diff --git a/lab2/.clang-format b/lab2/.clang-format
new file mode 100644
index 000000000..ccc9b9397
--- /dev/null
+++ b/lab2/.clang-format
@@ -0,0 +1,743 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# clang-format configuration file. Intended for clang-format >= 11.
+#
+# For more information, see:
+#
+#   Documentation/process/clang-format.rst
+#   https://clang.llvm.org/docs/ClangFormat.html
+#   https://clang.llvm.org/docs/ClangFormatStyleOptions.html
+#
+---
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: Left
+AlignOperands: true
+AlignTrailingComments: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: false
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterClass: false
+  AfterControlStatement: false
+  AfterEnum: false
+  AfterFunction: true
+  AfterNamespace: true
+  AfterObjCDeclaration: false
+  AfterStruct: false
+  AfterUnion: false
+  AfterExternBlock: false
+  BeforeCatch: false
+  BeforeElse: false
+  IndentBraces: false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Custom
+BreakBeforeInheritanceComma: false
+BreakBeforeTernaryOperators: false
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeComma
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: false
+ColumnLimit: 80
+CommentPragmas: '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 8
+ContinuationIndentWidth: 8
+Cpp11BracedListStyle: false
+DerivePointerAlignment: false
+DisableFormat: false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: false
+
+# Taken from:
+#   git grep -h '^#define [^[:space:]]*for_each[^[:space:]]*(' include/ tools/ \
+#   | sed "s,^#define \([^[:space:]]*for_each[^[:space:]]*\)(.*$,  - '\1'," \
+#   | LC_ALL=C sort -u
+ForEachMacros:
+  - '__ata_qc_for_each'
+  - '__bio_for_each_bvec'
+  - '__bio_for_each_segment'
+  - '__evlist__for_each_entry'
+  - '__evlist__for_each_entry_continue'
+  - '__evlist__for_each_entry_from'
+  - '__evlist__for_each_entry_reverse'
+  - '__evlist__for_each_entry_safe'
+  - '__for_each_mem_range'
+  - '__for_each_mem_range_rev'
+  - '__for_each_thread'
+  - '__hlist_for_each_rcu'
+  - '__map__for_each_symbol_by_name'
+  - '__pci_bus_for_each_res0'
+  - '__pci_bus_for_each_res1'
+  - '__pci_dev_for_each_res0'
+  - '__pci_dev_for_each_res1'
+  - '__perf_evlist__for_each_entry'
+  - '__perf_evlist__for_each_entry_reverse'
+  - '__perf_evlist__for_each_entry_safe'
+  - '__rq_for_each_bio'
+  - '__shost_for_each_device'
+  - '__sym_for_each'
+  - 'apei_estatus_for_each_section'
+  - 'ata_for_each_dev'
+  - 'ata_for_each_link'
+  - 'ata_qc_for_each'
+  - 'ata_qc_for_each_raw'
+  - 'ata_qc_for_each_with_internal'
+  - 'ax25_for_each'
+  - 'ax25_uid_for_each'
+  - 'bio_for_each_bvec'
+  - 'bio_for_each_bvec_all'
+  - 'bio_for_each_folio_all'
+  - 'bio_for_each_integrity_vec'
+  - 'bio_for_each_segment'
+  - 'bio_for_each_segment_all'
+  - 'bio_list_for_each'
+  - 'bip_for_each_vec'
+  - 'bond_for_each_slave'
+  - 'bond_for_each_slave_rcu'
+  - 'bpf_for_each'
+  - 'bpf_for_each_reg_in_vstate'
+  - 'bpf_for_each_reg_in_vstate_mask'
+  - 'bpf_for_each_spilled_reg'
+  - 'bpf_object__for_each_map'
+  - 'bpf_object__for_each_program'
+  - 'btree_for_each_safe128'
+  - 'btree_for_each_safe32'
+  - 'btree_for_each_safe64'
+  - 'btree_for_each_safel'
+  - 'card_for_each_dev'
+  - 'cgroup_taskset_for_each'
+  - 'cgroup_taskset_for_each_leader'
+  - 'cpu_aggr_map__for_each_idx'
+  - 'cpufreq_for_each_efficient_entry_idx'
+  - 'cpufreq_for_each_entry'
+  - 'cpufreq_for_each_entry_idx'
+  - 'cpufreq_for_each_valid_entry'
+  - 'cpufreq_for_each_valid_entry_idx'
+  - 'css_for_each_child'
+  - 'css_for_each_descendant_post'
+  - 'css_for_each_descendant_pre'
+  - 'damon_for_each_region'
+  - 'damon_for_each_region_from'
+  - 'damon_for_each_region_safe'
+  - 'damon_for_each_scheme'
+  - 'damon_for_each_scheme_safe'
+  - 'damon_for_each_target'
+  - 'damon_for_each_target_safe'
+  - 'damos_for_each_filter'
+  - 'damos_for_each_filter_safe'
+  - 'data__for_each_file'
+  - 'data__for_each_file_new'
+  - 'data__for_each_file_start'
+  - 'device_for_each_child_node'
+  - 'displayid_iter_for_each'
+  - 'dma_fence_array_for_each'
+  - 'dma_fence_chain_for_each'
+  - 'dma_fence_unwrap_for_each'
+  - 'dma_resv_for_each_fence'
+  - 'dma_resv_for_each_fence_unlocked'
+  - 'do_for_each_ftrace_op'
+  - 'drm_atomic_crtc_for_each_plane'
+  - 'drm_atomic_crtc_state_for_each_plane'
+  - 'drm_atomic_crtc_state_for_each_plane_state'
+  - 'drm_atomic_for_each_plane_damage'
+  - 'drm_client_for_each_connector_iter'
+  - 'drm_client_for_each_modeset'
+  - 'drm_connector_for_each_possible_encoder'
+  - 'drm_exec_for_each_locked_object'
+  - 'drm_exec_for_each_locked_object_reverse'
+  - 'drm_for_each_bridge_in_chain'
+  - 'drm_for_each_connector_iter'
+  - 'drm_for_each_crtc'
+  - 'drm_for_each_crtc_reverse'
+  - 'drm_for_each_encoder'
+  - 'drm_for_each_encoder_mask'
+  - 'drm_for_each_fb'
+  - 'drm_for_each_legacy_plane'
+  - 'drm_for_each_plane'
+  - 'drm_for_each_plane_mask'
+  - 'drm_for_each_privobj'
+  - 'drm_gem_for_each_gpuva'
+  - 'drm_gem_for_each_gpuva_safe'
+  - 'drm_gpuva_for_each_op'
+  - 'drm_gpuva_for_each_op_from_reverse'
+  - 'drm_gpuva_for_each_op_safe'
+  - 'drm_gpuvm_for_each_va'
+  - 'drm_gpuvm_for_each_va_range'
+  - 'drm_gpuvm_for_each_va_range_safe'
+  - 'drm_gpuvm_for_each_va_safe'
+  - 'drm_mm_for_each_hole'
+  - 'drm_mm_for_each_node'
+  - 'drm_mm_for_each_node_in_range'
+  - 'drm_mm_for_each_node_safe'
+  - 'dsa_switch_for_each_available_port'
+  - 'dsa_switch_for_each_cpu_port'
+  - 'dsa_switch_for_each_cpu_port_continue_reverse'
+  - 'dsa_switch_for_each_port'
+  - 'dsa_switch_for_each_port_continue_reverse'
+  - 'dsa_switch_for_each_port_safe'
+  - 'dsa_switch_for_each_user_port'
+  - 'dsa_tree_for_each_cpu_port'
+  - 'dsa_tree_for_each_user_port'
+  - 'dsa_tree_for_each_user_port_continue_reverse'
+  - 'dso__for_each_symbol'
+  - 'dsos__for_each_with_build_id'
+  - 'elf_hash_for_each_possible'
+  - 'elf_symtab__for_each_symbol'
+  - 'evlist__for_each_cpu'
+  - 'evlist__for_each_entry'
+  - 'evlist__for_each_entry_continue'
+  - 'evlist__for_each_entry_from'
+  - 'evlist__for_each_entry_reverse'
+  - 'evlist__for_each_entry_safe'
+  - 'flow_action_for_each'
+  - 'for_each_acpi_consumer_dev'
+  - 'for_each_acpi_dev_match'
+  - 'for_each_active_dev_scope'
+  - 'for_each_active_drhd_unit'
+  - 'for_each_active_iommu'
+  - 'for_each_active_route'
+  - 'for_each_aggr_pgid'
+  - 'for_each_and_bit'
+  - 'for_each_andnot_bit'
+  - 'for_each_available_child_of_node'
+  - 'for_each_bench'
+  - 'for_each_bio'
+  - 'for_each_board_func_rsrc'
+  - 'for_each_btf_ext_rec'
+  - 'for_each_btf_ext_sec'
+  - 'for_each_bvec'
+  - 'for_each_card_auxs'
+  - 'for_each_card_auxs_safe'
+  - 'for_each_card_components'
+  - 'for_each_card_dapms'
+  - 'for_each_card_pre_auxs'
+  - 'for_each_card_prelinks'
+  - 'for_each_card_rtds'
+  - 'for_each_card_rtds_safe'
+  - 'for_each_card_widgets'
+  - 'for_each_card_widgets_safe'
+  - 'for_each_cgroup_storage_type'
+  - 'for_each_child_of_node'
+  - 'for_each_clear_bit'
+  - 'for_each_clear_bit_from'
+  - 'for_each_clear_bitrange'
+  - 'for_each_clear_bitrange_from'
+  - 'for_each_cmd'
+  - 'for_each_cmsghdr'
+  - 'for_each_collection'
+  - 'for_each_comp_order'
+  - 'for_each_compatible_node'
+  - 'for_each_component_dais'
+  - 'for_each_component_dais_safe'
+  - 'for_each_conduit'
+  - 'for_each_console'
+  - 'for_each_console_srcu'
+  - 'for_each_cpu'
+  - 'for_each_cpu_and'
+  - 'for_each_cpu_andnot'
+  - 'for_each_cpu_or'
+  - 'for_each_cpu_wrap'
+  - 'for_each_dapm_widgets'
+  - 'for_each_dedup_cand'
+  - 'for_each_dev_addr'
+  - 'for_each_dev_scope'
+  - 'for_each_dma_cap_mask'
+  - 'for_each_dpcm_be'
+  - 'for_each_dpcm_be_rollback'
+  - 'for_each_dpcm_be_safe'
+  - 'for_each_dpcm_fe'
+  - 'for_each_drhd_unit'
+  - 'for_each_dss_dev'
+  - 'for_each_efi_memory_desc'
+  - 'for_each_efi_memory_desc_in_map'
+  - 'for_each_element'
+  - 'for_each_element_extid'
+  - 'for_each_element_id'
+  - 'for_each_endpoint_of_node'
+  - 'for_each_event'
+  - 'for_each_event_tps'
+  - 'for_each_evictable_lru'
+  - 'for_each_fib6_node_rt_rcu'
+  - 'for_each_fib6_walker_rt'
+  - 'for_each_free_mem_pfn_range_in_zone'
+  - 'for_each_free_mem_pfn_range_in_zone_from'
+  - 'for_each_free_mem_range'
+  - 'for_each_free_mem_range_reverse'
+  - 'for_each_func_rsrc'
+  - 'for_each_gpiochip_node'
+  - 'for_each_group_evsel'
+  - 'for_each_group_evsel_head'
+  - 'for_each_group_member'
+  - 'for_each_group_member_head'
+  - 'for_each_hstate'
+  - 'for_each_if'
+  - 'for_each_inject_fn'
+  - 'for_each_insn'
+  - 'for_each_insn_prefix'
+  - 'for_each_intid'
+  - 'for_each_iommu'
+  - 'for_each_ip_tunnel_rcu'
+  - 'for_each_irq_nr'
+  - 'for_each_lang'
+  - 'for_each_link_codecs'
+  - 'for_each_link_cpus'
+  - 'for_each_link_platforms'
+  - 'for_each_lru'
+  - 'for_each_matching_node'
+  - 'for_each_matching_node_and_match'
+  - 'for_each_media_entity_data_link'
+  - 'for_each_mem_pfn_range'
+  - 'for_each_mem_range'
+  - 'for_each_mem_range_rev'
+  - 'for_each_mem_region'
+  - 'for_each_member'
+  - 'for_each_memory'
+  - 'for_each_migratetype_order'
+  - 'for_each_missing_reg'
+  - 'for_each_mle_subelement'
+  - 'for_each_mod_mem_type'
+  - 'for_each_net'
+  - 'for_each_net_continue_reverse'
+  - 'for_each_net_rcu'
+  - 'for_each_netdev'
+  - 'for_each_netdev_continue'
+  - 'for_each_netdev_continue_rcu'
+  - 'for_each_netdev_continue_reverse'
+  - 'for_each_netdev_dump'
+  - 'for_each_netdev_feature'
+  - 'for_each_netdev_in_bond_rcu'
+  - 'for_each_netdev_rcu'
+  - 'for_each_netdev_reverse'
+  - 'for_each_netdev_safe'
+  - 'for_each_new_connector_in_state'
+  - 'for_each_new_crtc_in_state'
+  - 'for_each_new_mst_mgr_in_state'
+  - 'for_each_new_plane_in_state'
+  - 'for_each_new_plane_in_state_reverse'
+  - 'for_each_new_private_obj_in_state'
+  - 'for_each_new_reg'
+  - 'for_each_node'
+  - 'for_each_node_by_name'
+  - 'for_each_node_by_type'
+  - 'for_each_node_mask'
+  - 'for_each_node_state'
+  - 'for_each_node_with_cpus'
+  - 'for_each_node_with_property'
+  - 'for_each_nonreserved_multicast_dest_pgid'
+  - 'for_each_numa_hop_mask'
+  - 'for_each_of_allnodes'
+  - 'for_each_of_allnodes_from'
+  - 'for_each_of_cpu_node'
+  - 'for_each_of_pci_range'
+  - 'for_each_old_connector_in_state'
+  - 'for_each_old_crtc_in_state'
+  - 'for_each_old_mst_mgr_in_state'
+  - 'for_each_old_plane_in_state'
+  - 'for_each_old_private_obj_in_state'
+  - 'for_each_oldnew_connector_in_state'
+  - 'for_each_oldnew_crtc_in_state'
+  - 'for_each_oldnew_mst_mgr_in_state'
+  - 'for_each_oldnew_plane_in_state'
+  - 'for_each_oldnew_plane_in_state_reverse'
+  - 'for_each_oldnew_private_obj_in_state'
+  - 'for_each_online_cpu'
+  - 'for_each_online_node'
+  - 'for_each_online_pgdat'
+  - 'for_each_or_bit'
+  - 'for_each_path'
+  - 'for_each_pci_bridge'
+  - 'for_each_pci_dev'
+  - 'for_each_pcm_streams'
+  - 'for_each_physmem_range'
+  - 'for_each_populated_zone'
+  - 'for_each_possible_cpu'
+  - 'for_each_present_blessed_reg'
+  - 'for_each_present_cpu'
+  - 'for_each_prime_number'
+  - 'for_each_prime_number_from'
+  - 'for_each_probe_cache_entry'
+  - 'for_each_process'
+  - 'for_each_process_thread'
+  - 'for_each_prop_codec_conf'
+  - 'for_each_prop_dai_codec'
+  - 'for_each_prop_dai_cpu'
+  - 'for_each_prop_dlc_codecs'
+  - 'for_each_prop_dlc_cpus'
+  - 'for_each_prop_dlc_platforms'
+  - 'for_each_property_of_node'
+  - 'for_each_reg'
+  - 'for_each_reg_filtered'
+  - 'for_each_reloc'
+  - 'for_each_reloc_from'
+  - 'for_each_requested_gpio'
+  - 'for_each_requested_gpio_in_range'
+  - 'for_each_reserved_mem_range'
+  - 'for_each_reserved_mem_region'
+  - 'for_each_rtd_codec_dais'
+  - 'for_each_rtd_components'
+  - 'for_each_rtd_cpu_dais'
+  - 'for_each_rtd_dais'
+  - 'for_each_sband_iftype_data'
+  - 'for_each_script'
+  - 'for_each_sec'
+  - 'for_each_set_bit'
+  - 'for_each_set_bit_from'
+  - 'for_each_set_bit_wrap'
+  - 'for_each_set_bitrange'
+  - 'for_each_set_bitrange_from'
+  - 'for_each_set_clump8'
+  - 'for_each_sg'
+  - 'for_each_sg_dma_page'
+  - 'for_each_sg_page'
+  - 'for_each_sgtable_dma_page'
+  - 'for_each_sgtable_dma_sg'
+  - 'for_each_sgtable_page'
+  - 'for_each_sgtable_sg'
+  - 'for_each_sibling_event'
+  - 'for_each_sta_active_link'
+  - 'for_each_subelement'
+  - 'for_each_subelement_extid'
+  - 'for_each_subelement_id'
+  - 'for_each_sublist'
+  - 'for_each_subsystem'
+  - 'for_each_supported_activate_fn'
+  - 'for_each_supported_inject_fn'
+  - 'for_each_sym'
+  - 'for_each_test'
+  - 'for_each_thread'
+  - 'for_each_token'
+  - 'for_each_unicast_dest_pgid'
+  - 'for_each_valid_link'
+  - 'for_each_vif_active_link'
+  - 'for_each_vma'
+  - 'for_each_vma_range'
+  - 'for_each_vsi'
+  - 'for_each_wakeup_source'
+  - 'for_each_zone'
+  - 'for_each_zone_zonelist'
+  - 'for_each_zone_zonelist_nodemask'
+  - 'func_for_each_insn'
+  - 'fwnode_for_each_available_child_node'
+  - 'fwnode_for_each_child_node'
+  - 'fwnode_for_each_parent_node'
+  - 'fwnode_graph_for_each_endpoint'
+  - 'gadget_for_each_ep'
+  - 'genradix_for_each'
+  - 'genradix_for_each_from'
+  - 'genradix_for_each_reverse'
+  - 'hash_for_each'
+  - 'hash_for_each_possible'
+  - 'hash_for_each_possible_rcu'
+  - 'hash_for_each_possible_rcu_notrace'
+  - 'hash_for_each_possible_safe'
+  - 'hash_for_each_rcu'
+  - 'hash_for_each_safe'
+  - 'hashmap__for_each_entry'
+  - 'hashmap__for_each_entry_safe'
+  - 'hashmap__for_each_key_entry'
+  - 'hashmap__for_each_key_entry_safe'
+  - 'hctx_for_each_ctx'
+  - 'hists__for_each_format'
+  - 'hists__for_each_sort_list'
+  - 'hlist_bl_for_each_entry'
+  - 'hlist_bl_for_each_entry_rcu'
+  - 'hlist_bl_for_each_entry_safe'
+  - 'hlist_for_each'
+  - 'hlist_for_each_entry'
+  - 'hlist_for_each_entry_continue'
+  - 'hlist_for_each_entry_continue_rcu'
+  - 'hlist_for_each_entry_continue_rcu_bh'
+  - 'hlist_for_each_entry_from'
+  - 'hlist_for_each_entry_from_rcu'
+  - 'hlist_for_each_entry_rcu'
+  - 'hlist_for_each_entry_rcu_bh'
+  - 'hlist_for_each_entry_rcu_notrace'
+  - 'hlist_for_each_entry_safe'
+  - 'hlist_for_each_entry_srcu'
+  - 'hlist_for_each_safe'
+  - 'hlist_nulls_for_each_entry'
+  - 'hlist_nulls_for_each_entry_from'
+  - 'hlist_nulls_for_each_entry_rcu'
+  - 'hlist_nulls_for_each_entry_safe'
+  - 'i3c_bus_for_each_i2cdev'
+  - 'i3c_bus_for_each_i3cdev'
+  - 'idr_for_each_entry'
+  - 'idr_for_each_entry_continue'
+  - 'idr_for_each_entry_continue_ul'
+  - 'idr_for_each_entry_ul'
+  - 'in_dev_for_each_ifa_rcu'
+  - 'in_dev_for_each_ifa_rtnl'
+  - 'inet_bind_bucket_for_each'
+  - 'interval_tree_for_each_span'
+  - 'intlist__for_each_entry'
+  - 'intlist__for_each_entry_safe'
+  - 'kcore_copy__for_each_phdr'
+  - 'key_for_each'
+  - 'key_for_each_safe'
+  - 'klp_for_each_func'
+  - 'klp_for_each_func_safe'
+  - 'klp_for_each_func_static'
+  - 'klp_for_each_object'
+  - 'klp_for_each_object_safe'
+  - 'klp_for_each_object_static'
+  - 'kunit_suite_for_each_test_case'
+  - 'kvm_for_each_memslot'
+  - 'kvm_for_each_memslot_in_gfn_range'
+  - 'kvm_for_each_vcpu'
+  - 'libbpf_nla_for_each_attr'
+  - 'list_for_each'
+  - 'list_for_each_codec'
+  - 'list_for_each_codec_safe'
+  - 'list_for_each_continue'
+  - 'list_for_each_entry'
+  - 'list_for_each_entry_continue'
+  - 'list_for_each_entry_continue_rcu'
+  - 'list_for_each_entry_continue_reverse'
+  - 'list_for_each_entry_from'
+  - 'list_for_each_entry_from_rcu'
+  - 'list_for_each_entry_from_reverse'
+  - 'list_for_each_entry_lockless'
+  - 'list_for_each_entry_rcu'
+  - 'list_for_each_entry_reverse'
+  - 'list_for_each_entry_safe'
+  - 'list_for_each_entry_safe_continue'
+  - 'list_for_each_entry_safe_from'
+  - 'list_for_each_entry_safe_reverse'
+  - 'list_for_each_entry_srcu'
+  - 'list_for_each_from'
+  - 'list_for_each_prev'
+  - 'list_for_each_prev_safe'
+  - 'list_for_each_rcu'
+  - 'list_for_each_reverse'
+  - 'list_for_each_safe'
+  - 'llist_for_each'
+  - 'llist_for_each_entry'
+  - 'llist_for_each_entry_safe'
+  - 'llist_for_each_safe'
+  - 'lwq_for_each_safe'
+  - 'map__for_each_symbol'
+  - 'map__for_each_symbol_by_name'
+  - 'maps__for_each_entry'
+  - 'maps__for_each_entry_safe'
+  - 'mas_for_each'
+  - 'mci_for_each_dimm'
+  - 'media_device_for_each_entity'
+  - 'media_device_for_each_intf'
+  - 'media_device_for_each_link'
+  - 'media_device_for_each_pad'
+  - 'media_entity_for_each_pad'
+  - 'media_pipeline_for_each_entity'
+  - 'media_pipeline_for_each_pad'
+  - 'mlx5_lag_for_each_peer_mdev'
+  - 'msi_domain_for_each_desc'
+  - 'msi_for_each_desc'
+  - 'mt_for_each'
+  - 'nanddev_io_for_each_page'
+  - 'netdev_for_each_lower_dev'
+  - 'netdev_for_each_lower_private'
+  - 'netdev_for_each_lower_private_rcu'
+  - 'netdev_for_each_mc_addr'
+  - 'netdev_for_each_synced_mc_addr'
+  - 'netdev_for_each_synced_uc_addr'
+  - 'netdev_for_each_uc_addr'
+  - 'netdev_for_each_upper_dev_rcu'
+  - 'netdev_hw_addr_list_for_each'
+  - 'nft_rule_for_each_expr'
+  - 'nla_for_each_attr'
+  - 'nla_for_each_nested'
+  - 'nlmsg_for_each_attr'
+  - 'nlmsg_for_each_msg'
+  - 'nr_neigh_for_each'
+  - 'nr_neigh_for_each_safe'
+  - 'nr_node_for_each'
+  - 'nr_node_for_each_safe'
+  - 'of_for_each_phandle'
+  - 'of_property_for_each_string'
+  - 'of_property_for_each_u32'
+  - 'pci_bus_for_each_resource'
+  - 'pci_dev_for_each_resource'
+  - 'pcl_for_each_chunk'
+  - 'pcl_for_each_segment'
+  - 'pcm_for_each_format'
+  - 'perf_config_items__for_each_entry'
+  - 'perf_config_sections__for_each_entry'
+  - 'perf_config_set__for_each_entry'
+  - 'perf_cpu_map__for_each_cpu'
+  - 'perf_cpu_map__for_each_idx'
+  - 'perf_evlist__for_each_entry'
+  - 'perf_evlist__for_each_entry_reverse'
+  - 'perf_evlist__for_each_entry_safe'
+  - 'perf_evlist__for_each_evsel'
+  - 'perf_evlist__for_each_mmap'
+  - 'perf_hpp_list__for_each_format'
+  - 'perf_hpp_list__for_each_format_safe'
+  - 'perf_hpp_list__for_each_sort_list'
+  - 'perf_hpp_list__for_each_sort_list_safe'
+  - 'perf_tool_event__for_each_event'
+  - 'plist_for_each'
+  - 'plist_for_each_continue'
+  - 'plist_for_each_entry'
+  - 'plist_for_each_entry_continue'
+  - 'plist_for_each_entry_safe'
+  - 'plist_for_each_safe'
+  - 'pnp_for_each_card'
+  - 'pnp_for_each_dev'
+  - 'protocol_for_each_card'
+  - 'protocol_for_each_dev'
+  - 'queue_for_each_hw_ctx'
+  - 'radix_tree_for_each_slot'
+  - 'radix_tree_for_each_tagged'
+  - 'rb_for_each'
+  - 'rbtree_postorder_for_each_entry_safe'
+  - 'rdma_for_each_block'
+  - 'rdma_for_each_port'
+  - 'rdma_umem_for_each_dma_block'
+  - 'resort_rb__for_each_entry'
+  - 'resource_list_for_each_entry'
+  - 'resource_list_for_each_entry_safe'
+  - 'rhl_for_each_entry_rcu'
+  - 'rhl_for_each_rcu'
+  - 'rht_for_each'
+  - 'rht_for_each_entry'
+  - 'rht_for_each_entry_from'
+  - 'rht_for_each_entry_rcu'
+  - 'rht_for_each_entry_rcu_from'
+  - 'rht_for_each_entry_safe'
+  - 'rht_for_each_from'
+  - 'rht_for_each_rcu'
+  - 'rht_for_each_rcu_from'
+  - 'rq_for_each_bvec'
+  - 'rq_for_each_segment'
+  - 'rq_list_for_each'
+  - 'rq_list_for_each_safe'
+  - 'sample_read_group__for_each'
+  - 'scsi_for_each_prot_sg'
+  - 'scsi_for_each_sg'
+  - 'sctp_for_each_hentry'
+  - 'sctp_skb_for_each'
+  - 'sec_for_each_insn'
+  - 'sec_for_each_insn_continue'
+  - 'sec_for_each_insn_from'
+  - 'sec_for_each_sym'
+  - 'shdma_for_each_chan'
+  - 'shost_for_each_device'
+  - 'sk_for_each'
+  - 'sk_for_each_bound'
+  - 'sk_for_each_bound_bhash2'
+  - 'sk_for_each_entry_offset_rcu'
+  - 'sk_for_each_from'
+  - 'sk_for_each_rcu'
+  - 'sk_for_each_safe'
+  - 'sk_nulls_for_each'
+  - 'sk_nulls_for_each_from'
+  - 'sk_nulls_for_each_rcu'
+  - 'snd_array_for_each'
+  - 'snd_pcm_group_for_each_entry'
+  - 'snd_soc_dapm_widget_for_each_path'
+  - 'snd_soc_dapm_widget_for_each_path_safe'
+  - 'snd_soc_dapm_widget_for_each_sink_path'
+  - 'snd_soc_dapm_widget_for_each_source_path'
+  - 'strlist__for_each_entry'
+  - 'strlist__for_each_entry_safe'
+  - 'sym_for_each_insn'
+  - 'sym_for_each_insn_continue_reverse'
+  - 'symbols__for_each_entry'
+  - 'tb_property_for_each'
+  - 'tcf_act_for_each_action'
+  - 'tcf_exts_for_each_action'
+  - 'ttm_resource_manager_for_each_res'
+  - 'twsk_for_each_bound_bhash2'
+  - 'udp_portaddr_for_each_entry'
+  - 'udp_portaddr_for_each_entry_rcu'
+  - 'usb_hub_for_each_child'
+  - 'v4l2_device_for_each_subdev'
+  - 'v4l2_m2m_for_each_dst_buf'
+  - 'v4l2_m2m_for_each_dst_buf_safe'
+  - 'v4l2_m2m_for_each_src_buf'
+  - 'v4l2_m2m_for_each_src_buf_safe'
+  - 'virtio_device_for_each_vq'
+  - 'while_for_each_ftrace_op'
+  - 'xa_for_each'
+  - 'xa_for_each_marked'
+  - 'xa_for_each_range'
+  - 'xa_for_each_start'
+  - 'xas_for_each'
+  - 'xas_for_each_conflict'
+  - 'xas_for_each_marked'
+  - 'xbc_array_for_each_value'
+  - 'xbc_for_each_key_value'
+  - 'xbc_node_for_each_array_value'
+  - 'xbc_node_for_each_child'
+  - 'xbc_node_for_each_key_value'
+  - 'xbc_node_for_each_subkey'
+  - 'zorro_for_each_dev'
+
+IncludeBlocks: Preserve
+IncludeCategories:
+  - Regex: '.*'
+    Priority: 1
+IncludeIsMainRegex: '(Test)?$'
+IndentCaseLabels: false
+IndentGotoLabels: false
+IndentPPDirectives: None
+IndentWidth: 8
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 8
+ObjCSpaceAfterProperty: true
+ObjCSpaceBeforeProtocolList: true
+
+# Taken from git's rules
+PenaltyBreakAssignment: 10
+PenaltyBreakBeforeFirstCallParameter: 30
+PenaltyBreakComment: 10
+PenaltyBreakFirstLessLess: 0
+PenaltyBreakString: 10
+PenaltyExcessCharacter: 100
+PenaltyReturnTypeOnItsOwnLine: 60
+
+PointerAlignment: Right
+ReflowComments: false
+SortIncludes: false
+SortUsingDeclarations: false
+SpaceAfterCStyleCast: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatementsExceptForEachMacros
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInContainerLiterals: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: Cpp03
+TabWidth: 8
+UseTab: Always
+...
diff --git a/lab2/bootloader/Makefile b/lab2/bootloader/Makefile
new file mode 100644
index 000000000..aa1f2eda5
--- /dev/null
+++ b/lab2/bootloader/Makefile
@@ -0,0 +1,36 @@
+CC = aarch64-linux-gnu-gcc
+LD = aarch64-linux-gnu-ld
+AR = aarch64-linux-gnu-ar
+OBJCOPY = aarch64-linux-gnu-objcopy
+LINKER_SCRIPT = linker.ld
+START = start
+IMG_NAME = bootloader
+BUILD = ../build
+
+CFLAGS := -fno-stack-protector -I ../include/
+
+all: $(BUILD)/$(IMG_NAME).img
+
+$(BUILD)/$(START).o: $(START).S
+	$(CC) $(CFLAGS) -c $(START).S -o $(BUILD)/$(START).o
+
+OBJS := \
+	bootloader.o \
+	uart.o \
+	string.o
+
+
+OBJS := $(addprefix $(BUILD)/, $(OBJS))
+
+$(BUILD)/%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(BUILD)/$(IMG_NAME).img: $(BUILD)/$(START).o $(OBJS)
+	$(LD) $(BUILD)/$(START).o $(OBJS) -T $(LINKER_SCRIPT) -o $(BUILD)/$(IMG_NAME).elf
+	$(OBJCOPY) -O binary $(BUILD)/$(IMG_NAME).elf $(BUILD)/$(IMG_NAME).img
+
+clean:
+	rm -f $(BUILD)/$(IMG_NAME).elf $(BUILD)/$(IMG_NAME).img $(BUILD)/*.o
+
+run:
+	qemu-system-aarch64 -M raspi3b -kernel $(BUILD)/$(IMG_NAME).img -serial null -serial stdio
diff --git a/lab2/bootloader/bootloader.c b/lab2/bootloader/bootloader.c
new file mode 100644
index 000000000..aed17eebc
--- /dev/null
+++ b/lab2/bootloader/bootloader.c
@@ -0,0 +1,69 @@
+#include <stddef.h>
+
+#include "uart.h"
+#include "string.h"
+
+#define MAX_BUFFER_LEN 1024
+
+void bootloader_main(void *dtb)
+{
+	char buffer[MAX_BUFFER_LEN];
+	size_t buffer_index = 0;
+	char ch;
+
+	uart_init();
+	uart_puts("Starting the shell!\r\n");
+
+	while (1) {
+		uart_puts("# ");
+		buffer_index = 0;
+		buffer[0] = '\0';
+
+		while (1) {
+			ch = uart_getc();
+			if (buffer_index + 1 >= sizeof(buffer)) {
+				uart_puts(
+					"ERROR: Exceed buffer length limit!\r\n");
+				buffer_index = 0;
+				buffer[0] = '\0';
+				break;
+			}
+			if (ch == '\n') {
+				uart_puts("\r\n");
+				buffer[buffer_index] = '\0';
+				break;
+			}
+			uart_send(ch);
+			buffer[buffer_index++] = ch;
+		}
+		// dispatch_cmd(buffer);
+
+		if (strcmp(buffer, "boot") == 0) {
+			unsigned int size = 0;
+			unsigned char *size_buffer = (unsigned char *)&size;
+
+			uart_puts("Use send_loader.py to load kernel\r\n");
+			for (int i = 0; i < 4; i++)
+				size_buffer[i] = uart_getc();
+			uart_puts("Start receiving kernel\r\n");
+
+			char *kernel = (char *)0x80000; // load kernel in 0x80000
+			while (size--)
+				*kernel++ = uart_getc();
+
+			uart_puts("kernel loaded!\r\n");
+
+			void (*kernel_entry)(void) = (void (*)(void))0x80000;
+			kernel_entry();
+
+			return;
+		} else {
+			uart_puts("ERROR: Unrecognized command!\r\n");
+		}
+	}
+
+	// echo everything back
+	while (1) {
+		uart_send(uart_getc());
+	}
+}
diff --git a/lab2/bootloader/config.txt b/lab2/bootloader/config.txt
new file mode 100644
index 000000000..49fc25695
--- /dev/null
+++ b/lab2/bootloader/config.txt
@@ -0,0 +1,3 @@
+kernel=bootloader.img
+arm_64bit=1
+initramfs initramfs.cpio 0x20000000
diff --git a/lab2/bootloader/linker.ld b/lab2/bootloader/linker.ld
new file mode 100644
index 000000000..d903ec733
--- /dev/null
+++ b/lab2/bootloader/linker.ld
@@ -0,0 +1,22 @@
+SECTIONS
+{
+    . = 0x60000; /*start loading from 0x60000*/
+    
+    .text : { KEEP(*(.text.boot)) *(.text .text.* .gnu.linkonce.t*) }
+    .rodata : { *(.rodata .rodata.* .gnu.linkonce.r*) }
+    PROVIDE(_data = .); /* let _data = current address */
+    .data : { *(.data .data.* .gnu.linkonce.d*) }
+    .bss (NOLOAD) : { /*don't require space in executable*/
+        . = ALIGN(16); /*align with 16 bit for efficiency*/
+        /*put all .bss, .bss. segments and other segments into .bss */
+        __bss_start = .; 
+        *(.bss .bss.*)
+        *(COMMON)
+        __bss_end = .;
+    }
+    _end = .;
+    
+   /DISCARD/ : { *(.comment) *(.gnu*) *(.note*) *(.eh_frame*) }
+}
+__bss_size = (__bss_end - __bss_start)>>3; /* bss size for start.S */
+__bootloader_size = (_end - 0x60000)>>3;
diff --git a/lab2/bootloader/send_loader.py b/lab2/bootloader/send_loader.py
new file mode 100644
index 000000000..83702004f
--- /dev/null
+++ b/lab2/bootloader/send_loader.py
@@ -0,0 +1,31 @@
+import os
+import os.path
+import argparse
+import time
+
+# Set up argument parser
+parser = argparse.ArgumentParser(description='Send a file over serial connection.')
+parser.add_argument('-s', '--serial_path', default='/dev/ttyUSB0', help='The path to the serial device (default: /dev/ttyUSB0)')
+parser.add_argument('-f', '--file_path', default='kernel8.img', help='The file to send (default: kernel8.img)')
+args = parser.parse_args()
+
+# Check if file exists
+if not os.path.exists(args.file_path):
+    print(f"File {args.file_path} not found.")
+    exit(1)
+
+# Get file size
+size = os.stat(args.file_path).st_size
+size_bytes = size.to_bytes(4, "little")  #little endian to fit the environment (8bit 8bit 8bit 8bit)
+
+# Open serial connection write binary
+with open(args.serial_path, "wb", buffering=0) as tty:
+    # Send file size
+    tty.write(size_bytes) 
+    print("wrote data")
+    time.sleep(3)
+    print("sending kernel")
+
+    # Open and send the file
+    with open(args.file_path, "rb") as f:
+        tty.write(f.read())
diff --git a/lab2/bootloader/start.S b/lab2/bootloader/start.S
new file mode 100644
index 000000000..2a1df108e
--- /dev/null
+++ b/lab2/bootloader/start.S
@@ -0,0 +1,48 @@
+.section ".text.boot"
+
+.global _start
+
+_start:
+	// relocate bootloader
+    mov x28, x0
+	ldr x1, =0x80000 //64 bits for address, 0x1 = 1 byte
+	ldr x2, =0x60000 //ldr: put address to register
+	ldr w3, =__bootloader_size //size, 32 bit is enough
+
+relocate: //since its 64-bit architecture, move 8 bytes every time
+	ldr x4,[x1],#8 //store value from x1 to x4, then mov x1 ([] means read value in the address)
+	str x4,[x2],#8 //store value from x4 to x2, then mov x2 ([] means write value in the address)
+	sub w3,w3,#1 //size is >>3, so 1 means 8 bytes
+	cbnz w3,relocate //keep relocate if size is not 0
+
+init_cpu:
+    // read cpu id, stop slave cores
+    mrs     x1, mpidr_el1 //get cpu num
+    and     x1, x1, #3 //see if cpu num is 0
+    cbz     x1, 2f //cpu 0 jump to 2f (others wfe)
+    // cpu id > 0, stop
+
+1:  wfe
+    b       1b
+    
+2:  // cpu id == 0
+
+    // set top of stack just before our code (stack grows to a lower address per AAPCS64)
+    ldr     x1, =_start //ldr: load Register
+    mov     sp, x1 //stack pointer before _start
+
+    // clear bss
+    ldr     x1, =__bss_start
+    ldr     w2, =__bss_size
+    
+3:  cbz     w2, 4f //see if bss is cleared, if cleared go to 4
+    str     xzr, [x1], #8 //xzr means zero, clear to zzero from start
+    sub     w2, w2, #1 //1 count means 8bit
+    cbnz    w2, 3b //if not zero go back
+
+    // jump to C code, should not return
+
+4:  mov     x0, x28
+    bl      bootloader_main-0x20000
+    // for failsafe, halt this core too
+    b       1b
diff --git a/lab2/build.sh b/lab2/build.sh
new file mode 100755
index 000000000..582d50a49
--- /dev/null
+++ b/lab2/build.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+rm ./build/*
+cd kernel
+make
+cd ..
+rm ./build/start.o
+cd bootloader
+make
diff --git a/lab2/include/cpio.h b/lab2/include/cpio.h
new file mode 100644
index 000000000..498ac2fda
--- /dev/null
+++ b/lab2/include/cpio.h
@@ -0,0 +1,25 @@
+#pragma once
+
+struct cpio_newc_header {
+	//file metadata
+	char c_magic[6]; // Magic number identifying the CPIO format
+	char c_ino[8]; // Inode number
+	char c_mode[8]; // File mode and type
+	char c_uid[8]; // User ID of file owner
+	char c_gid[8]; // Group ID of file owner
+	char c_nlink[8]; // Number of hard links
+	char c_mtime[8]; // Modification time of file
+	char c_filesize[8]; // Size of file (in hexadecimal)
+	char c_devmajor[8]; // Major device number (for device files)
+	char c_devminor[8]; // Minor device number (for device files)
+	char c_rdevmajor
+		[8]; // Major device number for the device file node referenced by the symlink
+	char c_rdevminor
+		[8]; // Minor device number for the device file node referenced by the symlink
+	char c_namesize[8]; // Size of filename (in hexadecimal)
+	char c_check[8]; // Checksum
+};
+// Link: https://manpages.ubuntu.com/manpages/bionic/man5/cpio.5.html
+
+void cpio_ls();
+void cpio_cat();
diff --git a/lab2/include/gpio.h b/lab2/include/gpio.h
new file mode 100644
index 000000000..a86df0de7
--- /dev/null
+++ b/lab2/include/gpio.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#define MMIO_BASE 0x3F000000
+
+#define GPFSEL0 ((volatile unsigned int *)(MMIO_BASE + 0x00200000))
+#define GPFSEL1 ((volatile unsigned int *)(MMIO_BASE + 0x00200004))
+#define GPFSEL2 ((volatile unsigned int *)(MMIO_BASE + 0x00200008))
+#define GPFSEL3 ((volatile unsigned int *)(MMIO_BASE + 0x0020000C))
+#define GPFSEL4 ((volatile unsigned int *)(MMIO_BASE + 0x00200010))
+#define GPFSEL5 ((volatile unsigned int *)(MMIO_BASE + 0x00200014))
+#define GPSET0 ((volatile unsigned int *)(MMIO_BASE + 0x0020001C))
+#define GPSET1 ((volatile unsigned int *)(MMIO_BASE + 0x00200020))
+#define GPCLR0 ((volatile unsigned int *)(MMIO_BASE + 0x00200028))
+#define GPLEV0 ((volatile unsigned int *)(MMIO_BASE + 0x00200034))
+#define GPLEV1 ((volatile unsigned int *)(MMIO_BASE + 0x00200038))
+#define GPEDS0 ((volatile unsigned int *)(MMIO_BASE + 0x00200040))
+#define GPEDS1 ((volatile unsigned int *)(MMIO_BASE + 0x00200044))
+#define GPHEN0 ((volatile unsigned int *)(MMIO_BASE + 0x00200064))
+#define GPHEN1 ((volatile unsigned int *)(MMIO_BASE + 0x00200068))
+#define GPPUD ((volatile unsigned int *)(MMIO_BASE + 0x00200094))
+#define GPPUDCLK0 ((volatile unsigned int *)(MMIO_BASE + 0x00200098))
+#define GPPUDCLK1 ((volatile unsigned int *)(MMIO_BASE + 0x0020009C))
diff --git a/lab2/include/mbox.h b/lab2/include/mbox.h
new file mode 100644
index 000000000..ec2bede20
--- /dev/null
+++ b/lab2/include/mbox.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+/* a properly aligned buffer */
+extern volatile unsigned int mbox[36];
+
+#define MBOX_REQUEST 0
+
+/* channels */
+#define MBOX_CH_POWER 0
+#define MBOX_CH_FB 1
+#define MBOX_CH_VUART 2
+#define MBOX_CH_VCHIQ 3
+#define MBOX_CH_LEDS 4
+#define MBOX_CH_BTNS 5
+#define MBOX_CH_TOUCH 6
+#define MBOX_CH_COUNT 7
+#define MBOX_CH_PROP 8
+
+/* tags */
+#define TAG_REQUEST_CODE 0x00000000
+#define MBOX_TAG_GETSERIAL 0x10004
+#define MBOX_TAG_GETBOARD 0x00010002
+#define MBOX_TAG_GETARMMEM 0x00010005
+#define MBOX_TAG_LAST 0
+
+int mbox_call(unsigned char ch);
+void get_board_revision();
+void get_serial_number();
+void get_arm_mem();
diff --git a/lab2/include/memory.h b/lab2/include/memory.h
new file mode 100644
index 000000000..458e9bcd1
--- /dev/null
+++ b/lab2/include/memory.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <stddef.h>
+
+#define MEMORY_SIZE 1024
+
+static char memory_pool[MEMORY_SIZE];
+static char *memory_ptr = memory_pool;
+
+void *simple_alloc(size_t size)
+{
+	void *allocated = memory_ptr;
+
+	if (memory_ptr + size - memory_pool > MEMORY_SIZE)
+		return NULL;
+
+	memory_ptr += size;
+
+	return allocated;
+}
diff --git a/lab2/include/reset.h b/lab2/include/reset.h
new file mode 100644
index 000000000..a2d8f22bb
--- /dev/null
+++ b/lab2/include/reset.h
@@ -0,0 +1,5 @@
+#pragma once
+
+void set(long addr, unsigned int value);
+void reset(int tick);
+void cancel_reset();
diff --git a/lab2/include/shell.h b/lab2/include/shell.h
new file mode 100644
index 000000000..32f4288fb
--- /dev/null
+++ b/lab2/include/shell.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#define MAX_BUFFER_LEN 1024
+
+void shell();
diff --git a/lab2/include/string.h b/lab2/include/string.h
new file mode 100644
index 000000000..781afa59f
--- /dev/null
+++ b/lab2/include/string.h
@@ -0,0 +1,3 @@
+#pragma once
+
+int strcmp(const char *s1, const char *s2);
diff --git a/lab2/include/uart.h b/lab2/include/uart.h
new file mode 100644
index 000000000..99b2be48c
--- /dev/null
+++ b/lab2/include/uart.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+void uart_init();
+void uart_send(unsigned int c);
+char uart_getc();
+void uart_puts(char *s);
+void uart_hex(unsigned int d);
diff --git a/lab2/initramfs.cpio b/lab2/initramfs.cpio
new file mode 100644
index 000000000..3891c6098
Binary files /dev/null and b/lab2/initramfs.cpio differ
diff --git a/lab2/kernel/Makefile b/lab2/kernel/Makefile
new file mode 100644
index 000000000..07dcf647b
--- /dev/null
+++ b/lab2/kernel/Makefile
@@ -0,0 +1,41 @@
+CC = aarch64-linux-gnu-gcc
+LD = aarch64-linux-gnu-ld
+AR = aarch64-linux-gnu-ar
+OBJCOPY = aarch64-linux-gnu-objcopy
+LINKER_SCRIPT = linker.ld
+START = start
+BUILD = ../build
+
+CFLAGS := -fno-stack-protector -I ../include/
+
+all: $(BUILD)/kernel8.img
+
+$(BUILD)/$(START).o: $(START).S
+	$(CC) $(CFLAGS) -c $(START).S -o $(BUILD)/$(START).o
+
+OBJS := \
+	main.o \
+	mbox.o \
+	uart.o \
+	shell.o \
+	string.o \
+	reset.o \
+	cpio.o
+
+OBJS := $(addprefix $(BUILD)/, $(OBJS))
+
+$(BUILD)/%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(BUILD)/kernel8.img: $(BUILD)/$(START).o $(OBJS)
+	$(LD) $(BUILD)/$(START).o $(OBJS) -T $(LINKER_SCRIPT) -o $(BUILD)/kernel8.elf
+	$(OBJCOPY) -O binary $(BUILD)/kernel8.elf $(BUILD)/kernel8.img
+
+clean:
+	rm -f $(BUILD)/kernel8.elf $(BUILD)/kernel8.img $(BUILD)/*.o
+
+run:
+	qemu-system-aarch64 -M raspi3b -kernel $(BUILD)/kernel8.img -serial null -serial stdio
+
+run_with_fs:
+	qemu-system-aarch64 -M raspi3b -kernel $(BUILD)/kernel8.img -serial null -serial stdio -initrd ../initramfs.cpio
diff --git a/lab2/kernel/bcm2710-rpi-3-b-plus.dtb b/lab2/kernel/bcm2710-rpi-3-b-plus.dtb
new file mode 100644
index 000000000..c83b0817e
Binary files /dev/null and b/lab2/kernel/bcm2710-rpi-3-b-plus.dtb differ
diff --git a/lab2/kernel/cpio.c b/lab2/kernel/cpio.c
new file mode 100644
index 000000000..39e91f281
--- /dev/null
+++ b/lab2/kernel/cpio.c
@@ -0,0 +1,102 @@
+#include "cpio.h"
+#include "string.h"
+#include "uart.h"
+
+static int hex_to_int(char *p, int len)
+{
+	int val = 0;
+	int tmp;
+
+	for (int i = 0; i < len; i++) {
+		tmp = *(p + i);
+		if (tmp >= 'A')
+			tmp = tmp - 'A' + 10;
+		else
+			tmp -= '0';
+		val <<= 4;
+		val |= tmp;
+	}
+	return val;
+}
+
+// For cpio alignment issue: https://stackoverflow.com/questions/59138551/extra-bytes-are-padding-in-the-generated-file-from-cpio
+
+void cpio_ls()
+{
+	struct cpio_newc_header *fs = (struct cpio_newc_header *)0x20000000;
+	char *current = (char *)0x20000000;
+
+	while (1) {
+		fs = (struct cpio_newc_header *)current;
+		int name_size = hex_to_int(fs->c_namesize, 8);
+		int file_size = hex_to_int(fs->c_filesize, 8);
+
+		current += sizeof(*fs);
+		if (strcmp(current, "TRAILER!!!") == 0)
+			break;
+
+		uart_puts(current);
+		uart_puts("\r\n");
+		current += name_size;
+		if ((current - (char *)fs) % 4 != 0)
+			current += (4 - (current - (char *)fs) % 4);
+
+		current += file_size;
+		if ((current - (char *)fs) % 4 != 0)
+			current += (4 - (current - (char *)fs) % 4);
+	}
+}
+
+void cpio_cat()
+{
+	char ch;
+	char filename[1024];
+	int idx = 0;
+
+	uart_puts("\r\n");
+	uart_puts("filename: ");
+	while (1) {
+		ch = uart_getc();
+		uart_send(ch);
+		if (ch == '\n') {
+			filename[idx] = '\0';
+			idx = 0;
+			break;
+		} else {
+			filename[idx] = ch;
+			idx++;
+		}
+	}
+
+	struct cpio_newc_header *fs = (struct cpio_newc_header *)0x20000000;
+	char *current = (char *)0x20000000;
+	while (1) {
+		fs = (struct cpio_newc_header *)current;
+		int name_size = hex_to_int(fs->c_namesize, 8);
+		int file_size = hex_to_int(fs->c_filesize, 8);
+		current += sizeof(*fs);
+		if (strcmp(current, "TRAILER!!!") == 0) {
+			uart_puts("\r\n");
+			uart_puts(filename);
+			uart_puts(": No such file.\n");
+			break;
+		}
+		if (strcmp(current, filename) == 0) {
+			current += name_size;
+			if ((current - (char *)fs) % 4 != 0)
+				current += (4 - (current - (char *)fs) % 4);
+			// uart_puts(current);
+            for (int i = 0; i < file_size; i++)
+                uart_send(current[i]);
+			uart_puts("\r\n");
+			break;
+		}
+		current += name_size;
+		if ((current - (char *)fs) % 4 != 0)
+			current += (4 - (current - (char *)fs) % 4);
+
+		current += file_size;
+		if ((current - (char *)fs) % 4 != 0)
+			current += (4 - (current - (char *)fs) % 4);
+	}
+}
diff --git a/lab2/kernel/linker.ld b/lab2/kernel/linker.ld
new file mode 100644
index 000000000..1352bfb14
--- /dev/null
+++ b/lab2/kernel/linker.ld
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+SECTIONS
+{
+    . = 0x80000;
+    .text : { KEEP(*(.text.boot)) *(.text .text.* .gnu.linkonce.t*) }
+    .rodata : { *(.rodata .rodata.* .gnu.linkonce.r*) }
+    PROVIDE(_data = .);
+    .data : { *(.data .data.* .gnu.linkonce.d*) }
+    .bss (NOLOAD) : {
+        . = ALIGN(16);
+        __bss_start = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        __bss_end = .;
+    }
+    _end = .;
+
+   /DISCARD/ : { *(.comment) *(.gnu*) *(.note*) *(.eh_frame*) }
+}
+__bss_size = (__bss_end - __bss_start)>>3;
diff --git a/lab2/kernel/main.c b/lab2/kernel/main.c
new file mode 100644
index 000000000..1d9cf5d91
--- /dev/null
+++ b/lab2/kernel/main.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "uart.h"
+#include "mbox.h"
+#include "shell.h"
+
+void main()
+{
+	// set up serial console
+	uart_init();
+	shell();
+}
diff --git a/lab2/kernel/mbox.c b/lab2/kernel/mbox.c
new file mode 100644
index 000000000..14496db96
--- /dev/null
+++ b/lab2/kernel/mbox.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "gpio.h"
+#include "mbox.h"
+
+/* mailbox message buffer */
+volatile unsigned int __attribute__((aligned(16))) mbox[36];
+
+#define VIDEOCORE_MBOX (MMIO_BASE + 0x0000B880)
+#define MBOX_READ ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x0))
+#define MBOX_POLL ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x10))
+#define MBOX_SENDER ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x14))
+#define MBOX_STATUS ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x18))
+#define MBOX_CONFIG ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x1C))
+#define MBOX_WRITE ((volatile unsigned int *)(VIDEOCORE_MBOX + 0x20))
+#define MBOX_RESPONSE 0x80000000
+#define MBOX_FULL 0x80000000
+#define MBOX_EMPTY 0x40000000
+
+/**
+ * Make a mailbox call. Returns 0 on failure, non-zero on success
+ */
+int mbox_call(unsigned char ch)
+{
+	unsigned int r =
+		(((unsigned int)((unsigned long)&mbox) & ~0xF) | (ch & 0xF));
+	/* wait until we can write to the mailbox */
+	do {
+		asm volatile("nop");
+	} while (*MBOX_STATUS & MBOX_FULL);
+	/* write the address of our message to the mailbox with channel identifier */
+	*MBOX_WRITE = r;
+	/* now wait for the response */
+	while (1) {
+		/* is there a response? */
+		do {
+			asm volatile("nop");
+		} while (*MBOX_STATUS & MBOX_EMPTY);
+		/* is it a response to our message? */
+		if (r == *MBOX_READ)
+			/* is it a valid successful response? */
+			return mbox[1] == MBOX_RESPONSE;
+	}
+	return 0;
+}
+
+void get_board_revision()
+{
+	mbox[0] = 7 * 4; // buffer size in bytes
+	mbox[1] = MBOX_REQUEST;
+	// tags begin
+	mbox[2] = MBOX_TAG_GETBOARD; // tag identifier
+	mbox[3] = 4; // maximum of request and response value buffer's length.
+	mbox[4] = TAG_REQUEST_CODE;
+	mbox[5] = 0; // value buffer
+	// tags end
+	mbox[6] = MBOX_TAG_LAST;
+}
+
+void get_serial_number()
+{
+	mbox[0] = 8 * 4; // buffer size in bytes
+	mbox[1] = MBOX_REQUEST;
+	// tags begin
+	mbox[2] = MBOX_TAG_GETSERIAL; // tag identifier
+	mbox[3] = 8; // maximum of request and response value buffer's length.
+	mbox[4] = 8;
+	mbox[5] = 0;
+	mbox[6] = 0;
+	// tags end
+	mbox[7] = MBOX_TAG_LAST;
+}
+
+void get_arm_mem()
+{
+	mbox[0] = 8 * 4; // buffer size in bytes
+	mbox[1] = MBOX_REQUEST;
+	// tags begin
+	mbox[2] = MBOX_TAG_GETARMMEM; // tag identifier
+	mbox[3] = 8; // maximum of request and response value buffer's length.
+	mbox[4] = TAG_REQUEST_CODE;
+	mbox[5] = 0; // value buffer
+	mbox[6] = 0; // value buffer
+	// tags end
+	mbox[7] = MBOX_TAG_LAST;
+}
diff --git a/lab2/kernel/reset.c b/lab2/kernel/reset.c
new file mode 100644
index 000000000..e9104fc95
--- /dev/null
+++ b/lab2/kernel/reset.c
@@ -0,0 +1,23 @@
+#include "reset.h"
+
+#define PM_PASSWORD 0x5a000000
+#define PM_RSTC 0x3F10001c
+#define PM_WDOG 0x3F100024
+
+void set(long addr, unsigned int value)
+{
+	volatile unsigned int *point = (unsigned int *)addr;
+	*point = value;
+}
+
+void reset(int tick)
+{ // reboot after watchdog timer expire
+	set(PM_RSTC, PM_PASSWORD | 0x20); // full reset
+	set(PM_WDOG, PM_PASSWORD | tick); // number of watchdog tick
+}
+
+void cancel_reset()
+{
+	set(PM_RSTC, PM_PASSWORD | 0); // full reset
+	set(PM_WDOG, PM_PASSWORD | 0); // number of watchdog tick
+}
diff --git a/lab2/kernel/shell.c b/lab2/kernel/shell.c
new file mode 100644
index 000000000..670fb4189
--- /dev/null
+++ b/lab2/kernel/shell.c
@@ -0,0 +1,122 @@
+#include <stddef.h>
+
+#include "shell.h"
+#include "uart.h"
+#include "string.h"
+#include "reset.h"
+#include "mbox.h"
+#include "cpio.h"
+
+static void dispatch_cmd(const char *cmd)
+{
+	if (strcmp(cmd, "hello") == 0) {
+		uart_puts("Hello, world!\r\n");
+		return;
+	}
+	if (strcmp(cmd, "help") == 0) {
+		uart_puts("Available commands:\r\n");
+		uart_puts("  hello - print a greeting\r\n");
+		uart_puts("  help - print this help message\r\n");
+		uart_puts("  reboot - reboot the system\r\n");
+		uart_puts(
+			"  info - print the board revision, memory base address, memory size, and serial number\r\n");
+		uart_puts("  ls - List information about the FILEs\r\n");
+		uart_puts("  cat - Concatenate FILE(s)\r\n");
+		return;
+	}
+	if (strcmp(cmd, "reboot") == 0) {
+		uart_puts("rebooting...\r\n");
+		reset(1000);
+		do {
+			asm volatile("nop");
+		} while (1);
+	}
+	if (strcmp(cmd, "info") == 0) {
+		get_board_revision();
+		if (mbox_call(MBOX_CH_PROP)) {
+			uart_puts("Revision: ");
+			uart_puts("0x");
+			uart_hex(mbox[5]);
+			uart_puts("\r\n");
+		} else {
+			uart_puts("Unable to query revision!\n");
+		}
+		get_arm_mem();
+		if (mbox_call(MBOX_CH_PROP)) {
+			uart_puts("Memory base address: ");
+			uart_puts("0x");
+			uart_hex(mbox[5]);
+			uart_puts("\r\n");
+			uart_puts("Memory size: ");
+			uart_puts("0x");
+			uart_hex(mbox[6]);
+			uart_puts("\r\n");
+		} else {
+			uart_puts("Unable to query memory info!\n");
+		}
+		get_serial_number();
+		if (mbox_call(MBOX_CH_PROP)) {
+			uart_puts("Serial Number: ");
+			uart_puts("0x");
+			uart_hex(mbox[6]);
+			uart_hex(mbox[5]);
+			uart_puts("\r\n");
+		} else {
+			uart_puts("Unable to query serial!\n");
+		}
+		return;
+	}
+	if (strcmp(cmd, "ls") == 0) {
+		cpio_ls();
+		return;
+	}
+	if (strcmp(cmd, "cat") == 0) {
+		cpio_cat();
+		return;
+	}
+
+	uart_puts("ERROR: Unrecognized command!\r\n");
+}
+
+void shell()
+{
+	char buffer[MAX_BUFFER_LEN];
+	size_t buffer_index = 0;
+	char ch;
+
+	// set up serial console
+	uart_init();
+
+	// say hello
+	uart_puts("Starting the shell!\r\n");
+
+	while (1) {
+		uart_puts("# ");
+		buffer_index = 0;
+		buffer[0] = '\0';
+
+		while (1) {
+			ch = uart_getc();
+			if (buffer_index + 1 >= sizeof(buffer)) {
+				uart_puts(
+					"ERROR: Exceed buffer length limit!\r\n");
+				buffer_index = 0;
+				buffer[0] = '\0';
+				break;
+			}
+			if (ch == '\n') {
+				uart_puts("\r\n");
+				buffer[buffer_index] = '\0';
+				break;
+			}
+			uart_send(ch);
+			buffer[buffer_index++] = ch;
+		}
+		dispatch_cmd(buffer);
+	}
+
+	// echo everything back
+	while (1) {
+		uart_send(uart_getc());
+	}
+}
diff --git a/lab2/kernel/start.S b/lab2/kernel/start.S
new file mode 100644
index 000000000..53618397f
--- /dev/null
+++ b/lab2/kernel/start.S
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+.section ".text.boot"
+
+.global _start
+
+_start:
+    // read cpu id, stop slave cores
+    mrs     x1, mpidr_el1
+    and     x1, x1, #3
+    cbz     x1, 2f
+    // cpu id > 0, stop
+1:  wfe
+    b       1b
+2:  // cpu id == 0
+
+    // set top of stack just before our code (stack grows to a lower address per AAPCS64)
+    ldr     x1, =_start
+    mov     sp, x1
+
+    // clear bss
+    ldr     x1, =__bss_start
+    ldr     w2, =__bss_size
+3:  cbz     w2, 4f
+    str     xzr, [x1], #8
+    sub     w2, w2, #1
+    cbnz    w2, 3b
+
+    // jump to C code, should not return
+4:  bl      main
+    // for failsafe, halt this core too
+    b       1b
diff --git a/lab2/kernel/string.c b/lab2/kernel/string.c
new file mode 100644
index 000000000..227b33fe4
--- /dev/null
+++ b/lab2/kernel/string.c
@@ -0,0 +1,18 @@
+#include "string.h"
+
+int strcmp(const char *s1, const char *s2)
+{
+	char *_s1 = (char *)s1;
+	char *_s2 = (char *)s2;
+	while (_s1 && _s2) {
+		if (*_s1 == '\n' || *_s2 == '\0')
+			return 0;
+		if (*_s1 == '\r' || *_s2 == '\0')
+			return 0;
+		if (*_s1 != *_s2)
+			return *_s1 - *_s2;
+		_s1++;
+		_s2++;
+	}
+	return *_s2 != '\0';
+}
diff --git a/lab2/kernel/uart.c b/lab2/kernel/uart.c
new file mode 100644
index 000000000..cd5f000f2
--- /dev/null
+++ b/lab2/kernel/uart.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2018 bzt (bztsrc@github)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "gpio.h"
+
+/* Auxilary mini UART registers */
+#define AUX_ENABLE ((volatile unsigned int *)(MMIO_BASE + 0x00215004))
+#define AUX_MU_IO ((volatile unsigned int *)(MMIO_BASE + 0x00215040))
+#define AUX_MU_IER ((volatile unsigned int *)(MMIO_BASE + 0x00215044))
+#define AUX_MU_IIR ((volatile unsigned int *)(MMIO_BASE + 0x00215048))
+#define AUX_MU_LCR ((volatile unsigned int *)(MMIO_BASE + 0x0021504C))
+#define AUX_MU_MCR ((volatile unsigned int *)(MMIO_BASE + 0x00215050))
+#define AUX_MU_LSR ((volatile unsigned int *)(MMIO_BASE + 0x00215054))
+#define AUX_MU_MSR ((volatile unsigned int *)(MMIO_BASE + 0x00215058))
+#define AUX_MU_SCRATCH ((volatile unsigned int *)(MMIO_BASE + 0x0021505C))
+#define AUX_MU_CNTL ((volatile unsigned int *)(MMIO_BASE + 0x00215060))
+#define AUX_MU_STAT ((volatile unsigned int *)(MMIO_BASE + 0x00215064))
+#define AUX_MU_BAUD ((volatile unsigned int *)(MMIO_BASE + 0x00215068))
+
+/**
+ * Set baud rate and characteristics (115200 8N1) and map to GPIO
+ */
+void uart_init()
+{
+	register unsigned int r;
+
+	/* initialize UART */
+	*AUX_ENABLE |= 1; // enable UART1, AUX mini uart
+	*AUX_MU_IER = 0;
+	*AUX_MU_CNTL = 0;
+	*AUX_MU_LCR = 3; // 8 bits
+	*AUX_MU_MCR = 0;
+	*AUX_MU_IER = 0;
+	*AUX_MU_IIR = 0xc6; // disable interrupts
+	*AUX_MU_BAUD = 270; // 115200 baud
+	/* map UART1 to GPIO pins */
+	r = *GPFSEL1;
+	r &= ~((7 << 12) | (7 << 15)); // gpio14, gpio15
+	r |= (2 << 12) | (2 << 15); // alt5
+	*GPFSEL1 = r;
+	*GPPUD = 0; // enable pins 14 and 15
+	r = 150;
+	while (r--) {
+		asm volatile("nop");
+	}
+	*GPPUDCLK0 = (1 << 14) | (1 << 15);
+	r = 150;
+	while (r--) {
+		asm volatile("nop");
+	}
+	*GPPUDCLK0 = 0; // flush GPIO setup
+	*AUX_MU_CNTL = 3; // enable Tx, Rx
+}
+
+/**
+ * Send a character
+ */
+void uart_send(unsigned int c)
+{
+	/* wait until we can send */
+	do {
+		asm volatile("nop");
+	} while (!(*AUX_MU_LSR & 0x20));
+	/* write the character to the buffer */
+	*AUX_MU_IO = c;
+}
+
+/**
+ * Receive a character
+ */
+char uart_getc()
+{
+	char r;
+	/* wait until something is in the buffer */
+	do {
+		asm volatile("nop");
+	} while (!(*AUX_MU_LSR & 0x01));
+	/* read it and return */
+	r = (char)(*AUX_MU_IO);
+	/* convert carrige return to newline */
+	return r == '\r' ? '\n' : r;
+}
+
+/**
+ * Display a string
+ */
+void uart_puts(char *s)
+{
+	while (*s) {
+		/* convert newline to carrige return + newline */
+		if (*s == '\n')
+			uart_send('\r');
+		uart_send(*s++);
+	}
+}
+
+/**
+ * Display a binary value in hexadecimal
+ */
+void uart_hex(unsigned int d)
+{
+	unsigned int n;
+	int c;
+	for (c = 28; c >= 0; c -= 4) {
+		// get highest tetrad
+		n = (d >> c) & 0xF;
+		// 0-9 => '0'-'9', 10-15 => 'A'-'F'
+		n += n > 9 ? 0x37 : 0x30;
+		uart_send(n);
+	}
+}
diff --git a/lab2/pack_fs.sh b/lab2/pack_fs.sh
new file mode 100755
index 000000000..9b0159ea9
--- /dev/null
+++ b/lab2/pack_fs.sh
@@ -0,0 +1,3 @@
+cd rootfs
+find . | cpio -o -H newc > ../initramfs.cpio
+cd ..
diff --git a/lab2/rootfs/file1.txt b/lab2/rootfs/file1.txt
new file mode 100644
index 000000000..5c1170f2e
--- /dev/null
+++ b/lab2/rootfs/file1.txt
@@ -0,0 +1 @@
+This is file 1.
diff --git a/lab2/rootfs/file2.txt b/lab2/rootfs/file2.txt
new file mode 100644
index 000000000..3eac351c9
--- /dev/null
+++ b/lab2/rootfs/file2.txt
@@ -0,0 +1 @@
+This is file 2.