diff --git a/01_git/scissors/Makefile b/01_git/scissors/Makefile
new file mode 100644
index 0000000..341ed08
--- /dev/null
+++ b/01_git/scissors/Makefile
@@ -0,0 +1,18 @@
+CC=gcc
+CFLAGS=-I.
+CRYPTOLAGS=-lcrypto
+OUT_NAME=rock-paper-scissors
+
+all: $(OUT_NAME)
+
+$(OUT_NAME): rock_paper_scissors.o main.o
+	$(CC) rock_paper_scissors.o main.o -o $(OUT_NAME) $(CFLAGS) $(CRYPTOLAGS)
+
+main.o: main.c
+	$(CC) -c main.c $(CFLAGS)
+
+rock_paper_scissors.o: rock_paper_scissors.c
+	$(CC) -c rock_paper_scissors.c $(CFLAGS)
+
+clean:
+	/bin/rm -rf *.o a.out $(OUT_NAME)
diff --git a/01_git/scissors/main.c b/01_git/scissors/main.c
new file mode 100644
index 0000000..6e584a4
--- /dev/null
+++ b/01_git/scissors/main.c
@@ -0,0 +1,7 @@
+#include <rock_paper_scissors.h>
+
+int main()
+{
+    RPS_run_game();
+    return 0;
+}
diff --git a/01_git/scissors/rock_paper_scissors.c b/01_git/scissors/rock_paper_scissors.c
new file mode 100644
index 0000000..20b3040
--- /dev/null
+++ b/01_git/scissors/rock_paper_scissors.c
@@ -0,0 +1,161 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <openssl/md5.h>
+
+#include "rock_paper_scissors.h"
+
+static RPS_CHOICES_E get_human_choice(void);
+static RPS_CHOICES_E get_random_choice(void);
+static void RPS_show_game_result(RPS_CHOICES_E comp_choice, RPS_CHOICES_E human_choice);
+static void RPS_print_md5(char value);
+
+static RPS_CHOICE_ENTRY_S choices_arr[] = {{RPS_CHOICE_ROCK, "rock", 'r'},
+                                           {RPS_CHOICE_PAPER, "paper", 'p'},
+                                           {RPS_CHOICE_SCISSORS, "scissors", 's'},
+                                           {RPS_CHOICE_UNKNOWN, "unknown", 'u'}};
+
+static RPS_CHOICES_E RPS_get_random_choice(void)
+{
+    unsigned char buff;
+    RPS_CHOICES_E choice = RPS_CHOICE_UNKNOWN;
+
+    int fd = open("/dev/urandom", O_RDONLY);
+
+    if (!fd)
+    {
+        printf("Error opening /dev/urandom\n");
+        exit(1);
+    }
+
+    read(fd, &buff, sizeof buff);
+    close(fd);
+    choice = buff % RPS_N_VALUABLE_CHOICES;
+
+    return choice;
+}
+
+
+static RPS_CHOICES_E RPS_get_human_choice(void)
+{
+    RPS_CHOICES_E choice = RPS_CHOICE_UNKNOWN;
+    char read_value = '?';
+
+    printf("Please choose: rock (r) - paper (p) - scissors (s)\n");
+    scanf(" %c", &read_value);
+
+    switch (read_value)
+    {
+        case 'r':
+            {
+                choice = RPS_CHOICE_ROCK;
+                break;
+            }
+
+        case 'p':
+            {
+                choice = RPS_CHOICE_PAPER;
+                break;
+            }
+        case 's':
+            {
+                choice = RPS_CHOICE_SCISSORS;
+                break;
+            }
+        default:
+            {
+                choice = RPS_CHOICE_UNKNOWN;
+                break;
+            }
+    }
+
+    return choice;
+}
+
+
+static void RPS_print_md5(char value)
+{
+    MD5_CTX ctx;
+    unsigned char md5digest[MD5_DIGEST_LENGTH];
+
+    MD5_Init(&ctx);
+    MD5_Update(&ctx, (const void *)&value, sizeof value);
+    MD5_Final(md5digest, &ctx);
+
+    printf("Random choice: %c md5: ", value);
+
+    for ( int i=0;i < MD5_DIGEST_LENGTH; i++ ) {
+        printf("%02x", md5digest[i]);
+    };
+    printf("\n");
+}
+
+
+static void RPS_show_game_result(RPS_CHOICES_E comp_choice, RPS_CHOICES_E human_choice)
+{
+    RPS_CHOICE_ENTRY_S *p_human_entry;
+    RPS_CHOICE_ENTRY_S *p_comp_entry;
+    int game_result;
+
+    p_comp_entry = &choices_arr[comp_choice];
+    p_human_entry = &choices_arr[human_choice];
+
+    printf("You choose %s, I choose %s\n", p_human_entry->long_name, p_comp_entry->long_name);
+
+    game_result = comp_choice - human_choice;
+
+    switch (game_result)
+    {
+        case 0:
+            {
+                printf("Draw: %s and %s\n", p_human_entry->long_name, p_comp_entry->long_name);
+                break;
+            }
+
+        case 1:
+            {
+                printf("I win: %s beats %s\n", p_comp_entry->long_name, p_human_entry->long_name);
+                break;
+            }
+        case 2:
+            {
+                printf("You win: %s beats %s\n", p_human_entry->long_name, p_comp_entry->long_name);
+                break;
+            }
+        case -1:
+            {
+                printf("You win: %s beats %s\n", p_human_entry->long_name, p_comp_entry->long_name);
+                break;
+            }
+        case -2:
+            {
+                printf("I win: %s beats %s\n", p_comp_entry->long_name, p_human_entry->long_name);
+                break;
+            }
+        default:
+            {
+                printf("Error game result: %i\n", game_result);
+                exit(1);
+                break;
+            }
+    }
+}
+
+
+void RPS_run_game(void)
+{
+    RPS_CHOICES_E human_choice = RPS_CHOICE_UNKNOWN;
+    RPS_CHOICES_E comp_choice = RPS_CHOICE_UNKNOWN;
+
+    comp_choice = RPS_get_random_choice();
+    // Optional task: add printing md5 checksum of computer's choice before human's move.
+    RPS_print_md5(choices_arr[comp_choice].short_name);
+
+    for ( ; human_choice == RPS_CHOICE_UNKNOWN; )
+    {
+        human_choice = RPS_get_human_choice();
+    }
+
+    RPS_show_game_result(comp_choice, human_choice);
+}
diff --git a/01_git/scissors/rock_paper_scissors.h b/01_git/scissors/rock_paper_scissors.h
new file mode 100644
index 0000000..f4cd09b
--- /dev/null
+++ b/01_git/scissors/rock_paper_scissors.h
@@ -0,0 +1,23 @@
+#ifndef __ROCK_PAPER_SCISSORS_H_
+#define __ROCK_PAPER_SCISSORS_H_
+
+#define RPS_N_VALUABLE_CHOICES 3
+
+typedef enum RPS_CHOICES {
+    RPS_CHOICE_ROCK,
+    RPS_CHOICE_PAPER,
+    RPS_CHOICE_SCISSORS,
+    RPS_CHOICE_UNKNOWN
+} RPS_CHOICES_E;
+
+
+typedef struct RPS_CHOICE_ENTRY {
+    RPS_CHOICES_E id;
+    char long_name[16];
+    char short_name;
+} RPS_CHOICE_ENTRY_S;
+
+
+void RPS_run_game(void);
+
+#endif // __ROCK_PAPER_SCISSORS_H_
diff --git a/02_bash/hwdetect/hwdetect.sh b/02_bash/hwdetect/hwdetect.sh
new file mode 100755
index 0000000..5325c95
--- /dev/null
+++ b/02_bash/hwdetect/hwdetect.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+FOLDER=${1:-/dev}
+echo "Polling folder: $FOLDER"
+
+PREV=$(stat --terse --format="%n %z" ${FOLDER}/*|sort -n)
+
+while true
+do
+    NEW=$(stat --terse --format="%n %z" ${FOLDER}/*|sort -n)
+    DELTA=$(diff <(echo "$PREV") <(echo "$NEW") | grep '^>')
+
+    if [[ "${#DELTA}" != 0 ]]
+    then
+        echo "$DELTA"
+    fi
+    PREV=$NEW
+    sleep 1
+done
diff --git a/03_module/Makefile b/03_module/Makefile
new file mode 100644
index 0000000..8dbe20a
--- /dev/null
+++ b/03_module/Makefile
@@ -0,0 +1,9 @@
+KERNELDIR ?= ../output/build/linux-5.10.7
+
+obj-m := hello.o
+
+all:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
diff --git a/03_module/README.md b/03_module/README.md
new file mode 100644
index 0000000..739d55a
--- /dev/null
+++ b/03_module/README.md
@@ -0,0 +1,15 @@
+## module home work: create a simple loadable module with parameters 
+
+Create a loadadle kernel module which should accept two integer parameters and provide:
+ - A sum of parameters upon driver load
+ - A substration of parameters upon driver unload
+
+Info about module parameters can be found at: https://devarea.com/linux-kernel-development-kernel-module-parameters/#.YZfWcpFByV4
+
+Task should be performed using buildroot+qemu approach
+
+The task results should contain:
+- The module code
+- The Makefile
+- Dump of the kernel logs from the target system 
+
diff --git a/03_module/dump.txt b/03_module/dump.txt
new file mode 100644
index 0000000..1eef35d
--- /dev/null
+++ b/03_module/dump.txt
@@ -0,0 +1,11 @@
+# insmod /tmp/hello.ko n1=42 n2=-10
+hello add n1: 42 and n2: -10 result: 32
+# cd /sys/module/hello/parameters/
+# ls
+n1  n2
+# cat n1
+42
+# cat n2
+-10
+# rmmod hello.ko
+Bye substract n1: 42 and n2: -10 result: 52
diff --git a/03_module/hello.c b/03_module/hello.c
new file mode 100644
index 0000000..7ecdbc1
--- /dev/null
+++ b/03_module/hello.c
@@ -0,0 +1,26 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+
+
+static int n1=0;
+module_param(n1, int, 0660);
+
+static int n2=0;
+module_param(n2, int, 0660);
+
+int init_module(void)
+{
+    printk(KERN_INFO "hello add n1: %d and n2: %d result: %d\n", n1, n2, n1+n2);
+    return 0;
+}
+
+void cleanup_module(void)
+{
+    printk(KERN_INFO "Bye substract n1: %d and n2: %d result: %d\n", n1, n2, n1-n2);
+}
+
+MODULE_AUTHOR("Ivan Stepanenko <istepanenko@gmail.com>");
+MODULE_DESCRIPTION("Hello world module");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
diff --git a/04_basic_struct/Makefile b/04_basic_struct/Makefile
new file mode 100644
index 0000000..14231e1
--- /dev/null
+++ b/04_basic_struct/Makefile
@@ -0,0 +1,9 @@
+KERNELDIR ?= ../output/build/linux-5.10.7
+
+obj-m := wimbledon.o
+
+all:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
diff --git a/04_basic_struct/README.md b/04_basic_struct/README.md
new file mode 100644
index 0000000..445d6dc
--- /dev/null
+++ b/04_basic_struct/README.md
@@ -0,0 +1,7 @@
+## Basic structure homework
+Implement object with name “MyObject” which is parent of kernel_kobj.    
+Object should include linked_list structure.    
+This object should contain sysfs attribute with name “list”.    
+On read form attribute “list” it should show content of the objects linked list.    
+On write to attribute “list” it should add new string to the objects linked list.    
+!! Do not forget properly free all the resources during rmmod.    
diff --git a/04_basic_struct/dump.txt b/04_basic_struct/dump.txt
new file mode 100644
index 0000000..29f5ecb
--- /dev/null
+++ b/04_basic_struct/dump.txt
@@ -0,0 +1,37 @@
+# insmod /tmp/wimbledon.ko 
+wimbledon: loading out-of-tree module taints kernel.
+# echo  "1" > /sys/kernel/wimbledon/list 
+wimbledon: adding msg size: 2 to the list: '1
+'
+# echo  -n "2" > /sys/kernel/wimbledon/list 
+wimbledon: adding msg size: 1 to the list: '2'
+# echo  -n "33" > /sys/kernel/wimbledon/list 
+wimbledon: adding msg size: 2 to the list: '33'
+# echo   "44" > /sys/kernel/wimbledon/list 
+wimbledon: adding msg size: 3 to the list: '44
+'
+# echo  -n "55" > /sys/kernel/wimbledon/list 
+wimbledon: adding msg size: 2 to the list: '55'
+# cat /sys/kernel/wimbledon/list
+wimbledon: msg #0 size: 2 '1
+'
+wimbledon: msg #1 size: 1 '2'
+wimbledon: msg #2 size: 2 '33'
+wimbledon: msg #3 size: 3 '44
+'
+wimbledon: msg #4 size: 2 '55'
+1
+23344
+55# 
+
+# rmmod wimbledon.ko
+wimbledon: freeing msg size: 2 from the list: '55'
+wimbledon: freeing msg size: 3 from the list: '44
+'
+wimbledon: freeing msg size: 2 from the list: '33'
+wimbledon: freeing msg size: 1 from the list: '2'
+wimbledon: freeing msg size: 2 from the list: '1
+'
+wimbledon: list is empty: 1
+wimbledon: Module exited
+
diff --git a/04_basic_struct/wimbledon.c b/04_basic_struct/wimbledon.c
new file mode 100644
index 0000000..c05e758
--- /dev/null
+++ b/04_basic_struct/wimbledon.c
@@ -0,0 +1,118 @@
+/*
+ * Name of this module is English wiki random article choice.
+ * To get away from "hello", "foo", "bar", "baz"... names.
+ */
+#define DEBUG
+#define pr_fmt(fmt) "%s: " fmt,  KBUILD_MODNAME
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+
+struct msg_item {
+        struct list_head list;
+        char *msg;
+        size_t msg_len;
+};
+static LIST_HEAD(msg_list_head);
+
+static ssize_t wimbledon_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff);
+static ssize_t wimbledon_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count);
+static int wimbledon_init(void);
+static void wimbledon_exit(void);
+
+static struct kobj_attribute list_attribute =
+        __ATTR(list, 0644, wimbledon_show, wimbledon_store);
+static struct kobject *wimbledon_kobj;
+
+
+static ssize_t wimbledon_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff)
+{
+    struct msg_item *pos = NULL;
+    size_t item_number = 0;
+    size_t count = 0;
+    char *p_buff = buff;
+
+    list_for_each_entry_reverse(pos, &msg_list_head, list) {
+        pr_info("msg #%lu size: %lu '%.*s'\n",
+                item_number, pos->msg_len, (int)pos->msg_len, (char *)pos->msg);
+
+        memcpy(p_buff, (char *)pos->msg, pos->msg_len);
+        p_buff += pos->msg_len;
+        count += pos->msg_len;
+        item_number += 1;
+    }
+    return count;
+}
+
+
+static ssize_t wimbledon_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count)
+{
+    char *p_msg = NULL;
+    struct msg_item *p_item = NULL;
+
+    p_msg = kmalloc(count, GFP_KERNEL);
+    if (!p_msg) {
+        pr_err("could not allocate msg cnt: %lu\n", count);
+        return -ENOMEM;
+    }
+    p_item = kmalloc(sizeof(struct msg_item), GFP_KERNEL);
+    if (!p_item) {
+        pr_err("could not allocate msg_item\n");
+        return -ENOMEM;
+    }
+    memcpy(p_msg, buff, count);
+    p_item->msg = p_msg;
+    p_item->msg_len = count;
+
+    pr_info("adding msg size: %lu to the list: '%.*s'\n",
+            p_item->msg_len, (int)p_item->msg_len, (char *)p_item->msg);
+    list_add(&p_item->list, &msg_list_head);
+    return count;
+}
+
+
+static int wimbledon_init(void)
+{
+    int res = 0;
+    wimbledon_kobj = kobject_create_and_add("wimbledon", kernel_kobj);
+    if (!wimbledon_kobj)
+        return -ENOMEM;
+    res = sysfs_create_file(wimbledon_kobj, &list_attribute.attr);
+    if (res)
+        kobject_put(wimbledon_kobj);
+
+    return res;
+}
+
+
+static void wimbledon_exit(void)
+{
+    struct list_head *pos = NULL;
+    struct list_head *n = NULL;
+    struct msg_item *p_item = NULL;
+
+    list_for_each_safe(pos, n, &msg_list_head) {
+         p_item = list_entry(pos, struct msg_item, list);
+         pr_info("freeing msg size: %lu from the list: '%.*s'\n",
+                 p_item->msg_len, (int)p_item->msg_len, (char *)p_item->msg);
+         list_del(pos);
+         kfree(p_item->msg);
+         kfree(p_item);
+    }
+    pr_info("list is empty: %d\n", list_empty_careful(&msg_list_head));
+    kobject_put(wimbledon_kobj);
+    pr_info("Module exited\n");
+}
+
+module_init(wimbledon_init);
+module_exit(wimbledon_exit);
+
+MODULE_AUTHOR("Ivan Stepanenko <istepanenko@gmail.com>");
+MODULE_DESCRIPTION("Wimbledon module");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
diff --git a/05_timers/README.md b/05_timers/README.md
new file mode 100644
index 0000000..55b41f2
--- /dev/null
+++ b/05_timers/README.md
@@ -0,0 +1,10 @@
+## Homework: Linux Kernel Time Management
+
+1. Implement program which return absolute time in user space.
+Use clock_gettime() from time.h. Try different clock id.
+Find the difference. Show possible clock resolution provided by clock_getres().
+
+2. Implement kernel module with API in sysfs, which returns relative
+time in maximum possible resolution passed since previous read of it.
+Implement kernel module with API in sysfs which returns absolute time
+of previous reading with maximum resolution like ‘400.123567’ seconds.
diff --git a/05_timers/kernel_module/Makefile b/05_timers/kernel_module/Makefile
new file mode 100644
index 0000000..a7fac31
--- /dev/null
+++ b/05_timers/kernel_module/Makefile
@@ -0,0 +1,9 @@
+KERNELDIR ?= ../output/build/linux-5.10.7
+
+obj-m := time_attr_presenter.o
+
+all:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
diff --git a/05_timers/kernel_module/dump.txt b/05_timers/kernel_module/dump.txt
new file mode 100644
index 0000000..bb7d3f0
--- /dev/null
+++ b/05_timers/kernel_module/dump.txt
@@ -0,0 +1,25 @@
+# insmod /tmp/time_attr_presenter.ko 
+# cat /sys/kernel/time_attr_presenter/last_abs_time  
+-1
+# cat /sys/kernel/time_attr_presenter/last_abs_time  
+1639337982.183260522
+# cat /sys/kernel/time_attr_presenter/last_abs_time  
+1639337984.166915503
+# cat /sys/kernel/time_attr_presenter/last_relative_time 
+-1
+# cat /sys/kernel/time_attr_presenter/last_relative_time 
+0.636000000
+# cat /sys/kernel/time_attr_presenter/last_relative_time 
+1.812000000
+# cat /sys/kernel/time_attr_presenter/last_relative_time 
+0.752000000
+# rmmod time_attr_presenter.ko
+time_attr_presenter: Module exited
+# ls /sys/kernel/time_attr_presenter
+ls: /sys/kernel/time_attr_presenter: No such file or directory
+
+# unix timestamps are matched with real time
+date -d @1639337984.166915503
+неділя, 12 грудня 2021 21:39:44 +0200
+date -d @1639337982.183260522
+неділя, 12 грудня 2021 21:39:42 +0200
diff --git a/05_timers/kernel_module/time_attr_presenter.c b/05_timers/kernel_module/time_attr_presenter.c
new file mode 100644
index 0000000..abc0510
--- /dev/null
+++ b/05_timers/kernel_module/time_attr_presenter.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 1 Implement kernel module with API in sysfs,
+ *   which returns relative time in maximum possible
+ *   resolution passed since previous read of it.
+ * 2 Implement kernel module with API in sysfs
+ *   which returns absolute time of previous reading
+ *   with maximum resolution like ‘400.123567’ seconds.
+ */
+
+
+#define DEBUG
+#define pr_fmt(fmt) "%s: " fmt,  KBUILD_MODNAME
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/time.h>
+#include <linux/timekeeping.h>
+#include <linux/jiffies.h>
+
+
+static ssize_t time_attr_presenter_last_abs_time_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff);
+static ssize_t time_attr_presenter_last_relative_time_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff);
+static ssize_t time_attr_presenter_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count);
+static int time_attr_presenter_init(void);
+static void time_attr_presenter_exit(void);
+
+
+static struct kobject *time_attr_presenter_kobj;
+static u64 last_read_jiffies;
+static struct timespec64 last_read_time;
+
+static struct kobj_attribute param_abs_attribute =
+		__ATTR(last_abs_time, 0644, time_attr_presenter_last_abs_time_show, time_attr_presenter_store);
+static struct kobj_attribute param_relative_attribute =
+		__ATTR(last_relative_time, 0644, time_attr_presenter_last_relative_time_show, time_attr_presenter_store);
+
+
+static ssize_t time_attr_presenter_last_abs_time_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff)
+{
+	if (last_read_time.tv_sec == 0 && last_read_time.tv_nsec == 0)
+		sprintf(buff, "-1\n");
+	else
+		sprintf(buff, "%lli.%li\n", last_read_time.tv_sec, last_read_time.tv_nsec);
+
+	ktime_get_real_ts64(&last_read_time);
+
+	return strlen(buff);
+}
+
+static ssize_t time_attr_presenter_last_relative_time_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff)
+{
+	u64 delta = 0;
+	struct timespec64 ts;
+
+	if (last_read_jiffies == 0) {
+		sprintf(buff, "-1\n");
+	} else {
+		delta = get_jiffies_64() - last_read_jiffies;
+		jiffies_to_timespec64(delta, &ts);
+		sprintf(buff, "%lli.%li\n", ts.tv_sec, ts.tv_nsec);
+	}
+	last_read_jiffies = get_jiffies_64();
+
+	return strlen(buff);
+}
+
+
+static ssize_t time_attr_presenter_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count)
+{
+	return count;
+}
+
+
+static int time_attr_presenter_init(void)
+{
+	int res = 0;
+
+	time_attr_presenter_kobj = kobject_create_and_add("time_attr_presenter", kernel_kobj);
+	if (!time_attr_presenter_kobj)
+		return -ENOMEM;
+	res = sysfs_create_file(time_attr_presenter_kobj, &param_relative_attribute.attr);
+	if (res)
+		kobject_put(time_attr_presenter_kobj);
+	res = sysfs_create_file(time_attr_presenter_kobj, &param_abs_attribute.attr);
+	if (res)
+		kobject_put(time_attr_presenter_kobj);
+
+	last_read_jiffies = 0;
+	last_read_time.tv_sec = 0;
+	last_read_time.tv_nsec = 0;
+
+	return res;
+}
+
+
+static void time_attr_presenter_exit(void)
+{
+	kobject_put(time_attr_presenter_kobj);
+	pr_info("Module exited\n");
+}
+
+module_init(time_attr_presenter_init);
+module_exit(time_attr_presenter_exit);
+
+MODULE_AUTHOR("Ivan Stepanenko <istepanenko@gmail.com>");
+MODULE_DESCRIPTION("Time attribute presenter module");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
diff --git a/05_timers/user_space/Makefile b/05_timers/user_space/Makefile
new file mode 100644
index 0000000..4142923
--- /dev/null
+++ b/05_timers/user_space/Makefile
@@ -0,0 +1,11 @@
+CC=gcc
+CFLAGS=-I. -std=c99 -D_POSIX_C_SOURCE=199309L
+OUT_NAME=user-space-timers
+
+all: $(OUT_NAME)
+
+$(OUT_NAME): user_space_timers.c
+	$(CC) user_space_timers.c -o $(OUT_NAME) $(CFLAGS)
+
+clean:
+	/bin/rm -rf *.o a.out $(OUT_NAME)
diff --git a/05_timers/user_space/dump1.txt b/05_timers/user_space/dump1.txt
new file mode 100644
index 0000000..fa0ef03
--- /dev/null
+++ b/05_timers/user_space/dump1.txt
@@ -0,0 +1,41 @@
+ivan@ivan-VirtualBox:~/buildroot/buildroot-2021.02.7/05-timers$ gcc -std=c99 -D_POSIX_C_SOURCE=199309L main.c && ./a.out ; echo $?
+getting clock resolution...
+----------------------------------------------------------------
+|clock_id            |sec                 |nsec                |
+----------------------------------------------------------------
+|CLOCK_REALTIME      |0                   |1                   |
+|CLOCK_MONOTONIC     |0                   |1                   |
+|CLOCK_PROCESS_CPUTIM|0                   |1                   |
+|CLOCK_THREAD_CPUTIME|0                   |1                   |
+|CLOCK_BOOTTIME      |0                   |1                   |
+
+getting actual clock values...
+----------------------------------------------------------------
+|clock_id            |sec                 |nsec                |
+----------------------------------------------------------------
+|CLOCK_REALTIME      |1638701883          |825167534           |
+|CLOCK_MONOTONIC     |6539                |56162158            |
+|CLOCK_PROCESS_CPUTIM|0                   |625613              |
+|CLOCK_THREAD_CPUTIME|0                   |626629              |
+|CLOCK_BOOTTIME      |6539                |56164193            |
+
+Conclusion:
+*1 I have started with clock resolutions for different clock_id.
+In my case all of them have 1nsec resolution which is expected for the host system.
+
+*2 Then I have contnued with actual clock values.
+CLOCK_REALTIME is matched with localtime
+
+ivan@ivan-VirtualBox:~/buildroot/buildroot-2021.02.7/05-timers$ date -d @1638701883.825167534
+неділя, 5 грудня 2021 12:58:03 +0200
+
+CLOCK_MONOTONIC is coresponding with the system uptime (take into account time taken for this report writing).
+6539/60=108 minutes
+van@ivan-VirtualBox:~$ w
+ 13:08:06 up  1:59,  1 user,  load average: 0,05, 0,07, 0,08
+
+The difference is explained by the time spent on this report writing.
+
+CLOCK_PROCESS_CPUTIM and CLOCK_THREAD_CPUTIME are short and very close. In this task I do not expect another result.
+CLOCK_BOOTTIME is mathched with CLOCK_MONOTONIC here, but also includes suspended time which I do not have for the moment.
+have not managed to get difference between CLOCK_BOOTTIME and CLOCK_MONOTONIC
diff --git a/05_timers/user_space/user_space_timers.c b/05_timers/user_space/user_space_timers.c
new file mode 100644
index 0000000..7f23a39
--- /dev/null
+++ b/05_timers/user_space/user_space_timers.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Implement program which return absolute time in user space.
+ * Use clock_gettime() from time.h. Try different clock id. Find the difference.
+ * Show possible clock resolution provided by clock_getres().
+ */
+
+#include <time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+int main(void)
+{
+    struct timespec real_ts, mono_ts, pcpu_ts, tcpu_ts, boot_ts;
+    struct timespec real_tp, mono_tp, pcpu_tp, tcpu_tp, boot_tp;
+
+    printf("getting clock resolution...\n");
+    if (clock_getres(CLOCK_REALTIME, &real_ts))
+	perror(strerror(errno));
+    if (clock_getres(CLOCK_MONOTONIC, &mono_ts))
+	perror(strerror(errno));
+    if (clock_getres(CLOCK_PROCESS_CPUTIME_ID, &pcpu_ts))
+	perror(strerror(errno));
+    if (clock_getres(CLOCK_THREAD_CPUTIME_ID, &tcpu_ts))
+	perror(strerror(errno));
+    if (clock_getres(CLOCK_BOOTTIME, &boot_ts))
+	perror(strerror(errno));
+
+    printf("----------------------------------------------------------------\n");
+    printf("|%-20.20s|%-20.20s|%-20.20s|\n", "clock_id", "sec", "nsec");
+    printf("----------------------------------------------------------------\n");
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_REALTIME", real_ts.tv_sec, real_ts.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_MONOTONIC", mono_ts.tv_sec, mono_ts.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_PROCESS_CPUTIME_ID", pcpu_ts.tv_sec, pcpu_ts.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_THREAD_CPUTIME_ID", tcpu_ts.tv_sec, tcpu_ts.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_BOOTTIME", boot_ts.tv_sec, boot_ts.tv_nsec);
+    printf("\n");
+
+    printf("getting actual clock values...\n");
+    if (clock_gettime(CLOCK_REALTIME, &real_tp))
+	perror(strerror(errno));
+    if (clock_gettime(CLOCK_MONOTONIC, &mono_tp))
+	perror(strerror(errno));
+    if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &pcpu_tp))
+	perror(strerror(errno));
+    if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tcpu_tp))
+	perror(strerror(errno));
+    if (clock_gettime(CLOCK_BOOTTIME, &boot_tp))
+	perror(strerror(errno));
+
+    printf("----------------------------------------------------------------\n");
+    printf("|%-20.20s|%-20.20s|%-20.20s|\n", "clock_id", "sec", "nsec");
+    printf("----------------------------------------------------------------\n");
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_REALTIME", real_tp.tv_sec, real_tp.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_MONOTONIC", mono_tp.tv_sec, mono_tp.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_PROCESS_CPUTIME_ID", pcpu_tp.tv_sec, pcpu_tp.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_THREAD_CPUTIME_ID", tcpu_tp.tv_sec, tcpu_tp.tv_nsec);
+    printf("|%-20.20s|%-20li|%-20li|\n", "CLOCK_BOOTTIME", boot_tp.tv_sec, boot_tp.tv_nsec);
+    printf("\n");
+
+    return 0;
+}
diff --git a/06_memory/README.md b/06_memory/README.md
new file mode 100644
index 0000000..4c22613
--- /dev/null
+++ b/06_memory/README.md
@@ -0,0 +1,22 @@
+# Memory management
+
+## Homework
+1. Create user-space C or C++ program which tries to allocate buffers
+  with sizes 2^x for x in range from 0 to maximium possible value 
+  using functions:
+  **malloc, calloc, alloca, (optional for C++) new **.
+  Measure time of each allocation/freeing.
+  2^x means x power of 2 in this task.
+Pull request should contains program source code and program output
+in text format.
+
+2. Create kernel module and test allocation/freeing time for functions:
+  **kmalloc, kzmalloc, vmalloc, get_free_pages,
+   (optional and only for drivers integrated to kernel)alloc_bootmem**.
+  Measure the time of each allocation/freeing except alloc_bootmem.
+  The results should be presented in text file table with followed columns:
+  Buffer size, allocation time, freeing time.
+  Size unit is 1 byte, time unit is 1 ns.
+
+Pull request should contains source code of developed driver, Makefile
+and program output from system log in text format.
diff --git a/07_procfs/Makefile b/07_procfs/Makefile
new file mode 100644
index 0000000..d8a8ac9
--- /dev/null
+++ b/07_procfs/Makefile
@@ -0,0 +1,9 @@
+KERNELDIR ?= ../output/build/linux-5.10.10
+
+obj-m := wimbledon.o
+
+all:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
diff --git a/07_procfs/README.md b/07_procfs/README.md
new file mode 100644
index 0000000..7fa3528
--- /dev/null
+++ b/07_procfs/README.md
@@ -0,0 +1,10 @@
+## Lesson 07 - ProcFS interface and orange pi bootup
+
+* Update your existing sysfs kernel module with procfs API:
+* Create folder in procfs file system;
+* Create entry that returns module author name;
+* Create entry that returns amount of "store" callback calls;
+* Create entry that returns amount of "show" callback calls.
+* Build image for orange pi zero
+* Attach console output from your development board
+
diff --git a/07_procfs/report.txt b/07_procfs/report.txt
new file mode 100644
index 0000000..991775b
--- /dev/null
+++ b/07_procfs/report.txt
@@ -0,0 +1,45 @@
+$ insmod wimbledon.ko 
+$ echo "a1" >> /sys/kernel/wimbledon/list 
+$ cat /proc/wimbeldon/nshow 
+0
+$ cat /proc/wimbeldon/nstore 
+1
+$ cat /proc/wimbeldon/auth_name 
+Ivan Stepanenko <istepanenko@gmail.com>
+$ cat /proc/wimbeldon/nshow 
+0
+$ cat /sys/kernel/wimbledon/list 
+a1
+$ cat /proc/wimbeldon/nshow 
+1
+$ echo "b2" >> /sys/kernel/wimbledon/list 
+$ cat /proc/wimbeldon/nstore 
+2
+$ cat /sys/kernel/wimbledon/list 
+a1
+b2
+$ cat /proc/wimbeldon/nshow 
+2
+$ uname -a
+Linux orange 5.10.10 #1 SMP Mon Dec 13 18:03:39 EET 2021 armv7l GNU/Linux
+$ rmmod wimbledon.ko 
+
+$ dmesg
+[ 3395.465083] wimbledon: adding msg size: 3 to the list: 'a1
+[ 3395.465083] '
+[ 3437.850684] wimbledon: msg #0 size: 3 'a1
+[ 3437.850684] '
+[ 3455.577961] wimbledon: adding msg size: 3 to the list: 'b2
+[ 3455.577961] '
+[ 3468.681388] wimbledon: msg #0 size: 3 'a1
+[ 3468.681388] '
+[ 3468.686988] wimbledon: msg #1 size: 3 'b2
+[ 3468.686988] '
+[ 3498.512991] wimbledon: freeing msg size: 3 from the list: 'b2
+[ 3498.512991] '
+[ 3498.520373] wimbledon: freeing msg size: 3 from the list: 'a1
+[ 3498.520373] '
+[ 3498.527719] wimbledon: list is empty: 1
+[ 3498.531576] wimbledon: removing procfs entries
+[ 3498.536034] wimbledon: Module exited
+$
diff --git a/07_procfs/wimbledon.c b/07_procfs/wimbledon.c
new file mode 100644
index 0000000..e1b1325
--- /dev/null
+++ b/07_procfs/wimbledon.c
@@ -0,0 +1,254 @@
+#define DEBUG
+#define pr_fmt(fmt) "%s: " fmt,  KBUILD_MODNAME
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+#include <linux/minmax.h>
+#include <asm/uaccess.h>
+
+#define AUTHOR "Ivan Stepanenko <istepanenko@gmail.com>"
+
+#define PROCFS_BUFF_SIZE     64
+#define PROCFS_DIR           "wimbeldon"
+#define PROCFS_FN_NSHOW      "nshow"
+#define PROCFS_FN_NSTORE     "nstore"
+#define PROCFS_FN_AUTH_NAME  "auth_name"
+
+struct msg_item {
+        struct list_head list;
+        char *msg;
+        size_t msg_len;
+};
+static LIST_HEAD(msg_list_head);
+
+static unsigned int show_cb_counter = 0;
+static unsigned int store_cb_counter = 0;
+
+
+static ssize_t wimbledon_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff)
+{
+    struct msg_item *pos = NULL;
+    size_t item_number = 0;
+    size_t count = 0;
+    char *p_buff = buff;
+
+    show_cb_counter += 1;
+
+    list_for_each_entry_reverse(pos, &msg_list_head, list) {
+        pr_info("msg #%u size: %u '%.*s'\n", item_number, pos->msg_len, (int)pos->msg_len, (char *)pos->msg);
+
+        memcpy(p_buff, (char *)pos->msg, pos->msg_len);
+        p_buff += pos->msg_len;
+        count += pos->msg_len;
+        item_number += 1;
+    }
+
+    return count;
+}
+
+
+static ssize_t wimbledon_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count)
+{
+    char *p_msg = NULL;
+    struct msg_item *p_item = NULL;
+
+    store_cb_counter += 1;
+
+    p_msg = kmalloc(count, GFP_KERNEL);
+    if (!p_msg) {
+        pr_err("could not allocate msg cnt: %u\n", count);
+        return -ENOMEM;
+    }
+    p_item = kmalloc(sizeof(struct msg_item), GFP_KERNEL);
+    if (!p_item) {
+        pr_err("could not allocate msg_item\n");
+        return -ENOMEM;
+    }
+    memcpy(p_msg, buff, count);
+    p_item->msg = p_msg;
+    p_item->msg_len = count;
+
+    pr_info("adding msg size: %u to the list: '%.*s'\n", p_item->msg_len, (int)p_item->msg_len, (char *)p_item->msg);
+    list_add(&p_item->list, &msg_list_head);
+    return count;
+}
+
+/* procfs operations */
+
+static struct proc_dir_entry *procfs_root_entry, *procfs_nshow_entry, *procfs_nstore_entry, *procfs_auth_name_entry;
+
+
+static ssize_t procfs_op_nshow_read(struct file *file, char __user *p_ubuf, size_t count, loff_t *ppos)
+{
+    char msg_buf[PROCFS_BUFF_SIZE];
+    int len = 0;
+
+    if(*ppos > 0)
+        return 0;
+
+    len = snprintf(NULL, 0, "%u\n", show_cb_counter);
+    if (len < 0 || len >= sizeof(msg_buf)) {
+        pr_err("msg len: %i doesn't fit buffer: %i\n", len, sizeof(msg_buf));
+        return -ENOMEM;
+    }
+
+    snprintf(msg_buf, len+1, "%u\n", show_cb_counter);
+
+    if (copy_to_user(p_ubuf, msg_buf, len)) {
+        pr_err("can't copy msg size: %i to user space\n", len);
+        return -EFAULT;
+    }
+
+    *ppos = len;
+
+    return len;
+}
+
+
+static ssize_t procfs_op_nstore_read(struct file *file, char __user *p_ubuf, size_t count, loff_t *ppos)
+{
+    char msg_buf[PROCFS_BUFF_SIZE];
+    int len = 0;
+
+    if(*ppos > 0)
+        return 0;
+
+    len = snprintf(NULL, 0, "%u\n", store_cb_counter);
+    if (len < 0 || len >= sizeof(msg_buf)) {
+        pr_err("msg len: %i doesn't fit buffer: %i\n", len, sizeof(msg_buf));
+        return -ENOMEM;
+    }
+    snprintf(msg_buf, len+1, "%u\n", store_cb_counter);
+
+    if (copy_to_user(p_ubuf, msg_buf, len)) {
+        pr_err("can't copy msg size: %i to user space\n", len);
+        return -EFAULT;
+    }
+
+    *ppos = len;
+
+    return len;
+}
+
+
+static ssize_t procfs_op_auth_name_read(struct file *file, char __user *p_ubuf, size_t count, loff_t *ppos)
+{
+    char msg_buf[sizeof(AUTHOR)+1];
+    int len = 0;
+
+    if(*ppos > 0)
+        return 0;
+
+    len = snprintf(NULL, 0, "%s\n", AUTHOR);
+    if (len < 0 || len >= sizeof(msg_buf)) {
+        pr_err("msg len: %i doesn't fit buffer: %i\n", len, sizeof(msg_buf));
+        return -ENOMEM;
+    }
+
+    snprintf(msg_buf, len+1, "%s\n", AUTHOR);
+
+    if (copy_to_user(p_ubuf, msg_buf, len)) {
+        pr_err("can't copy msg size: %i to user space\n", len);
+        return -EFAULT;
+    }
+
+    *ppos = len;
+
+    return len;
+}
+
+
+static struct proc_ops procfs_nshow_ops =
+{
+    .proc_read = procfs_op_nshow_read
+};
+
+static struct proc_ops procfs_nstore_ops =
+{
+    .proc_read= procfs_op_nstore_read
+};
+
+static struct proc_ops procfs_auth_name_ops =
+{
+    .proc_read= procfs_op_auth_name_read
+};
+
+/* end procsfs operations */
+
+static struct kobj_attribute list_attribute =
+        __ATTR(list, 0644, wimbledon_show, wimbledon_store);
+
+static struct kobject *wimbledon_kobj;
+
+static int wimbledon_init(void)
+{
+    int res = 0;
+    wimbledon_kobj = kobject_create_and_add("wimbledon", kernel_kobj);
+    if (!wimbledon_kobj)
+        return -ENOMEM;
+    res = sysfs_create_file(wimbledon_kobj, &list_attribute.attr);
+    if (res)
+        kobject_put(wimbledon_kobj);
+
+    procfs_root_entry = proc_mkdir(PROCFS_DIR, NULL);
+    if (procfs_root_entry == NULL) {
+        pr_err("error creating procfs: %s entry\n", PROCFS_DIR);
+        return -ENOMEM;
+    }
+    procfs_nshow_entry = proc_create(PROCFS_FN_NSHOW, 0444, procfs_root_entry, &procfs_nshow_ops);
+    if (procfs_nshow_entry == NULL) {
+        pr_err("error creating procfs: %s entry\n", PROCFS_FN_NSHOW);
+        return -ENOMEM;
+    }
+    procfs_nstore_entry = proc_create(PROCFS_FN_NSTORE, 0444, procfs_root_entry, &procfs_nstore_ops);
+    if (procfs_nstore_entry == NULL) {
+        pr_err("error creating procfs: %s entry\n", PROCFS_FN_NSTORE);
+        return -ENOMEM;
+    }
+    procfs_auth_name_entry = proc_create(PROCFS_FN_AUTH_NAME, 0444, procfs_root_entry, &procfs_auth_name_ops);
+    if (procfs_nstore_entry == NULL) {
+        pr_err("error creating procfs: %s entry\n", PROCFS_FN_AUTH_NAME);
+        return -ENOMEM;
+    }
+
+    return res;
+}
+
+static void wimbledon_exit(void)
+{
+    struct list_head *pos = NULL;
+    struct list_head *n = NULL;
+    struct msg_item *p_item = NULL;
+
+    list_for_each_safe(pos, n, &msg_list_head) {
+         p_item = list_entry(pos, struct msg_item, list);
+         pr_info("freeing msg size: %u from the list: '%.*s'\n", p_item->msg_len, (int)p_item->msg_len, (char *)p_item->msg);
+         list_del(pos);
+         kfree(p_item->msg);
+         kfree(p_item);
+    }
+    pr_info("list is empty: %d\n", list_empty_careful(&msg_list_head));
+    kobject_put(wimbledon_kobj);
+
+    pr_info("removing procfs entries\n");
+    proc_remove(procfs_auth_name_entry);
+    proc_remove(procfs_nstore_entry);
+    proc_remove(procfs_nshow_entry);
+    proc_remove(procfs_root_entry);
+
+    pr_info("Module exited\n");
+}
+
+module_init(wimbledon_init);
+module_exit(wimbledon_exit);
+
+MODULE_AUTHOR(AUTHOR);
+MODULE_DESCRIPTION("Shows num of store/show callbacks, stores data in the list items.");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");