Fix file specification, zap partition bits, rectify disk naming errors

In boot_macppc(8), the current format a) claims to support specific disk/MBR
partitions which ofwboot clearly does not parse as such and b) lacks markup
to make clear which optional parts can (not) be omitted in what way.

Fixing both turns
	promdev:partition/filename options
into
	[[promdev:]filename] [-acds]

Same goes for boot(8/macppc), which has been apparently has been copied
from boot(8/amd64) without accounting for all platform specific details.

On amd64, biosboot(8) sees disks as 'sd' which (accidentially?) matches the
kernel driver's sd(4) name;  it also supports specific disklabel(5) slices,
so amd64 can do 'sd0a:/bsd'.

On macppc, disks show up as 'ide', 'cd' or 'hd' which stems from
OpenFirmware alone, not matching the wd(4) driver's name.  Also, ofwboot
always boots off the 'a' label, so macppc can only do 'hd:/bsd'.


Found while installing OpenBSD/macppc from CD inside QEMU but failing to
boot from disk inside QEMU and consulting our manual pages for help wrt.
specifying a boot device.  Turns out QEMU's OpenBIOS simply cannot boot from
MSDOS filesystems (thanks gkoehler), so it wouldn't work no matter what
boot file specification I'd use.


tests/agreement gkoehler
Feedback OK miod
OK tobhe
OK jmc on a previous boot_macppc.8 diff

2 files changed, 16 insertions, 18 deletions

diff --git a/sys/arch/macppc/stand/boot.8 b/sys/arch/macppc/stand/boot.8
index 911bb5057d8..153a904bb00 100644
--- a/sys/arch/macppc/stand/boot.8
+++ b/sys/arch/macppc/stand/boot.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: boot.8,v 1.4 2019/12/23 12:44:34 bluhm Exp $
+.\"	$OpenBSD: boot.8,v 1.5 2022/09/05 10:03:50 kn Exp $
 .\"
 .\" Copyright (c) 1997-2001 Michael Shalayeff
 .\" All rights reserved.
@@ -25,7 +25,7 @@
 .\" THE POSSIBILITY OF SUCH DAMAGE.
 .\"
 .\"
-.Dd $Mdocdate: December 23 2019 $
+.Dd $Mdocdate: September 5 2022 $
 .Dt BOOT 8 macppc
 .Os
 .Sh NAME
@@ -125,29 +125,26 @@ The following commands are accepted at the
 .Nm
 prompt:
 .Bl -tag -width shorten
-.It Ic boot Op Ar image Op Fl acds
-Boots the kernel image specified by
+.It Ic boot Oo Oo Ar device : Oc Ns Ar image Oc Op Fl acds
+Boots the specified kernel image with any options given.
+If
+.Ar device
+or
 .Ar image
-with any options given.
-Image specification consists of a pair
-.Ar device : Ns Ar filename ;
-either or both can be omitted (`:' is not needed if both are omitted),
-in which case values from
+are omitted, values from the
 .Nm
 variables will be used.
 .Pp
 The only bootable devices, at the moment, are IDE devices connected to
 the internal controller;
 they are detected as
-.Sq wd
+.Sq hd
 devices.
 Therefore, to boot kernel
 .Pa /bsd
-from slice
-.Sq a
 on the first hard drive,
 specify
-.Dq boot wd0a:/bsd .
+.Dq boot hd:/bsd .
 .Bl -tag -width _a_
 .It Fl a
 Causes the kernel to ask for the
@@ -205,8 +202,10 @@ Debug flag if
 was compiled with DEBUG defined.
 .It Ic device
 Boot device name (e.g.,
-.Li wd0a ,
-.Li wd1a ) .
+.Li ide ,
+.Li ide0 ,
+.Li hd ,
+.Li hd1 ) .
 .It Ic howto
 Options to pass to the loaded kernel.
 .It Ic image
@@ -277,7 +276,7 @@ Once booted, such changes can be made permanent by using
 .Fl e
 option.
 .Pp
-.Dl boot> boot wd1a:/bsd -c
+.Dl boot> boot hd:/bsd -c
 .Sh SEE ALSO
 .Xr gzip 1 ,
 .Xr autoconf 4 ,
diff --git a/sys/arch/macppc/stand/ofdev.c b/sys/arch/macppc/stand/ofdev.c
index 0ce6e9a933a..066403f2a41 100644
--- a/sys/arch/macppc/stand/ofdev.c
+++ b/sys/arch/macppc/stand/ofdev.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofdev.c,v 1.26 2021/03/11 11:16:59 jsg Exp $	*/
+/*	$OpenBSD: ofdev.c,v 1.27 2022/09/05 10:03:50 kn Exp $	*/
 /*	$NetBSD: ofdev.c,v 1.1 1997/04/16 20:29:20 thorpej Exp $	*/
 
 /*
@@ -55,7 +55,6 @@ char opened_name[256];
 
 /*
  * this function is passed [device specifier]:[kernel]
- * however a device specifier may contain a ':'
  */
 static int
 parsename(char *str, char **file)