Index: contrib/xz/src/common/mythread.h
===================================================================
--- contrib/xz/src/common/mythread.h
+++ contrib/xz/src/common/mythread.h
@@ -81,15 +81,19 @@
 
 #if !(defined(_WIN32) && !defined(__CYGWIN__))
 // Use sigprocmask() to set the signal mask in single-threaded programs.
+#ifndef _KERNEL
 #include <signal.h>
+#endif
 
 static inline void
 mythread_sigmask(int how, const sigset_t *restrict set,
 		sigset_t *restrict oset)
 {
+#ifndef _KERNEL
 	int ret = sigprocmask(how, set, oset);
 	assert(ret == 0);
 	(void)ret;
+#endif
 }
 #endif
 
Index: contrib/xz/src/common/sysdefs.h
===================================================================
--- contrib/xz/src/common/sysdefs.h
+++ contrib/xz/src/common/sysdefs.h
@@ -16,6 +16,22 @@
 #ifndef LZMA_SYSDEFS_H
 #define LZMA_SYSDEFS_H
 
+#ifdef _KERNEL
+#include <sys/param.h>
+#include <sys/endian.h>
+#include <sys/libkern.h>
+#include <sys/limits.h>
+#include <sys/stdint.h>
+#include <sys/systm.h>
+
+#include <machine/_inttypes.h>
+
+#define	assert(c, ...)		if (!(c)) panic(__VA_ARGS__)
+#define HAVE_CHECK_CRC64	1
+#define HAVE_VISIBILITY		1
+#define LZMA_MANUAL_HEADERS	1
+#else /* !_KERNEL */
+
 //////////////
 // Includes //
 //////////////
@@ -176,6 +192,8 @@
 #	endif
 #endif
 
+#endif /* _KERNEL */
+
 ////////////
 // Macros //
 ////////////
Index: contrib/xz/src/common/tuklib_config.h
===================================================================
--- contrib/xz/src/common/tuklib_config.h
+++ contrib/xz/src/common/tuklib_config.h
@@ -1,4 +1,4 @@
-#ifdef HAVE_CONFIG_H
+#if defined(HAVE_CONFIG_H) || defined(_KERNEL)
 #	include "sysdefs.h"
 #else
 #	include <stddef.h>
Index: contrib/xz/src/liblzma/check/check.c
===================================================================
--- contrib/xz/src/liblzma/check/check.c
+++ contrib/xz/src/liblzma/check/check.c
@@ -172,3 +172,11 @@
 
 	return;
 }
+
+#ifdef _KERNEL
+uint32_t
+lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
+{
+	return (~crc32_raw(buf, size, ~crc));
+}
+#endif
Index: contrib/xz/src/liblzma/common/common.c
===================================================================
--- contrib/xz/src/liblzma/common/common.c
+++ contrib/xz/src/liblzma/common/common.c
@@ -35,6 +35,13 @@
 // Memory allocation //
 ///////////////////////
 
+#ifdef _KERNEL
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+
+static MALLOC_DEFINE(M_LZMA, "lzma", "lzma allocations");
+#endif
+
 extern void * lzma_attribute((__malloc__)) lzma_attr_alloc_size(1)
 lzma_alloc(size_t size, const lzma_allocator *allocator)
 {
@@ -47,7 +54,11 @@
 	if (allocator != NULL && allocator->alloc != NULL)
 		ptr = allocator->alloc(allocator->opaque, 1, size);
 	else
+#ifdef _KERNEL
+		ptr = malloc(size, M_LZMA, M_WAITOK);
+#else
 		ptr = malloc(size);
+#endif
 
 	return ptr;
 }
@@ -67,7 +78,11 @@
 		if (ptr != NULL)
 			memzero(ptr, size);
 	} else {
+#ifdef _KERNEL
+		ptr = malloc(size, M_LZMA, M_WAITOK | M_ZERO);
+#else
 		ptr = calloc(1, size);
+#endif
 	}
 
 	return ptr;
@@ -80,7 +95,11 @@
 	if (allocator != NULL && allocator->free != NULL)
 		allocator->free(allocator->opaque, ptr);
 	else
+#ifdef _KERNEL
+		free(ptr, M_LZMA);
+#else
 		free(ptr);
+#endif
 
 	return;
 }
Index: contrib/xz/src/liblzma/rangecoder/price_table.c
===================================================================
--- contrib/xz/src/liblzma/rangecoder/price_table.c
+++ contrib/xz/src/liblzma/rangecoder/price_table.c
@@ -1,5 +1,6 @@
 /* This file has been automatically generated by price_tablegen.c. */
 
+#include "sysdefs.h"
 #include "range_encoder.h"
 
 const uint8_t lzma_rc_prices[RC_PRICE_TABLE_SIZE] = {
Index: sys/conf/files
===================================================================
--- sys/conf/files
+++ sys/conf/files
@@ -4681,3 +4681,84 @@
 xdr/xdr_mem.c			optional krpc | nfslockd | nfscl | nfsd
 xdr/xdr_reference.c		optional krpc | nfslockd | nfscl | nfsd
 xdr/xdr_sizeof.c		optional krpc | nfslockd | nfscl | nfsd
+# liblzma
+# Disabled features: Redundant checksum algorithms, multithreading.
+contrib/liblzma/check/check.c				standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc32_fast.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc32_small.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc32_table.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc32_tablegen.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/check/crc64_fast.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc64_small.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/check/crc64_table.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/crc64_tablegen.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/check/sha256.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/alone_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/alone_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/auto_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_buffer_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_buffer_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_header_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_header_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/block_util.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/common.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/easy_buffer_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/easy_decoder_memusage.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/easy_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/easy_encoder_memusage.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/easy_preset.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/file_info.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_buffer_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_buffer_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_common.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_flags_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/filter_flags_encoder.c		standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/common/hardware_cputhreads.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/hardware_physmem.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/index.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/index_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/index_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/index_hash.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/common/outqueue.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_buffer_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_buffer_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_encoder.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/common/stream_encoder_mt.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_flags_common.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_flags_decoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/stream_flags_encoder.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/vli_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/vli_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/common/vli_size.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/delta/delta_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/delta/delta_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/delta/delta_common.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lz/lz_encoder.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lz/lz_encoder_mf.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lz/lz_decoder.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/fastpos_table.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/lzma/fastpos_tablegen.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma_encoder_optimum_fast.c	standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma_encoder_optimum_normal.c	standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma_encoder_presets.c		standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma2_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/lzma/lzma2_encoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/rangecoder/price_table.c		standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/rangecoder/price_tablegen.c		standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/simple/arm.c				standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/simple/armthumb.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/simple/ia64.c				standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/simple/powerpc.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/simple/simple_coder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/simple/simple_decoder.c			standard compile-with ${LIBLZMA_C}
+contrib/liblzma/simple/simple_encoder.c			standard compile-with ${LIBLZMA_C}
+#contrib/liblzma/simple/sparc.c				standard compile-with ${LIBLZMA_C}
+contrib/liblzma/simple/x86.c				standard compile-with ${LIBLZMA_C}
+contrib/xz-common/tuklib_physmem.c			standard compile-with ${LIBLZMA_C}
Index: sys/conf/kern.pre.mk
===================================================================
--- sys/conf/kern.pre.mk
+++ sys/conf/kern.pre.mk
@@ -109,6 +109,17 @@
 # Optional linting. This can be overridden in /etc/make.conf.
 LINTFLAGS=	${LINTOBJKERNFLAGS}
 
+LIBLZMA_C= ${CC} -c ${CFLAGS} ${WERROR} -Wno-cast-qual ${PROF} ${.IMPSRC} -DTUKLIB_SYMBOL_PREFIX=lzma_ \
+	   -I$S/contrib/liblzma \
+	   -I$S/contrib/liblzma/api \
+	   -I$S/contrib/liblzma/check \
+	   -I$S/contrib/liblzma/common \
+	   -I$S/contrib/liblzma/delta \
+	   -I$S/contrib/liblzma/lz \
+	   -I$S/contrib/liblzma/lzma \
+	   -I$S/contrib/liblzma/rangecoder \
+	   -I$S/contrib/liblzma/simple \
+	   -I$S/contrib/xz-common
 NORMAL_C= ${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
 NORMAL_S= ${CC:N${CCACHE_BIN}} -c ${ASM_CFLAGS} ${WERROR} ${.IMPSRC}
 PROFILE_C= ${CC} -c ${CFLAGS} ${WERROR} ${.IMPSRC}