[PATCH 2/4] Disable GRUB video support for IBM power machines

[Lubomir Rintel]

From: Paulo Flabiano Smorigo <address@hidden>

A 64bit address property exposed via Matrox card's FCode to openfirmware is of
no use in 32bit GRUB and attempting to access the truncated address results in
a crash.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=973205

address@hidden: Clarify the commit message]
address@hidden: Add Changelog]
---
 ChangeLog                        | 10 ++++++++++
 grub-core/kern/ieee1275/cmain.c  |  5 ++++-
 grub-core/video/ieee1275.c       |  9 ++++++---
 include/grub/ieee1275/ieee1275.h |  2 ++
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c1b22f5..8bbb59f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
 2014-01-20  Paulo Flabiano Smorigo  <address@hidden>
 
+       * grub-core/kern/ieee1275/cmain.c (grub_ieee1275_find_options): Set
+       GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT flag if "model" property is
+       "IBM".
+       * grub-core/video/ieee1275.c (GRUB_MOD_INIT(ieee1275_fb)): Skip video
+       initialization if GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT is set.
+       * include/grub/ieee1275/ieee1275.h: Declare
+       GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT.
+
+2014-01-20  Paulo Flabiano Smorigo  <address@hidden>
+
        * grub-core/kern/ieee1275/openfw.c (grub_ieee1275_cas_reboot): Add.
        * (grub_ieee1275_set_boot_last_label): Add.
        * grub-core/normal/main.c [GRUB_MACHINE_IEEE1275]: Include
diff --git a/grub-core/kern/ieee1275/cmain.c b/grub-core/kern/ieee1275/cmain.c
index d92ae14..409c922 100644
--- a/grub-core/kern/ieee1275/cmain.c
+++ b/grub-core/kern/ieee1275/cmain.c
@@ -88,7 +88,10 @@ grub_ieee1275_find_options (void)
     is_qemu = 1;
 
   if (rc >= 0 && grub_strncmp (tmp, "IBM", 3) == 0)
-    grub_ieee1275_set_flag (GRUB_IEEE1275_FLAG_NO_TREE_SCANNING_FOR_DISKS);
+    {
+      grub_ieee1275_set_flag (GRUB_IEEE1275_FLAG_NO_TREE_SCANNING_FOR_DISKS);
+      grub_ieee1275_set_flag (GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT);
+    }
 
   /* Old Macs have no key repeat, newer ones have fully working one.
      The ones inbetween when repeated key generates an escaoe sequence
diff --git a/grub-core/video/ieee1275.c b/grub-core/video/ieee1275.c
index 0b150ec..813ab38 100644
--- a/grub-core/video/ieee1275.c
+++ b/grub-core/video/ieee1275.c
@@ -351,9 +351,12 @@ static struct grub_video_adapter 
grub_video_ieee1275_adapter =
 
 GRUB_MOD_INIT(ieee1275_fb)
 {
-  find_display ();
-  if (display)
-    grub_video_register (&grub_video_ieee1275_adapter);
+  if (! grub_ieee1275_test_flag (GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT))
+    {
+      find_display ();
+      if (display)
+        grub_video_register (&grub_video_ieee1275_adapter);
+    }
 }
 
 GRUB_MOD_FINI(ieee1275_fb)
diff --git a/include/grub/ieee1275/ieee1275.h b/include/grub/ieee1275/ieee1275.h
index 35618f4..d31e1db 100644
--- a/include/grub/ieee1275/ieee1275.h
+++ b/include/grub/ieee1275/ieee1275.h
@@ -145,6 +145,8 @@ enum grub_ieee1275_flag
   GRUB_IEEE1275_FLAG_BROKEN_REPEAT,
 
   GRUB_IEEE1275_FLAG_CURSORONOFF_ANSI_BROKEN,
+
+  GRUB_IEEE1275_FLAG_DISABLE_VIDEO_SUPPORT
 };
 
 extern int EXPORT_FUNC(grub_ieee1275_test_flag) (enum grub_ieee1275_flag flag);
-- 
1.8.3.1