1 files changed, 86 insertions, 10 deletions

diff --git a/qemu/roms/ipxe/src/util/zbin.c b/qemu/roms/ipxe/src/util/zbin.c
index 3b7cf95b3..1862a3827 100644
--- a/qemu/roms/ipxe/src/util/zbin.c
+++ b/qemu/roms/ipxe/src/util/zbin.c
@@ -1,13 +1,21 @@
+#include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
 #include <sys/stat.h>
-
-#define ENCODE
-#define VERBOSE
-#include "nrv2b.c"
-FILE *infile, *outfile;
+#include <lzma.h>
 
 #define DEBUG 0
 
+/* LZMA filter choices.  Must match those used by unlzma.S */
+#define LZMA_LC 2
+#define LZMA_LP 0
+#define LZMA_PB 0
+
+/* LZMA preset choice.  This is a policy decision */
+#define LZMA_PRESET ( LZMA_PRESET_DEFAULT | LZMA_PRESET_EXTREME )
+
 struct input_file {
 	void *buf;
 	size_t len;
@@ -177,13 +185,75 @@ static int process_zinfo_copy ( struct input_file *input,
 	return 0;
 }
 
+#define OPCODE_CALL 0xe8
+#define OPCODE_JMP 0xe9
+
+static void bcj_filter ( void *data, size_t len ) {
+	struct {
+		uint8_t opcode;
+		int32_t target;
+	} __attribute__ (( packed )) *jump;
+	ssize_t limit = ( len - sizeof ( *jump ) );
+	ssize_t offset;
+
+	/* liblzma does include an x86 BCJ filter, but it's hideously
+	 * convoluted and undocumented.  This BCJ filter is
+	 * substantially simpler and achieves the same compression (at
+	 * the cost of requiring the decompressor to know the size of
+	 * the decompressed data, which we already have in iPXE).
+	 */
+	for ( offset = 0 ; offset <= limit ; offset++ ) {
+		jump = ( data + offset );
+
+		/* Skip instructions that are not followed by a rel32 address */
+		if ( ( jump->opcode != OPCODE_CALL ) &&
+		     ( jump->opcode != OPCODE_JMP ) )
+			continue;
+
+		/* Convert rel32 address to an absolute address.  To
+		 * avoid false positives (which damage the compression
+		 * ratio), we should check that the jump target is
+		 * within the range [0,limit).
+		 *
+		 * Some output values would then end up being mapped
+		 * from two distinct input values, making the
+		 * transformation irreversible.  To solve this, we
+		 * transform such values back into the part of the
+		 * range which would otherwise correspond to no input
+		 * values.
+		 */
+		if ( ( jump->target >= -offset ) &&
+		     ( jump->target < ( limit - offset ) ) ) {
+			/* Convert relative addresses in the range
+			 * [-offset,limit-offset) to absolute
+			 * addresses in the range [0,limit).
+			 */
+			jump->target += offset;
+		} else if ( ( jump->target >= ( limit - offset ) ) &&
+			    ( jump->target < limit ) ) {
+			/* Convert positive numbers in the range
+			 * [limit-offset,limit) to negative numbers in
+			 * the range [-offset,0).
+			 */
+			jump->target -= limit;
+		}
+		offset += sizeof ( jump->target );
+	};
+}
+
 static int process_zinfo_pack ( struct input_file *input,
 				struct output_file *output,
 				union zinfo_record *zinfo ) {
 	struct zinfo_pack *pack = &zinfo->pack;
 	size_t offset = pack->offset;
 	size_t len = pack->len;
-	unsigned long packed_len;
+	size_t packed_len = 0;
+	size_t remaining = ( output->max_len - output->len );
+	lzma_options_lzma options;
+	const lzma_filter filters[] = {
+		{ .id = LZMA_FILTER_LZMA1, .options = &options },
+		{ .id = LZMA_VLI_UNKNOWN }
+	};
 
 	if ( ( offset + len ) > input->len ) {
 		fprintf ( stderr, "Input buffer overrun on pack\n" );
@@ -196,9 +266,15 @@ static int process_zinfo_pack ( struct input_file *input,
 		return -1;
 	}
 
-	if ( ucl_nrv2b_99_compress ( ( input->buf + offset ), len,
-				     ( output->buf + output->len ),
-				     &packed_len, 0 ) != UCL_E_OK ) {
+	bcj_filter ( ( input->buf + offset ), len );
+
+	lzma_lzma_preset ( &options, LZMA_PRESET );
+	options.lc = LZMA_LC;
+	options.lp = LZMA_LP;
+	options.pb = LZMA_PB;
+	if ( lzma_raw_buffer_encode ( filters, NULL, ( input->buf + offset ),
+				      len, ( output->buf + output->len ),
+				      &packed_len, remaining ) != LZMA_OK ) {
 		fprintf ( stderr, "Compression failure\n" );
 		return -1;
 	}
@@ -206,7 +282,7 @@ static int process_zinfo_pack ( struct input_file *input,
 	if ( DEBUG ) {
 		fprintf ( stderr, "PACK [%#zx,%#zx) to [%#zx,%#zx)\n",
 			  offset, ( offset + len ), output->len,
-			  ( size_t )( output->len + packed_len ) );
+			  ( output->len + packed_len ) );
 	}
 
 	output->len += packed_len;