proposed solution using "ofpathname -a" (Re: OF disk naming scheme)

[Robert Millan <rmh@aybabtu.com>]

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On Sun, Jul 22, 2007 at 10:25:05PM +0200, Robert Millan wrote:
> 
> AFAIK we can only read the full OF path from /proc (with helper tools like
> ofpath / ofpathname), but not the short alias which grub uses.  These can only
> be obtained when grub is running.
> 
> If the proposed solution is not good, maybe we could instead remap all disks
> to "standard" grub device names (hd0, hd1..), which grub-mkdevicemap already
> knows how to guess reasonably well.

Ok, I think I finally managed to make it work the way you wanted.  Please see
attached patch.

You will also need alias.diff for ofpathname (I've sent it to the author
already).

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call, if you are unable to speak?
(as seen on /.)

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2007-08-12  Robert Millan  <rmh@aybabtu.com>

	* util/i386/get_disk_name.c: New.  Implement grub_util_get_disk_name()
	to tell grub-mkdevicemap how to name devices.
	* util/ieee1275/get_disk_name.c: Likewise (using "ofpathname -a"
	feature).

	* conf/i386-efi.rmk (grub_mkdevicemap_SOURCES): Add
	util/i386/get_disk_name.c.
	* conf/i386-pc.rmk (grub_mkdevicemap_SOURCES): Likewise.
	* conf/powerpc-ieee1275.rmk (grub_mkdevicemap_SOURCES): Add
	util/ieee1275/get_disk_name.c.

	* include/grub/util/misc.h: grub_util_get_disk_name() declaration.

	* DISTLIST: Add util/i386/get_disk_name.c and
	util/ieee1275/get_disk_name.c.

	* util/grub-mkdevicemap.c: Replace device naming logic with
	grub_util_get_disk_name() calls.

diff -Nur grub2/conf/i386-efi.rmk grub2.mkdevicemap/conf/i386-efi.rmk
--- grub2/conf/i386-efi.rmk	2007-08-02 22:42:19.000000000 +0200
+++ grub2.mkdevicemap/conf/i386-efi.rmk	2007-08-12 15:26:42.000000000 +0200
@@ -24,7 +24,8 @@
 #	kern/fs.c kern/env.c fs/fshelp.c
 
 # For grub-mkdevicemap.
-grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c
+grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c		\
+	util/i386/get_disk_name.c
 
 # For grub-probe.
 grub_probe_DEPENDENCIES = grub_probe_init.h
diff -Nur grub2/conf/i386-pc.rmk grub2.mkdevicemap/conf/i386-pc.rmk
--- grub2/conf/i386-pc.rmk	2007-08-02 22:42:19.000000000 +0200
+++ grub2.mkdevicemap/conf/i386-pc.rmk	2007-08-12 15:26:42.000000000 +0200
@@ -72,7 +72,8 @@
 	util/raid.c util/lvm.c grub_setup_init.c
 
 # For grub-mkdevicemap.
-grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c
+grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c		\
+	util/i386/get_disk_name.c
 
 # For grub-probe.
 grub_probe_DEPENDENCIES = grub_probe_init.h
diff -Nur grub2/conf/powerpc-ieee1275.rmk grub2.mkdevicemap/conf/powerpc-ieee1275.rmk
--- grub2/conf/powerpc-ieee1275.rmk	2007-08-02 22:42:19.000000000 +0200
+++ grub2.mkdevicemap/conf/powerpc-ieee1275.rmk	2007-08-12 15:26:42.000000000 +0200
@@ -36,7 +36,8 @@
         util/resolve.c 
 
 # For grub-mkdevicemap.
-grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c
+grub_mkdevicemap_SOURCES = util/grub-mkdevicemap.c util/misc.c		\
+	util/ieee1275/get_disk_name.c
 
 # For grub-probe.
 grub_probe_DEPENDENCIES = grub_probe_init.h
diff -Nur grub2/include/grub/util/misc.h grub2.mkdevicemap/include/grub/util/misc.h
--- grub2/include/grub/util/misc.h	2007-07-22 01:32:25.000000000 +0200
+++ grub2.mkdevicemap/include/grub/util/misc.h	2007-08-12 15:26:42.000000000 +0200
@@ -53,5 +53,6 @@
 void grub_util_write_image (const char *img, size_t size, FILE *out);
 void grub_util_write_image_at (const void *img, size_t size, off_t offset,
 			       FILE *out);
+char *grub_util_get_disk_name (int disk, char *name);
 
 #endif /* ! GRUB_UTIL_MISC_HEADER */
diff -Nur grub2/util/grub-mkdevicemap.c grub2.mkdevicemap/util/grub-mkdevicemap.c
--- grub2/util/grub-mkdevicemap.c	2007-07-22 01:32:31.000000000 +0200
+++ grub2.mkdevicemap/util/grub-mkdevicemap.c	2007-08-12 15:26:42.000000000 +0200
@@ -402,8 +402,11 @@
 	  
 	  if (realpath (discn, name))
 	    {
+	      char *p;
 	      strcat (name, "/disc");
-	      fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+	      p = grub_util_get_disk_name (num_hd, name);
+	      fprintf (fp, "(%s)\t%s\n", p, name);
+	      free (p);
 	    }
 	  
 	  num_hd++;
@@ -421,7 +424,10 @@
       get_ide_disk_name (name, i);
       if (check_device (name))
 	{
-	  fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+	  char *p;
+	  p = grub_util_get_disk_name (num_hd, name);
+	  fprintf (fp, "(%s)\t%s\n", p, name);
+	  free (p);
 	  num_hd++;
 	}
     }
@@ -435,7 +441,10 @@
       get_ataraid_disk_name (name, i);
       if (check_device (name))
 	{
-	  fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+	  char *p;
+	  p = grub_util_get_disk_name (num_hd, name);
+	  fprintf (fp, "(%s)\t%s\n", p, name);
+	  free (p);
           num_hd++;
         }
     }
@@ -449,7 +458,10 @@
       get_scsi_disk_name (name, i);
       if (check_device (name))
 	{
-	  fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+	  char *p;
+	  p = grub_util_get_disk_name (num_hd, name);
+	  fprintf (fp, "(%s)\t%s\n", p, name);
+	  free (p);
 	  num_hd++;
 	}
     }
@@ -472,7 +484,10 @@
 	    get_dac960_disk_name (name, controller, drive);
 	    if (check_device (name))
 	      {
-		fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+		char *p;
+		p = grub_util_get_disk_name (num_hd, name);
+		fprintf (fp, "(%s)\t%s\n", p, name);
+		free (p);
 		num_hd++;
 	      }
 	  }
@@ -490,7 +505,10 @@
 	get_i2o_disk_name (name, unit);
 	if (check_device (name))
 	  {
-	    fprintf (fp, "(hd%d)\t%s\n", num_hd, name);
+	    char *p;
+	    p = grub_util_get_disk_name (num_hd, name);
+	    fprintf (fp, "(%s)\t%s\n", p, name);
+	    free (p);
 	    num_hd++;
 	  }
       }
diff -Nur grub2/util/i386/get_disk_name.c grub2.mkdevicemap/util/i386/get_disk_name.c
--- grub2/util/i386/get_disk_name.c	1970-01-01 01:00:00.000000000 +0100
+++ grub2.mkdevicemap/util/i386/get_disk_name.c	2007-08-12 15:26:42.000000000 +0200
@@ -0,0 +1,31 @@
+/* get_disk_name.c */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2007 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/util/misc.h>
+
+char *
+grub_util_get_disk_name (int disk, char *name)
+{
+  char *p;
+
+  p = xmalloc (16);
+  sprintf (p, "hd%d", disk);
+  
+  return p;
+}
diff -Nur grub2/util/ieee1275/get_disk_name.c grub2.mkdevicemap/util/ieee1275/get_disk_name.c
--- grub2/util/ieee1275/get_disk_name.c	1970-01-01 01:00:00.000000000 +0100
+++ grub2.mkdevicemap/util/ieee1275/get_disk_name.c	2007-08-12 16:16:56.000000000 +0200
@@ -0,0 +1,60 @@
+/* get_disk_name.c */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2007 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <grub/util/misc.h>
+
+char *
+grub_util_get_disk_name (int disk, char *name)
+{
+  int p[2];
+
+  char *line = NULL;
+  int zero = 0;
+  int len;
+
+  pipe (p);
+
+  switch (fork ())
+    {
+    case -1:
+      perror ("fork");
+      exit (1);
+    case 0:
+      close (1);
+      dup (p[1]);
+      close (p[0]);
+      close (p[1]);
+      execlp ("ofpathname", "ofpathname", "-a", name, NULL);
+      perror ("execlp");
+    default:
+      close (0);
+      dup (p[0]);
+      close (p[0]);
+      close (p[1]);
+    }
+
+  len = getline (&line, &zero, stdin);
+  if (len < 2)
+    grub_util_error ("ofpathname didn't print a meaningful alias name");
+
+  line[len - 1] = '\0';
+  
+  return line;
+}
--- grub2/DISTLIST	2007-08-02 22:42:19.000000000 +0200
+++ grub2.mkdevicemap/DISTLIST	2007-08-12 16:33:22.000000000 +0200
@@ -285,11 +285,13 @@
 util/grub.d/README
 util/i386/efi/grub-install.in
 util/i386/efi/grub-mkimage.c
+util/i386/get_disk_name.c
 util/i386/pc/grub-install.in
 util/i386/pc/grub-mkimage.c
 util/i386/pc/grub-setup.c
 util/i386/pc/misc.c
 util/i386/pc/grub-mkrescue.in
+util/ieee1275/get_disk_name.c
 util/powerpc/ieee1275/grub-install.in
 util/powerpc/ieee1275/grub-mkimage.c
 util/powerpc/ieee1275/misc.c

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--- ofpathname.orig	2007-07-17 16:10:47.000000000 +0200
+++ ofpathname	2007-08-12 13:00:21.000000000 +0200
@@ -27,6 +33,7 @@
     echo "Optional arguments."
     echo "  -l               Convert Open Firmware device pathname to"
     echo "                   logical device name."
+    echo "  -a               Find matching Open Firmware device alias[es]."
     echo "  -q, --quiet      do not report failures, exit quietly"
     echo "  -V, --version    display version information and exit"         
     echo "  -h, --help       display this help information and exit"
@@ -226,7 +234,16 @@
         OF_PATH=$OFPATH:1\\ppc\\bootinfo.txt
     fi
 
-    echo $OF_PATH
+    if [[ $do_alias = "0" ]]; then
+      echo $OF_PATH
+    else
+      (shopt -s nullglob
+       for i in /proc/device-tree/aliases/* ; do
+         if sed -e "s/\x00$//g" $i | grep -qx "$OF_PATH" ; then
+           basename $i
+         fi
+       done)
+    fi
 }
 
 #
@@ -613,10 +638,14 @@
 
 # default: convert logical => OFpath
 do_of2l=0
+# default: do not alias-ize
+do_alias=0
 
 getopt -o "l:Vqh" -l "help,version,quiet" $@ > /dev/null 2>&1
 while [[ -n $1 ]]; do
     case "$1" in
+        -a)             do_alias=1 ;;
+
         -l)             do_of2l=1 
                         DEVNAME_ARG=$2
                         shift ;;