link/graphics: Add support for EDID

This code is taken from an EDID reader written at Red Hat.

The key function is
int decode_edid(unsigned char *edid, int size, struct edid *out)

Which takes a pointer to an EDID blob, and a size, and decodes it into
a machine-independent format in out, which may be used for driving
chipsets. The EDID blob might come for IO, or a compiled-in EDID
BLOB, or CBFS.

Also included are the changes needed to use the EDID code on Link.

Change-Id: I66b275b8ed28fd77cfa5978bdec1eeef9e9425f1
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/2837
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 1388 insertions, 0 deletions

diff --git a/src/lib/edid.c b/src/lib/edid.c
new file mode 100644
index 0000000000..460d68dcb2
--- /dev/null
+++ b/src/lib/edid.c
@@ -0,0 +1,1388 @@
+/*
+ * Copyright 2013 Google Inc.
+ * Copyright 2006-2012 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+/* Author: Adam Jackson <ajax@nwnk.net> */
+
+/* this is a pretty robust parser for EDID, and we're tasked with parsing
+ * an arbitrary panel. We will pass it a raw EDID block and a struct which
+ * it must fill in with values. The set of values we need is pretty limited
+ * at present.
+ */
+
+#include <stddef.h>
+#include <console/console.h>
+#include <arch/io.h>
+#include <arch/byteorder.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <edid.h>
+
+static int claims_one_point_oh = 0;
+static int claims_one_point_two = 0;
+static int claims_one_point_three = 0;
+static int claims_one_point_four = 0;
+static int nonconformant_digital_display = 0;
+static int nonconformant_extension = 0;
+static int did_detailed_timing = 0;
+static int has_name_descriptor = 0;
+static int name_descriptor_terminated = 0;
+static int has_range_descriptor = 0;
+static int has_preferred_timing = 0;
+static int has_valid_checksum = 0;
+static int has_valid_cvt = 1;
+static int has_valid_dummy_block = 1;
+static int has_valid_week = 0;
+static int has_valid_year = 0;
+static int has_valid_detailed_blocks = 0;
+static int has_valid_extension_count = 0;
+static int has_valid_descriptor_ordering = 1;
+static int has_valid_descriptor_pad = 1;
+static int has_valid_range_descriptor = 1;
+static int has_valid_max_dotclock = 1;
+static int has_valid_string_termination = 1;
+static int manufacturer_name_well_formed = 0;
+static int seen_non_detailed_descriptor = 0;
+
+static int warning_excessive_dotclock_correction = 0;
+static int warning_zero_preferred_refresh = 0;
+
+static int conformant = 1;
+
+static char *manufacturer_name(struct edid *out, unsigned char *x)
+{
+	out->manuf_name[0] = ((x[0] & 0x7C) >> 2) + '@';
+	out->manuf_name[1] = ((x[0] & 0x03) << 3) + ((x[1] & 0xE0) >> 5) + '@';
+	out->manuf_name[2] = (x[1] & 0x1F) + '@';
+	out->manuf_name[3] = 0;
+
+	if (isupper(out->manuf_name[0]) &&
+	    isupper(out->manuf_name[1]) &&
+	    isupper(out->manuf_name[2]))
+		manufacturer_name_well_formed = 1;
+
+	return out->manuf_name;
+}
+
+static int
+detailed_cvt_descriptor(struct edid *out, unsigned char *x, int first)
+{
+	const unsigned char empty[3] = { 0, 0, 0 };
+	const char *names[] = { "50", "60", "75", "85" };
+	int width = 0, height = 0;
+	int valid = 1;
+	int fifty = 0, sixty = 0, seventyfive = 0, eightyfive = 0, reduced = 0;
+
+	if (!first && !memcmp(x, empty, 3))
+		return valid;
+
+	height = x[0];
+	height |= (x[1] & 0xf0) << 4;
+	height++;
+	height *= 2;
+
+	switch (x[1] & 0x0c) {
+	case 0x00:
+		width = (height * 4) / 3; break;
+	case 0x04:
+		width = (height * 16) / 9; break;
+	case 0x08:
+		width = (height * 16) / 10; break;
+	case 0x0c:
+		width = (height * 15) / 9; break;
+	}
+
+	if (x[1] & 0x03)
+		valid = 0;
+	if (x[2] & 0x80)
+		valid = 0;
+	if (!(x[2] & 0x1f))
+		valid = 0;
+
+	fifty	= (x[2] & 0x10);
+	sixty	= (x[2] & 0x08);
+	seventyfive = (x[2] & 0x04);
+	eightyfive  = (x[2] & 0x02);
+	reduced	= (x[2] & 0x01);
+
+	if (!valid) {
+		printk(BIOS_SPEW, "    (broken)\n");
+	} else {
+		printk(BIOS_SPEW, "    %dx%d @ ( %s%s%s%s%s) Hz (%s%s preferred)\n",
+		       width, height,
+		       fifty ? "50 " : "",
+		       sixty ? "60 " : "",
+		       seventyfive ? "75 " : "",
+		       eightyfive ? "85 " : "",
+		       reduced ? "60RB " : "",
+		       names[(x[2] & 0x60) >> 5],
+		       (((x[2] & 0x60) == 0x20) && reduced) ? "RB" : "");
+	}
+
+	return valid;
+}
+
+static int isalnum(char x)
+{
+	if (x >= 'a' && x <= 'z')
+		return 1;
+	if (x >= 'A' && x <= 'Z')
+		return 1;
+	if (x >= '0' && x <= '9')
+		return 1;
+	return 0;
+
+}
+/* extract a string from a detailed subblock, checking for termination */
+static char *
+extract_string(unsigned char *x, int *valid_termination, int len)
+{
+	static char ret[128];
+	int i, seen_newline = 0;
+
+	memset(ret, 0, sizeof(ret));
+
+	for (i = 0; i < len; i++) {
+		if (isalnum(x[i])) {
+			ret[i] = x[i];
+		} else if (!seen_newline) {
+			if (x[i] == 0x0a) {
+				seen_newline = 1;
+			} else {
+				*valid_termination = 0;
+				return ret;
+			}
+		} else {
+			if (x[i] != 0x20) {
+				*valid_termination = 0;
+				return ret;
+			}
+		}
+	}
+
+	return ret;
+}
+
+/* 1 means valid data */
+static int
+detailed_block(struct edid *out, unsigned char *x, int in_extension)
+{
+	static unsigned char name[53];
+	int i;
+#if 1
+	printk(BIOS_SPEW, "Hex of detail: ");
+	for (i = 0; i < 18; i++)
+		printk(BIOS_SPEW, "%02x", x[i]);
+	printk(BIOS_SPEW, "\n");
+#endif
+
+	if (x[0] == 0 && x[1] == 0) {
+		/* Monitor descriptor block, not detailed timing descriptor. */
+		if (x[2] != 0) {
+			/* 1.3, 3.10.3 */
+			printk(BIOS_SPEW, "Monitor descriptor block has byte 2 nonzero (0x%02x)\n",
+			       x[2]);
+			has_valid_descriptor_pad = 0;
+		}
+		if (x[3] != 0xfd && x[4] != 0x00) {
+			/* 1.3, 3.10.3 */
+			printk(BIOS_SPEW, "Monitor descriptor block has byte 4 nonzero (0x%02x)\n",
+			       x[4]);
+			has_valid_descriptor_pad = 0;
+		}
+
+		seen_non_detailed_descriptor = 1;
+		if (x[3] <= 0xF) {
+			/*
+			 * in principle we can decode these, if we know what they are.
+			 * 0x0f seems to be common in laptop panels.
+			 * 0x0e is used by EPI: http://www.epi-standard.org/
+			 */
+			printk(BIOS_SPEW, "Manufacturer-specified data, tag %d\n", x[3]);
+			return 0;
+		}
+		switch (x[3]) {
+		case 0x10:
+			printk(BIOS_SPEW, "Dummy block\n");
+			for (i = 5; i < 18; i++)
+				if (x[i] != 0x00)
+					has_valid_dummy_block = 0;
+			return 0;
+		case 0xF7:
+			/* TODO */
+			printk(BIOS_SPEW, "Established timings III\n");
+			return 0;
+		case 0xF8:
+		{
+			int valid_cvt = 1; /* just this block */
+			printk(BIOS_SPEW, "CVT 3-byte code descriptor:\n");
+			if (x[5] != 0x01) {
+				has_valid_cvt = 0;
+				return 0;
+			}
+			for (i = 0; i < 4; i++)
+				valid_cvt &= detailed_cvt_descriptor(out, x + 6 + (i * 3), (i == 0));
+			has_valid_cvt &= valid_cvt;
+			return 0;
+		}
+		case 0xF9:
+			/* TODO */
+			printk(BIOS_SPEW, "Color management data\n");
+			return 0;
+		case 0xFA:
+			/* TODO */
+			printk(BIOS_SPEW, "More standard timings\n");
+			return 0;
+		case 0xFB:
+			/* TODO */
+			printk(BIOS_SPEW, "Color point\n");
+			return 0;
+		case 0xFC:
+			/* XXX should check for spaces after the \n */
+			/* XXX check: terminated with 0x0A, padded with 0x20 */
+			has_name_descriptor = 1;
+			if (strchr((char *)name, '\n')) return 0;
+			/* avoid strncat
+			strncat((char *)name, (char *)x + 5, 13);
+			*/
+			if (strchr((char *)name, '\n') || strchr((char *)x+5, '\n')) {
+				name_descriptor_terminated = 1;
+				/* later.
+				printk(BIOS_SPEW, "Monitor name: %s\n",
+				       extract_string(name, &has_valid_string_termination,
+						      strlen((char *)name)));
+				*/
+			}
+			return 0;
+		case 0xFD:
+		{
+			int h_max_offset = 0, h_min_offset = 0;
+			int v_max_offset = 0, v_min_offset = 0;
+			int is_cvt = 0;
+			has_range_descriptor = 1;
+			out->range_class = "";
+			/*
+			 * XXX todo: implement feature flags, vtd blocks
+			 * XXX check: ranges are well-formed; block termination if no vtd
+			 */
+			if (claims_one_point_four) {
+				if (x[4] & 0x02) {
+					v_max_offset = 255;
+					if (x[4] & 0x01) {
+						v_min_offset = 255;
+					}
+				}
+				if (x[4] & 0x04) {
+					h_max_offset = 255;
+					if (x[4] & 0x03) {
+						h_min_offset = 255;
+					}
+				}
+			} else if (x[4]) {
+				has_valid_range_descriptor = 0;
+			}
+
+			/*
+			 * despite the values, this is not a bitfield.
+			 */
+			switch (x[10]) {
+			case 0x00: /* default gtf */
+				out->range_class = "GTF";
+				break;
+			case 0x01: /* range limits only */
+				out->range_class = "bare limits";
+				if (!claims_one_point_four)
+					has_valid_range_descriptor = 0;
+				break;
+			case 0x02: /* secondary gtf curve */
+				out->range_class = "GTF with icing";
+				break;
+			case 0x04: /* cvt */
+				out->range_class = "CVT";
+				is_cvt = 1;
+				if (!claims_one_point_four)
+					has_valid_range_descriptor = 0;
+				break;
+			default: /* invalid */
+				has_valid_range_descriptor = 0;
+				out->range_class = "invalid";
+				break;
+			}
+
+			if (x[5] + v_min_offset > x[6] + v_max_offset)
+				has_valid_range_descriptor = 0;
+			if (x[7] + h_min_offset > x[8] + h_max_offset)
+				has_valid_range_descriptor = 0;
+			printk(BIOS_SPEW, "Monitor ranges (%s): %d-%dHz V, %d-%dkHz H",
+			       out->range_class,
+			       x[5] + v_min_offset, x[6] + v_max_offset,
+			       x[7] + h_min_offset, x[8] + h_max_offset);
+			if (x[9])
+				printk(BIOS_SPEW, ", max dotclock %dMHz\n", x[9] * 10);
+			else {
+				if (claims_one_point_four)
+					has_valid_max_dotclock = 0;
+				printk(BIOS_SPEW, "\n");
+			}
+
+			if (is_cvt) {
+				int max_h_pixels = 0;
+
+				printk(BIOS_SPEW, "CVT version %d.%d\n", x[11] & 0xf0 >> 4, x[11] & 0x0f);
+
+				if (x[12] & 0xfc) {
+					int raw_offset = (x[12] & 0xfc) >> 2;
+					printk(BIOS_SPEW, "Real max dotclock: %.2fMHz\n",
+					       (x[9] * 10) - (raw_offset * 0.25));
+					if (raw_offset >= 40)
+						warning_excessive_dotclock_correction = 1;
+				}
+
+				max_h_pixels = x[12] & 0x03;
+				max_h_pixels <<= 8;
+				max_h_pixels |= x[13];
+				max_h_pixels *= 8;
+				if (max_h_pixels)
+					printk(BIOS_SPEW, "Max active pixels per line: %d\n", max_h_pixels);
+
+				printk(BIOS_SPEW, "Supported aspect ratios: %s %s %s %s %s\n",
+				       x[14] & 0x80 ? "4:3" : "",
+				       x[14] & 0x40 ? "16:9" : "",
+				       x[14] & 0x20 ? "16:10" : "",
+				       x[14] & 0x10 ? "5:4" : "",
+				       x[14] & 0x08 ? "15:9" : "");
+				if (x[14] & 0x07)
+					has_valid_range_descriptor = 0;
+
+				printk(BIOS_SPEW, "Preferred aspect ratio: ");
+				switch((x[15] & 0xe0) >> 5) {
+				case 0x00: printk(BIOS_SPEW, "4:3"); break;
+				case 0x01: printk(BIOS_SPEW, "16:9"); break;
+				case 0x02: printk(BIOS_SPEW, "16:10"); break;
+				case 0x03: printk(BIOS_SPEW, "5:4"); break;
+				case 0x04: printk(BIOS_SPEW, "15:9"); break;
+				default: printk(BIOS_SPEW, "(broken)"); break;
+				}
+				printk(BIOS_SPEW, "\n");
+
+				if (x[15] & 0x04)
+					printk(BIOS_SPEW, "Supports CVT standard blanking\n");
+				if (x[15] & 0x10)
+					printk(BIOS_SPEW, "Supports CVT reduced blanking\n");
+
+				if (x[15] & 0x07)
+					has_valid_range_descriptor = 0;
+
+				if (x[16] & 0xf0) {
+					printk(BIOS_SPEW, "Supported display scaling:\n");
+					if (x[16] & 0x80)
+						printk(BIOS_SPEW, "    Horizontal shrink\n");
+					if (x[16] & 0x40)
+						printk(BIOS_SPEW, "    Horizontal stretch\n");
+					if (x[16] & 0x20)
+						printk(BIOS_SPEW, "    Vertical shrink\n");
+					if (x[16] & 0x10)
+						printk(BIOS_SPEW, "    Vertical stretch\n");
+				}
+
+				if (x[16] & 0x0f)
+					has_valid_range_descriptor = 0;
+
+				if (x[17])
+					printk(BIOS_SPEW, "Preferred vertical refresh: %d Hz\n", x[17]);
+				else
+					warning_zero_preferred_refresh = 1;
+			}
+
+			/*
+			 * Slightly weird to return a global, but I've never seen any
+			 * EDID block wth two range descriptors, so it's harmless.
+			 */
+			return 0;
+		}
+		case 0xFE:
+			/*
+			 * TODO: Two of these in a row, in the third and fourth slots,
+			 * seems to be specified by SPWG: http://www.spwg.org/
+			 */
+			printk(BIOS_SPEW, "ASCII string: %s\n",
+			       extract_string(x + 5, &has_valid_string_termination, 13));
+			return 0;
+		case 0xFF:
+			printk(BIOS_SPEW, "Serial number: %s\n",
+			       extract_string(x + 5, &has_valid_string_termination, 13));
+			return 0;
+		default:
+			printk(BIOS_SPEW, "Unknown monitor description type %d\n", x[3]);
+			return 0;
+		}
+	}
+
+	if (seen_non_detailed_descriptor && !in_extension) {
+		has_valid_descriptor_ordering = 0;
+	}
+
+	if (! did_detailed_timing){
+		out->ha = (x[2] + ((x[4] & 0xF0) << 4));
+		out->hbl = (x[3] + ((x[4] & 0x0F) << 8));
+		out->hso = (x[8] + ((x[11] & 0xC0) << 2));
+		out->hspw = (x[9] + ((x[11] & 0x30) << 4));
+		out->hborder = x[15];
+		out->va = (x[5] + ((x[7] & 0xF0) << 4));
+		out->vbl = (x[6] + ((x[7] & 0x0F) << 8));
+		out->vso = ((x[10] >> 4) + ((x[11] & 0x0C) << 2));
+		out->vspw = ((x[10] & 0x0F) + ((x[11] & 0x03) << 4));
+		out->vborder = x[16];
+		printk(BIOS_SPEW, "Did detailed timing\n");
+	}
+	did_detailed_timing = 1;
+	switch ((x[17] & 0x18) >> 3) {
+	case 0x00:
+		out->syncmethod = " analog composite";
+		break;
+	case 0x01:
+		out->syncmethod = " bipolar analog composite";
+		break;
+	case 0x02:
+		out->syncmethod = " digital composite";
+		break;
+	case 0x03:
+		out->syncmethod = "";
+		break;
+	}
+	out->pvsync = (x[17] & (1 << 2)) ? '+' : '-';
+	out->phsync = (x[17] & (1 << 1)) ? '+' : '-';
+	switch (x[17] & 0x61) {
+	case 0x20:
+		out->stereo = "field sequential L/R";
+		break;
+	case 0x40:
+		out->stereo = "field sequential R/L";
+		break;
+	case 0x21:
+		out->stereo = "interleaved right even";
+		break;
+	case 0x41:
+		out->stereo = "interleaved left even";
+		break;
+	case 0x60:
+		out->stereo = "four way interleaved";
+		break;
+	case 0x61:
+		out->stereo = "side by side interleaved";
+		break;
+	default:
+		out->stereo = "";
+		break;
+	}
+
+	printk(BIOS_SPEW, "Detailed mode (IN HEX): Clock %d0 KHz, %x mm x %x mm\n"
+	       "               %04x %04x %04x %04x hborder %x\n"
+	       "               %04x %04x %04x %04x vborder %x\n"
+	       "               %chsync %cvsync%s%s %s\n",
+	       (x[0] + (x[1] << 8)),
+	       (x[12] + ((x[14] & 0xF0) << 4)),
+	       (x[13] + ((x[14] & 0x0F) << 8)),
+	       out->ha, out->ha + out->hso, out->ha + out->hso + out->hspw,
+	       out->ha + out->hbl, out->hborder,
+	       out->va, out->va + out->vso, out->va + out->vso + out->vspw,
+	       out->va + out->vbl, out->vborder,
+	       out->phsync, out->pvsync,
+	       out->syncmethod, x[17] & 0x80 ?" interlaced" : "",
+	       out->stereo
+		);
+	return 1;
+}
+
+static int
+do_checksum(unsigned char *x)
+{
+	printk(BIOS_SPEW, "Checksum: 0x%hx", x[0x7f]);
+	{
+		unsigned char sum = 0;
+		int i;
+		for (i = 0; i < 128; i++)
+			sum += x[i];
+		if (sum) {
+			printk(BIOS_SPEW, " (should be 0x%hx)", (unsigned char)(x[0x7f] - sum));
+			has_valid_checksum = 0;
+		} else {
+			has_valid_checksum = 1;
+			printk(BIOS_SPEW, " (valid)");
+		}
+	}
+	printk(BIOS_SPEW, "\n");
+	return has_valid_checksum;
+}
+
+/* CEA extension */
+
+static const char *
+audio_format(unsigned char x)
+{
+	switch (x) {
+	case 0: return "RESERVED";
+	case 1: return "Linear PCM";
+	case 2: return "AC-3";
+	case 3: return "MPEG 1 (Layers 1 & 2)";
+	case 4: return "MPEG 1 Layer 3 (MP3)";
+	case 5: return "MPEG2 (multichannel)";
+	case 6: return "AAC";
+	case 7: return "DTS";
+	case 8: return "ATRAC";
+	case 9: return "One Bit Audio";
+	case 10: return "Dolby Digital+";
+	case 11: return "DTS-HD";
+	case 12: return "MAT (MLP)";
+	case 13: return "DST";
+	case 14: return "WMA Pro";
+	case 15: return "RESERVED";
+	}
+	return "BROKEN"; /* can't happen */
+}
+
+static void
+cea_audio_block(unsigned char *x)
+{
+	int i, format;
+	int length = x[0] & 0x1f;
+
+	if (length % 3) {
+		printk(BIOS_SPEW, "Broken CEA audio block length %d\n", length);
+		/* XXX non-conformant */
+		return;
+	}
+
+	for (i = 1; i < length; i += 3) {
+		format = (x[i] & 0x78) >> 3;
+		printk(BIOS_SPEW, "    %s, max channels %d\n", audio_format(format),
+		       x[i] & 0x07);
+		printk(BIOS_SPEW, "    Supported sample rates (kHz):%s%s%s%s%s%s%s\n",
+		       (x[i+1] & 0x40) ? " 192" : "",
+		       (x[i+1] & 0x20) ? " 176.4" : "",
+		       (x[i+1] & 0x10) ? " 96" : "",
+		       (x[i+1] & 0x08) ? " 88.2" : "",
+		       (x[i+1] & 0x04) ? " 48" : "",
+		       (x[i+1] & 0x02) ? " 44.1" : "",
+		       (x[i+1] & 0x01) ? " 32" : "");
+		if (format == 1) {
+			printk(BIOS_SPEW, "    Supported sample sizes (bits):%s%s%s\n",
+			       (x[2] & 0x04) ? " 24" : "",
+			       (x[2] & 0x02) ? " 20" : "",
+			       (x[2] & 0x01) ? " 16" : "");
+		} else if (format <= 8) {
+			printk(BIOS_SPEW, "    Maximum bit rate: %d kHz\n", x[2] * 8);
+		}
+	}
+}
+
+static void
+cea_video_block(unsigned char *x)
+{
+	int i;
+	int length = x[0] & 0x1f;
+
+	for (i = 1; i < length; i++)
+		printk(BIOS_SPEW,"    VIC %02d %s\n", x[i] & 0x7f,
+		       x[i] & 0x80 ? "(native)" : "");
+}
+
+static void
+cea_hdmi_block(struct edid *out, unsigned char *x)
+{
+	int length = x[0] & 0x1f;
+
+	printk(BIOS_SPEW, " (HDMI)\n");
+	printk(BIOS_SPEW,
+	       "    Source physical address %d.%d.%d.%d\n",
+	       x[4] >> 4, x[4] & 0x0f, x[5] >> 4, x[5] & 0x0f);
+
+	if (length > 5) {
+		if (x[6] & 0x80)
+			printk(BIOS_SPEW, "    Supports_AI\n");
+		if (x[6] & 0x40)
+			printk(BIOS_SPEW, "    DC_48bit\n");
+		if (x[6] & 0x20)
+			printk(BIOS_SPEW, "    DC_36bit\n");
+		if (x[6] & 0x10)
+			printk(BIOS_SPEW, "    DC_30bit\n");
+		if (x[6] & 0x08)
+			printk(BIOS_SPEW, "    DC_Y444\n");
+		/* two reserved */
+		if (x[6] & 0x01)
+			printk(BIOS_SPEW, "    DVI_Dual\n");
+	}
+
+	if (length > 6)
+		printk(BIOS_SPEW, "    Maximum TMDS clock: %dMHz\n", x[7] * 5);
+
+	/* XXX the walk here is really ugly, and needs to be length-checked */
+	if (length > 7) {
+		int b = 0;
+
+		if (x[8] & 0x80) {
+			printk(BIOS_SPEW, "    Video latency: %d\n", x[9 + b]);
+			printk(BIOS_SPEW, "    Audio latency: %d\n", x[10 + b]);
+			b += 2;
+		}
+
+		if (x[8] & 0x40) {
+			printk(BIOS_SPEW, "    Interlaced video latency: %d\n", x[9 + b]);
+			printk(BIOS_SPEW, "    Interlaced audio latency: %d\n", x[10 + b]);
+			b += 2;
+		}
+
+		if (x[8] & 0x20) {
+			int mask = 0, formats = 0;
+			int len_xx, len_3d;
+			printk(BIOS_SPEW, "    Extended HDMI video details:\n");
+			if (x[9 + b] & 0x80)
+				printk(BIOS_SPEW, "      3D present\n");
+			if ((x[9 + b] & 0x60) == 0x20) {
+				printk(BIOS_SPEW, "      All advertised VICs are 3D-capable\n");
+				formats = 1;
+			}
+			if ((x[9 + b] & 0x60) == 0x40) {
+				printk(BIOS_SPEW, "      3D-capable-VIC mask present\n");
+				formats = 1;
+				mask = 1;
+			}
+			switch (x[9 + b] & 0x18) {
+			case 0x00: break;
+			case 0x08:
+				printk(BIOS_SPEW, "      Base EDID image size is aspect ratio\n");
+				break;
+			case 0x10:
+				printk(BIOS_SPEW, "      Base EDID image size is in units of 1cm\n");
+				break;
+			case 0x18:
+				printk(BIOS_SPEW, "      Base EDID image size is in units of 5cm\n");
+				break;
+			}
+			len_xx = (x[10 + b] & 0xe0) >> 5;
+			len_3d = (x[10 + b] & 0x1f) >> 0;
+			b += 2;
+
+			if (len_xx) {
+				printk(BIOS_SPEW, "      Skipping %d bytes that HDMI refuses to publicly"
+				       " document\n", len_xx);
+				b += len_xx;
+			}
+
+			if (len_3d) {
+				if (formats) {
+					if (x[9 + b] & 0x01)
+						printk(BIOS_SPEW, "      Side-by-side 3D supported\n");
+					if (x[10 + b] & 0x40)
+						printk(BIOS_SPEW, "      Top-and-bottom 3D supported\n");
+					if (x[10 + b] & 0x01)
+						printk(BIOS_SPEW, "      Frame-packing 3D supported\n");
+					b += 2;
+				}
+				if (mask) {
+					int i;
+					printk(BIOS_SPEW, "      3D VIC indices:");
+					/* worst bit ordering ever */
+					for (i = 0; i < 8; i++)
+						if (x[10 + b] & (1 << i))
+							printk(BIOS_SPEW, " %d", i);
+					for (i = 0; i < 8; i++)
+						if (x[9 + b] & (1 << i))
+							printk(BIOS_SPEW, " %d", i + 8);
+					printk(BIOS_SPEW, "\n");
+					b += 2;
+				}
+
+				/*
+				 * XXX list of nibbles:
+				 * 2D_VIC_Order_X
+				 * 3D_Structure_X
+				 * (optionally: 3D_Detail_X and reserved)
+				 */
+			}
+
+		}
+	}
+}
+
+static void
+cea_block(struct edid *out, unsigned char *x)
+{
+	unsigned int oui;
+
+	switch ((x[0] & 0xe0) >> 5) {
+	case 0x01:
+		printk(BIOS_SPEW, "  Audio data block\n");
+		cea_audio_block(x);
+		break;
+	case 0x02:
+		printk(BIOS_SPEW, "  Video data block\n");
+		cea_video_block(x);
+		break;
+	case 0x03:
+		/* yes really, endianness lols */
+		oui = (x[3] << 16) + (x[2] << 8) + x[1];
+		printk(BIOS_SPEW, "  Vendor-specific data block, OUI %06x", oui);
+		if (oui == 0x000c03)
+			cea_hdmi_block(out, x);
+		else
+			printk(BIOS_SPEW, "\n");
+		break;
+	case 0x04:
+		printk(BIOS_SPEW, "  Speaker allocation data block\n");
+		break;
+	case 0x05:
+		printk(BIOS_SPEW, "  VESA DTC data block\n");
+		break;
+	case 0x07:
+		printk(BIOS_SPEW, "  Extended tag: ");
+		switch (x[1]) {
+		case 0x00:
+			printk(BIOS_SPEW, "video capability data block\n");
+			break;
+		case 0x01:
+			printk(BIOS_SPEW, "vendor-specific video data block\n");
+			break;
+		case 0x02:
+			printk(BIOS_SPEW, "VESA video display device information data block\n");
+			break;
+		case 0x03:
+			printk(BIOS_SPEW, "VESA video data block\n");
+			break;
+		case 0x04:
+			printk(BIOS_SPEW, "HDMI video data block\n");
+			break;
+		case 0x05:
+			printk(BIOS_SPEW, "Colorimetry data block\n");
+			break;
+		case 0x10:
+			printk(BIOS_SPEW, "CEA miscellaneous audio fields\n");
+			break;
+		case 0x11:
+			printk(BIOS_SPEW, "Vendor-specific audio data block\n");
+			break;
+		case 0x12:
+			printk(BIOS_SPEW, "HDMI audio data block\n");
+			break;
+		default:
+			if (x[1] >= 6 && x[1] <= 15)
+				printk(BIOS_SPEW, "Reserved video block (%02x)\n", x[1]);
+			else if (x[1] >= 19 && x[1] <= 31)
+				printk(BIOS_SPEW, "Reserved audio block (%02x)\n", x[1]);
+			else
+				printk(BIOS_SPEW, "Unknown (%02x)\n", x[1]);
+			break;
+		}
+		break;
+	default:
+	{
+		int tag = (*x & 0xe0) >> 5;
+		int length = *x & 0x1f;
+		printk(BIOS_SPEW,
+		       "  Unknown tag %d, length %d (raw %02x)\n", tag, length, *x);
+		break;
+	}
+	}
+}
+
+static int
+parse_cea(struct edid *out, unsigned char *x)
+{
+	int ret = 0;
+	int version = x[1];
+	int offset = x[2];
+	unsigned char *detailed;
+
+	if (version >= 1) do {
+			if (version == 1 && x[3] != 0)
+				ret = 1;
+
+			if (offset < 4)
+				break;
+
+			if (version < 3) {
+				printk(BIOS_SPEW, "%d 8-byte timing descriptors\n", (offset - 4) / 8);
+				if (offset - 4 > 0)
+					/* do stuff */ ;
+			} else if (version == 3) {
+				int i;
+				printk(BIOS_SPEW, "%d bytes of CEA data\n", offset - 4);
+				for (i = 4; i < offset; i += (x[i] & 0x1f) + 1) {
+					cea_block(out, x + i);
+				}
+			}
+
+			if (version >= 2) {
+				if (x[3] & 0x80)
+					printk(BIOS_SPEW, "Underscans PC formats by default\n");
+				if (x[3] & 0x40)
+					printk(BIOS_SPEW, "Basic audio support\n");
+				if (x[3] & 0x20)
+					printk(BIOS_SPEW, "Supports YCbCr 4:4:4\n");
+				if (x[3] & 0x10)
+					printk(BIOS_SPEW, "Supports YCbCr 4:2:2\n");
+				printk(BIOS_SPEW, "%d native detailed modes\n", x[3] & 0x0f);
+			}
+
+			for (detailed = x + offset; detailed + 18 < x + 127; detailed += 18)
+				if (detailed[0])
+					detailed_block(out, detailed, 1);
+		} while (0);
+
+	do_checksum(x);
+
+	return ret;
+}
+
+/* generic extension code */
+
+static void
+extension_version(struct edid *out, unsigned char *x)
+{
+	printk(BIOS_SPEW, "Extension version: %d\n", x[1]);
+}
+
+static int
+parse_extension(struct edid *out, unsigned char *x)
+{
+	int conformant_extension = 0;
+	printk(BIOS_SPEW, "\n");
+
+	switch(x[0]) {
+	case 0x02:
+		printk(BIOS_SPEW, "CEA extension block\n");
+		extension_version(out, x);
+		conformant_extension = parse_cea(out, x);
+		break;
+	case 0x10: printk(BIOS_SPEW, "VTB extension block\n"); break;
+	case 0x40: printk(BIOS_SPEW, "DI extension block\n"); break;
+	case 0x50: printk(BIOS_SPEW, "LS extension block\n"); break;
+	case 0x60: printk(BIOS_SPEW, "DPVL extension block\n"); break;
+	case 0xF0: printk(BIOS_SPEW, "Block map\n"); break;
+	case 0xFF: printk(BIOS_SPEW, "Manufacturer-specific extension block\n");
+	default:
+		printk(BIOS_SPEW, "Unknown extension block\n");
+		break;
+	}
+
+	printk(BIOS_SPEW, "\n");
+
+	return conformant_extension;
+}
+
+static const struct {
+	int x, y, refresh;
+} established_timings[] = {
+	/* 0x23 bit 7 - 0 */
+	{720, 400, 70},
+	{720, 400, 88},
+	{640, 480, 60},
+	{640, 480, 67},
+	{640, 480, 72},
+	{640, 480, 75},
+	{800, 600, 56},
+	{800, 600, 60},
+	/* 0x24 bit 7 - 0 */
+	{800, 600, 72},
+	{800, 600, 75},
+	{832, 624, 75},
+	{1280, 768, 87},
+	{1024, 768, 60},
+	{1024, 768, 70},
+	{1024, 768, 75},
+	{1280, 1024, 75},
+	/* 0x25 bit 7*/
+	{1152, 870, 75},
+};
+
+static void print_subsection(const char *name, unsigned char *edid, int start,
+			     int end)
+{
+	int i;
+
+	printk(BIOS_SPEW, "%s:", name);
+	for (i = strlen(name); i < 15; i++)
+		printk(BIOS_SPEW, " ");
+	for (i = start; i <= end; i++)
+		printk(BIOS_SPEW, " %02x", edid[i]);
+	printk(BIOS_SPEW, "\n");
+}
+
+static void dump_breakdown(unsigned char *edid)
+{
+	printk(BIOS_SPEW, "Extracted contents:\n");
+	print_subsection("header", edid, 0, 7);
+	print_subsection("serial number", edid, 8, 17);
+	print_subsection("version", edid,18, 19);
+	print_subsection("basic params", edid, 20, 24);
+	print_subsection("chroma info", edid, 25, 34);
+	print_subsection("established", edid, 35, 37);
+	print_subsection("standard", edid, 38, 53);
+	print_subsection("descriptor 1", edid, 54, 71);
+	print_subsection("descriptor 2", edid, 72, 89);
+	print_subsection("descriptor 3", edid, 90, 107);
+	print_subsection("descriptor 4", edid, 108, 125);
+	print_subsection("extensions", edid, 126, 126);
+	print_subsection("checksum", edid, 127, 127);
+	printk(BIOS_SPEW, "\n");
+}
+
+/*
+ * Given a raw edid bloc, decode it into a form
+ * that other parts of coreboot can use -- mainly
+ * graphics bringup functions. The raw block is
+ * required to be 128 bytes long, per the standard,
+ * but we have no way of checking this minimum length.
+ * We accept what we are given.
+ */
+int decode_edid(unsigned char *edid, int size, struct edid *out)
+{
+	int analog, i;
+
+	dump_breakdown(edid);
+
+	if (!edid || memcmp(edid, "\x00\xFF\xFF\xFF\xFF\xFF\xFF\x00", 8)) {
+		printk(BIOS_SPEW, "No header found\n");
+		return 1;
+	}
+	memset(out, 0, sizeof(*out));
+	manufacturer_name(out, edid + 0x08);
+	out->model = (unsigned short)(edid[0x0A] + (edid[0x0B] << 8));
+	out->serial = (unsigned int)(edid[0x0C] + (edid[0x0D] << 8)
+				     + (edid[0x0E] << 16) + (edid[0x0F] << 24));
+
+	printk(BIOS_SPEW, "Manufacturer: %s Model %x Serial Number %u\n",
+	       out->manuf_name,
+	       (unsigned short)(edid[0x0A] + (edid[0x0B] << 8)),
+	       (unsigned int)(edid[0x0C] + (edid[0x0D] << 8)
+			      + (edid[0x0E] << 16) + (edid[0x0F] << 24)));
+		/* XXX need manufacturer ID table */
+
+		if (edid[0x10] < 55 || edid[0x10] == 0xff) {
+			has_valid_week = 1;
+			if (edid[0x11] > 0x0f) {
+				if (edid[0x10] == 0xff) {
+					has_valid_year = 1;
+					printk(BIOS_SPEW, "Made week %hd of model year %hd\n", edid[0x10],
+					       edid[0x11]);
+					out->week = edid[0x10];
+					out->year = edid[0x11];
+				} else {
+					/* we know it's at least 2013, when this code was written */
+					if (edid[0x11] + 90 <= 2013) {
+						has_valid_year = 1;
+						printk(BIOS_SPEW, "Made week %hd of %hd\n",
+						       edid[0x10], edid[0x11] + 1990);
+						out->week = edid[0x10];
+						out->year = edid[0x11] + 1990;
+					}
+				}
+			}
+		}
+
+
+	printk(BIOS_SPEW, "EDID version: %hd.%hd\n", edid[0x12], edid[0x13]);
+	out->version[0] = edid[0x12];
+	out->version[1] = edid[0x13];
+
+	if (edid[0x12] == 1) {
+		if (edid[0x13] > 4) {
+			printk(BIOS_SPEW, "Claims > 1.4, assuming 1.4 conformance\n");
+			edid[0x13] = 4;
+		}
+		switch (edid[0x13]) {
+		case 4:
+			claims_one_point_four = 1;
+		case 3:
+			claims_one_point_three = 1;
+		case 2:
+			claims_one_point_two = 1;
+		default:
+			break;
+		}
+		claims_one_point_oh = 1;
+	}
+
+	/* display section */
+
+	if (edid[0x14] & 0x80) {
+		int conformance_mask;
+		analog = 0;
+		printk(BIOS_SPEW, "Digital display\n");
+		if (claims_one_point_four) {
+			conformance_mask = 0;
+			if ((edid[0x14] & 0x70) == 0x00)
+				printk(BIOS_SPEW, "Color depth is undefined\n");
+			else if ((edid[0x14] & 0x70) == 0x70)
+				nonconformant_digital_display = 1;
+			else
+				printk(BIOS_SPEW, "%d bits per primary color channel\n",
+				       ((edid[0x14] & 0x70) >> 3) + 4);
+			out->bpp = ((edid[0x14] & 0x70) >> 3) + 4;
+
+			switch (edid[0x14] & 0x0f) {
+			case 0x00: printk(BIOS_SPEW, "Digital interface is not defined\n"); break;
+			case 0x01: printk(BIOS_SPEW, "DVI interface\n"); break;
+			case 0x02: printk(BIOS_SPEW, "HDMI-a interface\n"); break;
+			case 0x03: printk(BIOS_SPEW, "HDMI-b interface\n"); break;
+			case 0x04: printk(BIOS_SPEW, "MDDI interface\n"); break;
+			case 0x05: printk(BIOS_SPEW, "DisplayPort interface\n"); break;
+			default:
+				nonconformant_digital_display = 1;
+			}
+			out->type = edid[0x14] & 0x0f;
+		} else 	if (claims_one_point_two) {
+			conformance_mask = 0x7E;
+			if (edid[0x14] & 0x01) {
+				printk(BIOS_SPEW, "DFP 1.x compatible TMDS\n");
+			}
+		} else
+			conformance_mask = 0x7F;
+
+		if (!nonconformant_digital_display)
+			nonconformant_digital_display = edid[0x14] & conformance_mask;
+		out->nonconformant = nonconformant_digital_display;
+	} else {
+		analog = 1;
+		int voltage = (edid[0x14] & 0x60) >> 5;
+		int sync = (edid[0x14] & 0x0F);
+		out->voltage = voltage;
+		out->sync = sync;
+
+		printk(BIOS_SPEW, "Analog display, Input voltage level: %s V\n",
+		       voltage == 3 ? "0.7/0.7" :
+		       voltage == 2 ? "1.0/0.4" :
+		       voltage == 1 ? "0.714/0.286" :
+		       "0.7/0.3");
+
+		if (claims_one_point_four) {
+			if (edid[0x14] & 0x10)
+				printk(BIOS_SPEW, "Blank-to-black setup/pedestal\n");
+			else
+				printk(BIOS_SPEW, "Blank level equals black level\n");
+		} else if (edid[0x14] & 0x10) {
+			/*
+			 * XXX this is just the X text.  1.3 says "if set, display expects
+			 * a blank-to-black setup or pedestal per appropriate Signal
+			 * Level Standard".  Whatever _that_ means.
+			 */
+			printk(BIOS_SPEW, "Configurable signal levels\n");
+		}
+
+		printk(BIOS_SPEW, "Sync: %s%s%s%s\n", sync & 0x08 ? "Separate " : "",
+		       sync & 0x04 ? "Composite " : "",
+		       sync & 0x02 ? "SyncOnGreen " : "",
+		       sync & 0x01 ? "Serration " : "");
+	}
+
+
+		if (edid[0x15] && edid[0x16]) {
+			printk(BIOS_SPEW, "Maximum image size: %d cm x %d cm\n",
+			       edid[0x15], edid[0x16]);
+			out->xsize_cm = edid[0x15];
+			out->ysize_cm = edid[0x16];
+		} else if (claims_one_point_four && (edid[0x15] || edid[0x16])) {
+			if (edid[0x15]) {
+				printk(BIOS_SPEW, "Aspect ratio is %f (landscape)\n",
+				       100.0/(edid[0x16] + 99));
+				/* truncated to integer %. We try to avoid floating point */
+				out->aspect_landscape = 10000 /(edid[0x16] + 99);
+			} else {
+				printk(BIOS_SPEW, "Aspect ratio is %f (portrait)\n",
+				       100.0/(edid[0x15] + 99));
+				out->aspect_portrait = 10000 /(edid[0x16] + 99);
+			}
+		} else {
+			/* Either or both can be zero for 1.3 and before */
+			printk(BIOS_SPEW, "Image size is variable\n");
+		}
+
+		if (edid[0x17] == 0xff) {
+			if (claims_one_point_four)
+				printk(BIOS_SPEW, "Gamma is defined in an extension block\n");
+			else
+				/* XXX Technically 1.3 doesn't say this... */
+				printk(BIOS_SPEW, "Gamma: 1.0\n");
+		} else printk(BIOS_SPEW, "Gamma: %d%%\n", ((edid[0x17] + 100)));
+		printk(BIOS_SPEW, "Check DPMS levels\n");
+		if (edid[0x18] & 0xE0) {
+			printk(BIOS_SPEW, "DPMS levels:");
+			if (edid[0x18] & 0x80) printk(BIOS_SPEW, " Standby");
+			if (edid[0x18] & 0x40) printk(BIOS_SPEW, " Suspend");
+			if (edid[0x18] & 0x20) printk(BIOS_SPEW, " Off");
+			printk(BIOS_SPEW, "\n");
+		}
+
+/* FIXME: this is from 1.4 spec, check earlier */
+		if (analog) {
+			switch (edid[0x18] & 0x18) {
+			case 0x00: printk(BIOS_SPEW, "Monochrome or grayscale display\n"); break;
+			case 0x08: printk(BIOS_SPEW, "RGB color display\n"); break;
+			case 0x10: printk(BIOS_SPEW, "Non-RGB color display\n"); break;
+			case 0x18: printk(BIOS_SPEW, "Undefined display color type\n");
+			}
+		} else {
+			printk(BIOS_SPEW, "Supported color formats: RGB 4:4:4");
+			if (edid[0x18] & 0x10)
+				printk(BIOS_SPEW, ", YCrCb 4:4:4");
+			if (edid[0x18] & 0x08)
+				printk(BIOS_SPEW, ", YCrCb 4:2:2");
+			printk(BIOS_SPEW, "\n");
+		}
+
+		if (edid[0x18] & 0x04)
+			printk(BIOS_SPEW, "Default (sRGB) color space is primary color space\n");
+		if (edid[0x18] & 0x02) {
+			printk(BIOS_SPEW, "First detailed timing is preferred timing\n");
+			has_preferred_timing = 1;
+		}
+		if (edid[0x18] & 0x01)
+			printk(BIOS_SPEW, "Supports GTF timings within operating range\n");
+
+		/* XXX color section */
+
+		printk(BIOS_SPEW, "Established timings supported:\n");
+		/* it's not yet clear we want all this stuff in the edid struct.
+		 * Let's wait.
+		 */
+		for (i = 0; i < 17; i++) {
+			if (edid[0x23 + i / 8] & (1 << (7 - i % 8))) {
+				printk(BIOS_SPEW, "  %dx%d@%dHz\n", established_timings[i].x,
+				       established_timings[i].y, established_timings[i].refresh);
+			}
+		}
+
+		printk(BIOS_SPEW, "Standard timings supported:\n");
+		for (i = 0; i < 8; i++) {
+			uint8_t b1 = edid[0x26 + i * 2], b2 = edid[0x26 + i * 2 + 1];
+			unsigned int x, y, refresh;
+
+			if (b1 == 0x01 && b2 == 0x01)
+				continue;
+
+			if (b1 == 0) {
+				printk(BIOS_SPEW, "non-conformant standard timing (0 horiz)\n");
+				continue;
+			}
+			x = (b1 + 31) * 8;
+			switch ((b2 >> 6) & 0x3) {
+			case 0x00:
+				if (claims_one_point_three)
+					y = x * 10 / 16;
+				else
+					y = x;
+				break;
+			case 0x01:
+				y = x * 3 / 4;
+				break;
+			case 0x02:
+				y = x * 4 / 5;
+				break;
+			case 0x03:
+				y = x * 9 / 16;
+				break;
+			}
+			refresh = 60 + (b2 & 0x3f);
+
+			printk(BIOS_SPEW, "  %dx%d@%dHz\n", x, y, refresh);
+		}
+
+		/* detailed timings */
+		printk(BIOS_SPEW, "Detailed timings\n");
+		has_valid_detailed_blocks = detailed_block(out, edid + 0x36, 0);
+		if (has_preferred_timing && !did_detailed_timing)
+			has_preferred_timing = 0; /* not really accurate... */
+		has_valid_detailed_blocks &= detailed_block(out, edid + 0x48, 0);
+		has_valid_detailed_blocks &= detailed_block(out, edid + 0x5A, 0);
+		has_valid_detailed_blocks &= detailed_block(out, edid + 0x6C, 0);
+
+		/* check this, 1.4 verification guide says otherwise */
+		if (edid[0x7e]) {
+			printk(BIOS_SPEW, "Has %d extension blocks\n", edid[0x7e]);
+			/* 2 is impossible because of the block map */
+			if (edid[0x7e] != 2)
+				has_valid_extension_count = 1;
+		} else {
+			has_valid_extension_count = 1;
+		}
+
+		printk(BIOS_SPEW, "Checksum\n");
+		do_checksum(edid);
+		for(i = 0; i < size; i += 128)
+			nonconformant_extension = parse_extension(out, &edid[i]);
+/*
+		x = edid;
+		for (edid_lines /= 8; edid_lines > 1; edid_lines--) {
+			x += 128;
+			nonconformant_extension += parse_extension(x);
+		}
+*/
+
+		if (claims_one_point_three) {
+			if (nonconformant_digital_display ||
+			    !has_valid_string_termination ||
+			    !has_valid_descriptor_pad ||
+			    !has_name_descriptor ||
+			    !name_descriptor_terminated ||
+			    !has_preferred_timing ||
+			    !has_range_descriptor)
+				conformant = 0;
+			if (!conformant)
+				printk(BIOS_ERR, "EDID block does NOT conform to EDID 1.3!\n");
+			if (nonconformant_digital_display)
+				printk(BIOS_ERR, "\tDigital display field contains garbage: %x\n",
+				       nonconformant_digital_display);
+			if (!has_name_descriptor)
+				printk(BIOS_ERR, "\tMissing name descriptor\n");
+			else if (!name_descriptor_terminated)
+				printk(BIOS_ERR, "\tName descriptor not terminated with a newline\n");
+			if (!has_preferred_timing)
+				printk(BIOS_ERR, "\tMissing preferred timing\n");
+			if (!has_range_descriptor)
+				printk(BIOS_ERR, "\tMissing monitor ranges\n");
+			if (!has_valid_descriptor_pad) /* Might be more than just 1.3 */
+				printk(BIOS_ERR, "\tInvalid descriptor block padding\n");
+			if (!has_valid_string_termination) /* Likewise */
+				printk(BIOS_ERR, "\tDetailed block string not properly terminated\n");
+		} else if (claims_one_point_two) {
+			if (nonconformant_digital_display ||
+			    (has_name_descriptor && !name_descriptor_terminated))
+				conformant = 0;
+			if (!conformant)
+				printk(BIOS_ERR, "EDID block does NOT conform to EDID 1.2!\n");
+			if (nonconformant_digital_display)
+				printk(BIOS_ERR, "\tDigital display field contains garbage: %x\n",
+				       nonconformant_digital_display);
+			if (has_name_descriptor && !name_descriptor_terminated)
+				printk(BIOS_ERR, "\tName descriptor not terminated with a newline\n");
+		} else if (claims_one_point_oh) {
+			if (seen_non_detailed_descriptor)
+				conformant = 0;
+			if (!conformant)
+				printk(BIOS_ERR, "EDID block does NOT conform to EDID 1.0!\n");
+			if (seen_non_detailed_descriptor)
+				printk(BIOS_ERR, "\tHas descriptor blocks other than detailed timings\n");
+		}
+
+		if (nonconformant_extension ||
+		    !has_valid_checksum ||
+		    !has_valid_cvt ||
+		    !has_valid_year ||
+		    !has_valid_week ||
+		    !has_valid_detailed_blocks ||
+		    !has_valid_dummy_block ||
+		    !has_valid_extension_count ||
+		    !has_valid_descriptor_ordering ||
+		    !has_valid_range_descriptor ||
+		    !manufacturer_name_well_formed) {
+			conformant = 0;
+			printk(BIOS_ERR, "EDID block does not conform at all!\n");
+			if (nonconformant_extension)
+				printk(BIOS_ERR, "\tHas %d nonconformant extension block(s)\n",
+				       nonconformant_extension);
+			if (!has_valid_checksum)
+				printk(BIOS_ERR, "\tBlock has broken checksum\n");
+			if (!has_valid_cvt)
+				printk(BIOS_ERR, "\tBroken 3-byte CVT blocks\n");
+			if (!has_valid_year)
+				printk(BIOS_ERR, "\tBad year of manufacture\n");
+			if (!has_valid_week)
+				printk(BIOS_ERR, "\tBad week of manufacture\n");
+			if (!has_valid_detailed_blocks)
+				printk(BIOS_ERR, "\tDetailed blocks filled with garbage\n");
+			if (!has_valid_dummy_block)
+				printk(BIOS_ERR, "\tDummy block filled with garbage\n");
+			if (!has_valid_extension_count)
+				printk(BIOS_ERR, "\tImpossible extension block count\n");
+			if (!manufacturer_name_well_formed)
+				printk(BIOS_ERR, "\tManufacturer name field contains garbage\n");
+			if (!has_valid_descriptor_ordering)
+				printk(BIOS_ERR, "\tInvalid detailed timing descriptor ordering\n");
+			if (!has_valid_range_descriptor)
+				printk(BIOS_ERR, "\tRange descriptor contains garbage\n");
+			if (!has_valid_max_dotclock)
+				printk(BIOS_ERR, "\tEDID 1.4 block does not set max dotclock\n");
+		}
+
+		if (warning_excessive_dotclock_correction)
+			printk(BIOS_ERR,
+			       "Warning: CVT block corrects dotclock by more than 9.75MHz\n");
+		if (warning_zero_preferred_refresh)
+			printk(BIOS_ERR,
+			       "Warning: CVT block does not set preferred refresh rate\n");
+		return !conformant;
+	}
+
+/*
+ * Notes on panel extensions: (TODO, implement me in the code)
+ *
+ * EPI: http://www.epi-standard.org/fileadmin/spec/EPI_Specification1.0.pdf
+ * at offset 0x6c (fourth detailed block): (all other bits reserved)
+ * 0x6c: 00 00 00 0e 00
+ * 0x71: bit 6-5: data color mapping (00 conventional/fpdi/vesa, 01 openldi)
+ *       bit 4-3: pixels per clock (00 1, 01 2, 10 4, 11 reserved)
+ *       bit 2-0: bits per pixel (000 18, 001 24, 010 30, else reserved)
+ * 0x72: bit 5: FPSCLK polarity (0 normal 1 inverted)
+ *       bit 4: DE polarity (0 high active 1 low active)
+ *       bit 3-0: interface (0000 LVDS TFT
+ *                           0001 mono STN 4/8bit
+ *                           0010 color STN 8/16 bit
+ *                           0011 18 bit tft
+ *                           0100 24 bit tft
+ *                           0101 tmds
+ *                           else reserved)
+ * 0x73: bit 1: horizontal display mode (0 normal 1 right/left reverse)
+ *       bit 0: vertical display mode (0 normal 1 up/down reverse)
+ * 0x74: bit 7-4: total poweroff seq delay (0000 vga controller default
+ *                                          else time in 10ms (10ms to 150ms))
+ *       bit 3-0: total poweron seq delay (as above)
+ * 0x75: contrast power on/off seq delay, same as 0x74
+ * 0x76: bit 7: backlight control enable (1 means this field is valid)
+ *       bit 6: backlight enabled at boot (0 on 1 off)
+ *       bit 5-0: backlight brightness control steps (0..63)
+ * 0x77: bit 7: contrast control, same bit pattern as 0x76 except bit 6 resvd
+ * 0x78 - 0x7c: reserved
+ * 0x7d: bit 7-4: EPI descriptor major version (1)
+ *       bit 3-0: EPI descriptor minor version (0)
+ *
+ * ----
+ *
+ * SPWG: http://www.spwg.org/spwg_spec_version3.8_3-14-2007.pdf
+ *
+ * Since these are "dummy" blocks, terminate with 0a 20 20 20 ... as usual
+ *
+ * detailed descriptor 3:
+ * 0x5a - 0x5e: 00 00 00 fe 00
+ * 0x5f - 0x63: PC maker part number
+ * 0x64: LCD supplier revision #
+ * 0x65 - 0x6b: manufacturer part number
+ *
+ * detailed descriptor 4:
+ * 0x6c - 0x70: 00 00 00 fe 00
+ * 0x71 - 0x78: smbus nits values (whut)
+ * 0x79: number of lvds channels (1 or 2)
+ * 0x7A: panel self test (1 if present)
+ * and then dummy terminator
+ *
+ * SPWG also says something strange about the LSB of detailed descriptor 1:
+ * "LSB is set to "1" if panel is DE-timing only. H/V can be ignored."
+ */