From: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Date: Mon, 9 Jan 2023 18:30:38 -0500
Subject: Add fw_path variable to detect config file on efi

This patch makes grub look for its config file on efi where the app was
found.

Resolves: rhbz#857936, rhbz#1616395
Co-authored-by: Matthew Garrett
Co-authored-by: Javier Martinez Canillas <javierm@redhat.com>
Co-authored-by: Robbie Harwood <rharwood@redhat.com>
Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Robbie Harwood <rharwood@redhat.com>
---
 grub-core/kern/main.c   | 14 +++++++-------
 grub-core/normal/main.c | 25 ++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
index 60eed47..99fa13f 100644
--- a/grub-core/kern/main.c
+++ b/grub-core/kern/main.c
@@ -133,16 +133,16 @@ grub_set_prefix_and_root (void)
 
   grub_machine_get_bootlocation (&fwdevice, &fwpath);
 
-  if (fwdevice)
+  if (fwdevice && fwpath)
     {
-      char *cmdpath;
+      char *fw_path;
 
-      cmdpath = grub_xasprintf ("(%s)%s", fwdevice, fwpath ? : "");
-      if (cmdpath)
+      fw_path = grub_xasprintf ("(%s)/%s", fwdevice, fwpath);
+      if (fw_path)
 	{
-	  grub_env_set ("cmdpath", cmdpath);
-	  grub_env_export ("cmdpath");
-	  grub_free (cmdpath);
+	  grub_env_set ("fw_path", fw_path);
+	  grub_env_export ("fw_path");
+	  grub_free (fw_path);
 	}
     }
 
diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c
index c363874..51bce0e 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -320,7 +320,30 @@ grub_cmd_normal (struct grub_command *cmd __attribute__ ((unused)),
       /* Guess the config filename. It is necessary to make CONFIG static,
 	 so that it won't get broken by longjmp.  */
       char *config;
-      const char *prefix;
+      const char *prefix, *fw_path;
+
+      fw_path = grub_env_get ("fw_path");
+      if (fw_path)
+	{
+	  config = grub_xasprintf ("%s/grub.cfg", fw_path);
+	  if (config)
+	    {
+	      grub_file_t file;
+
+	      file = grub_file_open (config, GRUB_FILE_TYPE_CONFIG);
+	      if (file)
+		{
+		  grub_file_close (file);
+		  grub_enter_normal_mode (config);
+		}
+              else
+                {
+                  /* Ignore all errors.  */
+                  grub_errno = 0;
+                }
+	      grub_free (config);
+	    }
+	}
 
       prefix = grub_env_get ("prefix");
       if (prefix)