blscfg: add blscfg module to parse Boot Loader Specification snippets

http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec

Works like this:

 insmod blscfg
 bls_import

Done! You should now have menu items for your snippets in place.

Signed-off-by: Peter Jones <grub2-owner@fedoraproject.org>

grub-core/Makefile.core.def

@@ -768,6 +768,14 @@ module = {
   common = commands/blocklist.c;
 };
 
+module = {
+  name = blscfg;
+  common = commands/blscfg.c;
+  enable = i386_efi;
+  enable = x86_64_efi;
+  enable = i386_pc;
+};
+
 module = {
   name = boot;
   common = commands/boot.c;

grub-core/commands/blscfg.c

@@ -0,0 +1,201 @@
+/*-*- Mode: C; c-basic-offset: 2; indent-tabs-mode: t -*-*/
+
+/* bls.c - implementation of the boot loader spec */
+
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *
+ *  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/types.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/err.h>
+#include <grub/dl.h>
+#include <grub/extcmd.h>
+#include <grub/i18n.h>
+#include <grub/fs.h>
+#include <grub/env.h>
+#include <grub/file.h>
+#include <grub/normal.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#ifdef GRUB_MACHINE_EFI
+#define GRUB_LINUX_CMD "linuxefi"
+#define GRUB_INITRD_CMD "initrdefi"
+#define GRUB_BLS_CONFIG_PATH "/EFI/fedora/loader/entries/"
+#define GRUB_BOOT_DEVICE "($boot)"
+#else
+#define GRUB_LINUX_CMD "linux"
+#define GRUB_INITRD_CMD "initrd"
+#define GRUB_BLS_CONFIG_PATH "/loader/entries/"
+#define GRUB_BOOT_DEVICE "($root)"
+#endif
+
+static int parse_entry (
+    const char *filename,
+    const struct grub_dirhook_info *info __attribute__ ((unused)),
+    void *data __attribute__ ((unused)))
+{
+  grub_size_t n;
+  char *p;
+  grub_file_t f = NULL;
+  grub_off_t sz;
+  char *title = NULL, *options = NULL, *clinux = NULL, *initrd = NULL, *src = NULL;
+  const char *args[2] = { NULL, NULL };
+
+  if (filename[0] == '.')
+    return 0;
+
+  n = grub_strlen (filename);
+  if (n <= 5)
+    return 0;
+
+  if (grub_strcmp (filename + n - 5, ".conf") != 0)
+    return 0;
+
+  p = grub_xasprintf (GRUB_BLS_CONFIG_PATH "%s", filename);
+
+  f = grub_file_open (p);
+  if (!f)
+    goto finish;
+
+  sz = grub_file_size (f);
+  if (sz == GRUB_FILE_SIZE_UNKNOWN || sz > 1024*1024)
+    goto finish;
+
+  for (;;)
+    {
+      char *buf;
+
+      buf = grub_file_getline (f);
+      if (!buf)
+	break;
+
+      if (grub_strncmp (buf, "title ", 6) == 0)
+	{
+	  grub_free (title);
+	  title = grub_strdup (buf + 6);
+	  if (!title)
+	    goto finish;
+	}
+      else if (grub_strncmp (buf, "options ", 8) == 0)
+	{
+	  grub_free (options);
+	  options = grub_strdup (buf + 8);
+	  if (!options)
+	    goto finish;
+	}
+      else if (grub_strncmp (buf, "linux ", 6) == 0)
+	{
+	  grub_free (clinux);
+	  clinux = grub_strdup (buf + 6);
+	  if (!clinux)
+	    goto finish;
+	}
+      else if (grub_strncmp (buf, "initrd ", 7) == 0)
+	{
+	  grub_free (initrd);
+	  initrd = grub_strdup (buf + 7);
+	  if (!initrd)
+	    goto finish;
+	}
+
+      grub_free(buf);
+    }
+
+  if (!linux)
+    {
+      grub_printf ("Skipping file %s with no 'linux' key.", p);
+      goto finish;
+    }
+
+  args[0] = title ? title : filename;
+
+  src = grub_xasprintf ("load_video\n"
+			"set gfx_payload=keep\n"
+			"insmod gzio\n"
+			GRUB_LINUX_CMD " %s%s%s%s\n"
+			"%s%s%s%s",
+			GRUB_BOOT_DEVICE, clinux, options ? " " : "", options ? options : "",
+			initrd ? GRUB_INITRD_CMD " " : "", initrd ? GRUB_BOOT_DEVICE : "", initrd ? initrd : "", initrd ? "\n" : "");
+
+  grub_normal_add_menu_entry (1, args, NULL, NULL, "bls", NULL, NULL, src, 0);
+
+finish:
+  grub_free (p);
+  grub_free (title);
+  grub_free (options);
+  grub_free (clinux);
+  grub_free (initrd);
+  grub_free (src);
+
+  if (f)
+    grub_file_close (f);
+
+  return 0;
+}
+
+static grub_err_t
+grub_cmd_bls_import (grub_extcmd_context_t ctxt __attribute__ ((unused)),
+		     int argc __attribute__ ((unused)),
+		     char **args __attribute__ ((unused)))
+{
+  grub_fs_t fs;
+  grub_device_t dev;
+  static grub_err_t r;
+  const char *devid;
+
+  devid = grub_env_get ("root");
+  if (!devid)
+    return grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("variable `%s' isn't set"), "root");
+
+  dev = grub_device_open (devid);
+  if (!dev)
+    return grub_errno;
+
+  fs = grub_fs_probe (dev);
+  if (!fs)
+    {
+      r = grub_errno;
+      goto finish;
+    }
+
+  r = fs->dir (dev, GRUB_BLS_CONFIG_PATH, parse_entry, NULL);
+
+finish:
+  if (dev)
+    grub_device_close (dev);
+
+  return r;
+}
+
+static grub_extcmd_t cmd;
+
+GRUB_MOD_INIT(bls)
+{
+  cmd = grub_register_extcmd ("bls_import",
+			      grub_cmd_bls_import,
+			      0,
+			      NULL,
+			      N_("Import Boot Loader Specification snippets."),
+			      NULL);
+}
+
+GRUB_MOD_FINI(bls)
+{
+  grub_unregister_extcmd (cmd);
+}