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* [PATCH 1/1] add --partuuid to probe
@ 2017-02-14 18:00 Steve Kenton
  2017-02-14 19:12 ` Andrei Borzenkov
  2017-02-15 10:56 ` Vladimir 'phcoder' Serbinenko
  0 siblings, 2 replies; 18+ messages in thread
From: Steve Kenton @ 2017-02-14 18:00 UTC (permalink / raw)
  To: grub-devel; +Cc: Steve Kenton

Support both EFI and NT Disk Signature for passing to kernel as root=PARTUUID=$val

Signed-off-by: Steve Kenton <skenton@ou.edu>
---
It's been six months so I thought I'd resend this so it does not get lost
in case I get hit by a meteor or something before the next release

 grub-core/commands/probe.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/grub-core/commands/probe.c b/grub-core/commands/probe.c
index cf2793e..3afc8b8 100644
--- a/grub-core/commands/probe.c
+++ b/grub-core/commands/probe.c
@@ -45,6 +45,7 @@ static const struct grub_arg_option options[] =
     {"fs",		'f', 0, N_("Determine filesystem type."), 0, 0},
     {"fs-uuid",		'u', 0, N_("Determine filesystem UUID."), 0, 0},
     {"label",		'l', 0, N_("Determine filesystem label."), 0, 0},
+    {"partuuid",	'g', 0, N_("Determine partition GUID/UUID."), 0, 0}, /* GUID but Linux kernel calls it "PARTUUID" */
     {0, 0, 0, 0, 0, 0}
   };
 
@@ -154,6 +155,58 @@ grub_cmd_probe (grub_extcmd_context_t ctxt, int argc, char **args)
       grub_device_close (dev);
       return GRUB_ERR_NONE;
     }
+  if (state[6].set)
+    {
+      char *partuuid = NULL; /* NULL to silence a spurious GCC warning */
+      grub_uint8_t diskbuf[16];
+      if (dev->disk && dev->disk->partition)
+	{
+	  grub_partition_t p = dev->disk->partition;
+	  if (!grub_strcmp (p->partmap->name, "msdos"))
+	    {
+	      const int diskid_offset = 440; /* location in MBR */
+	      dev->disk->partition = p->parent;
+	      /* little-endian 4-byte NT disk signature */
+	      err = grub_disk_read (dev->disk, 0, diskid_offset, 4, diskbuf);
+	      dev->disk->partition = p;
+	      if (err)
+	        return grub_errno;
+	      partuuid = grub_xasprintf ("%02x%02x%02x%02x-%02x",
+					 diskbuf[3], diskbuf[2], diskbuf[1], diskbuf[0],
+					 p->number + 1); /* one based partition number */
+	    }
+	  else if (!grub_strcmp (p->partmap->name, "gpt"))
+	    {
+	      const int guid_offset = 16; /* location in entry */
+	      dev->disk->partition = p->parent;
+	      /* little-endian 16-byte EFI partition GUID */
+	      err = grub_disk_read (dev->disk, p->offset, p->index + guid_offset, 16, diskbuf);
+	      dev->disk->partition = p;
+	      if (err)
+	        return grub_errno;
+	      partuuid = grub_xasprintf ("%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+					 diskbuf[3], diskbuf[2], diskbuf[1], diskbuf[0],
+					 diskbuf[5], diskbuf[4],
+					 diskbuf[7], diskbuf[6],
+					 diskbuf[8], diskbuf[9],
+					 diskbuf[10], diskbuf[11], diskbuf[12], diskbuf[13], diskbuf[14], diskbuf[15]);
+	    }
+	  else
+	    return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
+			       N_("partition map %s does not support partition UUIDs"),
+			       dev->disk->partition->partmap->name);
+	}
+      else
+	partuuid = grub_strdup (""); /* a freeable empty string */
+
+      if (state[0].set)
+	grub_env_set (state[0].arg, partuuid);
+      else
+	grub_printf ("%s", partuuid);
+      grub_free (partuuid);
+      grub_device_close (dev);
+      return GRUB_ERR_NONE;
+    }
   grub_device_close (dev);
   return grub_error (GRUB_ERR_BAD_ARGUMENT, "unrecognised target");
 }
-- 
2.9.0.137.gcf4c2cf



^ permalink raw reply related	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2017-03-01  3:39 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-14 18:00 [PATCH 1/1] add --partuuid to probe Steve Kenton
2017-02-14 19:12 ` Andrei Borzenkov
2017-02-14 19:39   ` Steve Kenton
2017-02-15  3:36     ` Nick Vinson
2017-02-15 10:56 ` Vladimir 'phcoder' Serbinenko
2017-02-15 16:26   ` Andrei Borzenkov
2017-02-15 17:25     ` Vladimir 'phcoder' Serbinenko
2017-02-19  6:12       ` Andrei Borzenkov
2017-02-27  0:37         ` Vladimir 'phcoder' Serbinenko
2017-02-27 17:53           ` Andrei Borzenkov
2017-02-27 18:20             ` Vladimir 'phcoder' Serbinenko
2017-02-28  4:11               ` Andrei Borzenkov
2017-02-28 14:08                 ` Vladimir 'phcoder' Serbinenko
2017-02-28 17:13                   ` grub-probe for nested BSD partition on Linux (was: [PATCH 1/1] add --partuuid to probe) Andrei Borzenkov
2017-02-28 18:31                     ` Lennart Sorensen
2017-02-28 18:50                       ` grub-probe for nested BSD partition on Linux Andrei Borzenkov
2017-02-28 22:05                         ` Lennart Sorensen
2017-03-01  3:39                           ` Andrei Borzenkov

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