[src/trunk]: src/sys/kern Restore code to create md0, this fixes booting an I...

[mlelstv <mlelstv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8e62bbbc4bb5
branches:  trunk
changeset: 995781:8e62bbbc4bb5
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sat Jan 05 18:03:41 2019 +0000

description:
Restore code to create md0, this fixes booting an INSTALL kernel.

diffstat:

 sys/kern/kern_subr.c |  30 +++++++++++++++++++++++++-----
 1 files changed, 25 insertions(+), 5 deletions(-)

diffs (74 lines):

diff -r 8f5b5907c4ee -r 8e62bbbc4bb5 sys/kern/kern_subr.c
--- a/sys/kern/kern_subr.c      Sat Jan 05 16:56:25 2019 +0000
+++ b/sys/kern/kern_subr.c      Sat Jan 05 18:03:41 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_subr.c,v 1.221 2019/01/05 09:39:56 mlelstv Exp $  */
+/*     $NetBSD: kern_subr.c,v 1.222 2019/01/05 18:03:41 mlelstv Exp $  */
 
 /*-
  * Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -79,7 +79,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_subr.c,v 1.221 2019/01/05 09:39:56 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_subr.c,v 1.222 2019/01/05 18:03:41 mlelstv Exp $");
 
 #include "opt_ddb.h"
 #include "opt_md.h"
@@ -112,6 +112,7 @@
 static const char *getwedgename(const char *, int);
 
 static void setroot_nfs(device_t);
+static void setroot_md(device_t *);
 static void setroot_ask(device_t, int);
 static void setroot_root(device_t, int);
 static void setroot_dump(device_t, device_t);
@@ -193,7 +194,7 @@
         * force boot device to md0
         */
        if (md_is_root)
-               rootspec = "md0";
+               setroot_md(&bootdv);
 
 #ifdef TFTPROOT
        /*
@@ -203,10 +204,10 @@
         * reuses NFS init code to set up network
         * fetch image into ram disk
         *
-        * if successful, we change rootspec
+        * if successful, we change boot device
         */
        if (tftproot_dhcpboot(bootdv) == 0)
-               rootspec = "md0";
+               setroot_md(&bootdv);
 #endif
        
        /*
@@ -280,6 +281,25 @@
                vfs_delref(vops);
 }
 
+/*
+ * Change boot device to md0
+ *
+ * md0 only exists when it is opened once.
+ */
+static void
+setroot_md(device_t *dvp)
+{
+       int md_major;
+       dev_t md_dev;
+
+       md_major = devsw_name2blk("md", NULL, 0);
+       if (md_major >= 0) {
+               md_dev = MAKEDISKDEV(md_major, 0, RAW_PART);
+               if (bdev_open(md_dev, FREAD, S_IFBLK, curlwp) == 0)
+                       *dvp = device_find_by_xname("md0");
+       }
+}
+
 static void
 setroot_ask(device_t bootdv, int bootpartition)
 {