This became a frequently requested item now.

The files in this directory are modified version of "biosboot".  The
only difference is in that they perform their I/O via a serial port,
so their preferrable usage is to form bootblocks for systems where the
kernel happens to have an "options COMCONSOLE".  Most of the code is
actually shared with "biosboot", and make will not (and should not)
descend into this directory by default.  It is in the responsibility
of the user to build these bootblocks instead of the original ones.

3 files changed, 709 insertions, 0 deletions

diff --git a/sys/i386/boot/serialboot/Makefile b/sys/i386/boot/serialboot/Makefile
new file mode 100644
index 0000000..a282843
--- /dev/null
+++ b/sys/i386/boot/serialboot/Makefile
@@ -0,0 +1,59 @@
+#	$Id: Makefile,v 1.22 1994/11/05 21:06:16 ache Exp $
+#
+
+PROG=	boot
+
+.PATH:	${.CURDIR}/../biosboot
+# Order is very important on the SRCS line for this prog
+SRCS=	start.S table.c boot2.S boot.c asm.S bios.S io.c disk.c sys.c
+
+BINDIR=		/usr/mdec
+BINMODE=	444
+CFLAGS=         -O -DDO_BAD144 -DBOOTWAIT=${BOOTWAIT} -DCOMCONSOLE=0x3F8
+CFLAGS+=	-DBOOTSEG=${BOOTSEG} -DBOOTSTACK=${BOOTSTACK}
+CFLAGS+=	-I${.CURDIR} -I${.CURDIR}/../biosboot -I${.CURDIR}/../..
+CLEANFILES+=	boot.nohdr boot.strip boot1 boot2
+DPADD=		${LIBC}
+LDFLAGS+=	-N -T 0 -nostdlib
+LDADD=		-lc
+LINKS=		${BINDIR}/sdboot ${BINDIR}/wdboot\
+		${BINDIR}/sdboot ${BINDIR}/fdboot\
+		${BINDIR}/bootsd ${BINDIR}/bootwd\
+		${BINDIR}/bootsd ${BINDIR}/bootfd
+NOSHARED=	YES
+NOMAN=
+STRIP=
+
+# tunable timeout parameter, waiting for keypress, calibrated in mS
+BOOTWAIT?=	5000
+
+# Location that boot2 is loaded at
+BOOTSEG=	0x1000
+
+# Offset in BOOTSEG for the top of the stack, keep this 16 byte aligned
+BOOTSTACK=	0xFFF0
+
+boot.strip:	boot
+	cp -p boot boot.strip
+	strip boot.strip
+	size boot.strip
+
+boot.nohdr:	boot.strip
+	dd if=boot.strip of=boot.nohdr ibs=32 skip=1 obs=1024b
+	ls -l boot.nohdr
+
+boot1:		boot.nohdr
+	dd if=boot.nohdr of=boot1 bs=512 count=1
+
+boot2:		boot.nohdr
+	dd if=boot.nohdr of=boot2 bs=512 skip=1
+
+all:		boot1 boot2
+
+beforeinstall:
+	install ${COPY} -o ${BINOWN} -g ${BINGRP} -m ${BINMODE}\
+		boot1 ${DESTDIR}${BINDIR}/sdboot
+	install ${COPY} -o ${BINOWN} -g ${BINGRP} -m ${BINMODE}\
+		boot2 ${DESTDIR}${BINDIR}/bootsd
+	
+.include <bsd.prog.mk>
diff --git a/sys/i386/boot/serialboot/bios.S b/sys/i386/boot/serialboot/bios.S
new file mode 100644
index 0000000..c292452
--- /dev/null
+++ b/sys/i386/boot/serialboot/bios.S
@@ -0,0 +1,366 @@
+/*
+ * Mach Operating System
+ * Copyright (c) 1992, 1991 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ *
+ *	from: Mach, Revision 2.2  92/04/04  11:34:26  rpd
+ *	$Id: bios.S,v 1.3 1994/10/02 05:18:25 rgrimes Exp $
+ */
+
+/*
+  Copyright 1988, 1989, 1990, 1991, 1992 
+   by Intel Corporation, Santa Clara, California.
+
+                All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby
+granted, provided that the above copyright notice appears in all
+copies and that both the copyright notice and this permission notice
+appear in supporting documentation, and that the name of Intel
+not be used in advertising or publicity pertaining to distribution
+of the software without specific, written prior permission.
+
+INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
+IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
+CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
+NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
+WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/*
+ * Serial bootblock interface routines
+ * Copyright (c) 1994, J"org Wunsch
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * THE AUTHOR ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  THE AUTHOR DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ */ 
+
+	.file	"bios.s"
+
+#include "asm.h"
+	.text
+
+/*
+ * biosread(dev, cyl, head, sec, nsec, offset)
+ *	Read "nsec" sectors from disk to offset "offset" in boot segment
+ * BIOS call "INT 0x13 Function 0x2" to read sectors from disk into memory
+ *	Call with	%ah = 0x2
+ *			%al = number of sectors
+ *			%ch = cylinder
+ *			%cl = sector
+ *			%dh = head
+ *			%dl = drive (0x80 for hard disk, 0x0 for floppy disk)
+ *			%es:%bx = segment:offset of buffer
+ *	Return:		
+ *			%al = 0x0 on success; err code on failure
+ */
+
+ENTRY(biosread)
+	push	%ebp
+	mov	%esp, %ebp
+
+	push	%ebx
+	push	%ecx
+	push	%edx
+	push	%es
+
+	movb	0x10(%ebp), %dh
+	movw	0x0c(%ebp), %cx
+	/* cylinder; the highest 2 bits of cyl is in %cl */
+	xchgb	%ch, %cl
+	rorb	$2, %cl
+	movb	0x14(%ebp), %al
+	orb	%al, %cl
+	incb	%cl			/* sector; sec starts from 1, not 0 */
+	movb	0x8(%ebp), %dl		/* device */
+	movl	0x1c(%ebp), %ebx	/* offset */
+
+	/* prot_to_real will set %es to BOOTSEG */
+	call	EXT(prot_to_real)	/* enter real mode */
+	movb	$0x2, %ah		/* subfunction */
+	addr32
+	movb	0x18(%ebp), %al		/* number of sectors */
+
+	sti
+	int	$0x13
+	cli
+
+	/* save return value (actually movw %ax, %bx) */
+	mov	%eax, %ebx
+
+	data32
+	call	EXT(real_to_prot)	/* back to protected mode */
+
+	xor	%eax, %eax
+	movb	%bh, %al		/* return value in %ax */
+
+	pop	%es
+	pop	%edx
+	pop	%ecx
+	pop	%ebx
+	pop	%ebp
+
+	ret
+
+/*
+ * The serial port interface routines implement a simple polled i/o
+ * interface to a standard serial port.  Due to the space restrictions
+ * for the boot blocks, no BIOS support is used (since BIOS requires
+ * expensive real/protected mode switches), instead the rudimentary
+ * BIOS support is duplicated here.
+ *
+ * The base address for the i/o port is passed from the Makefile in
+ * the COMCONSOLE preprocessor macro.  Console parameters are currently
+ * hard-coded to 9600 Bd, 8 bit.  This can be changed in the
+ * init_serial() function.
+ */
+
+/*
+ * void putc(char ch)
+ *	send ch to serial port
+ *
+ */
+
+ENTRY(putc)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%edx
+
+	mov	$COMCONSOLE + 5, %edx	# line status reg
+1:	inb	%dx, %al
+	test	$0x20, %al
+	jz	1b		# TX buffer not empty
+
+	movb	0x8(%ebp), %al
+
+	sub	$5, %edx	# TX output reg
+	outb	%al, %dx	# send this one
+
+	pop	%edx
+	pop	%ebp
+	ret
+
+/*
+ * int getc(void)
+ *	read a character from serial port
+ */
+
+ENTRY(getc)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%edx
+
+	mov	$COMCONSOLE + 5, %edx	# line status reg
+1:
+	inb	%dx, %al
+	testb	$0x01, %al
+	jz	1b		# no RX char available
+
+	xor	%eax, %eax
+	sub	$5, %edx	# RX buffer reg
+	inb	%dx, %al	# fetch (first) character
+
+	cmp	$0x7F, %eax	# make DEL...
+	jne	2f
+	mov	$0x08, %eax	# look like BS
+2:
+	pop	%edx
+	pop	%ebp
+	ret
+
+/*
+ * int ischar(void)
+ *       if there is a character pending, return true; otherwise return 0
+ */
+ENTRY(ischar)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%edx
+
+	xorl	%eax, %eax
+	mov	$COMCONSOLE + 5, %edx	# line status reg
+	inb	%dx, %al
+	andb	$0x01, %al		# RX char available?
+
+	pop	%edx
+	pop	%ebp
+	ret
+
+/*
+ * void init_serial(void)
+ * 	initialize the serial console port to 9600 Bd, 8 bpc
+ */
+ENTRY(init_serial)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%edx
+
+	mov	$COMCONSOLE + 3, %edx	# line control reg
+	movb	$0x80, %al
+	outb	%al, %dx	# enable DLAB
+
+	sub	$3, %edx	# divisor latch, low byte
+	mov	$12, %ax	# divisor 12: 9600 Bd
+	outb	%al, %dx
+	inc	%edx		# divisor latch, high byte
+	movb	%ah, %al
+	outb	%al, %dx
+
+	add	$2, %edx	# line control reg
+	movb	$0x13, %al
+	outb	%al, %dx	# 8 bit, no parity, 1 stop bit
+
+	inc	%edx		# modem control reg
+	mov	$3, %al
+	outb	%al, %dx	# enable DTR/RTS
+
+	/* now finally, flush the input buffer */
+	inc	%edx		# line status reg
+1:
+	inb	%dx, %al
+	testb	$0x01, %al
+	jz	2f		# no more characters buffered
+	sub	$5, %edx	# rx buffer reg
+	inb	%dx, %al	# throw away
+	add	$5, %edx
+	jmp	1b
+2:
+	pop	%edx
+	pop	%ebp
+	ret
+
+/*
+ *
+ * get_diskinfo():  return a word that represents the
+ *	max number of sectors and heads and drives for this device
+ *
+ */
+
+ENTRY(get_diskinfo)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%es
+	push	%ebx
+	push	%ecx
+	push	%edx
+
+	movb	0x8(%ebp), %dl		/* diskinfo(drive #) */
+	call	EXT(prot_to_real)	/* enter real mode */
+
+	movb	$0x8, %ah		/* ask for disk info */
+
+	sti
+	int	$0x13
+	cli
+
+	jnc	ok
+	/*
+	 * Urk.  Call failed.  It is not supported for floppies by old BIOS's.
+	 * Guess it's a 15-sector floppy.  Initialize all the registers for
+	 * documentation, although we only need head and sector counts.
+	 */
+	subb	%ah, %ah		/* %ax = 0 */
+	movb	%al, %al
+	movb	%ah, %bh		/* %bh = 0 */
+	movb	$2, %bl			/* %bl	bits 0-3 = drive type,
+						bit    2 = 1.2M */
+	movb	$79, %ch		/* max track */
+	movb	$15, %cl		/* max sector */
+	movb	$1, %dh			/* max head */
+	movb	$1, %dl			/* # floppy drives installed */
+	/* es:di = parameter table */
+	/* carry = 0 */
+ok:
+
+	data32
+	call	EXT(real_to_prot)	/* back to protected mode */
+
+	xor	%eax, %eax
+
+	/* form a longword representing all this gunk */
+	movb	%dh, %ah		/* max head */
+	andb	$0x3f, %cl		/* mask of cylinder gunk */
+	movb	%cl, %al		/* max sector (and # sectors) */
+
+	pop	%edx
+	pop	%ecx
+	pop	%ebx
+	pop	%es
+	pop	%ebp
+	ret
+
+/*
+ *
+ * memsize(i) :  return the memory size in KB. i == 0 for conventional memory,
+ *		i == 1 for extended memory
+ *	BIOS call "INT 12H" to get conventional memory size
+ *	BIOS call "INT 15H, AH=88H" to get extended memory size
+ *		Both have the return value in AX.
+ *
+ */
+
+ENTRY(memsize)
+	push	%ebp
+	mov	%esp, %ebp
+	push	%ebx
+
+	mov	8(%ebp), %ebx
+
+	call	EXT(prot_to_real)	/* enter real mode */
+
+	cmpb	$0x1, %bl
+	data32
+	je	xext
+	
+	sti
+	int	$0x12
+	cli
+	data32
+	jmp	xdone
+
+xext:	movb	$0x88, %ah
+	sti
+	int	$0x15
+	cli
+
+xdone:
+	mov	%eax, %ebx
+
+	data32
+	call	EXT(real_to_prot)
+
+	mov	%ebx, %eax
+	pop	%ebx
+	pop	%ebp
+	ret
+
diff --git a/sys/i386/boot/serialboot/boot.c b/sys/i386/boot/serialboot/boot.c
new file mode 100644
index 0000000..06bd6ba
--- /dev/null
+++ b/sys/i386/boot/serialboot/boot.c
@@ -0,0 +1,284 @@
+/*
+ * Mach Operating System
+ * Copyright (c) 1992, 1991 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ *
+ *	from: Mach, [92/04/03  16:51:14  rvb]
+ *	$Id: boot.c,v 1.22 1994/11/07 11:26:26 davidg Exp $
+ */
+
+
+/*
+  Copyright 1988, 1989, 1990, 1991, 1992 
+   by Intel Corporation, Santa Clara, California.
+
+                All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby
+granted, provided that the above copyright notice appears in all
+copies and that both the copyright notice and this permission notice
+appear in supporting documentation, and that the name of Intel
+not be used in advertising or publicity pertaining to distribution
+of the software without specific, written prior permission.
+
+INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
+IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
+CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
+NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
+WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include <sys/param.h>
+#include "boot.h"
+#include <a.out.h>
+#include <sys/reboot.h>
+#include <machine/bootinfo.h>
+
+struct exec head;
+struct bootinfo_t bootinfo;
+char *name;
+char *names[] = {
+	"/kernel"
+};
+#define NUMNAMES	(sizeof(names)/sizeof(char *))
+
+extern void init_serial(void);
+extern int end;
+boot(drive)
+int drive;
+{
+	int loadflags, currname = 0, ret;
+	char *t;
+
+	init_serial();
+		
+	printf("\n>> FreeBSD BOOT @ 0x%x: %d/%d k of memory\n",
+		ouraddr,
+		memsize(0),
+		memsize(1));
+	printf("Use hd(1,a)/kernel to boot sd0 when wd0 is also installed.\n");
+	printf("Usage: [[[%s(0,a)]%s][-s][-r][-a][-c][-d][-b]]\nUse ? for file list.\n\n"
+			, devs[(drive & 0x80) ? 0 : 2]
+			, names[0]);
+	gateA20();
+loadstart:
+	/***************************************************************\
+	* As a default set it to the first partition of the first	*
+	* floppy or hard drive						*
+	\***************************************************************/
+	part = unit = 0;
+	maj = (drive&0x80 ? 0 : 2);		/* a good first bet */
+	name = names[currname++];
+
+	loadflags = 0;
+	if (currname == NUMNAMES)
+		currname = 0;
+	printf("Boot: ");
+	getbootdev(&loadflags);
+	ret = openrd();
+	if (ret != 0) {
+		if (ret > 0)
+			printf("Can't find %s\n", name);
+		goto loadstart;
+	}
+/*	if (inode.i_mode&IEXEC)
+		loadflags |= RB_KDB;
+*/
+	loadprog(loadflags);
+	goto loadstart;
+}
+
+loadprog(howto)
+	int		howto;
+{
+	long int startaddr;
+	long int addr;	/* physical address.. not directly useable */
+	long int bootdev;
+	long int total;
+	int i;
+	unsigned char	tmpbuf[4096]; /* we need to load the first 4k here */
+
+	read(&head, sizeof(head));
+	if ( N_BADMAG(head)) {
+		printf("Invalid format!\n");
+		return;
+	}
+
+	poff = N_TXTOFF(head);
+	/*if(poff==0)
+		poff = 32;*/
+
+	startaddr = (int)head.a_entry & 0x00FFFFFF; /* some MEG boundary */
+	addr =  startaddr;
+	printf("Booting %s(%d,%c)%s @ 0x%x\n"
+			, devs[maj]
+			, unit
+			, 'a'+part
+			, name
+			, addr);
+	if(addr < ouraddr)
+	{
+		if((addr + head.a_text + head.a_data) > ouraddr)
+		{
+			printf("kernel overlaps loader\n");
+			return;
+		}
+		if((addr + head.a_text + head.a_data + head.a_bss) > 0xa0000)
+		{
+			printf("bss exceeds 640k limit\n");
+			return;
+		}
+	}
+	printf("text=0x%x ", head.a_text);
+	/********************************************************/
+	/* LOAD THE TEXT SEGMENT				*/
+	/* don't clobber the first 4k yet (BIOS NEEDS IT) 	*/
+	/********************************************************/
+	read(tmpbuf,4096);
+	addr += 4096; 
+	xread(addr, head.a_text - 4096);
+	addr += head.a_text - 4096;
+
+	/********************************************************/
+	/* Load the Initialised data after the text		*/
+	/********************************************************/
+	while (addr & CLOFSET)
+                *(char *)addr++ = 0;
+
+	printf("data=0x%x ", head.a_data);
+	xread(addr, head.a_data);
+	addr += head.a_data;
+
+	/********************************************************/
+	/* Skip over the uninitialised data			*/
+	/* (but clear it)					*/
+	/********************************************************/
+	printf("bss=0x%x ", head.a_bss);
+	if( (addr < ouraddr) && ((addr + head.a_bss) > ouraddr))
+	{
+		pbzero(addr,ouraddr - (int)addr);
+	}
+	else
+	{
+		pbzero(addr,head.a_bss);
+	}
+	addr += head.a_bss;
+
+#ifdef LOADSYMS /* not yet, haven't worked this out yet */
+	if (addr > 0x100000)
+	{
+		/********************************************************/
+		/*copy in the symbol header				*/
+		/********************************************************/
+		pcpy(&head.a_syms, addr, sizeof(head.a_syms));
+		addr += sizeof(head.a_syms);
+	
+		/********************************************************/
+		/* READ in the symbol table				*/
+		/********************************************************/
+		printf("symbols=[+0x%x", head.a_syms);
+		xread(addr, head.a_syms);
+		addr += head.a_syms;
+	
+		/********************************************************/
+		/* Followed by the next integer (another header)	*/
+		/* more debug symbols?					*/
+		/********************************************************/
+		read(&i, sizeof(int));
+		pcpy(&i, addr, sizeof(int));
+		i -= sizeof(int);
+		addr += sizeof(int);
+	
+	
+		/********************************************************/
+		/* and that many bytes of (debug symbols?)		*/
+		/********************************************************/
+		printf("+0x%x] ", i);
+		xread(addr, i);
+		addr += i;
+	}
+#endif	LOADSYMS
+	/********************************************************/
+	/* and note the end address of all this			*/
+	/********************************************************/
+
+	total = ((addr+sizeof(int)-1))&~(sizeof(int)-1);
+	printf("total=0x%x ", total);
+	bootdev = (MAKEBOOTDEV(maj, 0, 0, unit, part)) ;
+	/****************************************************************/
+	/* copy that first page and overwrite any BIOS variables	*/
+	/****************************************************************/
+	printf("entry point=0x%x\n" ,(int)startaddr);
+	/* Under no circumstances overwrite precious BIOS variables! */
+	pcpy(tmpbuf, startaddr, 0x400);
+	pcpy(tmpbuf + 0x500, startaddr + 0x500, 4096 - 0x500);
+	bootinfo.version=1;
+	bootinfo.kernelname=(char *)((int)name + (BOOTSEG<<4));
+	bootinfo.nfs_diskless=0;
+	startprog((int)startaddr, howto, bootdev, (int)&bootinfo+(BOOTSEG<<4));
+	return;
+}
+
+#define NAMEBUF_LEN	100
+
+char namebuf[NAMEBUF_LEN];
+getbootdev(howto)
+     int *howto;
+{
+	char c, *ptr = namebuf;
+	if (gets(namebuf)) {
+		while (c=*ptr) {
+			while (c==' ')
+				c = *++ptr;
+			if (!c)
+				return;
+			if (c=='-')
+				while ((c = *++ptr) && c!=' ')
+					switch (c) {
+					      case 'r':
+						*howto |= RB_DFLTROOT; continue;
+					      case 'a':
+						*howto |= RB_ASKNAME; continue;
+					      case 'c':
+						*howto |= RB_CONFIG; continue;
+					      case 's':
+						*howto |= RB_SINGLE; continue;
+					      case 'd':
+						*howto |= RB_KDB; continue;
+					      case 'b':
+						*howto |= RB_HALT; continue;
+					}
+			else {
+				name = ptr;
+				while ((c = *++ptr) && c!=' ');
+				if (c)
+					*ptr++ = 0;
+			}
+		}
+	} else
+		printf("\n");
+}
+