[patch] set prefix on PPC

[Hollis Blanchard <hollis@penguinppc.org>]

Any comments on this patch?

This code sets the GRUB "prefix" environment variable from the OF
/chosen/bootpath property. It must therefore translate between the two
syntaxes.

I believe most of this code could be moved to a kern/ieee1275/device.c
file, but that can wait until there is another supported OF platform.

I have verified that this works (a config file is loaded) from disk, and
netbooting is not broken. The subdirectory stuff works as well.

-Hollis

2005-02-13  Hollis Blanchard  <hollis@penguinppc.org>

	* include/grub/powerpc/ieee1275/ieee1275.h
	(grub_ieee1275_get_dev_encoding): New prototype.
	(grub_ieee1275_get_filename): Likewise.
	* kern/powerpc/ieee1275/init.c (translate_path): New function.
	(grub_set_prefix): Likewise.
	(grub_machine_init): Call grub_set_prefix.
	* kern/powerpc/ieee1275/openfw.c (GRUB_PARSE_FILENAME): New
	constant.
	(GRUB_PARSE_PARTITION): Likewise.
	(grub_ieee1275_get_devargs): New function.
	(grub_ieee1275_get_devname): Likewise.
	(grub_ieee1275_parse_args): Likewise.
	(grub_ieee1275_get_filename): Likewise.
	(grub_ieee1275_get_dev_encoding): Likewise.

Index: include/grub/powerpc/ieee1275/ieee1275.h
===================================================================
RCS file: /cvsroot/grub/grub2/include/grub/powerpc/ieee1275/ieee1275.h,v
retrieving revision 1.14
diff -u -p -r1.14 ieee1275.h
--- include/grub/powerpc/ieee1275/ieee1275.h	31 Jan 2005 21:28:34 -0000	1.14
+++ include/grub/powerpc/ieee1275/ieee1275.h	13 Feb 2005 17:16:17 -0000
@@ -132,5 +132,8 @@ int EXPORT_FUNC(grub_claimmap) (grub_add
 
 void EXPORT_FUNC(abort) (void);
 
+char *EXPORT_FUNC(grub_ieee1275_get_dev_encoding) (const char *path);
+char *EXPORT_FUNC(grub_ieee1275_get_filename) (const char *path);
+
 
 #endif /* ! GRUB_IEEE1275_MACHINE_HEADER */
Index: kern/powerpc/ieee1275/init.c
===================================================================
RCS file: /cvsroot/grub/grub2/kern/powerpc/ieee1275/init.c,v
retrieving revision 1.13
diff -u -p -r1.13 init.c
--- kern/powerpc/ieee1275/init.c	4 Jan 2005 14:01:45 -0000	1.13
+++ kern/powerpc/ieee1275/init.c	13 Feb 2005 17:16:17 -0000
@@ -42,6 +42,68 @@ abort (void)
   for (;;);
 }
 
+/* Translate an OF filesystem path (separated by backslashes), into a GRUB
+   path (separated by forward slashes).  */
+static void
+translate_path (char *filepath)
+{
+  char *backslash;
+
+  backslash = grub_strchr (filepath, '\\');
+  while (backslash != 0)
+    {
+      *backslash = '/';
+      backslash = grub_strchr (filepath, '\\');
+    }
+}
+
+static void
+grub_set_prefix (void)
+{
+  char bootpath[64]; /* XXX check length */
+  char *filename;
+  char *prefix;
+  grub_ieee1275_phandle_t chosen;
+
+  grub_ieee1275_finddevice ("/chosen", &chosen);
+  if (grub_ieee1275_get_property (chosen, "bootpath", &bootpath,
+				  sizeof (bootpath), 0))
+    { 
+      /* Should never happen.  */
+      grub_printf ("/chosen/bootpath property missing!\n");
+      grub_env_set ("prefix", "");
+    }
+
+  /* Transform an OF device path to a GRUB path.  */
+
+  prefix = grub_ieee1275_get_dev_encoding (bootpath);
+
+  filename = grub_ieee1275_get_filename (bootpath);
+  if (filename)
+    {
+      char *newprefix;
+      char *lastslash = grub_strrchr (filename, '\\');
+
+      /* Truncate at last directory.  */
+      if (lastslash)
+        {
+	  *lastslash = '\0';
+	  translate_path (filename);
+
+	  newprefix = grub_malloc (grub_strlen (prefix)
+				   + grub_strlen (filename));
+	  grub_sprintf (newprefix, "%s%s", prefix, filename);
+	  grub_free (prefix);
+	  prefix = newprefix;
+	}
+    }
+
+  grub_env_set ("prefix", prefix);
+
+  grub_free (filename);
+  grub_free (prefix);
+}
+
 void
 grub_machine_init (void)
 {
@@ -65,7 +127,7 @@ grub_machine_init (void)
     }
   grub_mm_init_region ((void *) heap_start, heap_len);
 
-  grub_env_set ("prefix", "");
+  grub_set_prefix ();
 
   grub_ofdisk_init ();
 }
Index: kern/powerpc/ieee1275/openfw.c
===================================================================
RCS file: /cvsroot/grub/grub2/kern/powerpc/ieee1275/openfw.c,v
retrieving revision 1.7
diff -u -p -r1.7 openfw.c
--- kern/powerpc/ieee1275/openfw.c	3 Jan 2005 17:44:25 -0000	1.7
+++ kern/powerpc/ieee1275/openfw.c	13 Feb 2005 17:16:17 -0000
@@ -23,6 +23,11 @@
 #include <grub/mm.h>
 #include <grub/machine/ieee1275.h>
 
+enum {
+  GRUB_PARSE_FILENAME,
+  GRUB_PARSE_PARTITION,
+};
+
 /* Walk children of 'devpath', calling hook for each.  */
 grub_err_t
 grub_children_iterate (char *devpath,
@@ -64,7 +69,7 @@ grub_children_iterate (char *devpath,
       if (actual == -1)
 	continue;
 
-      grub_sprintf(fullname, "%s/%s", devpath, childname);
+      grub_sprintf (fullname, "%s/%s", devpath, childname);
 
       alias.type = childtype;
       alias.path = childpath;
@@ -199,3 +204,133 @@ grub_claimmap (grub_addr_t addr, grub_si
 
   return 0;
 }
+
+/* Get the device arguments of the Open Firmware device specifier `path'.  */
+static char *
+grub_ieee1275_get_devargs (const char *path)
+{
+  char *colon = grub_strchr (path, ':');
+  char *end;
+
+  if (! colon)
+    return 0;
+
+  end = colon + grub_strlen (colon);
+
+  return grub_strndup (colon + 1, end - colon);
+}
+
+/* Get the device path of the Open Firmware device specifier `path'.  */
+static char *
+grub_ieee1275_get_devname (const char *path)
+{
+  char *colon = grub_strchr (path, ':');
+
+  if (! colon)
+    return grub_strdup (path);
+
+  return grub_strndup (path, (grub_size_t)(colon - path));
+}
+
+static char *
+grub_ieee1275_parse_args (const char *path, int field)
+{
+  char type[64]; /* XXX check size.  */
+  char *device = grub_ieee1275_get_devname (path);
+  char *args = grub_ieee1275_get_devargs (path);
+  char *ret = 0;
+  grub_ieee1275_phandle_t dev;
+
+  if (!args)
+    /* Shouldn't happen.  */
+    return 0;
+
+  /* We need to know what type of device it is in order to parse the full
+     file path properly.  */
+  if (grub_ieee1275_finddevice (device, &dev))
+    {
+      grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Device %s not found\n", device);
+      goto out;
+    }
+  if (grub_ieee1275_get_property (dev, "device_type", &type, sizeof type, 0))
+    {
+      grub_error (GRUB_ERR_UNKNOWN_DEVICE,
+		  "Device %s lacks a device_type property\n", device);
+      goto out;
+    }
+
+  if (!grub_strcmp ("block", type))
+    {
+      /* Example: "disk:<partition number>,<file name>".  */
+      char *comma = grub_strchr (args, ',');
+
+      if (field == GRUB_PARSE_FILENAME)
+	{
+	  if (comma)
+	    {
+	      char *filepath = comma + 1;
+
+	      ret = grub_malloc (grub_strlen (filepath) + 1);
+	      /* Make sure filepath has leading backslash.  */
+	      if (filepath[0] != '\\')
+		grub_sprintf (ret, "\\%s", filepath);
+	      else
+		grub_strcpy (ret, filepath);
+	    }
+	}
+      else if (field == GRUB_PARSE_PARTITION)
+        {
+	  if (!comma)
+	    ret = grub_strdup (args);
+	  else
+	    ret = grub_strndup (args, (grub_size_t)(comma - args));
+	}
+    }
+  else
+    {
+      /* XXX Handle net devices by configuring & registering a grub_net_dev
+	 here, then return its name?
+	 Example path: "net:<server ip>,<file name>,<client ip>,<gateway
+	 ip>,<bootp retries>,<tftp retries>".  */
+      grub_printf ("Unsupported type %s for device %s\n", type, device);
+    }
+
+out:
+  grub_free (device);
+  grub_free (args);
+  return ret;
+}
+
+char *
+grub_ieee1275_get_filename (const char *path)
+{
+  return grub_ieee1275_parse_args (path, GRUB_PARSE_FILENAME);
+}
+
+char *
+grub_ieee1275_get_dev_encoding (const char *path)
+{
+  char *device = grub_ieee1275_get_devname (path);
+  char *partition = grub_ieee1275_parse_args (path, GRUB_PARSE_PARTITION);
+  char *encoding;
+
+  if (partition)
+    {
+      unsigned int partno = grub_strtoul (partition, 0, 0);
+      partno--; /* GRUB partition numbering is 0-based.  */
+
+      /* XXX Assume partno will only require two bytes? */
+      encoding = grub_malloc (grub_strlen (device) + 5);
+      grub_sprintf (encoding, "(%s,%d)", device, partno);
+    }
+  else
+    {
+      encoding = grub_malloc (grub_strlen (device) + 2);
+      grub_sprintf (encoding, "(%s)", device);
+    }
+
+  grub_free (partition);
+  grub_free (device);
+
+  return encoding;
+}