From e03f549b3e11018b0ec0f44465f6bf5ca98ca993 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Tue, 14 Dec 2010 16:22:19 +0000
Subject: [PATCH 01/10] Preferred resolution detection for VBE.

* grub-core/video/i386/pc/vbe.c (grub_vbe_bios_get_flat_panel_info):
New function.
(grub_vbe_bios_get_ddc_capabilities): Likewise.
(grub_vbe_bios_read_edid): Likewise.
(grub_vbe_edid_checksum): Likewise.
(grub_vbe_get_preferred_mode): Likewise.  Try EDID followed by the
Flat Panel extension, in line with the X.org VESA driver.
(grub_video_vbe_setup): When the mode is "auto", try to get the
preferred mode from VBE, and use the largest mode that is no larger
than the preferred mode (some BIOSes expose a preferred mode that is
not in their mode list!).  If this fails, fall back to 640x480 as a
safe conservative choice.
* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
structure.
(struct grub_vbe_edid_info): Likewise.
(grub_vbe_bios_get_flat_panel_info): Add prototype.
(grub_vbe_bios_get_ddc_capabilities): Likewise.
(grub_vbe_bios_read_edid): Likewise.

* util/grub.d/00_header.in (GRUB_GFXMODE): Default to "auto".  This
is more appropriate on a wider range of platforms than 640x480.
---
 ChangeLog.vbe-autodetect      |  25 ++++++
 grub-core/video/i386/pc/vbe.c | 150 +++++++++++++++++++++++++++++++++-
 include/grub/i386/pc/vbe.h    |  84 +++++++++++++++++++
 util/grub.d/00_header.in      |   2 +-
 4 files changed, 256 insertions(+), 5 deletions(-)
 create mode 100644 ChangeLog.vbe-autodetect

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
new file mode 100644
index 000000000..7d16ebee2
--- /dev/null
+++ b/ChangeLog.vbe-autodetect
@@ -0,0 +1,25 @@
+2010-12-14  Colin Watson  <cjwatson@ubuntu.com>
+
+	Preferred resolution detection for VBE.
+
+	* grub-core/video/i386/pc/vbe.c (grub_vbe_bios_get_flat_panel_info):
+	New function.
+	(grub_vbe_bios_get_ddc_capabilities): Likewise.
+	(grub_vbe_bios_read_edid): Likewise.
+	(grub_vbe_edid_checksum): Likewise.
+	(grub_vbe_get_preferred_mode): Likewise.  Try EDID followed by the
+	Flat Panel extension, in line with the X.org VESA driver.
+	(grub_video_vbe_setup): When the mode is "auto", try to get the
+	preferred mode from VBE, and use the largest mode that is no larger
+	than the preferred mode (some BIOSes expose a preferred mode that is
+	not in their mode list!).  If this fails, fall back to 640x480 as a
+	safe conservative choice.
+	* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
+	structure.
+	(struct grub_vbe_edid_info): Likewise.
+	(grub_vbe_bios_get_flat_panel_info): Add prototype.
+	(grub_vbe_bios_get_ddc_capabilities): Likewise.
+	(grub_vbe_bios_read_edid): Likewise.
+
+	* util/grub.d/00_header.in (GRUB_GFXMODE): Default to "auto".  This
+	is more appropriate on a wider range of platforms than 640x480.
diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index 2ddb4ca80..1794addae 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -273,6 +273,56 @@ grub_vbe_bios_get_pm_interface (grub_uint16_t *segment, grub_uint16_t *offset,
   return regs.eax & 0xffff;
 }
 
+/* Call VESA BIOS 0x4f11 to get flat panel information, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_get_flat_panel_info (struct grub_vbe_flat_panel_info *flat_panel_info)
+{
+  struct grub_bios_int_registers regs;
+
+  regs.eax = 0x4f11;
+  regs.ebx = 0x0001;
+  regs.es = (((grub_addr_t) flat_panel_info) & 0xffff0000) >> 4;
+  regs.edi = ((grub_addr_t) flat_panel_info) & 0xffff;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x10, &regs);
+  return regs.eax & 0xffff;
+}
+
+/* Call VESA BIOS 0x4f15 to get DDC availability, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level)
+{
+  struct grub_bios_int_registers regs;
+
+  regs.eax = 0x4f15;
+  regs.ebx = 0x0000;
+  regs.ecx = 0x0000;
+  regs.es = 0x0000;
+  regs.edi = 0x0000;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x10, &regs);
+
+  *level = regs.ebx & 0xff;
+  return regs.eax & 0xffff;
+}
+
+/* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_read_edid (struct grub_vbe_edid_info *edid_info)
+{
+  struct grub_bios_int_registers regs;
+
+  regs.eax = 0x4f15;
+  regs.ebx = 0x0001;
+  regs.ecx = 0x0000;
+  regs.edx = 0x0000;
+  regs.es = (((grub_addr_t) edid_info) & 0xffff0000) >> 4;
+  regs.edi = ((grub_addr_t) edid_info) & 0xffff;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x10, &regs);
+  return regs.eax & 0xffff;
+}
+
 
 grub_err_t
 grub_vbe_probe (struct grub_vbe_info_block *info_block)
@@ -327,6 +377,70 @@ grub_vbe_probe (struct grub_vbe_info_block *info_block)
   return GRUB_ERR_NONE;
 }
 
+static grub_err_t
+grub_vbe_edid_checksum (struct grub_vbe_edid_info *edid_info)
+{
+  const char *edid_bytes = (const char *) edid_info;
+  int i;
+  char checksum = 0;
+
+  /* Check EDID checksum.  */
+  for (i = 0; i < 128; ++i)
+    checksum += edid_bytes[i];
+
+  if (checksum != 0)
+    return grub_error (GRUB_ERR_BAD_DEVICE,
+		       "invalid EDID checksum %d", checksum);
+
+  grub_errno = GRUB_ERR_NONE;
+  return grub_errno;
+}
+
+static grub_err_t
+grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
+{
+  grub_vbe_status_t status;
+  grub_uint8_t ddc_level;
+  struct grub_vbe_edid_info edid_info;
+  struct grub_vbe_flat_panel_info flat_panel_info;
+
+  if (controller_info.version >= 0x200
+      && (grub_vbe_bios_get_ddc_capabilities (&ddc_level) & 0xff)
+	 == GRUB_VBE_STATUS_OK)
+    {
+      status = grub_vbe_bios_read_edid (&edid_info);
+      /* Bit 1 in the Feature Support field indicates that the first
+         Detailed Timing Description is the preferred timing mode.  */
+      if (status == GRUB_VBE_STATUS_OK
+	  && grub_vbe_edid_checksum (&edid_info) == GRUB_ERR_NONE
+	  && edid_info.version == 1 /* we don't understand later versions */
+	  && (edid_info.feature_support
+	      & GRUB_VBE_EDID_FEATURE_PREFERRED_TIMING_MODE)
+	  && edid_info.detailed_timings[0].pixel_clock)
+	{
+	  *width = edid_info.detailed_timings[0].horizontal_active_lo
+		   | (((unsigned int)
+		       (edid_info.detailed_timings[0].horizontal_hi & 0xf0))
+		      << 4);
+	  *height = edid_info.detailed_timings[0].vertical_active_lo
+		    | (((unsigned int)
+			(edid_info.detailed_timings[0].vertical_hi & 0xf0))
+		       << 4);
+	  return GRUB_ERR_NONE;
+	}
+    }
+
+  status = grub_vbe_bios_get_flat_panel_info (&flat_panel_info);
+  if (status == GRUB_VBE_STATUS_OK)
+    {
+      *width = flat_panel_info.horizontal_size;
+      *height = flat_panel_info.vertical_size;
+      return GRUB_ERR_NONE;
+    }
+
+  return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "cannot get preferred mode");
+}
+
 grub_err_t
 grub_vbe_set_video_mode (grub_uint32_t vbe_mode,
 			 struct grub_vbe_mode_info_block *vbe_mode_info)
@@ -695,11 +809,28 @@ grub_video_vbe_setup (unsigned int width, unsigned int height,
   struct grub_vbe_mode_info_block best_vbe_mode_info;
   grub_uint32_t best_vbe_mode = 0;
   int depth;
+  int preferred_mode = 0;
 
   /* Decode depth from mode_type.  If it is zero, then autodetect.  */
   depth = (mode_type & GRUB_VIDEO_MODE_TYPE_DEPTH_MASK)
           >> GRUB_VIDEO_MODE_TYPE_DEPTH_POS;
 
+  if (width == 0 && height == 0)
+    {
+      grub_vbe_get_preferred_mode (&width, &height);
+      if (grub_errno == GRUB_ERR_NONE)
+	preferred_mode = 1;
+      else
+	{
+	  /* Fall back to 640x480.  This is conservative, but the largest
+	     mode supported by the graphics card may not be safe for the
+	     display device.  */
+	  grub_errno = GRUB_ERR_NONE;
+	  width = 640;
+	  height = 480;
+	}
+    }
+
   /* Walk thru mode list and try to find matching mode.  */
   for (p = vbe_mode_list; *p != 0xFFFF; p++)
     {
@@ -742,10 +873,21 @@ grub_video_vbe_setup (unsigned int width, unsigned int height,
 	/* Unsupported bitdepth . */
         continue;
 
-      if (((vbe_mode_info.x_resolution != width)
-	   || (vbe_mode_info.y_resolution != height)) && width != 0 && height != 0)
-        /* Non matching resolution.  */
-        continue;
+      if (preferred_mode)
+	{
+	  if (vbe_mode_info.x_resolution > width
+	      || vbe_mode_info.y_resolution > height)
+	    /* Resolution exceeds that of preferred mode.  */
+	    continue;
+	}
+      else
+	{
+	  if (((vbe_mode_info.x_resolution != width)
+	       || (vbe_mode_info.y_resolution != height))
+	      && width != 0 && height != 0)
+	    /* Non matching resolution.  */
+	    continue;
+	}
 
       /* Check if user requested RGB or index color mode.  */
       if ((mode_mask & GRUB_VIDEO_MODE_TYPE_COLOR_MASK) != 0)
diff --git a/include/grub/i386/pc/vbe.h b/include/grub/i386/pc/vbe.h
index fba3ee642..5be34fdec 100644
--- a/include/grub/i386/pc/vbe.h
+++ b/include/grub/i386/pc/vbe.h
@@ -169,6 +169,81 @@ struct grub_vbe_palette_data
   grub_uint8_t alignment;
 } __attribute__ ((packed));
 
+struct grub_vbe_flat_panel_info
+{
+  grub_uint16_t horizontal_size;
+  grub_uint16_t vertical_size;
+  grub_uint16_t panel_type;
+  grub_uint8_t red_bpp;
+  grub_uint8_t green_bpp;
+  grub_uint8_t blue_bpp;
+  grub_uint8_t reserved_bpp;
+  grub_uint32_t reserved_offscreen_mem_size;
+  grub_vbe_farptr_t reserved_offscreen_mem_ptr;
+
+  grub_uint8_t reserved[14];
+} __attribute__ ((packed));
+
+struct grub_vbe_edid_info
+{
+  grub_uint8_t header[8];
+  grub_uint16_t manufacturer_id;
+  grub_uint16_t product_id;
+  grub_uint32_t serial_number;
+  grub_uint8_t week_of_manufacture;
+  grub_uint8_t year_of_manufacture;
+  grub_uint8_t version;
+  grub_uint8_t revision;
+
+  grub_uint8_t video_input_definition;
+  grub_uint8_t max_horizontal_image_size;
+  grub_uint8_t max_vertical_image_size;
+  grub_uint8_t display_gamma;
+  grub_uint8_t feature_support;
+#define GRUB_VBE_EDID_FEATURE_PREFERRED_TIMING_MODE	(1 << 1)
+
+  grub_uint8_t red_green_lo;
+  grub_uint8_t blue_white_lo;
+  grub_uint8_t red_x_hi;
+  grub_uint8_t red_y_hi;
+  grub_uint8_t green_x_hi;
+  grub_uint8_t green_y_hi;
+  grub_uint8_t blue_x_hi;
+  grub_uint8_t blue_y_hi;
+  grub_uint8_t white_x_hi;
+  grub_uint8_t white_y_hi;
+
+  grub_uint8_t established_timings_1;
+  grub_uint8_t established_timings_2;
+  grub_uint8_t manufacturer_reserved_timings;
+
+  grub_uint16_t standard_timings[8];
+
+  struct {
+    grub_uint16_t pixel_clock;
+    /* Only valid if the pixel clock is non-null.  */
+    grub_uint8_t horizontal_active_lo;
+    grub_uint8_t horizontal_blanking_lo;
+    grub_uint8_t horizontal_hi;
+    grub_uint8_t vertical_active_lo;
+    grub_uint8_t vertical_blanking_lo;
+    grub_uint8_t vertical_hi;
+    grub_uint8_t horizontal_sync_offset_lo;
+    grub_uint8_t horizontal_sync_pulse_width_lo;
+    grub_uint8_t vertical_sync_lo;
+    grub_uint8_t sync_hi;
+    grub_uint8_t horizontal_image_size_lo;
+    grub_uint8_t vertical_image_size_lo;
+    grub_uint8_t image_size_hi;
+    grub_uint8_t horizontal_border;
+    grub_uint8_t vertical_border;
+    grub_uint8_t flags;
+  } detailed_timings[4];
+
+  grub_uint8_t extension_flag;
+  grub_uint8_t checksum;
+} __attribute__ ((packed));
+
 /* Prototypes for helper functions.  */
 /* Call VESA BIOS 0x4f00 to get VBE Controller Information, return status.  */
 grub_vbe_status_t 
@@ -197,6 +272,15 @@ grub_vbe_bios_get_scanline_length (grub_uint32_t *length);
 grub_vbe_status_t 
 grub_vbe_bios_get_display_start (grub_uint32_t *x,
 				 grub_uint32_t *y);
+/* Call VESA BIOS 0x4f11 to get flat panel information, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_get_flat_panel_info (struct grub_vbe_flat_panel_info *flat_panel_info);
+/* Call VESA BIOS 0x4f15 to get DDC availability, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level);
+/* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
+grub_vbe_status_t
+grub_vbe_bios_read_edid (struct grub_vbe_edid_info *edid_data);
 
 grub_vbe_status_t grub_vbe_bios_getset_dac_palette_width (int set, int *width);
 
diff --git a/util/grub.d/00_header.in b/util/grub.d/00_header.in
index a596e9c4a..55c686296 100644
--- a/util/grub.d/00_header.in
+++ b/util/grub.d/00_header.in
@@ -36,7 +36,7 @@ done
 if [ "x${GRUB_DEFAULT}" = "x" ] ; then GRUB_DEFAULT=0 ; fi
 if [ "x${GRUB_DEFAULT}" = "xsaved" ] ; then GRUB_DEFAULT='${saved_entry}' ; fi
 if [ "x${GRUB_TIMEOUT}" = "x" ] ; then GRUB_TIMEOUT=5 ; fi
-if [ "x${GRUB_GFXMODE}" = "x" ] ; then GRUB_GFXMODE=640x480 ; fi
+if [ "x${GRUB_GFXMODE}" = "x" ] ; then GRUB_GFXMODE=auto ; fi
 
 if [ "x${GRUB_DEFAULT_BUTTON}" = "x" ] ; then GRUB_DEFAULT_BUTTON="$GRUB_DEFAULT" ; fi
 if [ "x${GRUB_DEFAULT_BUTTON}" = "xsaved" ] ; then GRUB_DEFAULT_BUTTON='${saved_entry}' ; fi

From 25d884a52a1819792bc97cac9890d44a72446b7c Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Tue, 14 Dec 2010 17:06:32 +0000
Subject: [PATCH 02/10] move generic parts of EDID handling (structure,
 checksumming) to generic location

---
 ChangeLog.vbe-autodetect      |  7 ++--
 grub-core/video/i386/pc/vbe.c | 27 +++------------
 grub-core/video/video.c       | 19 +++++++++++
 include/grub/i386/pc/vbe.h    | 64 ++---------------------------------
 include/grub/video.h          | 62 +++++++++++++++++++++++++++++++++
 5 files changed, 92 insertions(+), 87 deletions(-)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index 7d16ebee2..0d96fc0a2 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -2,11 +2,11 @@
 
 	Preferred resolution detection for VBE.
 
+	* grub-core/video/video.c (grub_video_edid_checksum): New function.
 	* grub-core/video/i386/pc/vbe.c (grub_vbe_bios_get_flat_panel_info):
-	New function.
+	Likewise.
 	(grub_vbe_bios_get_ddc_capabilities): Likewise.
 	(grub_vbe_bios_read_edid): Likewise.
-	(grub_vbe_edid_checksum): Likewise.
 	(grub_vbe_get_preferred_mode): Likewise.  Try EDID followed by the
 	Flat Panel extension, in line with the X.org VESA driver.
 	(grub_video_vbe_setup): When the mode is "auto", try to get the
@@ -14,9 +14,10 @@
 	than the preferred mode (some BIOSes expose a preferred mode that is
 	not in their mode list!).  If this fails, fall back to 640x480 as a
 	safe conservative choice.
+	* include/grub/video.h (struct grub_vbe_edid_info): New structure.
+	(grub_video_edid_checksum): Add prototype.
 	* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
 	structure.
-	(struct grub_vbe_edid_info): Likewise.
 	(grub_vbe_bios_get_flat_panel_info): Add prototype.
 	(grub_vbe_bios_get_ddc_capabilities): Likewise.
 	(grub_vbe_bios_read_edid): Likewise.
diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index 1794addae..e2dcc151e 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -308,7 +308,7 @@ grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level)
 
 /* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
 grub_vbe_status_t
-grub_vbe_bios_read_edid (struct grub_vbe_edid_info *edid_info)
+grub_vbe_bios_read_edid (struct grub_video_edid_info *edid_info)
 {
   struct grub_bios_int_registers regs;
 
@@ -377,31 +377,12 @@ grub_vbe_probe (struct grub_vbe_info_block *info_block)
   return GRUB_ERR_NONE;
 }
 
-static grub_err_t
-grub_vbe_edid_checksum (struct grub_vbe_edid_info *edid_info)
-{
-  const char *edid_bytes = (const char *) edid_info;
-  int i;
-  char checksum = 0;
-
-  /* Check EDID checksum.  */
-  for (i = 0; i < 128; ++i)
-    checksum += edid_bytes[i];
-
-  if (checksum != 0)
-    return grub_error (GRUB_ERR_BAD_DEVICE,
-		       "invalid EDID checksum %d", checksum);
-
-  grub_errno = GRUB_ERR_NONE;
-  return grub_errno;
-}
-
 static grub_err_t
 grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
 {
   grub_vbe_status_t status;
   grub_uint8_t ddc_level;
-  struct grub_vbe_edid_info edid_info;
+  struct grub_video_edid_info edid_info;
   struct grub_vbe_flat_panel_info flat_panel_info;
 
   if (controller_info.version >= 0x200
@@ -412,10 +393,10 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
       /* Bit 1 in the Feature Support field indicates that the first
          Detailed Timing Description is the preferred timing mode.  */
       if (status == GRUB_VBE_STATUS_OK
-	  && grub_vbe_edid_checksum (&edid_info) == GRUB_ERR_NONE
+	  && grub_video_edid_checksum (&edid_info) == GRUB_ERR_NONE
 	  && edid_info.version == 1 /* we don't understand later versions */
 	  && (edid_info.feature_support
-	      & GRUB_VBE_EDID_FEATURE_PREFERRED_TIMING_MODE)
+	      & GRUB_VIDEO_EDID_FEATURE_PREFERRED_TIMING_MODE)
 	  && edid_info.detailed_timings[0].pixel_clock)
 	{
 	  *width = edid_info.detailed_timings[0].horizontal_active_lo
diff --git a/grub-core/video/video.c b/grub-core/video/video.c
index 7a1a446e4..f3ecab94d 100644
--- a/grub-core/video/video.c
+++ b/grub-core/video/video.c
@@ -374,6 +374,25 @@ grub_video_get_active_render_target (struct grub_video_render_target **target)
   return grub_video_adapter_active->get_active_render_target (target);
 }
 
+grub_err_t
+grub_video_edid_checksum (struct grub_video_edid_info *edid_info)
+{
+  const char *edid_bytes = (const char *) edid_info;
+  int i;
+  char checksum = 0;
+
+  /* Check EDID checksum.  */
+  for (i = 0; i < 128; ++i)
+    checksum += edid_bytes[i];
+
+  if (checksum != 0)
+    return grub_error (GRUB_ERR_BAD_DEVICE,
+		       "invalid EDID checksum %d", checksum);
+
+  grub_errno = GRUB_ERR_NONE;
+  return grub_errno;
+}
+
 /* Parse <width>x<height>[x<depth>]*/
 static grub_err_t
 parse_modespec (const char *current_mode, int *width, int *height, int *depth)
diff --git a/include/grub/i386/pc/vbe.h b/include/grub/i386/pc/vbe.h
index 5be34fdec..0422558db 100644
--- a/include/grub/i386/pc/vbe.h
+++ b/include/grub/i386/pc/vbe.h
@@ -19,6 +19,8 @@
 #ifndef GRUB_VBE_MACHINE_HEADER
 #define GRUB_VBE_MACHINE_HEADER	1
 
+#include <grub/video.h>
+
 /* Default video mode to be used.  */
 #define GRUB_VBE_DEFAULT_VIDEO_MODE     0x101
 
@@ -184,66 +186,6 @@ struct grub_vbe_flat_panel_info
   grub_uint8_t reserved[14];
 } __attribute__ ((packed));
 
-struct grub_vbe_edid_info
-{
-  grub_uint8_t header[8];
-  grub_uint16_t manufacturer_id;
-  grub_uint16_t product_id;
-  grub_uint32_t serial_number;
-  grub_uint8_t week_of_manufacture;
-  grub_uint8_t year_of_manufacture;
-  grub_uint8_t version;
-  grub_uint8_t revision;
-
-  grub_uint8_t video_input_definition;
-  grub_uint8_t max_horizontal_image_size;
-  grub_uint8_t max_vertical_image_size;
-  grub_uint8_t display_gamma;
-  grub_uint8_t feature_support;
-#define GRUB_VBE_EDID_FEATURE_PREFERRED_TIMING_MODE	(1 << 1)
-
-  grub_uint8_t red_green_lo;
-  grub_uint8_t blue_white_lo;
-  grub_uint8_t red_x_hi;
-  grub_uint8_t red_y_hi;
-  grub_uint8_t green_x_hi;
-  grub_uint8_t green_y_hi;
-  grub_uint8_t blue_x_hi;
-  grub_uint8_t blue_y_hi;
-  grub_uint8_t white_x_hi;
-  grub_uint8_t white_y_hi;
-
-  grub_uint8_t established_timings_1;
-  grub_uint8_t established_timings_2;
-  grub_uint8_t manufacturer_reserved_timings;
-
-  grub_uint16_t standard_timings[8];
-
-  struct {
-    grub_uint16_t pixel_clock;
-    /* Only valid if the pixel clock is non-null.  */
-    grub_uint8_t horizontal_active_lo;
-    grub_uint8_t horizontal_blanking_lo;
-    grub_uint8_t horizontal_hi;
-    grub_uint8_t vertical_active_lo;
-    grub_uint8_t vertical_blanking_lo;
-    grub_uint8_t vertical_hi;
-    grub_uint8_t horizontal_sync_offset_lo;
-    grub_uint8_t horizontal_sync_pulse_width_lo;
-    grub_uint8_t vertical_sync_lo;
-    grub_uint8_t sync_hi;
-    grub_uint8_t horizontal_image_size_lo;
-    grub_uint8_t vertical_image_size_lo;
-    grub_uint8_t image_size_hi;
-    grub_uint8_t horizontal_border;
-    grub_uint8_t vertical_border;
-    grub_uint8_t flags;
-  } detailed_timings[4];
-
-  grub_uint8_t extension_flag;
-  grub_uint8_t checksum;
-} __attribute__ ((packed));
-
 /* Prototypes for helper functions.  */
 /* Call VESA BIOS 0x4f00 to get VBE Controller Information, return status.  */
 grub_vbe_status_t 
@@ -280,7 +222,7 @@ grub_vbe_status_t
 grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level);
 /* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
 grub_vbe_status_t
-grub_vbe_bios_read_edid (struct grub_vbe_edid_info *edid_data);
+grub_vbe_bios_read_edid (struct grub_video_edid_info *edid_data);
 
 grub_vbe_status_t grub_vbe_bios_getset_dac_palette_width (int set, int *width);
 
diff --git a/include/grub/video.h b/include/grub/video.h
index 97bd85bd1..2cf1424c4 100644
--- a/include/grub/video.h
+++ b/include/grub/video.h
@@ -210,6 +210,66 @@ struct grub_video_palette_data
   grub_uint8_t a; /* Reserved bits value (0-255).  */
 };
 
+struct grub_video_edid_info
+{
+  grub_uint8_t header[8];
+  grub_uint16_t manufacturer_id;
+  grub_uint16_t product_id;
+  grub_uint32_t serial_number;
+  grub_uint8_t week_of_manufacture;
+  grub_uint8_t year_of_manufacture;
+  grub_uint8_t version;
+  grub_uint8_t revision;
+
+  grub_uint8_t video_input_definition;
+  grub_uint8_t max_horizontal_image_size;
+  grub_uint8_t max_vertical_image_size;
+  grub_uint8_t display_gamma;
+  grub_uint8_t feature_support;
+#define GRUB_VIDEO_EDID_FEATURE_PREFERRED_TIMING_MODE	(1 << 1)
+
+  grub_uint8_t red_green_lo;
+  grub_uint8_t blue_white_lo;
+  grub_uint8_t red_x_hi;
+  grub_uint8_t red_y_hi;
+  grub_uint8_t green_x_hi;
+  grub_uint8_t green_y_hi;
+  grub_uint8_t blue_x_hi;
+  grub_uint8_t blue_y_hi;
+  grub_uint8_t white_x_hi;
+  grub_uint8_t white_y_hi;
+
+  grub_uint8_t established_timings_1;
+  grub_uint8_t established_timings_2;
+  grub_uint8_t manufacturer_reserved_timings;
+
+  grub_uint16_t standard_timings[8];
+
+  struct {
+    grub_uint16_t pixel_clock;
+    /* Only valid if the pixel clock is non-null.  */
+    grub_uint8_t horizontal_active_lo;
+    grub_uint8_t horizontal_blanking_lo;
+    grub_uint8_t horizontal_hi;
+    grub_uint8_t vertical_active_lo;
+    grub_uint8_t vertical_blanking_lo;
+    grub_uint8_t vertical_hi;
+    grub_uint8_t horizontal_sync_offset_lo;
+    grub_uint8_t horizontal_sync_pulse_width_lo;
+    grub_uint8_t vertical_sync_lo;
+    grub_uint8_t sync_hi;
+    grub_uint8_t horizontal_image_size_lo;
+    grub_uint8_t vertical_image_size_lo;
+    grub_uint8_t image_size_hi;
+    grub_uint8_t horizontal_border;
+    grub_uint8_t vertical_border;
+    grub_uint8_t flags;
+  } detailed_timings[4];
+
+  grub_uint8_t extension_flag;
+  grub_uint8_t checksum;
+} __attribute__ ((packed));
+
 typedef enum grub_video_driver_id
   {
     GRUB_VIDEO_DRIVER_NONE,
@@ -423,6 +483,8 @@ grub_err_t EXPORT_FUNC (grub_video_set_active_render_target) (struct grub_video_
 
 grub_err_t grub_video_get_active_render_target (struct grub_video_render_target **target);
 
+grub_err_t grub_video_edid_checksum (struct grub_video_edid_info *edid_info);
+
 grub_err_t EXPORT_FUNC (grub_video_set_mode) (const char *modestring,
 					      unsigned int modemask,
 					      unsigned int modevalue);

From 129185cfaae5969be4e49f5d898ed553b18d8502 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Tue, 14 Dec 2010 18:03:34 +0000
Subject: [PATCH 03/10] move more EDID-handling functions to generic code, and
 make videoinfo display EDID information

---
 ChangeLog.vbe-autodetect       | 15 +++++++++---
 grub-core/commands/videoinfo.c | 31 ++++++++++++++++++++++++
 grub-core/video/i386/pc/vbe.c  | 36 +++++++++++++---------------
 grub-core/video/video.c        | 43 ++++++++++++++++++++++++++++++++++
 include/grub/video.h           |  6 +++++
 5 files changed, 108 insertions(+), 23 deletions(-)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index 0d96fc0a2..355ce00f6 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -3,24 +3,33 @@
 	Preferred resolution detection for VBE.
 
 	* grub-core/video/video.c (grub_video_edid_checksum): New function.
+	(grub_video_get_edid): Likewise.
+	(grub_video_edid_preferred_mode): Likewise.  Try EDID followed by
+	the Flat Panel extension, in line with the X.org VESA driver.
 	* grub-core/video/i386/pc/vbe.c (grub_vbe_bios_get_flat_panel_info):
-	Likewise.
+	New function.
 	(grub_vbe_bios_get_ddc_capabilities): Likewise.
 	(grub_vbe_bios_read_edid): Likewise.
-	(grub_vbe_get_preferred_mode): Likewise.  Try EDID followed by the
-	Flat Panel extension, in line with the X.org VESA driver.
+	(grub_vbe_get_preferred_mode): Likewise.
 	(grub_video_vbe_setup): When the mode is "auto", try to get the
 	preferred mode from VBE, and use the largest mode that is no larger
 	than the preferred mode (some BIOSes expose a preferred mode that is
 	not in their mode list!).  If this fails, fall back to 640x480 as a
 	safe conservative choice.
+	(grub_video_vbe_get_edid): New function.
+	(grub_video_vbe_adapter): Add get_edid.
 	* include/grub/video.h (struct grub_vbe_edid_info): New structure.
 	(grub_video_edid_checksum): Add prototype.
+	(grub_video_get_edid): Likewise.
+	(grub_video_edid_preferred_mode): Likewise.
 	* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
 	structure.
 	(grub_vbe_bios_get_flat_panel_info): Add prototype.
 	(grub_vbe_bios_get_ddc_capabilities): Likewise.
 	(grub_vbe_bios_read_edid): Likewise.
 
+	* grub-core/commands/videoinfo.c (print_edid): New function.
+	(grub_cmd_videoinfo): Print EDID if available.
+
 	* util/grub.d/00_header.in (GRUB_GFXMODE): Default to "auto".  This
 	is more appropriate on a wider range of platforms than 640x480.
diff --git a/grub-core/commands/videoinfo.c b/grub-core/commands/videoinfo.c
index 10f77915b..56df943ec 100644
--- a/grub-core/commands/videoinfo.c
+++ b/grub-core/commands/videoinfo.c
@@ -77,6 +77,30 @@ hook (const struct grub_video_mode_info *info)
   return 0;
 }
 
+static void
+print_edid (struct grub_video_edid_info *edid_info)
+{
+  unsigned int edid_width, edid_height;
+
+  if (grub_video_edid_checksum (edid_info))
+    {
+      grub_printf ("  EDID checksum invalid\n");
+      grub_errno = GRUB_ERR_NONE;
+      return;
+    }
+
+  grub_printf ("  EDID version: %u.%u\n",
+	       edid_info->version, edid_info->revision);
+  if (grub_video_edid_preferred_mode (edid_info, &edid_width, &edid_height)
+	== GRUB_ERR_NONE)
+    grub_printf ("    Preferred mode: %ux%u\n", edid_width, edid_height);
+  else
+    {
+      grub_printf ("    No preferred mode available\n");
+      grub_errno = GRUB_ERR_NONE;
+    }
+}
+
 static grub_err_t
 grub_cmd_videoinfo (grub_command_t cmd __attribute__ ((unused)),
 		    int argc, char **args)
@@ -120,6 +144,8 @@ grub_cmd_videoinfo (grub_command_t cmd __attribute__ ((unused)),
 
   FOR_VIDEO_ADAPTERS (adapter)
   {
+    struct grub_video_edid_info edid_info;
+
     grub_printf ("Adapter '%s':\n", adapter->name);
 
     if (!adapter->iterate)
@@ -143,6 +169,11 @@ grub_cmd_videoinfo (grub_command_t cmd __attribute__ ((unused)),
 
     adapter->iterate (hook);
 
+    if (adapter->get_edid (&edid_info) == GRUB_ERR_NONE)
+      print_edid (&edid_info);
+    else
+      grub_errno = GRUB_ERR_NONE;
+
     if (adapter->id != id)
       {
 	if (adapter->fini ())
diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index e2dcc151e..c6bb733a9 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -389,26 +389,12 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
       && (grub_vbe_bios_get_ddc_capabilities (&ddc_level) & 0xff)
 	 == GRUB_VBE_STATUS_OK)
     {
-      status = grub_vbe_bios_read_edid (&edid_info);
-      /* Bit 1 in the Feature Support field indicates that the first
-         Detailed Timing Description is the preferred timing mode.  */
-      if (status == GRUB_VBE_STATUS_OK
-	  && grub_video_edid_checksum (&edid_info) == GRUB_ERR_NONE
-	  && edid_info.version == 1 /* we don't understand later versions */
-	  && (edid_info.feature_support
-	      & GRUB_VIDEO_EDID_FEATURE_PREFERRED_TIMING_MODE)
-	  && edid_info.detailed_timings[0].pixel_clock)
-	{
-	  *width = edid_info.detailed_timings[0].horizontal_active_lo
-		   | (((unsigned int)
-		       (edid_info.detailed_timings[0].horizontal_hi & 0xf0))
-		      << 4);
-	  *height = edid_info.detailed_timings[0].vertical_active_lo
-		    | (((unsigned int)
-			(edid_info.detailed_timings[0].vertical_hi & 0xf0))
-		       << 4);
-	  return GRUB_ERR_NONE;
-	}
+      if (grub_video_get_edid (&edid_info) == GRUB_ERR_NONE
+	  && grub_video_edid_preferred_mode (&edid_info, width, height)
+	      == GRUB_ERR_NONE)
+	return GRUB_ERR_NONE;
+
+      grub_errno = GRUB_ERR_NONE;
     }
 
   status = grub_vbe_bios_get_flat_panel_info (&flat_panel_info);
@@ -978,6 +964,15 @@ grub_video_vbe_get_info_and_fini (struct grub_video_mode_info *mode_info,
   return grub_video_fb_get_info_and_fini (mode_info, framebuf);
 }
 
+static grub_err_t
+grub_video_vbe_get_edid (struct grub_video_edid_info *edid_info)
+{
+  if (grub_vbe_bios_read_edid (edid_info) != GRUB_VBE_STATUS_OK)
+    return grub_error (GRUB_ERR_BAD_DEVICE, "EDID information not available");
+
+  return GRUB_ERR_NONE;
+}
+
 static void
 grub_video_vbe_print_adapter_specific_info (void)
 {
@@ -1022,6 +1017,7 @@ static struct grub_video_adapter grub_video_vbe_adapter =
     .set_active_render_target = grub_video_fb_set_active_render_target,
     .get_active_render_target = grub_video_fb_get_active_render_target,
     .iterate = grub_video_vbe_iterate,
+    .get_edid = grub_video_vbe_get_edid,
     .print_adapter_specific_info = grub_video_vbe_print_adapter_specific_info,
 
     .next = 0
diff --git a/grub-core/video/video.c b/grub-core/video/video.c
index f3ecab94d..84e98bb67 100644
--- a/grub-core/video/video.c
+++ b/grub-core/video/video.c
@@ -393,6 +393,49 @@ grub_video_edid_checksum (struct grub_video_edid_info *edid_info)
   return grub_errno;
 }
 
+grub_err_t
+grub_video_get_edid (struct grub_video_edid_info *edid_info)
+{
+  if (! grub_video_adapter_active)
+    return grub_error (GRUB_ERR_BAD_DEVICE, "no video mode activated");
+
+  if (! grub_video_adapter_active->get_edid)
+    return grub_error (GRUB_ERR_BAD_DEVICE,
+		       "EDID information unavailable for this video mode");
+
+  if (grub_video_adapter_active->get_edid (edid_info) != GRUB_ERR_NONE)
+    return grub_errno;
+  if (grub_video_edid_checksum (edid_info) != GRUB_ERR_NONE)
+    return grub_errno;
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_video_edid_preferred_mode (struct grub_video_edid_info *edid_info,
+				unsigned int *width, unsigned int *height)
+{
+  /* Bit 1 in the Feature Support field indicates that the first
+     Detailed Timing Description is the preferred timing mode.  */
+  if (edid_info->version == 1 /* we don't understand later versions */
+      && (edid_info->feature_support
+	  & GRUB_VIDEO_EDID_FEATURE_PREFERRED_TIMING_MODE)
+      && edid_info->detailed_timings[0].pixel_clock)
+    {
+      *width = edid_info->detailed_timings[0].horizontal_active_lo
+	       | (((unsigned int)
+		   (edid_info->detailed_timings[0].horizontal_hi & 0xf0))
+		  << 4);
+      *height = edid_info->detailed_timings[0].vertical_active_lo
+		| (((unsigned int)
+		    (edid_info->detailed_timings[0].vertical_hi & 0xf0))
+		   << 4);
+      return GRUB_ERR_NONE;
+    }
+
+  return grub_error (GRUB_ERR_BAD_DEVICE, "no preferred mode available");
+}
+
 /* Parse <width>x<height>[x<depth>]*/
 static grub_err_t
 parse_modespec (const char *current_mode, int *width, int *height, int *depth)
diff --git a/include/grub/video.h b/include/grub/video.h
index 2cf1424c4..2251ed5f4 100644
--- a/include/grub/video.h
+++ b/include/grub/video.h
@@ -371,6 +371,8 @@ struct grub_video_adapter
 
   int (*iterate) (int (*hook) (const struct grub_video_mode_info *info));
 
+  grub_err_t (*get_edid) (struct grub_video_edid_info *edid_info);
+
   void (*print_adapter_specific_info) (void);
 };
 typedef struct grub_video_adapter *grub_video_adapter_t;
@@ -484,6 +486,10 @@ grub_err_t EXPORT_FUNC (grub_video_set_active_render_target) (struct grub_video_
 grub_err_t grub_video_get_active_render_target (struct grub_video_render_target **target);
 
 grub_err_t grub_video_edid_checksum (struct grub_video_edid_info *edid_info);
+grub_err_t grub_video_get_edid (struct grub_video_edid_info *edid_info);
+grub_err_t grub_video_edid_preferred_mode (struct grub_video_edid_info *edid_info,
+					   unsigned int *width,
+					   unsigned int *height);
 
 grub_err_t EXPORT_FUNC (grub_video_set_mode) (const char *modestring,
 					      unsigned int modemask,

From ef429417b2297c508685d9b1cc43e0bee74f0f44 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Tue, 14 Dec 2010 18:08:27 +0000
Subject: [PATCH 04/10] mention struct grub_video_adapter change

---
 ChangeLog.vbe-autodetect | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index 355ce00f6..d8034b885 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -19,6 +19,7 @@
 	(grub_video_vbe_get_edid): New function.
 	(grub_video_vbe_adapter): Add get_edid.
 	* include/grub/video.h (struct grub_vbe_edid_info): New structure.
+	(struct grub_video_adapter): Add get_edid.
 	(grub_video_edid_checksum): Add prototype.
 	(grub_video_get_edid): Likewise.
 	(grub_video_edid_preferred_mode): Likewise.

From 015e21571c2ecaacb7eb59c2cfde566d1290c445 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Tue, 14 Dec 2010 19:03:28 +0000
Subject: [PATCH 05/10] check that adapter->get_edid is non-NULL

---
 grub-core/commands/videoinfo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/grub-core/commands/videoinfo.c b/grub-core/commands/videoinfo.c
index 56df943ec..9bd0a0e78 100644
--- a/grub-core/commands/videoinfo.c
+++ b/grub-core/commands/videoinfo.c
@@ -169,7 +169,7 @@ grub_cmd_videoinfo (grub_command_t cmd __attribute__ ((unused)),
 
     adapter->iterate (hook);
 
-    if (adapter->get_edid (&edid_info) == GRUB_ERR_NONE)
+    if (adapter->get_edid && adapter->get_edid (&edid_info) == GRUB_ERR_NONE)
       print_edid (&edid_info);
     else
       grub_errno = GRUB_ERR_NONE;

From 13fc463f17281442f13c5ed3dc586f22efaaa2af Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Sat, 15 Jan 2011 14:18:16 -0600
Subject: [PATCH 06/10] Make new grub_vbe_bios_* functions static.

---
 ChangeLog.vbe-autodetect      | 5 +----
 grub-core/video/i386/pc/vbe.c | 6 +++---
 include/grub/i386/pc/vbe.h    | 9 ---------
 3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index d8034b885..46aacef7b 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -1,4 +1,4 @@
-2010-12-14  Colin Watson  <cjwatson@ubuntu.com>
+2011-01-15  Colin Watson  <cjwatson@ubuntu.com>
 
 	Preferred resolution detection for VBE.
 
@@ -25,9 +25,6 @@
 	(grub_video_edid_preferred_mode): Likewise.
 	* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
 	structure.
-	(grub_vbe_bios_get_flat_panel_info): Add prototype.
-	(grub_vbe_bios_get_ddc_capabilities): Likewise.
-	(grub_vbe_bios_read_edid): Likewise.
 
 	* grub-core/commands/videoinfo.c (print_edid): New function.
 	(grub_cmd_videoinfo): Print EDID if available.
diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index c6bb733a9..29b67beeb 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -274,7 +274,7 @@ grub_vbe_bios_get_pm_interface (grub_uint16_t *segment, grub_uint16_t *offset,
 }
 
 /* Call VESA BIOS 0x4f11 to get flat panel information, return status.  */
-grub_vbe_status_t
+static grub_vbe_status_t
 grub_vbe_bios_get_flat_panel_info (struct grub_vbe_flat_panel_info *flat_panel_info)
 {
   struct grub_bios_int_registers regs;
@@ -289,7 +289,7 @@ grub_vbe_bios_get_flat_panel_info (struct grub_vbe_flat_panel_info *flat_panel_i
 }
 
 /* Call VESA BIOS 0x4f15 to get DDC availability, return status.  */
-grub_vbe_status_t
+static grub_vbe_status_t
 grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level)
 {
   struct grub_bios_int_registers regs;
@@ -307,7 +307,7 @@ grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level)
 }
 
 /* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
-grub_vbe_status_t
+static grub_vbe_status_t
 grub_vbe_bios_read_edid (struct grub_video_edid_info *edid_info)
 {
   struct grub_bios_int_registers regs;
diff --git a/include/grub/i386/pc/vbe.h b/include/grub/i386/pc/vbe.h
index 0422558db..09ad7eb64 100644
--- a/include/grub/i386/pc/vbe.h
+++ b/include/grub/i386/pc/vbe.h
@@ -214,15 +214,6 @@ grub_vbe_bios_get_scanline_length (grub_uint32_t *length);
 grub_vbe_status_t 
 grub_vbe_bios_get_display_start (grub_uint32_t *x,
 				 grub_uint32_t *y);
-/* Call VESA BIOS 0x4f11 to get flat panel information, return status.  */
-grub_vbe_status_t
-grub_vbe_bios_get_flat_panel_info (struct grub_vbe_flat_panel_info *flat_panel_info);
-/* Call VESA BIOS 0x4f15 to get DDC availability, return status.  */
-grub_vbe_status_t
-grub_vbe_bios_get_ddc_capabilities (grub_uint8_t *level);
-/* Call VESA BIOS 0x4f15 to read EDID information, return status.  */
-grub_vbe_status_t
-grub_vbe_bios_read_edid (struct grub_video_edid_info *edid_data);
 
 grub_vbe_status_t grub_vbe_bios_getset_dac_palette_width (int set, int *width);
 

From 4f8ba1461b82f886557293c26da82fe590d556cd Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Mon, 17 Jan 2011 11:56:36 +0000
Subject: [PATCH 07/10] Use low memory scratch area for EDID and FP calls.

---
 grub-core/video/i386/pc/vbe.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index 29b67beeb..ea60c6074 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -383,7 +383,12 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
   grub_vbe_status_t status;
   grub_uint8_t ddc_level;
   struct grub_video_edid_info edid_info;
-  struct grub_vbe_flat_panel_info flat_panel_info;
+  struct grub_vbe_flat_panel_info *flat_panel_info;
+
+  /* Use low memory scratch area as temporary storage for VESA BIOS calls.  */
+  flat_panel_info = (struct grub_vbe_flat_panel_info *)
+    (GRUB_MEMORY_MACHINE_SCRATCH_ADDR + sizeof (struct grub_video_edid_info));
+  grub_memset (flat_panel_info, 0, sizeof (*flat_panel_info));
 
   if (controller_info.version >= 0x200
       && (grub_vbe_bios_get_ddc_capabilities (&ddc_level) & 0xff)
@@ -397,7 +402,7 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
       grub_errno = GRUB_ERR_NONE;
     }
 
-  status = grub_vbe_bios_get_flat_panel_info (&flat_panel_info);
+  status = grub_vbe_bios_get_flat_panel_info (flat_panel_info);
   if (status == GRUB_VBE_STATUS_OK)
     {
       *width = flat_panel_info.horizontal_size;
@@ -967,9 +972,18 @@ grub_video_vbe_get_info_and_fini (struct grub_video_mode_info *mode_info,
 static grub_err_t
 grub_video_vbe_get_edid (struct grub_video_edid_info *edid_info)
 {
-  if (grub_vbe_bios_read_edid (edid_info) != GRUB_VBE_STATUS_OK)
+  struct grub_video_edid_info *edid_info_lowmem;
+
+  /* Use low memory scratch area as temporary storage for VESA BIOS calls.  */
+  edid_info_lowmem =
+    (struct grub_video_edid_info *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR;
+  grub_memset (edid_info_lowmem, 0, sizeof (*edid_info_lowmem));
+
+  if (grub_vbe_bios_read_edid (edid_info_lowmem) != GRUB_VBE_STATUS_OK)
     return grub_error (GRUB_ERR_BAD_DEVICE, "EDID information not available");
 
+  grub_memcpy (edid_info, edid_info_lowmem, sizeof (*edid_info));
+
   return GRUB_ERR_NONE;
 }
 

From cb918eddf4fd5c2d2d07ac5da6fa8074604b3e5f Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Mon, 17 Jan 2011 12:05:12 +0000
Subject: [PATCH 08/10] fix FP info handling

---
 grub-core/video/i386/pc/vbe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index ea60c6074..c2b35a851 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -405,8 +405,8 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
   status = grub_vbe_bios_get_flat_panel_info (flat_panel_info);
   if (status == GRUB_VBE_STATUS_OK)
     {
-      *width = flat_panel_info.horizontal_size;
-      *height = flat_panel_info.vertical_size;
+      *width = flat_panel_info->horizontal_size;
+      *height = flat_panel_info->vertical_size;
       return GRUB_ERR_NONE;
     }
 

From 9b300caf8455dd0b8c3910330b063ff5777f0a36 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Mon, 17 Jan 2011 12:07:47 +0000
Subject: [PATCH 09/10] grub_video_get_edid is not usable from
 grub_vbe_get_preferred_mode, as a video adapter has not necessarily yet been
 set.  Use grub_video_vbe_get_edid and grub_video_edid_checksum directly
 instead.  Remove grub_video_get_edid as it now has no users. Reported by:
 Marjo Mercado.

---
 ChangeLog.vbe-autodetect      |  4 +---
 grub-core/video/i386/pc/vbe.c | 39 ++++++++++++++++++-----------------
 grub-core/video/video.c       | 18 ----------------
 include/grub/video.h          |  1 -
 4 files changed, 21 insertions(+), 41 deletions(-)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index 46aacef7b..3341e8cc3 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -1,9 +1,8 @@
-2011-01-15  Colin Watson  <cjwatson@ubuntu.com>
+2011-01-17  Colin Watson  <cjwatson@ubuntu.com>
 
 	Preferred resolution detection for VBE.
 
 	* grub-core/video/video.c (grub_video_edid_checksum): New function.
-	(grub_video_get_edid): Likewise.
 	(grub_video_edid_preferred_mode): Likewise.  Try EDID followed by
 	the Flat Panel extension, in line with the X.org VESA driver.
 	* grub-core/video/i386/pc/vbe.c (grub_vbe_bios_get_flat_panel_info):
@@ -21,7 +20,6 @@
 	* include/grub/video.h (struct grub_vbe_edid_info): New structure.
 	(struct grub_video_adapter): Add get_edid.
 	(grub_video_edid_checksum): Add prototype.
-	(grub_video_get_edid): Likewise.
 	(grub_video_edid_preferred_mode): Likewise.
 	* include/grub/i386/pc/vbe.h (struct grub_vbe_flat_panel_info): New
 	structure.
diff --git a/grub-core/video/i386/pc/vbe.c b/grub-core/video/i386/pc/vbe.c
index c2b35a851..f94b06060 100644
--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -377,6 +377,24 @@ grub_vbe_probe (struct grub_vbe_info_block *info_block)
   return GRUB_ERR_NONE;
 }
 
+static grub_err_t
+grub_video_vbe_get_edid (struct grub_video_edid_info *edid_info)
+{
+  struct grub_video_edid_info *edid_info_lowmem;
+
+  /* Use low memory scratch area as temporary storage for VESA BIOS calls.  */
+  edid_info_lowmem =
+    (struct grub_video_edid_info *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR;
+  grub_memset (edid_info_lowmem, 0, sizeof (*edid_info_lowmem));
+
+  if (grub_vbe_bios_read_edid (edid_info_lowmem) != GRUB_VBE_STATUS_OK)
+    return grub_error (GRUB_ERR_BAD_DEVICE, "EDID information not available");
+
+  grub_memcpy (edid_info, edid_info_lowmem, sizeof (*edid_info));
+
+  return GRUB_ERR_NONE;
+}
+
 static grub_err_t
 grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
 {
@@ -394,7 +412,8 @@ grub_vbe_get_preferred_mode (unsigned int *width, unsigned int *height)
       && (grub_vbe_bios_get_ddc_capabilities (&ddc_level) & 0xff)
 	 == GRUB_VBE_STATUS_OK)
     {
-      if (grub_video_get_edid (&edid_info) == GRUB_ERR_NONE
+      if (grub_video_vbe_get_edid (&edid_info) == GRUB_ERR_NONE
+	  && grub_video_edid_checksum (&edid_info) == GRUB_ERR_NONE
 	  && grub_video_edid_preferred_mode (&edid_info, width, height)
 	      == GRUB_ERR_NONE)
 	return GRUB_ERR_NONE;
@@ -969,24 +988,6 @@ grub_video_vbe_get_info_and_fini (struct grub_video_mode_info *mode_info,
   return grub_video_fb_get_info_and_fini (mode_info, framebuf);
 }
 
-static grub_err_t
-grub_video_vbe_get_edid (struct grub_video_edid_info *edid_info)
-{
-  struct grub_video_edid_info *edid_info_lowmem;
-
-  /* Use low memory scratch area as temporary storage for VESA BIOS calls.  */
-  edid_info_lowmem =
-    (struct grub_video_edid_info *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR;
-  grub_memset (edid_info_lowmem, 0, sizeof (*edid_info_lowmem));
-
-  if (grub_vbe_bios_read_edid (edid_info_lowmem) != GRUB_VBE_STATUS_OK)
-    return grub_error (GRUB_ERR_BAD_DEVICE, "EDID information not available");
-
-  grub_memcpy (edid_info, edid_info_lowmem, sizeof (*edid_info));
-
-  return GRUB_ERR_NONE;
-}
-
 static void
 grub_video_vbe_print_adapter_specific_info (void)
 {
diff --git a/grub-core/video/video.c b/grub-core/video/video.c
index 84e98bb67..01bdd1ff3 100644
--- a/grub-core/video/video.c
+++ b/grub-core/video/video.c
@@ -393,24 +393,6 @@ grub_video_edid_checksum (struct grub_video_edid_info *edid_info)
   return grub_errno;
 }
 
-grub_err_t
-grub_video_get_edid (struct grub_video_edid_info *edid_info)
-{
-  if (! grub_video_adapter_active)
-    return grub_error (GRUB_ERR_BAD_DEVICE, "no video mode activated");
-
-  if (! grub_video_adapter_active->get_edid)
-    return grub_error (GRUB_ERR_BAD_DEVICE,
-		       "EDID information unavailable for this video mode");
-
-  if (grub_video_adapter_active->get_edid (edid_info) != GRUB_ERR_NONE)
-    return grub_errno;
-  if (grub_video_edid_checksum (edid_info) != GRUB_ERR_NONE)
-    return grub_errno;
-
-  return GRUB_ERR_NONE;
-}
-
 grub_err_t
 grub_video_edid_preferred_mode (struct grub_video_edid_info *edid_info,
 				unsigned int *width, unsigned int *height)
diff --git a/include/grub/video.h b/include/grub/video.h
index 2251ed5f4..f42730a7d 100644
--- a/include/grub/video.h
+++ b/include/grub/video.h
@@ -486,7 +486,6 @@ grub_err_t EXPORT_FUNC (grub_video_set_active_render_target) (struct grub_video_
 grub_err_t grub_video_get_active_render_target (struct grub_video_render_target **target);
 
 grub_err_t grub_video_edid_checksum (struct grub_video_edid_info *edid_info);
-grub_err_t grub_video_get_edid (struct grub_video_edid_info *edid_info);
 grub_err_t grub_video_edid_preferred_mode (struct grub_video_edid_info *edid_info,
 					   unsigned int *width,
 					   unsigned int *height);

From 421284f2998aa3e9134372379a2bd03de08a2740 Mon Sep 17 00:00:00 2001
From: Colin Watson <cjwatson@ubuntu.com>
Date: Wed, 30 Mar 2011 10:19:08 +0100
Subject: [PATCH 10/10] * docs/grub.texi (Simple configuration): Update
 GRUB_GFXMODE documentation.

---
 ChangeLog.vbe-autodetect | 2 ++
 docs/grub.texi           | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.vbe-autodetect b/ChangeLog.vbe-autodetect
index 3341e8cc3..6308e5793 100644
--- a/ChangeLog.vbe-autodetect
+++ b/ChangeLog.vbe-autodetect
@@ -29,3 +29,5 @@
 
 	* util/grub.d/00_header.in (GRUB_GFXMODE): Default to "auto".  This
 	is more appropriate on a wider range of platforms than 640x480.
+	* docs/grub.texi (Simple configuration): Update GRUB_GFXMODE
+	documentation.
diff --git a/docs/grub.texi b/docs/grub.texi
index 54a2d8791..885bb4731 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -1140,7 +1140,8 @@ listed in @file{/boot/grub/video.lst}.
 Set the resolution used on the @samp{gfxterm} graphical terminal.  Note that
 you can only use modes which your graphics card supports via VESA BIOS
 Extensions (VBE), so for example native LCD panel resolutions may not be
-available.  The default is @samp{640x480}.
+available.  The default is @samp{auto}, which tries to select a preferred
+resolution.
 
 @item GRUB_BACKGROUND
 Set a background image for use with the @samp{gfxterm} graphical terminal.