diff --git a/MAINTAINERS b/MAINTAINERS
index e7a47b5210fd..6832972ad54b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9369,6 +9369,14 @@ F:	Documentation/core-api/atomic_ops.rst
 F:	Documentation/core-api/refcount-vs-atomic.rst
 F:	Documentation/memory-barriers.txt
 
+LINUX KERNEL LIBRARY
+M:	Octavian Purdila <octavian.purdila@intel.com>
+M:	Hajime Tazaki <thehajime@gmail.com>
+L:	linux-kernel-library@freelists.org
+S:	Maintained
+F:	arch/lkl/
+F:	tools/lkl/
+
 LIS3LV02D ACCELEROMETER DRIVER
 M:	Eric Piel <eric.piel@tremplin-utc.net>
 S:	Maintained
diff --git a/arch/um/lkl/.gitignore b/arch/um/lkl/.gitignore
new file mode 100644
index 000000000000..ced1c60d8235
--- /dev/null
+++ b/arch/um/lkl/.gitignore
@@ -0,0 +1,2 @@
+kernel/vmlinux.lds
+include/generated
diff --git a/arch/um/lkl/Kconfig b/arch/um/lkl/Kconfig
new file mode 100644
index 000000000000..1e68e474a21b
--- /dev/null
+++ b/arch/um/lkl/Kconfig
@@ -0,0 +1,96 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config UML_LKL
+       def_bool y
+       depends on !SMP && !MMU && !COREDUMP && !SECCOMP && !UPROBES && !COMPAT && !USER_RETURN_NOTIFIER
+       select ARCH_THREAD_STACK_ALLOCATOR
+       select RWSEM_GENERIC_SPINLOCK
+       select GENERIC_ATOMIC64
+       select GENERIC_HWEIGHT
+       select FLATMEM
+       select FLAT_NODE_MEM_MAP
+       select GENERIC_CLOCKEVENTS
+       select GENERIC_CPU_DEVICES
+       select NO_HZ_IDLE
+       select NO_PREEMPT
+       select ARCH_WANT_FRAME_POINTERS
+       select HAS_DMA
+       select DMA_DIRECT_OPS
+       select PHYS_ADDR_T_64BIT if 64BIT
+       select 64BIT if "$(OUTPUT_FORMAT)" = "elf64-x86-64"
+       select 64BIT if "$(OUTPUT_FORMAT)" = "pe-x86-64"
+       select HAVE_UNDERSCORE_SYMBOL_PREFIX if "$(OUTPUT_FORMAT)" = "pe-i386"
+       select 64BIT if "$(OUTPUT_FORMAT)" = "elf64-x86-64-freebsd"
+       select 64BIT if "$(OUTPUT_FORMAT)" = "elf64-littleaarch64"
+       select NET
+       select MULTIUSER
+       select INET
+       select IPV6
+       select IP_PNP
+       select IP_PNP_DHCP
+       select TCP_CONG_ADVANCED
+       select TCP_CONG_BBR
+       select HIGH_RES_TIMERS
+       select NET_SCHED
+       select NET_SCH_FQ
+       select IP_MULTICAST
+       select IPV6_MULTICAST
+       select IP_MULTIPLE_TABLES
+       select IPV6_MULTIPLE_TABLES
+       select IP_ROUTE_MULTIPATH
+       select IPV6_ROUTE_MULTIPATH
+       select IP_ADVANCED_ROUTER
+       select IPV6_ADVANCED_ROUTER
+       select ARCH_NO_COHERENT_DMA_MMAP
+       select HAVE_MEMBLOCK
+       select NO_BOOTMEM
+
+config OUTPUT_FORMAT
+       string "Output format"
+       default "$(OUTPUT_FORMAT)"
+
+config ARCH_DMA_ADDR_T_64BIT
+       def_bool 64BIT
+
+config 64BIT
+       def_bool n
+
+config COREDUMP
+       def_bool n
+
+config BIG_ENDIAN
+       def_bool n
+
+config GENERIC_CSUM
+       def_bool y
+
+config GENERIC_HWEIGHT
+       def_bool y
+
+config NO_IOPORT_MAP
+       def_bool y
+
+config RWSEM_GENERIC_SPINLOCK
+	bool
+	default y
+
+config HAVE_UNDERSCORE_SYMBOL_PREFIX
+       bool
+       help
+         Some architectures generate an _ in front of C symbols; things like
+         module loading and assembly files need to know about this.
+
+config HZ
+        int
+        default 100
+
+config CONSOLE_LOGLEVEL_QUIET
+	int "quiet console loglevel (1-15)"
+	range 1 15
+	default "4"
+	help
+	  loglevel to use when "quiet" is passed on the kernel commandline.
+
+	  When "quiet" is passed on the kernel commandline this loglevel
+	  will be used as the loglevel. IOW passing "quiet" will be the
+	  equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
diff --git a/arch/um/lkl/Kconfig.debug b/arch/um/lkl/Kconfig.debug
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/arch/um/lkl/Makefile b/arch/um/lkl/Makefile
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/arch/um/lkl/Makefile.um b/arch/um/lkl/Makefile.um
new file mode 100644
index 000000000000..612705870e82
--- /dev/null
+++ b/arch/um/lkl/Makefile.um
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: GPL-2.0
+
+include $(HOST_DIR)/auto.conf
+
+SRCARCH := um/$(SUBARCH)
+ARCH_INCLUDE += -I$(srctree)/$(HOST_DIR)/um/include
+LINUXINCLUDE := $(subst $(ARCH_DIR),$(HOST_DIR),$(LINUXINCLUDE)) $(ARCH_INCLUDE)
+KBUILD_CFLAGS += -fno-builtin
+
+ifneq (,$(filter $(OUTPUT_FORMAT),elf64-x86-64 elf32-i386 elf64-x86-64-freebsd elf32-littlearm elf64-littleaarch64))
+KBUILD_CFLAGS += -fPIC
+else ifneq (,$(filter $(OUTPUT_FORMAT),pe-i386 pe-x86-64 ))
+ifneq ($(OUTPUT_FORMAT),pe-x86-64)
+prefix=_
+endif
+# workaround for #include_next<stdarg.h> errors
+LINUXINCLUDE := -isystem $(HOST_DIR)/include/system $(LINUXINCLUDE)
+# workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52991
+KBUILD_CFLAGS += -mno-ms-bitfields
+else
+$(error Unrecognized platform: $(OUTPUT_FORMAT))
+endif
+
+ifeq ($(shell uname -s), Linux)
+NPROC=$(shell nproc)
+else # e.g., FreeBSD
+NPROC=$(shell sysctl -n hw.ncpu)
+endif
+
+LDFLAGS_vmlinux += -r
+LKL_ENTRY_POINTS := lkl_start_kernel lkl_sys_halt lkl_syscall lkl_trigger_irq \
+	lkl_get_free_irq lkl_put_irq lkl_is_running lkl_bug lkl_printf
+
+ifeq ($(OUTPUT_FORMAT),elf32-i386)
+LKL_ENTRY_POINTS += \
+	__x86.get_pc_thunk.bx __x86.get_pc_thunk.dx __x86.get_pc_thunk.ax \
+	__x86.get_pc_thunk.cx __x86.get_pc_thunk.si __x86.get_pc_thunk.di
+endif
+
+core-y += $(HOST_DIR)/kernel/
+core-y += $(HOST_DIR)/mm/
+
+all: lkl.o
+
+lkl.o: vmlinux
+	$(OBJCOPY) -R .eh_frame -R .syscall_defs $(foreach sym,$(LKL_ENTRY_POINTS),-G$(prefix)$(sym)) vmlinux lkl.o
+
+$(HOST_DIR)/include/generated/uapi/asm/syscall_defs.h: vmlinux
+	$(OBJCOPY) -j .syscall_defs -O binary --set-section-flags .syscall_defs=alloc $< $@
+	$(Q) export tmpfile=$(shell mktemp); \
+	sed 's/\x0//g' $@ > $$tmpfile; mv $$tmpfile $@ ; rm -f $$tmpfile
+
+install: lkl.o headers $(HOST_DIR)/include/generated/uapi/asm/syscall_defs.h
+	@echo "  INSTALL	$(INSTALL_PATH)/lib/lkl.o"
+	@mkdir -p $(INSTALL_PATH)/lib/
+	@cp lkl.o $(INSTALL_PATH)/lib/
+	@$(srctree)/$(HOST_DIR)/scripts/headers_install.py \
+		$(subst -j,-j$(NPROC),$(findstring -j,$(MAKEFLAGS))) \
+		$(INSTALL_PATH)/include
+
+archheaders:
+	$(Q)$(MAKE) -f $(srctree)/Makefile ARCH=$(SRCARCH) asm-generic archheaders
+
+archclean:
+	$(Q)rm -rf $(srctree)/$(HOST_DIR)/include/generated
+	$(Q)$(MAKE) $(clean)=$(boot)
+
+define archhelp
+  echo '  install	- Install library and headers to INSTALL_PATH/{lib,include}'
+endef
diff --git a/arch/um/lkl/configs/lkl_defconfig b/arch/um/lkl/configs/lkl_defconfig
new file mode 100644
index 000000000000..f91380beee7c
--- /dev/null
+++ b/arch/um/lkl/configs/lkl_defconfig
@@ -0,0 +1,95 @@
+# CONFIG_LOCALVERSION_AUTO is not set
+CONFIG_NO_HZ_IDLE=y
+# CONFIG_SYSFS_SYSCALL is not set
+CONFIG_KALLSYMS_USE_DATA_SECTION=y
+CONFIG_KALLSYMS_ALL=y
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_TIMERFD is not set
+# CONFIG_AIO is not set
+# CONFIG_ADVISE_SYSCALLS is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_COMPAT_BRK is not set
+# CONFIG_BLK_DEV_BSG is not set
+CONFIG_NET=y
+CONFIG_INET=y
+# CONFIG_WIRELESS is not set
+# CONFIG_UEVENT_HELPER is not set
+# CONFIG_FW_LOADER is not set
+CONFIG_VIRTIO_BLK=y
+CONFIG_NETDEVICES=y
+CONFIG_VIRTIO_NET=y
+# CONFIG_ETHERNET is not set
+# CONFIG_WLAN is not set
+# CONFIG_VT is not set
+CONFIG_VIRTIO_MMIO=y
+CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y
+CONFIG_EXT4_FS=y
+CONFIG_EXT4_FS_POSIX_ACL=y
+CONFIG_EXT4_FS_SECURITY=y
+CONFIG_XFS_FS=y
+CONFIG_XFS_POSIX_ACL=y
+CONFIG_BTRFS_FS=y
+CONFIG_BTRFS_FS_POSIX_ACL=y
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+CONFIG_VFAT_FS=y
+CONFIG_NLS_CODEPAGE_437=y
+CONFIG_NLS_CODEPAGE_737=y
+CONFIG_NLS_CODEPAGE_775=y
+CONFIG_NLS_CODEPAGE_850=y
+CONFIG_NLS_CODEPAGE_852=y
+CONFIG_NLS_CODEPAGE_855=y
+CONFIG_NLS_CODEPAGE_857=y
+CONFIG_NLS_CODEPAGE_860=y
+CONFIG_NLS_CODEPAGE_861=y
+CONFIG_NLS_CODEPAGE_862=y
+CONFIG_NLS_CODEPAGE_863=y
+CONFIG_NLS_CODEPAGE_864=y
+CONFIG_NLS_CODEPAGE_865=y
+CONFIG_NLS_CODEPAGE_866=y
+CONFIG_NLS_CODEPAGE_869=y
+CONFIG_NLS_CODEPAGE_936=y
+CONFIG_NLS_CODEPAGE_950=y
+CONFIG_NLS_CODEPAGE_932=y
+CONFIG_NLS_CODEPAGE_949=y
+CONFIG_NLS_CODEPAGE_874=y
+CONFIG_NLS_ISO8859_8=y
+CONFIG_NLS_CODEPAGE_1250=y
+CONFIG_NLS_CODEPAGE_1251=y
+CONFIG_NLS_ASCII=y
+CONFIG_NLS_ISO8859_1=y
+CONFIG_NLS_ISO8859_2=y
+CONFIG_NLS_ISO8859_3=y
+CONFIG_NLS_ISO8859_4=y
+CONFIG_NLS_ISO8859_5=y
+CONFIG_NLS_ISO8859_6=y
+CONFIG_NLS_ISO8859_7=y
+CONFIG_NLS_ISO8859_9=y
+CONFIG_NLS_ISO8859_13=y
+CONFIG_NLS_ISO8859_14=y
+CONFIG_NLS_ISO8859_15=y
+CONFIG_NLS_KOI8_R=y
+CONFIG_NLS_KOI8_U=y
+CONFIG_NLS_MAC_ROMAN=y
+CONFIG_NLS_MAC_CELTIC=y
+CONFIG_NLS_MAC_CENTEURO=y
+CONFIG_NLS_MAC_CROATIAN=y
+CONFIG_NLS_MAC_CYRILLIC=y
+CONFIG_NLS_MAC_GAELIC=y
+CONFIG_NLS_MAC_GREEK=y
+CONFIG_NLS_MAC_ICELAND=y
+CONFIG_NLS_MAC_INUIT=y
+CONFIG_NLS_MAC_ROMANIAN=y
+CONFIG_NLS_MAC_TURKISH=y
+CONFIG_NLS_UTF8=y
+CONFIG_HZ_100=y
+CONFIG_CRYPTO_ANSI_CPRNG=y
+CONFIG_PRINTK_TIME=y
+CONFIG_DEBUG_INFO=y
+CONFIG_DEBUG_INFO_REDUCED=y
+# CONFIG_ENABLE_WARN_DEPRECATED is not set
+# CONFIG_ENABLE_MUST_CHECK is not set
diff --git a/arch/um/lkl/include/asm/Kbuild b/arch/um/lkl/include/asm/Kbuild
new file mode 100644
index 000000000000..f6308985c61c
--- /dev/null
+++ b/arch/um/lkl/include/asm/Kbuild
@@ -0,0 +1,80 @@
+generic-y += atomic.h
+generic-y += barrier.h
+generic-y += bitops.h
+generic-y += bug.h
+generic-y += bugs.h
+generic-y += cache.h
+generic-y += cacheflush.h
+generic-y += checksum.h
+generic-y += cmpxchg-local.h
+generic-y += cmpxchg.h
+generic-y += compat.h
+generic-y += cputime.h
+generic-y += current.h
+generic-y += delay.h
+generic-y += device.h
+generic-y += div64.h
+generic-y += dma.h
+generic-y += dma-mapping.h
+generic-y += emergency-restart.h
+generic-y += errno.h
+generic-y += extable.h
+generic-y += exec.h
+generic-y += ftrace.h
+generic-y += futex.h
+generic-y += hardirq.h
+generic-y += hw_irq.h
+generic-y += ioctl.h
+generic-y += ipcbuf.h
+generic-y += irq_regs.h
+generic-y += irqflags.h
+generic-y += irq_work.h
+generic-y += kdebug.h
+generic-y += kmap_types.h
+generic-y += linkage.h
+generic-y += local.h
+generic-y += local64.h
+generic-y += mcs_spinlock.h
+generic-y += mmiowb.h
+generic-y += mmu.h
+generic-y += mmu_context.h
+generic-y += module.h
+generic-y += msgbuf.h
+generic-y += param.h
+generic-y += parport.h
+generic-y += pci.h
+generic-y += percpu.h
+generic-y += pgalloc.h
+generic-y += poll.h
+generic-y += preempt.h
+generic-y += resource.h
+generic-y += rwsem.h
+generic-y += scatterlist.h
+generic-y += seccomp.h
+generic-y += sections.h
+generic-y += segment.h
+generic-y += sembuf.h
+generic-y += serial.h
+generic-y += shmbuf.h
+generic-y += signal.h
+generic-y += simd.h
+generic-y += sizes.h
+generic-y += socket.h
+generic-y += sockios.h
+generic-y += stat.h
+generic-y += statfs.h
+generic-y += string.h
+generic-y += swab.h
+generic-y += switch_to.h
+generic-y += syscall.h
+generic-y += termbits.h
+generic-y += termios.h
+generic-y += time.h
+generic-y += timex.h
+generic-y += tlbflush.h
+generic-y += topology.h
+generic-y += trace_clock.h
+generic-y += unaligned.h
+generic-y += user.h
+generic-y += word-at-a-time.h
+generic-y += kprobes.h
diff --git a/arch/um/lkl/include/asm/bitsperlong.h b/arch/um/lkl/include/asm/bitsperlong.h
new file mode 100644
index 000000000000..5745d5e51274
--- /dev/null
+++ b/arch/um/lkl/include/asm/bitsperlong.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LKL_BITSPERLONG_H
+#define __LKL_BITSPERLONG_H
+
+#include <uapi/asm/bitsperlong.h>
+
+#define BITS_PER_LONG __BITS_PER_LONG
+
+#define BITS_PER_LONG_LONG 64
+
+#endif
diff --git a/arch/um/lkl/include/asm/byteorder.h b/arch/um/lkl/include/asm/byteorder.h
new file mode 100644
index 000000000000..5d0c4efaa44b
--- /dev/null
+++ b/arch/um/lkl/include/asm/byteorder.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_BYTEORDER_H
+#define _ASM_LKL_BYTEORDER_H
+
+#include <uapi/asm/byteorder.h>
+
+#endif /* _ASM_LKL_BYTEORDER_H */
diff --git a/arch/um/lkl/include/asm/cpu.h b/arch/um/lkl/include/asm/cpu.h
new file mode 100644
index 000000000000..d2b8c501c7b1
--- /dev/null
+++ b/arch/um/lkl/include/asm/cpu.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_CPU_H
+#define _ASM_LKL_CPU_H
+
+int lkl_cpu_get(void);
+void lkl_cpu_put(void);
+int lkl_cpu_try_run_irq(int irq);
+int lkl_cpu_init(void);
+void lkl_cpu_shutdown(void);
+void lkl_cpu_wait_shutdown(void);
+void lkl_cpu_change_owner(lkl_thread_t owner);
+void lkl_cpu_set_irqs_pending(void);
+
+#endif /* _ASM_LKL_CPU_H */
diff --git a/arch/um/lkl/include/asm/elf.h b/arch/um/lkl/include/asm/elf.h
new file mode 100644
index 000000000000..bb2456d638f4
--- /dev/null
+++ b/arch/um/lkl/include/asm/elf.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_ELF_H
+#define _ASM_LKL_ELF_H
+
+#define elf_check_arch(x) 0
+
+#ifdef CONFIG_64BIT
+#define ELF_CLASS ELFCLASS64
+#else
+#define ELF_CLASS ELFCLASS32
+#endif
+
+#define elf_gregset_t long
+#define elf_fpregset_t double
+#endif
diff --git a/arch/um/lkl/include/asm/mutex.h b/arch/um/lkl/include/asm/mutex.h
new file mode 100644
index 000000000000..492d04183f9c
--- /dev/null
+++ b/arch/um/lkl/include/asm/mutex.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_MUTEX_H
+#define _ASM_LKL_MUTEX_H
+
+#include <asm-generic/mutex-dec.h>
+
+#endif
diff --git a/arch/um/lkl/include/asm/processor.h b/arch/um/lkl/include/asm/processor.h
new file mode 100644
index 000000000000..c1aa8b3a266e
--- /dev/null
+++ b/arch/um/lkl/include/asm/processor.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_PROCESSOR_H
+#define _ASM_LKL_PROCESSOR_H
+
+struct task_struct;
+
+static inline void cpu_relax(void)
+{
+	unsigned long flags;
+
+	/* since this is usually called in a tight loop waiting for some
+	 * external condition (e.g. jiffies) lets run interrupts now to allow
+	 * the external condition to propagate
+	 */
+	local_irq_save(flags);
+	local_irq_restore(flags);
+}
+
+#define current_text_addr() ({ __label__ _l; _l: &&_l; })
+
+static inline unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+	return 0;
+}
+
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+static inline void prepare_to_copy(struct task_struct *tsk)
+{
+}
+
+static inline unsigned long get_wchan(struct task_struct *p)
+{
+	return 0;
+}
+
+static inline void flush_thread(void)
+{
+}
+
+static inline void trap_init(void)
+{
+}
+
+struct thread_struct { };
+
+#define INIT_THREAD { }
+
+#define task_pt_regs(tsk) (struct pt_regs *)(NULL)
+
+/* We don't have strict user/kernel spaces */
+#define TASK_SIZE ((unsigned long)-1)
+#define TASK_UNMAPPED_BASE 0
+
+#define KSTK_EIP(tsk) (0)
+#define KSTK_ESP(tsk) (0)
+
+#endif
diff --git a/arch/um/lkl/include/asm/ptrace.h b/arch/um/lkl/include/asm/ptrace.h
new file mode 100644
index 000000000000..28199be26dc0
--- /dev/null
+++ b/arch/um/lkl/include/asm/ptrace.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_PTRACE_H
+#define _ASM_LKL_PTRACE_H
+
+#include <linux/errno.h>
+
+struct task_struct;
+
+#define user_mode(regs) 0
+#define kernel_mode(regs) 1
+#define profile_pc(regs) 0
+#define instruction_pointer(regs) 0
+#define user_stack_pointer(regs) 0
+
+static inline long arch_ptrace(struct task_struct *child, long request,
+			       unsigned long addr, unsigned long data)
+{
+	return -EINVAL;
+}
+
+static inline void ptrace_disable(struct task_struct *child)
+{
+}
+
+#endif
diff --git a/arch/um/lkl/include/asm/sched.h b/arch/um/lkl/include/asm/sched.h
new file mode 100644
index 000000000000..4c2635921ec8
--- /dev/null
+++ b/arch/um/lkl/include/asm/sched.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_SCHED_H
+#define _ASM_LKL_SCHED_H
+
+#include <linux/sched.h>
+#include <uapi/asm/host_ops.h>
+
+static inline void thread_sched_jb(void)
+{
+	if (test_ti_thread_flag(current_thread_info(), TIF_HOST_THREAD)) {
+		set_ti_thread_flag(current_thread_info(), TIF_SCHED_JB);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		lkl_ops->jmp_buf_set(&current_thread_info()->sched_jb,
+				     schedule);
+	} else {
+		lkl_bug("%s() can be used only for host task\n", __func__);
+	}
+}
+
+void switch_to_host_task(struct task_struct *);
+int host_task_stub(void *unused);
+
+#endif /*  _ASM_LKL_SCHED_H */
diff --git a/arch/um/lkl/include/asm/syscalls.h b/arch/um/lkl/include/asm/syscalls.h
new file mode 100644
index 000000000000..2eaa870a9020
--- /dev/null
+++ b/arch/um/lkl/include/asm/syscalls.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_SYSCALLS_H
+#define _ASM_LKL_SYSCALLS_H
+
+int syscalls_init(void);
+void syscalls_cleanup(void);
+long lkl_syscall(long no, long *params);
+void wakeup_idle_host_task(void);
+
+#define sys_mmap sys_mmap_pgoff
+#define sys_mmap2 sys_mmap_pgoff
+#define sys_clone sys_ni_syscall
+#define sys_vfork sys_ni_syscall
+#define sys_rt_sigreturn sys_ni_syscall
+
+#include <asm-generic/syscalls.h>
+
+#endif /* _ASM_LKL_SYSCALLS_H */
diff --git a/arch/um/lkl/include/asm/syscalls_32.h b/arch/um/lkl/include/asm/syscalls_32.h
new file mode 100644
index 000000000000..0e1a7649c81b
--- /dev/null
+++ b/arch/um/lkl/include/asm/syscalls_32.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_SYSCALLS_32_H
+#define _ASM_SYSCALLS_32_H
+
+#include <linux/compiler.h>
+#include <linux/linkage.h>
+#include <linux/types.h>
+#include <linux/signal.h>
+
+#if __BITS_PER_LONG == 32
+
+/* kernel/syscalls_32.c */
+asmlinkage long sys32_truncate64(const char __user *, unsigned long,
+				 unsigned long);
+asmlinkage long sys32_ftruncate64(unsigned int, unsigned long, unsigned long);
+
+#ifdef CONFIG_MMU
+struct mmap_arg_struct32;
+asmlinkage long sys32_mmap(struct mmap_arg_struct32 __user *);
+#endif
+
+asmlinkage long sys32_wait4(pid_t, unsigned int __user *, int,
+			    struct rusage __user *);
+
+asmlinkage long sys32_pread64(unsigned int, char __user *, u32, u32, u32);
+asmlinkage long sys32_pwrite64(unsigned int, const char __user *, u32, u32,
+			       u32);
+
+long sys32_fadvise64_64(int a, __u32 b, __u32 c, __u32 d, __u32 e, int f);
+
+asmlinkage ssize_t sys32_readahead(int, unsigned int, unsigned int, size_t);
+asmlinkage long sys32_sync_file_range(int, unsigned int, unsigned int,
+				      unsigned int, unsigned int, unsigned int);
+asmlinkage long sys32_sync_file_range2(int, unsigned int, unsigned int,
+				       unsigned int, unsigned int,
+				       unsigned int);
+asmlinkage long sys32_fadvise64(int, unsigned int, unsigned int, size_t, int);
+asmlinkage long sys32_fallocate(int, int, unsigned int, unsigned int,
+				unsigned int, unsigned int);
+
+#endif /* __BITS_PER_LONG */
+
+#endif /* _ASM_SYSCALLS_32_H */
diff --git a/arch/um/lkl/include/asm/tlb.h b/arch/um/lkl/include/asm/tlb.h
new file mode 100644
index 000000000000..d474890d317d
--- /dev/null
+++ b/arch/um/lkl/include/asm/tlb.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_TLB_H
+#define _ASM_LKL_TLB_H
+
+#define tlb_start_vma(tlb, vma)				do { } while (0)
+#define tlb_end_vma(tlb, vma)				do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, pte, address)	do { } while (0)
+#define tlb_flush(tlb)					do { } while (0)
+
+#include <asm-generic/tlb.h>
+
+#endif /* _ASM_LKL_TLB_H */
diff --git a/arch/um/lkl/include/asm/uaccess.h b/arch/um/lkl/include/asm/uaccess.h
new file mode 100644
index 000000000000..f267ac3be8b3
--- /dev/null
+++ b/arch/um/lkl/include/asm/uaccess.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_UACCESS_H
+#define _ASM_LKL_UACCESS_H
+
+/* copied from old include/asm-generic/uaccess.h */
+static inline __must_check long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (__builtin_constant_p(n)) {
+		switch (n) {
+		case 1:
+			*(u8 *)to = *(u8 __force *)from;
+			return 0;
+		case 2:
+			*(u16 *)to = *(u16 __force *)from;
+			return 0;
+		case 4:
+			*(u32 *)to = *(u32 __force *)from;
+			return 0;
+#ifdef CONFIG_64BIT
+		case 8:
+			*(u64 *)to = *(u64 __force *)from;
+			return 0;
+#endif
+		default:
+			break;
+		}
+	}
+
+	memcpy(to, (const void __force *)from, n);
+	return 0;
+}
+
+static inline __must_check long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (__builtin_constant_p(n)) {
+		switch (n) {
+		case 1:
+			*(u8 __force *)to = *(u8 *)from;
+			return 0;
+		case 2:
+			*(u16 __force *)to = *(u16 *)from;
+			return 0;
+		case 4:
+			*(u32 __force *)to = *(u32 *)from;
+			return 0;
+#ifdef CONFIG_64BIT
+		case 8:
+			*(u64 __force *)to = *(u64 *)from;
+			return 0;
+#endif
+		default:
+			break;
+		}
+	}
+
+	memcpy((void __force *)to, from, n);
+	return 0;
+}
+
+#include <asm-generic/uaccess.h>
+
+#endif
diff --git a/arch/um/lkl/include/asm/unistd_32.h b/arch/um/lkl/include/asm/unistd_32.h
new file mode 100644
index 000000000000..8582a55e61e2
--- /dev/null
+++ b/arch/um/lkl/include/asm/unistd_32.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/bitsperlong.h>
+
+#ifndef __SYSCALL
+#define __SYSCALL(x, y)
+#endif
+
+#if __BITS_PER_LONG == 32
+__SYSCALL(__NR3264_truncate, sys32_truncate64)
+__SYSCALL(__NR3264_ftruncate, sys32_ftruncate64)
+
+#ifdef CONFIG_MMU
+__SYSCALL(__NR3264_mmap, sys32_mmap)
+#endif
+
+__SYSCALL(__NR_wait4, sys32_wait4)
+
+__SYSCALL(__NR_pread64, sys32_pread64)
+__SYSCALL(__NR_pwrite64, sys32_pwrite64)
+
+__SYSCALL(__NR_readahead, sys32_readahead)
+#ifdef __ARCH_WANT_SYNC_FILE_RANGE2
+__SYSCALL(__NR_sync_file_range2, sys32_sync_file_range2)
+#else
+__SYSCALL(__NR_sync_file_range, sys32_sync_file_range)
+#endif
+/* mm/fadvise.c */
+__SYSCALL(__NR3264_fadvise64, sys32_fadvise64_64)
+__SYSCALL(__NR_fallocate, sys32_fallocate)
+
+#endif
diff --git a/arch/um/lkl/include/asm/vmlinux.lds.h b/arch/um/lkl/include/asm/vmlinux.lds.h
new file mode 100644
index 000000000000..a3c285882dc4
--- /dev/null
+++ b/arch/um/lkl/include/asm/vmlinux.lds.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LKL_VMLINUX_LDS_H
+#define _LKL_VMLINUX_LDS_H
+
+/* we encode our own __ro_after_init section */
+#define RO_AFTER_INIT_DATA
+
+#ifdef __MINGW32__
+#define RODATA_SECTION .rdata
+#endif
+
+#include <asm-generic/vmlinux.lds.h>
+
+#endif
diff --git a/arch/um/lkl/include/asm/xor.h b/arch/um/lkl/include/asm/xor.h
new file mode 100644
index 000000000000..286ce75b5d9d
--- /dev/null
+++ b/arch/um/lkl/include/asm/xor.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_XOR_H
+#define _ASM_LKL_XOR_H
+
+#include <asm-generic/xor.h>
+
+#define XOR_SELECT_TEMPLATE(x) (&xor_block_8regs)
+
+#endif /* _ASM_LKL_XOR_H */
diff --git a/arch/um/lkl/include/uapi/asm/Kbuild b/arch/um/lkl/include/uapi/asm/Kbuild
new file mode 100644
index 000000000000..39d9a1f2e8f5
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/Kbuild
@@ -0,0 +1,9 @@
+# UAPI Header export list
+
+generic-y += elf.h
+generic-y += kvm_para.h
+generic-y += shmparam.h
+generic-y += timex.h
+
+# no header-y since we need special user headers handling
+# see arch/lkl/script/headers.py
diff --git a/arch/um/lkl/include/uapi/asm/bitsperlong.h b/arch/um/lkl/include/uapi/asm/bitsperlong.h
new file mode 100644
index 000000000000..8b4ebf2b0264
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/bitsperlong.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_UAPI_LKL_BITSPERLONG_H
+#define _ASM_UAPI_LKL_BITSPERLONG_H
+
+#ifdef CONFIG_64BIT
+#define __BITS_PER_LONG 64
+#else
+#define __BITS_PER_LONG 32
+#endif
+
+#define __ARCH_WANT_STAT64
+
+#endif /* _ASM_UAPI_LKL_BITSPERLONG_H */
diff --git a/arch/um/lkl/include/uapi/asm/byteorder.h b/arch/um/lkl/include/uapi/asm/byteorder.h
new file mode 100644
index 000000000000..3c4a58d2062f
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/byteorder.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_UAPI_LKL_BYTEORDER_H
+#define _ASM_UAPI_LKL_BYTEORDER_H
+
+#if defined(CONFIG_BIG_ENDIAN)
+#include <linux/byteorder/big_endian.h>
+#else
+#include <linux/byteorder/little_endian.h>
+#endif
+
+#endif /* _ASM_UAPI_LKL_BYTEORDER_H */
diff --git a/arch/um/lkl/include/uapi/asm/siginfo.h b/arch/um/lkl/include/uapi/asm/siginfo.h
new file mode 100644
index 000000000000..811916cf42c8
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/siginfo.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_LKL_SIGINFO_H
+#define _ASM_LKL_SIGINFO_H
+
+#ifdef CONFIG_64BIT
+#define __ARCH_SI_PREAMBLE_SIZE	(4 * sizeof(int))
+#endif
+
+#include <asm-generic/siginfo.h>
+
+#endif /* _ASM_LKL_SIGINFO_H */
diff --git a/arch/um/lkl/include/uapi/asm/swab.h b/arch/um/lkl/include/uapi/asm/swab.h
new file mode 100644
index 000000000000..1a1773e1bd35
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/swab.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_LKL_SWAB_H
+#define _ASM_LKL_SWAB_H
+
+#ifndef __arch_swab32
+#define __arch_swab32(x) ___constant_swab32(x)
+#endif
+
+#include <asm-generic/swab.h>
+
+#endif /* _ASM_LKL_SWAB_H */
diff --git a/arch/um/lkl/include/uapi/asm/syscalls.h b/arch/um/lkl/include/uapi/asm/syscalls.h
new file mode 100644
index 000000000000..a81534ffccb7
--- /dev/null
+++ b/arch/um/lkl/include/uapi/asm/syscalls.h
@@ -0,0 +1,348 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_UAPI_LKL_SYSCALLS_H
+#define _ASM_UAPI_LKL_SYSCALLS_H
+
+#include <autoconf.h>
+#include <linux/types.h>
+
+typedef __kernel_uid32_t	qid_t;
+typedef __kernel_fd_set		fd_set;
+typedef __kernel_mode_t		mode_t;
+typedef unsigned short		umode_t;
+typedef __u32			nlink_t;
+typedef __kernel_off_t		off_t;
+typedef __kernel_pid_t		pid_t;
+typedef __kernel_key_t		key_t;
+typedef __kernel_suseconds_t	suseconds_t;
+typedef __kernel_timer_t	timer_t;
+typedef __kernel_clockid_t	clockid_t;
+typedef __kernel_mqd_t		mqd_t;
+typedef __kernel_uid32_t	uid_t;
+typedef __kernel_gid32_t	gid_t;
+typedef __kernel_uid16_t        uid16_t;
+typedef __kernel_gid16_t        gid16_t;
+typedef unsigned long		uintptr_t;
+#ifdef CONFIG_UID16
+typedef __kernel_old_uid_t	old_uid_t;
+typedef __kernel_old_gid_t	old_gid_t;
+#endif
+typedef __kernel_loff_t		loff_t;
+typedef __kernel_size_t		size_t;
+typedef __kernel_ssize_t	ssize_t;
+typedef __kernel_time_t		time_t;
+typedef __kernel_clock_t	clock_t;
+typedef __u32			u32;
+typedef __s32			s32;
+typedef __u64			u64;
+typedef __s64			s64;
+
+#define __user
+
+#include <asm/unistd.h>
+/* Temporary undefine system calls that don't have data types defined in UAPI
+ * headers
+ */
+#undef __NR_kexec_load
+#undef __NR_getcpu
+#undef __NR_sched_getattr
+#undef __NR_sched_setattr
+#undef __NR_sched_setparam
+#undef __NR_sched_getparam
+#undef __NR_sched_setscheduler
+#undef __NR_name_to_handle_at
+#undef __NR_open_by_handle_at
+
+/* deprecated system calls */
+#undef __NR_epoll_create
+#undef __NR_epoll_wait
+#undef __NR_access
+#undef __NR_chmod
+#undef __NR_chown
+#undef __NR_lchown
+#undef __NR_open
+#undef __NR_creat
+#undef __NR_readlink
+#undef __NR_pipe
+#undef __NR_mknod
+#undef __NR_mkdir
+#undef __NR_rmdir
+#undef __NR_unlink
+#undef __NR_symlink
+#undef __NR_link
+#undef __NR_rename
+#undef __NR_getdents
+#undef __NR_select
+#undef __NR_poll
+#undef __NR_dup2
+#undef __NR_futimesat
+#undef __NR_utimes
+#undef __NR_ustat
+#undef __NR_eventfd
+#undef __NR_bdflush
+#undef __NR_send
+#undef __NR_recv
+
+#undef __NR_umount
+#define __NR_umount __NR_umount2
+
+#ifdef CONFIG_64BIT
+#define __NR_newfstat __NR3264_fstat
+#define __NR_newfstatat __NR3264_fstatat
+#endif
+
+#define __NR_mmap_pgoff __NR3264_mmap
+
+#include <linux/time.h>
+#include <linux/times.h>
+#include <linux/timex.h>
+#include <linux/capability.h>
+#define __KERNEL__ /* to pull in S_ definitions */
+#include <linux/stat.h>
+#undef __KERNEL__
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/fs.h>
+#include <asm/statfs.h>
+#include <asm/stat.h>
+#include <linux/bpf.h>
+#include <linux/msg.h>
+#include <linux/resource.h>
+#include <linux/sysinfo.h>
+#include <linux/shm.h>
+#include <linux/aio_abi.h>
+#include <linux/socket.h>
+#include <linux/perf_event.h>
+#include <linux/sem.h>
+#include <linux/futex.h>
+#include <linux/poll.h>
+#include <linux/mqueue.h>
+#include <linux/eventpoll.h>
+#include <linux/uio.h>
+#include <asm/signal.h>
+#include <asm/siginfo.h>
+#include <linux/utime.h>
+#include <asm/socket.h>
+#include <linux/icmp.h>
+#include <linux/ip.h>
+
+/* Define data structures used in system calls that are not defined in UAPI
+ * headers
+ */
+struct sockaddr {
+	unsigned short int sa_family;
+	char sa_data[14];
+};
+
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+#define __UAPI_DEF_IF_IFNAMSIZ	1
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1
+#define __UAPI_DEF_IF_IFREQ	1
+#define __UAPI_DEF_IF_IFMAP	1
+#include <linux/if.h>
+#define __UAPI_DEF_IN_IPPROTO	1
+#define __UAPI_DEF_IN_ADDR	1
+#define __UAPI_DEF_IN6_ADDR	1
+#define __UAPI_DEF_IP_MREQ	1
+#define __UAPI_DEF_IN_PKTINFO	1
+#define __UAPI_DEF_SOCKADDR_IN	1
+#define __UAPI_DEF_IN_CLASS	1
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/sockios.h>
+#include <linux/route.h>
+#include <linux/ipv6_route.h>
+#include <linux/ipv6.h>
+#include <linux/netlink.h>
+#include <linux/neighbour.h>
+#include <linux/rtnetlink.h>
+#include <linux/fib_rules.h>
+
+#include <linux/kdev_t.h>
+#include <asm/irq.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_net.h>
+#include <linux/virtio_ring.h>
+#include <linux/pkt_sched.h>
+#include <linux/io_uring.h>
+
+struct user_msghdr {
+	void		__user *msg_name;
+	int		msg_namelen;
+	struct iovec	__user *msg_iov;
+	__kernel_size_t	msg_iovlen;
+	void		__user *msg_control;
+	__kernel_size_t	msg_controllen;
+	unsigned int	msg_flags;
+};
+
+typedef __u32 key_serial_t;
+
+struct mmsghdr {
+	struct user_msghdr  msg_hdr;
+	unsigned int        msg_len;
+};
+
+struct linux_dirent64 {
+	u64		d_ino;
+	s64		d_off;
+	unsigned short	d_reclen;
+	unsigned char	d_type;
+	char		d_name[0];
+};
+
+struct linux_dirent {
+	unsigned long	d_ino;
+	unsigned long	d_off;
+	unsigned short	d_reclen;
+	char		d_name[1];
+};
+
+struct ustat {
+	__kernel_daddr_t	f_tfree;
+	__kernel_ino_t		f_tinode;
+	char			f_fname[6];
+	char			f_fpack[6];
+};
+
+typedef __kernel_rwf_t		rwf_t;
+
+#define AF_UNSPEC       0
+#define AF_UNIX         1
+#define AF_LOCAL        1
+#define AF_INET         2
+#define AF_AX25         3
+#define AF_IPX          4
+#define AF_APPLETALK    5
+#define AF_NETROM       6
+#define AF_BRIDGE       7
+#define AF_ATMPVC       8
+#define AF_X25          9
+#define AF_INET6        10
+#define AF_ROSE         11
+#define AF_DECnet       12
+#define AF_NETBEUI      13
+#define AF_SECURITY     14
+#define AF_KEY          15
+#define AF_NETLINK      16
+#define AF_ROUTE        AF_NETLINK
+#define AF_PACKET       17
+#define AF_ASH          18
+#define AF_ECONET       19
+#define AF_ATMSVC       20
+#define AF_RDS          21
+#define AF_SNA          22
+#define AF_IRDA         23
+#define AF_PPPOX        24
+#define AF_WANPIPE      25
+#define AF_LLC          26
+#define AF_IB           27
+#define AF_MPLS         28
+#define AF_CAN          29
+#define AF_TIPC         30
+#define AF_BLUETOOTH    31
+#define AF_IUCV         32
+#define AF_RXRPC        33
+#define AF_ISDN         34
+#define AF_PHONET       35
+#define AF_IEEE802154   36
+#define AF_CAIF         37
+#define AF_ALG          38
+#define AF_NFC          39
+#define AF_VSOCK        40
+
+#define SOCK_STREAM		1
+#define SOCK_DGRAM		2
+#define SOCK_RAW		3
+#define SOCK_RDM		4
+#define SOCK_SEQPACKET		5
+#define SOCK_DCCP		6
+#define SOCK_PACKET		10
+
+#define MSG_TRUNC 0x20
+#define MSG_DONTWAIT 0x40
+
+/* avoid colision with system headers defines */
+#define sa_handler sa_handler
+#define st_atime st_atime
+#define st_mtime st_mtime
+#define st_ctime st_ctime
+#define s_addr s_addr
+
+long lkl_syscall(long no, long *params);
+long lkl_sys_halt(void);
+
+#define __MAP0(m, ...)
+#define __MAP1(m, t, a) m(t, a)
+#define __MAP2(m, t, a, ...) m(t, a), __MAP1(m, __VA_ARGS__)
+#define __MAP3(m, t, a, ...) m(t, a), __MAP2(m, __VA_ARGS__)
+#define __MAP4(m, t, a, ...) m(t, a), __MAP3(m, __VA_ARGS__)
+#define __MAP5(m, t, a, ...) m(t, a), __MAP4(m, __VA_ARGS__)
+#define __MAP6(m, t, a, ...) m(t, a), __MAP5(m, __VA_ARGS__)
+#define __MAP(n, ...) __MAP##n(__VA_ARGS__)
+
+#define __SC_LONG(t, a) (long)a
+#define __SC_TABLE(t, a) {sizeof(t), (long long)(a)}
+#define __SC_DECL(t, a) t a
+
+#define LKL_SYSCALL0(name)					       \
+	static inline long lkl_sys##name(void)			       \
+	{							       \
+		long params[6];					       \
+		return lkl_syscall(__lkl__NR##name, params);	       \
+	}
+
+#if __BITS_PER_LONG == 32
+#define LKL_SYSCALLx(x, name, ...)					\
+	static inline							\
+	long lkl_sys##name(__MAP(x, __SC_DECL, __VA_ARGS__))		\
+	{								\
+		struct {						\
+			unsigned int size;				\
+			long long value;				\
+		} lkl_params[x] = { __MAP(x, __SC_TABLE, __VA_ARGS__) }; \
+		long sys_params[6], i, k;				\
+		for (i = k = 0; i < x && k < 6; i++, k++) {		\
+			if (lkl_params[i].size > sizeof(long) &&	\
+			    k + 1 < 6) {				\
+				sys_params[k] =				\
+					(long)(lkl_params[i].value & (-1UL)); \
+				k++;					\
+				sys_params[k] =				\
+					(long)(lkl_params[i].value >>	\
+					       __BITS_PER_LONG);	\
+			} else {					\
+				sys_params[k] = (long)(lkl_params[i].value); \
+			}						\
+		}							\
+		return lkl_syscall(__lkl__NR##name, sys_params);	\
+	}
+#else
+#define LKL_SYSCALLx(x, name, ...)					\
+	static inline							\
+	long lkl_sys##name(__MAP(x, __SC_DECL, __VA_ARGS__))		\
+	{								\
+		long lkl_params[6] = { __MAP(x, __SC_LONG, __VA_ARGS__) }; \
+		return lkl_syscall(__lkl__NR##name, lkl_params);	\
+	}
+#endif
+
+#define SYSCALL_DEFINE0(name, ...) LKL_SYSCALL0(name)
+#define SYSCALL_DEFINE1(name, ...) LKL_SYSCALLx(1, name, __VA_ARGS__)
+#define SYSCALL_DEFINE2(name, ...) LKL_SYSCALLx(2, name, __VA_ARGS__)
+#define SYSCALL_DEFINE3(name, ...) LKL_SYSCALLx(3, name, __VA_ARGS__)
+#define SYSCALL_DEFINE4(name, ...) LKL_SYSCALLx(4, name, __VA_ARGS__)
+#define SYSCALL_DEFINE5(name, ...) LKL_SYSCALLx(5, name, __VA_ARGS__)
+#define SYSCALL_DEFINE6(name, ...) LKL_SYSCALLx(6, name, __VA_ARGS__)
+
+#if __BITS_PER_LONG == 32
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpointer-to-int-cast"
+#endif
+
+#include <asm/syscall_defs.h>
+
+#if __BITS_PER_LONG == 32
+#pragma GCC diagnostic pop
+#endif
+
+#endif
diff --git a/arch/um/lkl/kernel/asm-offsets.c b/arch/um/lkl/kernel/asm-offsets.c
new file mode 100644
index 000000000000..6be0763698dc
--- /dev/null
+++ b/arch/um/lkl/kernel/asm-offsets.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Dummy asm-offsets.c file. Required by kbuild and ready to be used - hint! */
diff --git a/arch/um/lkl/kernel/misc.c b/arch/um/lkl/kernel/misc.c
new file mode 100644
index 000000000000..60f048f02ae6
--- /dev/null
+++ b/arch/um/lkl/kernel/misc.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <asm/ptrace.h>
+#include <asm/host_ops.h>
+
+#ifdef CONFIG_PRINTK
+void dump_stack(void)
+{
+	unsigned long dummy;
+	unsigned long *stack = &dummy;
+	unsigned long addr;
+
+	pr_info("Call Trace:\n");
+	while (((long)stack & (THREAD_SIZE - 1)) != 0) {
+		addr = *stack;
+		if (__kernel_text_address(addr)) {
+			pr_info("%p:  [<%08lx>] %pS", stack, addr,
+				(void *)addr);
+			pr_cont("\n");
+		}
+		stack++;
+	}
+	pr_info("\n");
+}
+#endif
+
+void show_regs(struct pt_regs *regs)
+{
+}
+
+#ifdef CONFIG_PROC_FS
+static void *cpuinfo_start(struct seq_file *m, loff_t *pos)
+{
+	return NULL;
+}
+
+static void *cpuinfo_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	return NULL;
+}
+
+static void cpuinfo_stop(struct seq_file *m, void *v)
+{
+}
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+	return 0;
+}
+
+const struct seq_operations cpuinfo_op = {
+	.start	= cpuinfo_start,
+	.next	= cpuinfo_next,
+	.stop	= cpuinfo_stop,
+	.show	= show_cpuinfo,
+};
+#endif
diff --git a/arch/um/lkl/kernel/vmlinux.lds.S b/arch/um/lkl/kernel/vmlinux.lds.S
new file mode 100644
index 000000000000..efe420f38110
--- /dev/null
+++ b/arch/um/lkl/kernel/vmlinux.lds.S
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/vmlinux.lds.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include <asm/cache.h>
+#include <linux/export.h>
+
+OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT)
+
+VMLINUX_SYMBOL(jiffies) = VMLINUX_SYMBOL(jiffies_64);
+
+SECTIONS
+{
+	VMLINUX_SYMBOL(__init_begin) = .;
+	HEAD_TEXT_SECTION
+	INIT_TEXT_SECTION(PAGE_SIZE)
+	INIT_DATA_SECTION(16)
+	PERCPU_SECTION(L1_CACHE_BYTES)
+	VMLINUX_SYMBOL(__init_end) = .;
+
+	VMLINUX_SYMBOL(_stext) = .;
+	VMLINUX_SYMBOL(_text) = . ;
+	VMLINUX_SYMBOL(text) = . ;
+	.text      :
+	{
+		TEXT_TEXT
+		SCHED_TEXT
+		LOCK_TEXT
+		CPUIDLE_TEXT
+	}
+	VMLINUX_SYMBOL(_etext) = .;
+
+	VMLINUX_SYMBOL(_sdata) = .;
+	RO_DATA_SECTION(PAGE_SIZE)
+	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	VMLINUX_SYMBOL(_edata) = .;
+
+	VMLINUX_SYMBOL(__start_ro_after_init) = .;
+	.data..ro_after_init : { *(.data..ro_after_init)}
+	EXCEPTION_TABLE(16)
+	VMLINUX_SYMBOL(__end_ro_after_init) = .;
+	NOTES
+
+	BSS_SECTION(0, 0, 0)
+	VMLINUX_SYMBOL(_end) = .;
+
+	STABS_DEBUG
+	DWARF_DEBUG
+
+	DISCARDS
+}
