0].p_fstype = FS_UNUSED;
+
+	/* The raw partition is special */
+	dip->disklabel.d_partitions[RAW_PART].p_offset = 0;
+	dip->disklabel.d_partitions[RAW_PART].p_size = 100;
+	dip->disklabel.d_partitions[RAW_PART].p_fstype = FS_UNUSED;
+
+	dip->disklabel.d_npartitions = RAW_PART + 1;
+
+	/* Add to queue of disks */
+	TAILQ_INSERT_TAIL(&disklist, dip, list);
+}
+
+
 /* Find info on given BIOS disk */
 struct diskinfo *
 dklookup(int dev)
@@ -227,9 +307,18 @@ dump_diskinfo(void)
 	for (dip = TAILQ_FIRST(&disklist); dip; dip = TAILQ_NEXT(dip, list)) {
 		bios_diskinfo_t *bdi = &dip->bios_info;
 		int d = bdi->bios_number;
+		int u = d & 0x7f;
+		char c;
+
+		if (bdi->flags & BDI_EL_TORITO) {
+			c = 'c';
+			u = 0;
+		} else {
+		    	c = (d & 0x80) ? 'h' : 'f';
+		}
 
 		printf("%cd%d\t0x%x\t%s\t%d\t%d\t%d\t0x%x\t0x%x\n",
-		    (d & 0x80)?'h':'f', d & 0x7F, d,
+		    c, u, d,
 		    (bdi->flags & BDI_BADLABEL)?"*none*":"label",
 		    bdi->bios_cylinders, bdi->bios_heads, bdi->bios_sectors,
 		    bdi->flags, bdi->checksum);
diff --git a/sys/arch/i386/stand/libsa/libsa.h b/sys/arch/i386/stand/libsa/libsa.h
index f2cae0987f1..2da7e66bd79 100644
--- a/sys/arch/i386/stand/libsa/libsa.h
+++ b/sys/arch/i386/stand/libsa/libsa.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: libsa.h,v 1.39 2004/03/19 13:48:18 tom Exp $	*/
+/*	$OpenBSD: libsa.h,v 1.40 2004/06/23 00:21:49 tom Exp $	*/
 
 /*
  * Copyright (c) 1996-1999 Michael Shalayeff
@@ -49,6 +49,7 @@ void ps2probe(void);
 void pciprobe(void);
 void memprobe(void);
 void diskprobe(void);
+void cdprobe(void);
 void apmprobe(void);
 void apmfixmem(void);
 void dump_biosmem(bios_memmap_t *);