From a8b13d23f29a08026eaa308b8b09be7e9d1ff5a6 Mon Sep 17 00:00:00 2001
From: Francis Rowe <info@gluglug.org.uk>
Date: Thu, 25 Dec 2014 16:25:49 -0500
Subject: ich9deblob: moved src to src/, .o files to obj/
---
(limited to 'resources/utilities/ich9deblob/src/gbe')
diff --git a/resources/utilities/ich9deblob/src/gbe/gbe.c b/resources/utilities/ich9deblob/src/gbe/gbe.c
new file mode 100644
index 0000000..9eee828
--- /dev/null
+++ b/resources/utilities/ich9deblob/src/gbe/gbe.c
@@ -0,0 +1,124 @@
+/*
+ * gbe/gbe.c
+ * This file is part of the ich9deblob utility from the libreboot project
+ *
+ * Copyright (C) 2014 Steve Shenton <sgsit@libreboot.org>
+ * Francis Rowe <info@gluglug.org.uk>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Provide gbe related functions.
+ */
+
+/* structs describing the data from gbe region */
+#include "gbe.h"
+
+/*
+ * ---------------------------------------------------------------------
+ * Gbe functions:
+ * ---------------------------------------------------------------------
+ */
+
+/* Read a 16-bit unsigned int from a supplied region buffer */
+unsigned short gbeGetRegionWordFrom8kBuffer(int index, char* regionData)
+{
+ return *((unsigned short*)(regionData + (index * 2)));
+}
+
+/*
+ * gbe checksum calculation (algorithm based on datasheet)
+ */
+unsigned short gbeGetChecksumFrom8kBuffer(char* regionData, unsigned short desiredValue, int byteOffset)
+{
+ int i;
+
+ /*
+ * byteOffset defines the byte address where the gbe begins in the buffer "regionData".
+ * However, this function works with 16-bit words. Shift the byte offset to the right for the word (16-bit) offset.
+ */
+ int wordOffset = byteOffset >> 1;
+
+ unsigned short regionWord; /* store words here for adding to checksum */
+ unsigned short checksum = 0; /* this gbe's checksum */
+
+ for (i = 0; i < 0x3F; i++) {
+ regionWord = gbeGetRegionWordFrom8kBuffer(i+wordOffset, regionData);
+ checksum += regionWord;
+ }
+ checksum = desiredValue - checksum;
+ return checksum;
+}
+
+/* checksum calculation for 4k gbe struct (algorithm based on datasheet) */
+unsigned short gbeGetChecksumFrom4kStruct(struct GBEREGIONRECORD_4K gbeStruct4k, unsigned short desiredValue)
+{
+ char gbeBuffer4k[GBEREGIONSIZE_4K];
+ memcpy(&gbeBuffer4k, &gbeStruct4k, GBEREGIONSIZE_4K);
+ return gbeGetChecksumFrom8kBuffer(gbeBuffer4k, desiredValue, 0);
+}
+
+/* modify the gbe region extracted from a factory.rom dump */
+struct GBEREGIONRECORD_8K deblobbedGbeStructFromFactory(struct GBEREGIONRECORD_8K factoryGbeStruct8k)
+{
+ /*
+ * Correct the main gbe region. By default, the X200 (as shipped from Lenovo) comes
+ * with a broken main gbe region, where the backup gbe region is used instead. Modify
+ * it so that the main region is usable.
+ */
+
+ struct GBEREGIONRECORD_8K deblobbedGbeStruct8k;
+ memcpy(&deblobbedGbeStruct8k, &factoryGbeStruct8k, GBEREGIONSIZE_8K);
+
+ deblobbedGbeStruct8k.backup.checkSum = gbeGetChecksumFrom4kStruct(deblobbedGbeStruct8k.backup, GBECHECKSUMTOTAL);
+ memcpy(&deblobbedGbeStruct8k.main, &deblobbedGbeStruct8k.backup, GBEREGIONSIZE_4K);
+
+ return deblobbedGbeStruct8k;
+}
+
+/*
+ * ---------------------------------------------------------------------
+ * Debugging functions:
+ * ---------------------------------------------------------------------
+ */
+
+/*
+ * show debugging info: show calculated (correct) gbe checksum and what
+ * is actually stored, in a 4K gbe struct. Only for a single region.
+ */
+void printGbeChecksumDataFromStruct4k(struct GBEREGIONRECORD_4K gbeStruct4k, char* romName, char* regionName)
+{
+ printf(
+ "%s Gbe (%s): calculated Gbe checksum: 0x%hx and actual GBe checksum: 0x%hx\n",
+ romName,
+ regionName,
+ gbeGetChecksumFrom4kStruct(gbeStruct4k, GBECHECKSUMTOTAL),
+ gbeStruct4k.checkSum
+ );
+
+ return;
+}
+
+/*
+ * show debugging info: show calculated (correct) gbe checksum and what
+ * is actually stored, in a 8K gbe struct. Do so for main and backup regions.
+ */
+void printGbeChecksumDataFromStruct8k(struct GBEREGIONRECORD_8K gbeStruct8k, char* romName)
+{
+ printGbeChecksumDataFromStruct4k(gbeStruct8k.main, romName, "main");
+ printGbeChecksumDataFromStruct4k(gbeStruct8k.backup, romName, "backup");
+
+ return;
+}
diff --git a/resources/utilities/ich9deblob/src/gbe/gbe.h b/resources/utilities/ich9deblob/src/gbe/gbe.h
new file mode 100644
index 0000000..bfcc002
--- /dev/null
+++ b/resources/utilities/ich9deblob/src/gbe/gbe.h
@@ -0,0 +1,101 @@
+/*
+ * gbe/gbe.h
+ * This file is part of the ich9deblob utility from the libreboot project
+ *
+ * Copyright (C) 2014 Steve Shenton <sgsit@libreboot.org>
+ * Francis Rowe <info@gluglug.org.uk>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Purpose: provide struct representing gbe region.
+ * Map actual buffers of this regions, directly to instances of these
+ * structs. This makes working with gbe really easy.
+ */
+
+/*
+ * bit fields used, corresponding to datasheet. See links to datasheets
+ * and documentation in ich9deblob.c
+ */
+
+#ifndef GBESTRUCT_H
+#define GBESTRUCT_H
+
+#include <stdio.h>
+#include <string.h>
+
+/* Size of the full gbe region in bytes */
+#define GBEREGIONSIZE_8K 0x2000
+/*
+ * Size of each sub-region in gbe.
+ * gbe contains two regions which
+ * can be identical: main and backup.
+ * These are each half the size of the full region
+ */
+#define GBEREGIONSIZE_4K 0x1000
+
+/*
+ * When adding up the first 0x3F 16-bit words
+ * in a 4KiB GBE region, it should be equal
+ * to 0xBABA
+ */
+#define GBECHECKSUMTOTAL 0xBABA
+
+/*
+ * These will have a modified descriptor+gbe based on what's in the factory.rom
+ * These will be joined into a single 12KiB buffer (descriptor, then gbe) and saved to a file
+ * NOTE: The GBE region of 8K is actually 2x 4K regions in a single region; both 4K blocks can be identical (and by default, are)
+ * The 2nd one is a "backup", but we don't know when it's used. perhaps it's used when the checksum on the first one does not match?
+ */
+
+/*
+ * ---------------------------------------------------------------------
+ * Gbe struct representing the data:
+ * ---------------------------------------------------------------------
+ */
+
+struct GBEREGIONRECORD_4K {
+ unsigned char macAddress[6]; /* 0x03 words, or 0x06 bytes */
+ unsigned char otherStuff[120]; /* 0x3c words, or 0x7E bytes */
+ unsigned short checkSum; /* when added to the sum of all words above, this should match GBECHECKSUMTOTAL */
+ unsigned char padding1[3968];
+};
+
+/* main and backup region in gbe */
+struct GBEREGIONRECORD_8K {
+ struct GBEREGIONRECORD_4K main;
+ struct GBEREGIONRECORD_4K backup;
+ /*
+ * Backup region:
+ * This is actually "main" on X200, since the real main has a bad checksum
+ * and other errors. You should do what you need on this one (if modifying
+ * lenovobios's gbe region) and then copy to main
+ */
+};
+
+/*
+ * ---------------------------------------------------------------------
+ * Function declarations (keep gcc/make happy. check them in gbe.c)
+ * ---------------------------------------------------------------------
+ */
+
+unsigned short gbeGetRegionWordFrom8kBuffer(int index, char* regionData);
+unsigned short gbeGetChecksumFrom8kBuffer(char* regionData, unsigned short desiredValue, int byteOffset);
+unsigned short gbeGetChecksumFrom4kStruct(struct GBEREGIONRECORD_4K gbeStruct4k, unsigned short desiredValue);
+struct GBEREGIONRECORD_8K deblobbedGbeStructFromFactory(struct GBEREGIONRECORD_8K factoryGbeStruct8k);
+void printGbeChecksumDataFromStruct4k(struct GBEREGIONRECORD_4K gbeStruct4k, char* romName, char* regionName);
+void printGbeChecksumDataFromStruct8k(struct GBEREGIONRECORD_8K gbeStruct8k, char* romName);
+
+#endif
--
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