Transition to hekate bdk layout

bdk/libs/compr/blz.c

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2018 rajkosto
+ * Copyright (c) 2018 SciresM
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "blz.h"
+
+const blz_footer *blz_get_footer(const unsigned char *compData, unsigned int compDataLen, blz_footer *outFooter)
+{
+	if (compDataLen < sizeof(blz_footer))
+		return NULL;
+
+	const blz_footer *srcFooter = (const blz_footer*)&compData[compDataLen - sizeof(blz_footer)];
+	if (outFooter != NULL)
+		memcpy(outFooter, srcFooter, sizeof(blz_footer)); // Must be a memcpy because no umaligned accesses on ARMv4.
+
+	return srcFooter;
+}
+
+// From https://github.com/SciresM/hactool/blob/master/kip.c which is exactly how kernel does it, thanks SciresM!
+int blz_uncompress_inplace(unsigned char *dataBuf, unsigned int compSize, const blz_footer *footer)
+{
+	u32 addl_size = footer->addl_size;
+	u32 header_size = footer->header_size;
+	u32 cmp_and_hdr_size = footer->cmp_and_hdr_size;
+
+	unsigned char* cmp_start = &dataBuf[compSize] - cmp_and_hdr_size;
+	u32 cmp_ofs = cmp_and_hdr_size - header_size;
+	u32 out_ofs = cmp_and_hdr_size + addl_size;
+
+	while (out_ofs)
+	{
+		unsigned char control = cmp_start[--cmp_ofs];
+		for (unsigned int i=0; i<8; i++)
+		{
+			if (control & 0x80)
+			{
+				if (cmp_ofs < 2)
+					return 0; // Out of bounds.
+
+				cmp_ofs -= 2;
+				u16 seg_val = ((unsigned int)(cmp_start[cmp_ofs + 1]) << 8) | cmp_start[cmp_ofs];
+				u32 seg_size = ((seg_val >> 12) & 0xF) + 3;
+				u32 seg_ofs = (seg_val & 0x0FFF) + 3;
+				if (out_ofs < seg_size) // Kernel restricts segment copy to stay in bounds.
+					seg_size = out_ofs;
+
+				out_ofs -= seg_size;
+
+				for (unsigned int j = 0; j < seg_size; j++)
+					cmp_start[out_ofs + j] = cmp_start[out_ofs + j + seg_ofs];
+			}
+			else
+			{
+				// Copy directly.
+				if (cmp_ofs < 1)
+					return 0; //out of bounds
+
+				cmp_start[--out_ofs] = cmp_start[--cmp_ofs];
+			}
+			control <<= 1;
+			if (out_ofs == 0) // Blz works backwards, so if it reaches byte 0, it's done.
+				return 1;
+			}
+		}
+
+	return 1;
+}
+
+int blz_uncompress_srcdest(const unsigned char *compData, unsigned int compDataLen, unsigned char *dstData, unsigned int dstSize)
+{
+	blz_footer footer;
+	const blz_footer *compFooterPtr = blz_get_footer(compData, compDataLen, &footer);
+	if (compFooterPtr == NULL)
+		return 0;
+
+	// Decompression must be done in-place, so need to copy the relevant compressed data first.
+	unsigned int numCompBytes = (const unsigned char*)(compFooterPtr)-compData;
+	memcpy(dstData, compData, numCompBytes);
+	memset(&dstData[numCompBytes], 0, dstSize - numCompBytes);
+
+	return blz_uncompress_inplace(dstData, compDataLen, &footer);
+}