feat(lab03): use timer on led on and off

+ separate timer function in dedicated class

.gitignore

@@ -54,3 +54,7 @@ solutions/**/build
 boot-scripts/boot.cifs
 boot-scripts/boot.net
 
+doc/**/*.pdf
+
+build
+src/03-led-controller/led-controller

doc/lab-01_02.typ

@@ -1,14 +1,10 @@
 // #import "@preview/hei-synd-report:0.1.1": *
-#import "@preview/hei-synd-thesis:0.4.0": *
 #import "/doc/metadata.typ": *
-#import "/doc/resources/glossary.typ": *
 #show:make-glossary
 #register-glossary(entry-list)
 
 #import "@preview/fractusist:0.1.1":*
 
-#import "@preview/grape-suite:3.1.0": exercise
-#import exercise: task, subtask
 
 //-------------------------------------
 // Template config
@@ -49,364 +45,31 @@
 //-------------------------------------
 // Content
 //
-
-= Embedded Linux Environment
-
-In this laboratory, we see how to setup our environnement and how to have several way to boot. That include a `boot.cifs` that allow us to load the rootfs from samba to easily share the rootfs between the host and the target. And also a `boot.tftp` that allow us to load the kernel by tftp, which is really usefull when we want to modify the kernel and test it without having to reflash the whole system.
-
-We also see how to debug our system with a remote debugger. That allow us to use debug in our code editor (vscode) a programm that run on the target.
-
-#figure(
-  image("/doc/resources/img/dev-environment.drawio.svg"),
-  caption: "Development environment schema"
-) <fig:dev-env>
-
-
-== Questions
-=== How to generate U-Boot?
-We use buildroot, a tool to build embedded Linux.
-It can generate the U-Boot bootloader.
-With `make menuconfig`, we can select the U-Boot package.
-U-boot can be configured with `make uboot-menuconfig`
-
-And finally, when we have configured everything, we can build the whole system with `make` command.
-Or only uboot with `make uboot` command.
-
-=== How to add and build a additional package in Buildroot?
-In buildroot, with `make menuconfig`, we can select the package we want in `Target packages` section. We can specifically build it with `make <package-name>` command. Otherwise, it will be built with the whole system when we run `make` command.
-
-=== How to modify the Linux kernel configuration?
-Like all package, with `make <package-name>-menuconfig` command. So, for Linux kernel:
-```bash
-|> make linux-menuconfig
-```
-
-=== How to generate a custom rootfs?
-First of all, select the type of filesystem you want to generate in `Filesystem images` section of `make menuconfig`. We can use an overlay to customise our rootfs.
-The overlay is a directory (inin the board folder) with the same structure as rootfs and it will merge with the generated rootfs. So, we can add files and directories in the overlay and they will be added to the final rootfs.
-
-
-=== How to use the eMMC card instead of the SD card?
-We need to change the boot script `(boot*.cmd)` to load from eMMC by changing the `fatload` command with the correct number. Probably 1 instead of 0.
-```
-fatload mmc 1 $kernel_addr_r Image
-```
-
-
-=== In cours support, we find several configurations of the development environment. What would be the optimal configuration for developing only user-space applications?
-If we develop only user space program, we don't need to load kernel by tftp. But it's really usefull to have rootfs load by samba. So the best approach is to use the `boot.cifs`.
-
-
-
-//--------------------------------------
+#include "lab00-env/main.typ"
 #pagebreak()
-= Linux Kernel Programming
-
-== Cheatsheet commands
-- `modinfo <module.ko>`: display information about a kernel module
-- `insmod <module.ko>`: install a kernel module (without checking for dependencies)
-- `rmmod <module.ko>`: uninstall a kernel module
-- `lsmod`: list the currently loaded kernel modules
-- `dmesg`: display the kernel log
-- `cat /proc/modules`: display the currently loaded kernel modules with more details
-- `modprobe <module>`: install a kernel module and its dependencies
-- `modprobe -r <module>`: uninstall a kernel module and its dependencies
-- `make`: build the kernel module
-- `make install`: install the kernel module in the root filesystem
-
-
-== Exercises
-
-//-------------------
-// Exercise 1: Generate kernel module out of tree
-//-------------------
-#task(
-  [Generate kernel module out of tree],
-  [],
-)
-
-//--------------
-#subtask[
-  Create the skeleton of a kernel module and generate it outside the kernel sources using a Makefile. The module should display a message when it is registered and when it is uninstalled.
-]
-
-We already have a skeleton in `src/02-modules/exercice01` (now `solutions/02_modules/exercice01` that we move to `src/01-skeleton`). We see on the Makefile that the module is generated outside the kernel sources with the `KDIR` variable imported from `src/kernel_settings`. This variable point to the kernel sources.
-The Makefile also use the `PWD` variable to the current directory.
-The `make` command will use these variables to generate the module in the current directory.
-
-```makefile
-$(MAKE) -C $(KDIR) M=$(PWD) ARCH=$(CPU) CROSS_COMPILE=$(TOOLS) modules
-```
-
-//--------------
-#subtask[
-  Test on the host machine the command modinfo1 on your module skeleton and compare the information returned with that of the source code.
-]
-
-```bash
-|> modinfo mymodule.ko
-filename:       /workspace/src/01-skeleton/mymodule.ko
-license:        GPL
-description:    Module skeleton
-author:         Klagarge <remi@heredero.ch>
-author:         Fastium <fastium.pro@proton.me>
-depends:        
-name:           mymodule
-vermagic:       5.15.148 SMP preempt mod_unload aarch64
-parm:           text:charp
-parm:           elements:int
-```
-//--------------
-#subtask[
-  Install the module (insmod) and check the kernel log (dmesg)
-]
-
-```bash
-|> insmod mymodule.ko
-[ 1727.896902] mymodule: loading out-of-tree module taints kernel.
-[ 1727.903442] Linux module 01 skeleton loaded
-```
-We can see the module is indead out-of-tree and correctly loaded.
-```bash
-|> dmesg | tail -5
-[ 1381.694764] CIFS: Attempting to mount \\192.168.53.4\workspace
-[ 1727.896902] mymodule: loading out-of-tree module taints kernel.
-[ 1727.903442] Linux module 01 skeleton loaded
-[ 1727.907659]   text: dummy text
-[ 1727.907659]   elements: 1
-```
-
-//--------------
-#subtask[
-  Compare the results obtained by the lsmod command with those obtained with the cat /proc/modules command
-]
-
-```bash
-|> lsmod
-Module                  Size  Used by    Tainted: G
-mymodule               16384  0
-···
-
-|> cat /proc/modules
-mymodule 16384 0 - Live 0xffff8000011bf000 (O)
-···
-```
-The `/proc/modules` file give us more details about the state of the module. We see it is now live (charged in memory and running)
-
-//--------------
-#subtask[
-  Uninstall the module (rmmod).
-]
-
-```bash
-|> rmmod mymodule.ko
-[ 2989.535793] Linux module skeleton unloaded
-```
-
-//--------------
-#subtask[
-  Adapt the Makefile of the module to allow the installation of the module with other kernel modules allowing the use of the modprobe command. The module should be installed in the root filesystem used in cifs by the target.
-]
-
-```bash
-# On host:
-|> make install
-
-# On target:
-|> modprobe mymodule
-[ 3359.811183] Linux module 01 skeleton loaded
-```
+#include "lab01-module/main.typ"
+#pagebreak()
+#include "lab02-peripheral/main.typ"
 
 #pagebreak()
-//-------------------
-// Exercise 2: Adapt the kernel module to receive parameters
-//-------------------
-#task(
-  [Adapt the kernel module to receive parameters],
-  [
-    Adapt the kernel module of the previous exercise to receive two or three parameters of your choice. These parameters will be displayed in the console when the module is loaded.
-  ],
-)
-
-```bash
-|> modprobe mymodule
-[ 3583.616662] Linux module skeleton ex02 loaded
-|> dmesg | tail -5
-[ 3559.279143]   number: 1
-[ 3581.198562] Linux module skeleton unloaded
-[ 3583.616662] Linux module skeleton ex03 loaded
-[ 3583.621085]   text: The answer to the Ultimate Question of Life, The Universe, and Everything
-[ 3583.621085]   number: 42
-|> modprobe -r mymodule
-[ 3588.404778] Linux module skeleton unloaded
-
-```
-
-//-------------------
-// Exercise 3: What does it mean the 4 values in ```/proc/sys/kernel/printk``` ?
-//-------------------
-#task(
-  [What does it mean the 4 values in ```/proc/sys/kernel/printk``` ?],
-  []
-)
-
-We can show what there is in:
-
-```bash
-|> cat /proc/sys/kernel/printk
-7	4	1	7
-```
-The number specified the level of output in a console.
-
-This file specifies the log level for: \
-current (7), default (4), minimum (1) and boot-time default (7).
-
-This number matches with this table (#link("https://www.kernel.org/doc/html/latest/core-api/printk-basics.html", [printk documentation])):
-
-#table(
-  columns: (2fr, 1fr, 3fr),
-
-  [*Name*], [*String*], [*Alias function*],
-
-  [KERN_EMERG], ["0"], [pr_emerg()],
-  [KERN_ALERT], ["1"], [pr_alert()],
-  [KERN_CRIT], ["2"], [pr_crit()],
-  [KERN_ERR], ["3"], [pr_err()],
-  [KERN_WARNING], ["4"], [pr_warning()],
-  [KERN_NOTICE], ["5"], [pr_notice()],
-  [KERN_INFO], ["6"], [pr_info()],
-  [KERN_DEBUG], ["7"], [pr_debug() and pr_devel() if DEBUG is defined],
-  [KERN_DEFAULT], [""], [],
-  [KERN_CONT], ["c"], [pr_cont()],
-)
+= #i18n("appendix-title", lang: option.lang) <sec:appendix>
+== Exercices Lab 01
 
+#include "lab01-module/ex01.typ"
 #pagebreak()
-//-------------------
-// Exercise 4: Create module with dynamic allocation and a chained list
-//-------------------
-
-#task(
-  [
-    Create module with dynamic allocation and a chained list
-  ],
-  [
-    Create dynamically elements in the kernel. Adapt a kernel module to specify at the installation the number of element to create a initial text.
-    Each element will contain a unique number. The elements are create at the installation of the module adn chained in a list.
-    These elements will be destruct during the uninstallation of the module.
-    Some information messages are emits to allow debugging.
-  ]
-)
-
-To allocate memory in the kernel, we can use the `kcalloc` function. It allows to allocate directly the memory for all element. It's also possible to use `kzalloc` in a loop to allocate memory for each element. We prefer allocate all the memory at once to avoid fragmentation and to be sure all the memory can be allocated.
-
-```bash
-struct element* element_ptr = kcalloc(elements, sizeof(struct element), GFP_KERNEL);
-
-for (int i = 0; i < elements; i++) {
-  struct element* e = element_ptr + i;
-      if (e != 0) {
-          strncpy(e->text, text, TEXT_LENGTH_MAX - 1);
-          e->unique_number = i;
-          list_add_tail(&e->node, &list_unique_elements);
-    pr_info ("add element %d: %s\n", e->unique_number, e->text);
-      }
-  }
-```
-
+#include "lab01-module/ex02.typ"
+#include "lab01-module/ex03.typ"
 #pagebreak()
-//-------------------
-// Exercise 5: Display the processor chip ID, CPU temperature and the MAC adress of the Ethernet controller
-//-------------------
-
-#task(
-  [
-    Display the processor chip ID, CPU temperature and the MAC adress of the Ethernet controller
-  ],
-  [
-    - Chip ID registers: _0x01c1'4200_ to _0x01c1'420c_
-    - 32 bits register of the temperature sensor: _0x01c2'5080_
-    - two 32 bits registers of the Ethernet controller MAC address: _0x01c3'0050_ and _0x01c3'0054_
-
-    To calculate the temperature value, there is this formul:
-    $
-      "temperature" = -1991 dot "register value" / 10 + 223000
-    $
-
-    The chip ID can be verified in ```/proc/iomem```. 
-    The register value of the temperature can be verified in the file: ```/sys/class/thermal/thermal_zone0/temp```. 
-    The MAC address can be verified with ``` ifconfig```.
-  ]
-)
-
-The resources are savec in a struct: 
-```c
-static struct resource* resources[3] = {[0] = 0,};
-```
-resources[0] is reserved for the chip ID, resources[1] for the temperature sensor and resources[2] for the Ethernet controller.
-
-We first allocate the resources with `request_mem_region` function. Then we can map the physical address to a virtual address with `ioremap` function. Finally, we can read the value of the registers with `ioread32` function. The request fail because we have an overlap with the EEPROM, but we can ignore this error because we can still read the registers with `ioremap` function.
-
-```c
-// Request the resource at (CHIP_ID_BASE_ADDR)
-resources[0] = request_mem_region(CHIP_ID_BASE_ADDR, 0x1000, "nanopi - chip ID");
-
-// Map the physical address (CHIP_ID_BASE_ADDR) to a virtual address (registers[0])
-registers[0] = ioremap(CHIP_ID_BASE_ADDR, 0x1000);
-```
-
-
-//-------------------
-// Exercise 6: Kernel thread
-//-------------------
-
-#task(
-  [
-    Kernel thread
-  ],
-  [
-    Develop a module which allows to instanciate a thread in the kernel. This thread will display a message every 5 seconds. Use the function ```ssleep(5)``` to sleep the thread from ``` linux/delay.h```.
-
-  ]
-)
-
-//-------------------
-// Exercise 7: Sleeping
-//-------------------
-
-#task(
-  [
-    Sleeping
-  ],
-  [
-    Develop a module which instanciate 2 threads in the kernel. The first one will wait a wake up notification from the second thread and will sleep. The second will send the notification every 5 seconds. Then it will sleep. We will use the waitqueue for the sleeping function. To allow debugging, each thread will send a message when it wakes up.
-  ]
-)
-
-//-------------------
-// Exercise 8: Interrupts
-//-------------------
-
-#task(
-  [
-    Interrupts
-  ],
-  [
-
-
-
-    Develop a module which allows to detect every push on the button of the nanopi with interrupt. Every interrupts will send a message for debugging.
-
-    - Use the service ``` gpio_request(<io_nr>, <label>)```
-    - Get the interrupt vector with ``` gpio_to_irq(<io_nr>)```
-    - Extension card information:
-      - k1 - gpio: A, pin_nr=0, io_nr=0
-      - k2 - gpio: A, pin_nr=2, io_nr=2
-      - k3 - gpio: A, pin_nr=3, io_nr=3
-  ]
-)
+#include "lab01-module/ex04.typ"
+#pagebreak()
+#include "lab01-module/ex05.typ"
+#include "lab01-module/ex06.typ"
+#pagebreak()
+#include "lab01-module/ex07.typ"
+#include "lab01-module/ex08.typ"
 
 //-------------------------------------
 // Glossary
 //
-#heading(numbering:none, outlined: false)[] <sec:end>
-#make_glossary(gloss:gloss, title:i18n("gloss-title"))
+// #heading(numbering:none, outlined: false)[] <sec:end>
+// #make_glossary(gloss:gloss, title:i18n("gloss-title"))

doc/lab-03_04.typ

@@ -47,7 +47,7 @@
 // Content
 // 
 
-= Linux System Programming
+#include "lab03-silly_led/main.typ"
 
 #lorem(150)
 

doc/lab00-env/main.typ

@@ -0,0 +1,45 @@
+= Embedded Linux Environment
+
+In this laboratory, we see how to setup our environnement and how to have several way to boot. That include a `boot.cifs` that allow us to load the rootfs from samba to easily share the rootfs between the host and the target. And also a `boot.tftp` that allow us to load the kernel by tftp, which is really usefull when we want to modify the kernel and test it without having to reflash the whole system.
+
+We also see how to debug our system with a remote debugger. That allow us to use debug in our code editor (vscode) a programm that run on the target.
+
+#figure(
+  image("./dev-environment.png"),
+  caption: "Development environment schema"
+) <fig:dev-env>
+
+
+== Questions
+=== How to generate U-Boot?
+We use buildroot, a tool to build embedded Linux.
+It can generate the U-Boot bootloader.
+With `make menuconfig`, we can select the U-Boot package.
+U-boot can be configured with `make uboot-menuconfig`
+
+And finally, when we have configured everything, we can build the whole system with `make` command.
+Or only uboot with `make uboot` command.
+
+=== How to add and build a additional package in Buildroot?
+In buildroot, with `make menuconfig`, we can select the package we want in `Target packages` section. We can specifically build it with `make <package-name>` command. Otherwise, it will be built with the whole system when we run `make` command.
+
+=== How to modify the Linux kernel configuration?
+Like all package, with `make <package-name>-menuconfig` command. So, for Linux kernel:
+```bash
+|> make linux-menuconfig
+```
+
+=== How to generate a custom rootfs?
+First of all, select the type of filesystem you want to generate in `Filesystem images` section of `make menuconfig`. We can use an overlay to customise our rootfs.
+The overlay is a directory (in the board folder) with the same structure as rootfs and it will merge with the generated rootfs. So, we can add files and directories in the overlay and they will be added to the final rootfs.
+
+
+=== How to use the eMMC card instead of the SD card?
+We need to change the boot script `(boot*.cmd)` to load from eMMC by changing the `fatload` command with the correct number. Probably 1 instead of 0.
+```
+fatload mmc 1 $kernel_addr_r Image
+```
+
+
+=== In cours support, we find several configurations of the development environment. What would be the optimal configuration for developing only user-space applications?
+If we develop only user space program, we don't need to load kernel by tftp. But it's really usefull to have rootfs load by samba. So the best approach is to use the `boot.cifs`.

doc/lab01-module/ex01.typ

@@ -0,0 +1,95 @@
+#import "/doc/metadata.typ": *
+
+=== Generate kernel module out of tree <lab01:ex01>
+
+#colorbox(title: "Exercise", color: hei-blue)[
+  Create the skeleton of a kernel module and generate it outside the kernel sources using a Makefile. The module should display a message when it is registered and when it is uninstalled.
+]
+//--------------
+
+We already have a skeleton in `src/02-modules/exercice01` (now `solutions/02_modules/exercice01` that we move to `src/01-skeleton`). We see on the Makefile that the module is generated outside the kernel sources with the `KDIR` variable imported from `src/kernel_settings`. This variable point to the kernel sources.
+The Makefile also use the `PWD` variable to the current directory.
+The `make` command will use these variables to generate the module in the current directory.
+
+```makefile
+$(MAKE) -C $(KDIR) M=$(PWD) ARCH=$(CPU) CROSS_COMPILE=$(TOOLS) modules
+```
+
+//--------------
+#colorbox(title: "Exercise", color: hei-blue)[
+  Test on the host machine the command modinfo1 on your module skeleton and compare the information returned with that of the source code.
+]
+
+```bash
+|> modinfo mymodule.ko
+filename:       /workspace/src/01-skeleton/mymodule.ko
+license:        GPL
+description:    Module skeleton
+author:         Klagarge <remi@heredero.ch>
+author:         Fastium <fastium.pro@proton.me>
+depends:
+name:           mymodule
+vermagic:       5.15.148 SMP preempt mod_unload aarch64
+parm:           text:charp
+parm:           elements:int
+```
+//--------------
+#colorbox(title: "Exercise", color: hei-blue)[
+  Install the module (insmod) and check the kernel log (dmesg)
+]
+
+```bash
+|> insmod mymodule.ko
+[ 1727.896902] mymodule: loading out-of-tree module taints kernel.
+[ 1727.903442] Linux module 01 skeleton loaded
+```
+We can see the module is indead out-of-tree and correctly loaded.
+```bash
+|> dmesg | tail -5
+[ 1381.694764] CIFS: Attempting to mount \\192.168.53.4\workspace
+[ 1727.896902] mymodule: loading out-of-tree module taints kernel.
+[ 1727.903442] Linux module 01 skeleton loaded
+[ 1727.907659]   text: dummy text
+[ 1727.907659]   elements: 1
+```
+
+//--------------
+#colorbox(title: "Exercise", color: hei-blue)[
+  Compare the results obtained by the lsmod command with those obtained with the cat /proc/modules command
+]
+
+```bash
+|> lsmod
+Module                  Size  Used by    Tainted: G
+mymodule               16384  0
+···
+
+|> cat /proc/modules
+mymodule 16384 0 - Live 0xffff8000011bf000 (O)
+···
+```
+The `/proc/modules` file give us more details about the state of the module. We see it is now live (charged in memory and running)
+
+//--------------
+#colorbox(title: "Exercise", color: hei-blue)[
+  Uninstall the module (rmmod).
+]
+
+```bash
+|> rmmod mymodule.ko
+[ 2989.535793] Linux module skeleton unloaded
+```
+
+//--------------
+#colorbox(title: "Exercise", color: hei-blue)[
+  Adapt the Makefile of the module to allow the installation of the module with other kernel modules allowing the use of the modprobe command. The module should be installed in the root filesystem used in cifs by the target.
+]
+
+```bash
+# On host:
+|> make install
+
+# On target:
+|> modprobe mymodule
+[ 3359.811183] Linux module 01 skeleton loaded
+```

doc/lab01-module/ex02.typ

@@ -0,0 +1,19 @@
+#import "/doc/metadata.typ": *
+
+=== Adapt the kernel module to receive parameters <lab01:ex02>
+#colorbox(title: "Exercise", color: hei-blue)[
+  Adapt the kernel module of the previous exercise to receive two or three parameters of your choice. These parameters will be displayed in the console when the module is loaded.
+]
+
+```bash
+|> modprobe mymodule
+[ 3583.616662] Linux module skeleton ex02 loaded
+|> dmesg | tail -5
+[ 3559.279143]   number: 1
+[ 3581.198562] Linux module skeleton unloaded
+[ 3583.616662] Linux module skeleton ex03 loaded
+[ 3583.621085]   text: The answer to the Ultimate Question of Life, The Universe, and Everything
+[ 3583.621085]   number: 42
+|> modprobe -r mymodule
+[ 3588.404778] Linux module skeleton unloaded
+```

doc/lab01-module/ex03.typ

@@ -0,0 +1,33 @@
+#import "/doc/metadata.typ": *
+
+=== What does it mean the 4 values in ```/proc/sys/kernel/printk``` ?  <lab01:ex03>
+
+We can show what there is in:
+
+```bash
+|> cat /proc/sys/kernel/printk
+7	4	1	7
+```
+The number specified the level of output in a console.
+
+This file specifies the log level for: \
+current (7), default (4), minimum (1) and boot-time default (7).
+
+This number matches with this table (#link("https://www.kernel.org/doc/html/latest/core-api/printk-basics.html", [printk documentation])):
+
+#table(
+  columns: (2fr, 1fr, 3fr),
+
+  [*Name*], [*String*], [*Alias function*],
+
+  [KERN_EMERG], ["0"], [pr_emerg()],
+  [KERN_ALERT], ["1"], [pr_alert()],
+  [KERN_CRIT], ["2"], [pr_crit()],
+  [KERN_ERR], ["3"], [pr_err()],
+  [KERN_WARNING], ["4"], [pr_warning()],
+  [KERN_NOTICE], ["5"], [pr_notice()],
+  [KERN_INFO], ["6"], [pr_info()],
+  [KERN_DEBUG], ["7"], [pr_debug() and pr_devel() if DEBUG is defined],
+  [KERN_DEFAULT], [""], [],
+  [KERN_CONT], ["c"], [pr_cont()],
+)

doc/lab01-module/ex04.typ

@@ -0,0 +1,25 @@
+#import "/doc/metadata.typ": *
+
+=== Create module with dynamic allocation and a chained list  <lab01:ex04>
+#colorbox(title: "Exercise", color: hei-blue)[
+  Create dynamically elements in the kernel. Adapt a kernel module to specify at the installation the number of element to create a initial text.
+  Each element will contain a unique number. The elements are create at the installation of the module adn chained in a list.
+  These elements will be destruct during the uninstallation of the module.
+  Some information messages are emits to allow debugging.
+]
+
+To allocate memory in the kernel, we can use the `kcalloc` function. It allows to allocate directly the memory for all element. It's also possible to use `kzalloc` in a loop to allocate memory for each element. We prefer allocate all the memory at once to avoid fragmentation and to be sure all the memory can be allocated.
+
+```bash
+struct element* element_ptr = kcalloc(elements, sizeof(struct element), GFP_KERNEL);
+
+for (int i = 0; i < elements; i++) {
+    struct element* e = element_ptr + i;
+    if (e != 0) {
+        strncpy(e->text, text, TEXT_LENGTH_MAX - 1);
+        e->unique_number = i;
+        list_add_tail(&e->node, &list_unique_elements);
+        pr_info ("add element %d: %s\n", e->unique_number, e->text);
+    }
+}
+```

doc/lab01-module/ex05.typ

@@ -0,0 +1,33 @@
+#import "/doc/metadata.typ": *
+
+=== Display the processor chip ID, CPU temperature and the MAC adress of the Ethernet controller  <lab01:ex05>
+#colorbox(title: "Exercise", color: hei-blue)[
+  - Chip ID registers: _0x01c1'4200_ to _0x01c1'420c_
+  - 32 bits register of the temperature sensor: _0x01c2'5080_
+  - two 32 bits registers of the Ethernet controller MAC address: _0x01c3'0050_ and _0x01c3'0054_
+
+  To calculate the temperature value, there is this formul:
+  $
+    "temperature" = -1991 dot "register value" / 10 + 223000
+  $
+
+  The chip ID can be verified in ```/proc/iomem```.
+  The register value of the temperature can be verified in the file: ```/sys/class/thermal/thermal_zone0/temp```.
+  The MAC address can be verified with ``` ifconfig```.
+]
+
+The resources are savec in a struct:
+```c
+static struct resource* resources[3] = {[0] = 0,};
+```
+resources[0] is reserved for the chip ID, resources[1] for the temperature sensor and resources[2] for the Ethernet controller.
+
+We first allocate the resources with `request_mem_region` function. Then we can map the physical address to a virtual address with `ioremap` function. Finally, we can read the value of the registers with `ioread32` function. The request fail because we have an overlap with the EEPROM, but we can ignore this error because we can still read the registers with `ioremap` function.
+
+```c
+// Request the resource at (CHIP_ID_BASE_ADDR)
+resources[0] = request_mem_region(CHIP_ID_BASE_ADDR, 0x1000, "nanopi - chip ID");
+
+// Map the physical address (CHIP_ID_BASE_ADDR) to a virtual address (registers[0])
+registers[0] = ioremap(CHIP_ID_BASE_ADDR, 0x1000);
+```

doc/lab01-module/ex06.typ

@@ -0,0 +1,8 @@
+#import "/doc/metadata.typ": *
+
+=== Kernel thread  <lab01:ex06>
+#colorbox(title: "Exercise", color: hei-blue)[
+  Develop a module which allows to instanciate a thread in the kernel. This thread will display a message every 5 seconds. Use the function ```ssleep(5)``` to sleep the thread from ``` linux/delay.h```.
+]
+
+Easy exercice, a thread in the kernel is a `struct task_struct*` that can be created with `kthread_run`

doc/lab01-module/ex07.typ

@@ -0,0 +1,15 @@
+#import "/doc/metadata.typ": *
+
+=== Sleeping  <lab01:ex07>
+#colorbox(title: "Exercise", color: hei-blue)[
+  Develop a module which instanciate 2 threads in the kernel. The first one will wait a wake up notification from the second thread and will sleep. The second will send the notification every 5 seconds. Then it will sleep. We will use the waitqueue for the sleeping function. To allow debugging, each thread will send a message when it wakes up.
+]
+
+This exercice make 2 threads in concurrency with wait queue. Here the queue ware declare
+statically with the macro `DECLARE_WAIT_QUEUE_HEAD`.  Then for this exercice we use an atomic
+trigger with 2 queues. It important that the trigger is atomic or protected by mutex because
+there is concurrency. The wait queues are used to wait until the trigger has changed to keep
+synchronization between the threads.
+
+It is very important to add `kthread_should_stop()` as a condition to wake up queue, because if there is
+a problem during the implementation, we cannot kill the code.

doc/lab01-module/ex08.typ

@@ -0,0 +1,24 @@
+#import "/doc/metadata.typ": *
+
+=== Interrupts  <lab01:ex08>
+#colorbox(title: "Exercise", color: hei-blue)[
+  Develop a module which allows to detect every push on the button of the nanopi with interrupt. Every interrupts will send a message for debugging.
+
+  - Use the service ``` gpio_request(<io_nr>, <label>)```
+  - Get the interrupt vector with ``` gpio_to_irq(<io_nr>)```
+  - Extension card information:
+    - k1 - gpio: A, pin_nr=0, io_nr=0
+    - k2 - gpio: A, pin_nr=2, io_nr=2
+    - k3 - gpio: A, pin_nr=3, io_nr=3
+]
+
+We made a custom structur for the gpio device that contain all useful information like the name and the id.
+```c
+struct gpio_nanopi {
+    int id;
+    char* name;
+};
+static struct gpio_nanopi switchK1 = {0, "K1: GPIOA.0"};
+static struct gpio_nanopi switchK2 = {2, "K2: GPIOA.2"};
+static struct gpio_nanopi switchK3 = {3, "K3: GPIOA.3"};
+```

doc/lab01-module/main.typ

@@ -0,0 +1,79 @@
+#import "/doc/metadata.typ": *
+#let ln(num) = {
+  let str_num = if int(num) < 10 { "0" + str(num) } else { str(num) }
+  let lbl = label("lab01:ex" + str_num)
+  link(lbl)[Ex 1.#num]
+}
+= Linux Kernel Programming
+
+In this lab, we learn how to develop a tiny kernel module. We initially create a tiny skeleton that just print a message when the module is loaded and unloaded in #ln(1). Then in #ln(2), we see how to use parameters with insmod and with modprobe. To make things easier for us, we’ve added a line to the makefile that copy the module’s configuration file (that contain the parameters for the modules) to the correct directory on the target. The `install` command is used as a combination of `mkdir`, `cp` and `chmod`.
+```makefile
+install:
+	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(MODPATH) modules_install
+	install -D -m 0644 $(SOURCE).conf $(MODPATH)/etc/modprobe.d/$(SOURCE).conf
+```
+
+
+The exercise 3 ask us what does it mean the 4 values in `/proc/sys/kernel/printk`?
+We can show what there is in:
+```bash
+|> cat /proc/sys/kernel/printk
+7	4	1	7
+```
+The number specified the level of output in a console.
+
+This file specifies the log level for: \
+current (7), default (4), minimum (1) and boot-time default (7).
+
+This number matches with this table (#link("https://www.kernel.org/doc/html/latest/core-api/printk-basics.html", [printk documentation])):
+
+#table(
+  columns: (2fr, 1fr, 3fr),
+
+  [*Name*], [*String*], [*Alias function*],
+
+  [KERN_EMERG], ["0"], [pr_emerg()],
+  [KERN_ALERT], ["1"], [pr_alert()],
+  [KERN_CRIT], ["2"], [pr_crit()],
+  [KERN_ERR], ["3"], [pr_err()],
+  [KERN_WARNING], ["4"], [pr_warning()],
+  [KERN_NOTICE], ["5"], [pr_notice()],
+  [KERN_INFO], ["6"], [pr_info()],
+  [KERN_DEBUG], ["7"], [pr_debug() and pr_devel() if DEBUG is defined],
+  [KERN_DEFAULT], [""], [],
+  [KERN_CONT], ["c"], [pr_cont()],
+)
+
+In #ln(4), we see how to dynamically create elements in the kernel. We use `kcallo` instead of `kzalloc` to allocate all the memory at once and be certain we have the necessary place for all elements of our module. It also a better approach in our opinion to avoid fragmentation.
+
+We spent some time on the #ln(5) to understand that the `request_mem_region` failed because we have an overlap with the EEPROM.
+
+The #ln(6) was a straightforward exercise where we had to develop a module that instantiated a thread.
+
+In the #ln(7) was on concurrency. We had 2 threads with a wait queue. We learn how to suspend a thread, how to wake it up and how to do atomic operation.
+
+In the last exercise of this lab, #ln(8), we see how to manage interruptions and connect them to a gpio.
+
+== Cheat sheet commands
+- `modinfo <module.ko>`: display information about a kernel module
+- `insmod <module.ko>`: install a kernel module (without checking for dependencies)
+- `rmmod <module.ko>`: uninstall a kernel module
+- `lsmod`: list the currently loaded kernel modules
+- `dmesg`: display the kernel log
+- `cat /proc/modules`: display the currently loaded kernel modules with more details
+- `modprobe <module>`: install a kernel module and its dependencies
+- `modprobe -r <module>`: uninstall a kernel module and its dependencies
+- `make`: build the kernel module
+- `make install`: install the kernel module in the root filesystem
+
+== Zed
+For this lab, we start to work with another code editor than vscode. Not because we don't like Microsoft, ... but mostly for this reason. We use zed with the new devcontainer implementation on this wonderful code editor. To be able to work in nice condition, we add our own `.clangd` build with the help `bear`.
+
+This clangd, allow us to have a perfect autocompletion and a enjoyable code navigation. We can easily jump to the definition of a function and see the documentation of a function.
+
+Thanks to Zed teams for this awesome code editor and \@Fastium for his clangd
+
+== Conclusion
+All this lab was done by iteration on the initial skeleton. We develop everything in the #link("https://github.com/Klagarge/MSE-MA-CSEL/tree/main/src/01-skeleton")[src/01-skeleton] folder.
+
+It was a very delightful introduction lab that show us some possibilities when we want to create a kernel module. Everything was new for us, so even it's basics concept, this was a bit challenging to grasp the subject.

doc/lab02-peripheral/ex01.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/ex02.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/ex03.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/ex04.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/ex05.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/ex07.typ

@@ -0,0 +1 @@
+#import "/doc/metadata.typ": *

doc/lab02-peripheral/main.typ

@@ -0,0 +1,34 @@
+#import "/doc/metadata.typ": *
+#let ln(num) = {
+  // let str_num = if int(num) < 10 { "0" + str(num) } else { str(num) }
+  // let lbl = label("lab02:ex" + str_num)
+  // link(lbl)[Ex 2.#num]
+  [Ex 2.#num]
+}
+
+= Linux Kernel Programming
+
+In the First exercise, we learn how to access a register thought the `/dev/mem` interface. The purpose was to read the chip ID, but we learn how to access in a specific region of the memory. How pages work and how to map them in the user space.
+
+For exercise 2, we see how to create a character device driver. We learn how to create a device file, how to write a read and write functions and how to test it with `echo` and `cat`. Our module has a `MAJOR` dynamically allocated (but should be 511 with default nanopi installation) and only one minor. To verify the major number, we can use `cat /proc/devices` and look for our module name. To test the module, we need to create a character device file with the right major and minor number. 
+```bash
+mknod /dev/test-device c 511 0 # Create character device 
+echo "lalalalalaalalalalallala" > /dev/test-device # Write to the device
+cat /dev/test-device # Read from the device
+```
+Quite easy to extend to exercise 3 by adding the parameters as we did in the previous lab. This parameters define the number of minor available. 
+
+Exercise 4 is the continuity, we had to create a tiny app that basically do the `echo` and `cat` for us. We can use the `open`, `write`, `read` and `close` system calls to interact with our device file. We still need to create the device file: 
+```bash
+mknod /dev/toto0 c 511 0
+```
+
+The next step in exercise 5 is to create a sysfs entry for our module. Lot of theory, but once the theory is grasped, it's relatively straightforward to use the sysfs functions in our module.
+
+The sysfs class is useful when we are attribute oriented. It's easy to store attributes in files. The platform driver is useful when we are processes oriented. The misc device simplify the peripheral instantiation.
+
+== Adaptation for Zed environment
+For this lab, we have to work with application and not with module. We have the same problem with clang for the LSP with Zed. To solve it, we include the Linux header files and specify the path of sysroot. Like this, clang have all the dependencies that we need. And tadam, the wonderful environment we had on previous lab is back!
+
+== Conclusion
+All the content of this is on #link("https://github.com/Klagarge/MSE-MA-CSEL/tree/main/src/02-driver")[src/02-driver]. It was pleasant to initially see how to manage a character device manually and step by step see how to do it with an easier method. I personally like to start from the bottom. 

doc/lab03-silly_led/main.typ

@@ -0,0 +1,3 @@
+#import "/doc/metadata.typ": *
+
+= Linux System Programming

doc/metadata.typ

@@ -1,3 +1,7 @@
+#import "@preview/hei-synd-thesis:0.4.0": *
+#import "/doc/resources/glossary.typ": *
+#import "@preview/grape-suite:3.1.0": exercise
+#import exercise: task, subtask
 //-------------------------------------
 // Document options
 //
@@ -55,4 +59,4 @@
   maxdepth: 3,
 )
 
-#let gloss = true
+#let gloss = true

solutions/04_system/silly/CMakeLists.txt

@@ -1,5 +1,4 @@
 cmake_minimum_required(VERSION 3.28)
 project(ex7-app)
 
-include(../../nanopi.cmake)
 add_executable(silly_led_control silly_led_control.c)

solutions/04_system/silly/Makefile

@@ -1,12 +1,13 @@
 # Makefile for CMake project with intelligent configuration
 
+
 # Default target
-all: build/build.ninja 
+all: build/build.ninja
 	cmake --build build
 
 # Create build directory and generate build files if needed
 build/build.ninja : CMakeLists.txt
-	cmake -S . -B build -G "Ninja"
+	cmake -S . -B build -G "Ninja" -DCMAKE_TOOLCHAIN_FILE=../../nanopi.cmake
 
 # Clean build directory
 clean:
@@ -16,4 +17,4 @@ clean:
 rebuild: clean all
 
 # Phony targets (targets that don't represent files)
-.PHONY: all clean rebuild
+.PHONY: all clean rebuild

src/01-skeleton/Makefile

@@ -28,8 +28,7 @@ clean:
 
 install:
 	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(MODPATH) modules_install
-	install -d $(MODPATH)/etc/modprobe.d
-	install -m 0644 $(SOURCE).conf $(MODPATH)/etc/modprobe.d/$(SOURCE).conf
+	install -D -m 0644 $(SOURCE).conf $(MODPATH)/etc/modprobe.d/$(SOURCE).conf
 
 endif
 

src/01-skeleton/kernel-module/s02e04-dynamic_allocation.c

@@ -49,7 +49,9 @@ void dynAlloc_exit(void) {
         e = list_entry(list_unique_elements.next, struct element, node);
         pr_info ("delete element %d: %s\n", e->unique_number, e->text);
         list_del(&e->node);
-        kfree(e);
+        if (e != 0) {
+            kfree(e);
+        }
     }
 
     pr_info("Memory allocated for dynamic allocation and linked list freed\n");

src/01-skeleton/kernel-module/s02e06-thread.c

@@ -0,0 +1,42 @@
+#include <linux/module.h>	// needed by all modules
+#include <linux/init.h>		// needed for macros
+#include <linux/kernel.h>	// needed for debugging
+
+
+#include <linux/kthread.h>
+#include <linux/delay.h>
+
+static struct task_struct* sample_thread;
+
+#define DELAY_S 5
+
+int thread_skeletonThread (void* data) {
+
+    pr_info("Thread started\n");
+
+    while (!kthread_should_stop()) {
+        pr_info("PING!\n");
+        ssleep(DELAY_S);
+    }
+
+    return 0;
+}
+
+void thread_init(void) {
+    pr_info("Initialize kernel thread\n");
+
+    sample_thread = kthread_run(thread_skeletonThread, NULL, "The Machine that goes");
+    if (IS_ERR(sample_thread)) {
+        pr_err("Failed to create kernel thread\n");
+        return;
+    }
+
+    pr_info("Kernel thread initialized\n");
+
+}
+
+void thread_exit(void) {
+    pr_info("Exiting kernel thread\n");
+    kthread_stop(sample_thread);
+    pr_info("Kernel thread exited\n");
+}

src/01-skeleton/kernel-module/s02e07-sleeping.c

@@ -0,0 +1,90 @@
+#include <linux/module.h>	// needed by all modules
+#include <linux/init.h>		// needed for macros
+#include <linux/kernel.h>	// needed for debugging
+
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/atomic.h>
+
+#define TIMEOUT_S 5
+
+DECLARE_WAIT_QUEUE_HEAD(queue_1);
+DECLARE_WAIT_QUEUE_HEAD(queue_2);
+
+static struct task_struct* thread_1;
+static struct task_struct* thread_2;
+static atomic_t trigger = ATOMIC_INIT(0);
+
+int thread_skeleton_1(void* data) {
+    // must wait 5 seconds and start thread 2
+
+    pr_info("Thread 1 started\n");
+
+    while (!kthread_should_stop()) {
+        pr_info("Thread 1 wakes up\n");
+        ssleep(TIMEOUT_S);
+
+        // Setup trigger for condition of the thread 2
+        atomic_set(&trigger, 1);
+
+        // Wake up thread 2
+        wake_up_interruptible(&queue_2);
+
+        // Wait until thread 2 has reset the trigger
+        wait_event_interruptible(queue_1, atomic_read(&trigger) == 0 || kthread_should_stop());
+    }
+
+    return 0;
+}
+
+int thread_skeleton_2(void* data) {
+    // have to PING when wakes up
+
+    pr_info("Thread 2 started\n");
+
+
+    while (!kthread_should_stop()) {
+
+        // wait until trigger is set up
+        wait_event_interruptible(queue_2, atomic_read(&trigger) == 1 || kthread_should_stop());
+        pr_info("Thread 2 wakes up\n");
+
+        // reset trigger
+        atomic_set(&trigger, 0);
+
+        // wake up thread 1
+        wake_up_interruptible(&queue_1);
+    }
+
+    return 0;
+}
+
+
+void sleeping_init(void) {
+    pr_info("Initialize kernel thread\n");
+
+    atomic_set(&trigger, 0);
+
+    thread_1 = kthread_run(thread_skeleton_1, NULL, "Thread 1 - sleeping");
+    if (IS_ERR(thread_1)) {
+        pr_err("Failed to create kernel thread 1\n");
+        return;
+    }
+
+    thread_2 = kthread_run(thread_skeleton_2, NULL, "Thread 2 - sleeping");
+    if (IS_ERR(thread_2)) {
+        pr_err("Failed to create kernel thread 1\n");
+        return;
+    }
+
+    pr_info("Kernel thread sleeping initialized\n");
+
+}
+
+void sleeping_exit(void) {
+    pr_info("Exiting kernel sleeping thread\n");
+    kthread_stop(thread_1);
+    kthread_stop(thread_2);
+    pr_info("Kernel thread sleeping exited\n");
+}

src/01-skeleton/kernel-module/s02e08-interrupt.c

@@ -0,0 +1,80 @@
+#include <linux/module.h>	// needed by all modules
+#include <linux/init.h>		// needed for macros
+#include <linux/kernel.h>	// needed for debugging
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include "linux/printk.h"
+
+struct gpio_nanopi {
+    int id;
+    char* name;
+};
+
+static struct gpio_nanopi switchK1 = {0, "K1: GPIOA.0"};
+static struct gpio_nanopi switchK2 = {2, "K2: GPIOA.2"};
+static struct gpio_nanopi switchK3 = {3, "K3: GPIOA.3"};
+
+irqreturn_t isrGPIO(int irq, void* gpio_struct) {
+    struct gpio_nanopi *gpio = (struct gpio_nanopi *)gpio_struct;
+    pr_info("GPIO pressed: %s\n", gpio->name);
+    return IRQ_HANDLED;
+}
+
+
+void interrupt_init(void) {
+    pr_info("Initializing interrupts\n");
+
+    int status = 0;
+
+    // Switch k1
+    if (gpio_request(switchK1.id, switchK1.name) == 0) {
+        status = request_irq(
+            gpio_to_irq(switchK1.id),
+            isrGPIO,
+            IRQF_TRIGGER_FALLING | IRQF_SHARED,
+            switchK1.name,
+            &switchK1
+        );
+    }
+
+    // Switch k2
+    if (gpio_request(switchK2.id, switchK2.name) == 0) {
+        status = request_irq(
+            gpio_to_irq(switchK2.id),
+            isrGPIO,
+            IRQF_TRIGGER_FALLING | IRQF_SHARED,
+            switchK2.name,
+            &switchK2
+        );
+    }
+
+    // Switch k3
+    if (gpio_request(switchK3.id, switchK3.name) == 0) {
+        status = request_irq(
+            gpio_to_irq(switchK3.id),
+            isrGPIO,
+            IRQF_TRIGGER_FALLING | IRQF_SHARED,
+            switchK3.name,
+            &switchK3
+        );
+    }
+
+    pr_info("Interrupt initialized\n");
+}
+
+void interrupt_exit(void) {
+    pr_info("Exiting interrupts\n");
+
+    gpio_free(switchK1.id);
+    free_irq(gpio_to_irq(switchK1.id), &switchK1);
+
+    gpio_free(switchK2.id);
+    free_irq(gpio_to_irq(switchK2.id), &switchK2);
+
+    gpio_free(switchK3.id);
+    free_irq(gpio_to_irq(switchK3.id), &switchK3);
+
+    pr_info ("Interrupt exited\n");
+
+}

src/01-skeleton/skeleton.c

@@ -3,47 +3,105 @@
 #include <linux/init.h>		// needed for macros
 #include <linux/kernel.h>	// needed for debugging
 
-#include "s02e02-parameters.c"
-#include "s02e04-dynamic_allocation.c"
-#include "s02e05-io_memory_mapped.c"
+#include "linux/printk.h"
+#include "kernel-module/s02e02-parameters.c"
+// #define PARAMETERS
+
+#include "kernel-module/s02e04-dynamic_allocation.c"
+// #define DYNAMIC_ALLOCATION
+
+#include "kernel-module/s02e05-io_memory_mapped.c"
+// #define IO_MEMORY_MAPPED
+
+#include "kernel-module/s02e06-thread.c"
+// #define THREAD
+
+#include "kernel-module/s02e07-sleeping.c"
+// #define SLEEPING
+
+#include "kernel-module/s02e08-interrupt.c"
+#define INTERRUPT
 
 
 static int __init skeleton_init(void) {
     pr_info("Linux module skeleton ex05 loading...\n");
-	pr_info("--------------------\n");
 
     // Lab02 - Exercise 2: Parameters
+    #ifdef PARAMETERS
+	pr_info("--------------------\n");
     parameters_print();
-
-    pr_info("--------------------\n");
+    #endif
 
     // Lab02 - Exercise 4: Dynamic memory allocation and linked list
-    dynAlloc_init();
-
+    #ifdef DYNAMIC_ALLOCATION
     pr_info("--------------------\n");
+    Alloc_init();
+    #endif
 
     // Lab02 - Exercise 5: Memory-mapped I/O
+    #ifdef IO_MEMORY_MAPPED
+    pr_info("--------------------\n");
     ioMemoryMapped_init();
+    #endif
+
+    // Lab02 - Exercise 6: Kernel thread
+    #ifdef THREAD
+    pr_info("--------------------\n");
+    thread_init();
+    #endif
+
+    // Lab02 - Exercise 7: Sleeping
+    #ifdef SLEEPING
+    pr_info("--------------------\n");
+    sleeping_init();
+    #endif
+
+    // Lab02 - Exercise 8: Interrupt
+    #ifdef INTERRUPT
+    pr_info("--------------------\n");
+    interrupt_init();
+    #endif
 
     pr_info("--------------------\n");
-
     pr_info("Linux module skeleton loaded\n");
 	return 0;
 }
 
 static void __exit skeleton_exit(void) {
 
-    
-    // Lab02 - Exercise 4: Dynamic memory allocation and linked list
-    dynAlloc_exit();
+    pr_info("Linux module skeleton unloading...\n");
 
+    // Lab02 - Exercise 4: Dynamic memory allocation and linked list
+    #ifdef DYNAMIC_ALLOCATION
     pr_info("--------------------\n");
+    dynAlloc_exit();
+    #endif
 
     // Lab02 - Exercise 5: Memory-mapped I/O
+    #ifdef IO_MEMORY_MAPPED
+    pr_info("--------------------\n");
     ioMemoryMapped_exit();
+    #endif
+
+    // Lab02 - Exercise 6: Kernel thread
+    #ifdef THREAD
+    pr_info("--------------------\n");
+    thread_exit();
+    #endif
+
+    // Lab02 - Exercise 7: Sleeping
+    #ifdef SLEEPING
+    pr_info("--------------------\n");
+    sleeping_exit();
+    #endif
+
+    // Lab02 - Exercise 8: Interrupt
+    #ifdef INTERRUPT
+    pr_info("--------------------\n");
+    interrupt_exit();
+    #endif
 
     pr_info("--------------------\n");
-
     pr_info ("Linux module skeleton unloaded\n");
 }
 

src/02-driver/.clangd

@@ -0,0 +1,13 @@
+CompileFlags:
+    Add:
+        # Architecture and cross-compilation
+        - "--target=aarch64-linux-gnu"
+
+        # Setup sysroot for buildroot
+        - "--sysroot=/buildroot/output/host/aarch64-buildroot-linux-gnu/sysroot"
+
+        # Add specific header of linux from buildroot
+        - "-I/buildroot/output/build/linux-headers-5.15.148/include"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/arch/arm64/include"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/arch/arm64/include/generated"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/**"

src/02-driver/Makefile

@@ -0,0 +1,44 @@
+EXE=app
+SRCS=$(wildcard *.c)
+
+ifeq ($(target),)
+target=nano
+endif
+
+CFLAGS=-Wall -Wextra -g -c -O0 -MD -std=gnu11
+
+TOOLCHAIN_PATH=/buildroot/output/host/usr/bin/
+TOOLCHAIN=$(TOOLCHAIN_PATH)aarch64-linux-
+CFLAGS+=-mcpu=cortex-a53 -funwind-tables
+##CFLAGS+=-O2 -fno-omit-frame-pointer
+OBJDIR=.obj/nano
+EXEC=$(EXE)
+
+CC=$(TOOLCHAIN)gcc
+LD=$(TOOLCHAIN)gcc
+AR=$(TOOLCHAIN)ar
+STRIP=$(TOOLCHAIN)strip
+
+OBJDIR=.obj/$(target)
+OBJS= $(addprefix $(OBJDIR)/, $(SRCS:.c=.o))
+
+$(OBJDIR)/%o: %c
+	$(CC) $(CFLAGS) $< -o $@
+
+all: $(OBJDIR)/ $(EXEC)
+
+$(EXEC): $(OBJS) $(LINKER_SCRIPT)
+	$(LD) $(OBJS) $(LDFLAGS) -o $@
+
+$(OBJDIR)/:
+	mkdir -p $(OBJDIR)
+
+clean:
+	rm -Rf $(OBJDIR) $(EXEC) $(EXEC)_s *~
+
+clean_all: clean
+	rm -Rf .obj $(EXE) $(EXE)_s $(EXE)_a $(EXE)_a_s $(EXE)_h $(EXE)_h_s
+
+-include $(OBJS:.o=.d)
+
+.PHONY: all clean clean_all

src/02-driver/character-oriented/.clangd

@@ -0,0 +1,33 @@
+CompileFlags:
+    Add:
+        # Architecture and cross-compilation
+        - "--target=aarch64-linux-gnu"
+
+        # Exclude standard library
+        - "-nostdinc"
+
+        # Mandatory kernel definitions
+        - "-D__KERNEL__"
+        - "-DMODULE"
+        - "-DCONFIG_CC_HAS_K_CONSTRAINT=1"
+
+        # Force-included files
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/compiler-version.h"
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/kconfig.h"
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/compiler_types.h"
+
+        # Kernel include paths
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/generated"
+        - "-I/buildroot/output/build/linux-5.15.148/include"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/generated/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/include/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/include/generated/uapi"
+
+        # GCC compiler system include path
+        - "-isystem"
+        - "/buildroot/output/host/lib/gcc/aarch64-buildroot-linux-gnu/11.3.0/include"

src/02-driver/character-oriented/Makefile

@@ -0,0 +1,22 @@
+# Part executed when called from kernel build system:
+ifneq ($(KERNELRELEASE),)
+obj-m += mymodule.o		## name of the generated module
+
+mymodule-objs := skeleton.o	## list of objects needed for that module
+
+# Part executed when called from standard make in module source directory:
+else
+include ../../buildroot_path
+include ../../kernel_settings
+PWD := $(shell pwd)
+
+all:
+	$(MAKE) -C $(KDIR) M=$(PWD) ARCH=$(CPU) CROSS_COMPILE=$(TOOLS) modules
+
+clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+
+install:
+	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(MODPATH) modules_install
+
+endif

src/02-driver/character-oriented/skeleton.c

@@ -0,0 +1,185 @@
+#include <linux/module.h>  // needed by all modules
+#include <linux/moduleparam.h>
+#include <linux/init.h>    // needed for macros
+#include <linux/kernel.h>  // needed for debugging
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/kdev_t.h>
+#include <linux/cdev.h>
+#include <linux/minmax.h>
+#include <stddef.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h> // dynamic memory allocation
+
+
+// linux theory: https://linux-kernel-labs.github.io/refs/heads/master/labs/device_drivers.html
+
+
+#define MY_MAJOR       42
+#define MY_MAX_MINORS  5
+
+#define BUFFER_SIZE 300
+
+// setup as argument the number of buffer available in the device
+static int instances = 3;
+module_param(instances, int, 0);
+
+struct my_device_data {
+    dev_t dev_t;
+    struct cdev cdev;
+    /* my data starts here */
+    char** buffers;
+};
+
+struct my_device_data devs;
+
+// inode: https://www.kernel.org/doc/html/latest/filesystems/ext4/inodes.html
+// file: https://docs.kernel.org/filesystems/api-summary.html#c.file
+
+int skeleton_open(struct inode* i, struct file* f) {
+
+    pr_info("Open file \n major:%d\n minor:%d\n",
+            imajor(i),
+            iminor(i));
+
+    if (iminor(i) >= instances) {
+        return -EFAULT;
+    }
+
+    if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) != 0) {
+        pr_info("skeleton : opened for reading & writing...\n");
+    } else if ((f->f_mode & FMODE_READ) != 0) {
+        pr_info("skeleton : opened for reading...\n");
+    } else if ((f->f_mode & FMODE_WRITE) != 0) {
+        pr_info("skeleton : opened for writing...\n");
+    }
+
+    // Get the stuct of my data
+    struct my_device_data *my_data = container_of(i->i_cdev, struct my_device_data, cdev);
+
+    // point private data on driver data, here this is a char buffer
+    // point on the right minor buffer
+    f->private_data = my_data->buffers[iminor(i)];
+
+    return 0;
+}
+
+int skeleton_release(struct inode* i, struct file* f) {
+
+    pr_info("Release file\n");
+
+    return 0;
+}
+
+ssize_t skeleton_read(struct file* f, char* __user buf, size_t count, loff_t* off) {
+
+    pr_info("Read file\n");
+
+    if (*off >= BUFFER_SIZE) {
+        return 0; // End of the file
+    }
+
+    ssize_t len = min((size_t)(BUFFER_SIZE - *off), count);
+
+    if (copy_to_user(buf, f->private_data + *off, len)) {
+        pr_info("Failed to copy to user space buffer\n");
+        return -EFAULT;
+    }
+
+    *off += len;
+    return len;
+}
+
+ssize_t skeleton_write(struct file* f, const char* __user buf, size_t count, loff_t* off) {
+
+    pr_info("Write file\n");
+
+    if (*off >= BUFFER_SIZE) {
+        return -ENOSPC; // No more space in buffer
+    }
+
+    ssize_t len = min((size_t)(BUFFER_SIZE - *off), count);
+
+    if (copy_from_user(f->private_data + *off, buf, len)) {
+        pr_info("Failed to copy from user space buffer\n");
+        return -EFAULT;
+    }
+
+    *off += len;
+    return len;
+}
+
+
+static struct file_operations skeleton_fops = {
+    .owner   = THIS_MODULE,
+    .open    = skeleton_open,
+    .read    = skeleton_read,
+    .write   = skeleton_write,
+    .release = skeleton_release,
+};
+
+static int __init skeleton_init(void) {
+    int ret = 0;
+
+    pr_info("My module loading...\n");
+    pr_info("----------------------\n");
+
+    pr_info("Load exercice 3\n");
+
+    // ret = register_chrdev_region(MKDEV(MY_MAJOR, 0), instances, "My module"); // register statically
+
+    ret = alloc_chrdev_region(&devs.dev_t, 0, instances, "mymodule"); //allocate major and minor
+
+    if (ret != 0) {
+        /* report error */
+        pr_info("Module registration error: %d\n", ret);
+        return ret;
+    }
+
+    /* initialize devs fields */
+    cdev_init(&devs.cdev, &skeleton_fops); // initialize device with files operations
+    ret = cdev_add(&devs.cdev, devs.dev_t, instances); // notify kernel
+
+    if (ret != 0) {
+        /* report error */
+        pr_info("cdev add error: %d\n", ret);
+        return ret;
+    }
+
+    // allocate the array of buffer
+    int i;
+    devs.buffers = kzalloc(sizeof(char*) * instances, GFP_KERNEL);
+    for (i = 0; i < instances; i++) {
+        devs.buffers[i] = kzalloc(BUFFER_SIZE, GFP_KERNEL);
+    }
+
+    pr_info("----------------------\n");
+    pr_info("My module is loaded\n");
+
+    return ret;
+}
+
+static void __exit skeleton_exit(void) {
+    pr_info("My module unloading...\n");
+    pr_info("----------------------\n");
+
+    cdev_del(&devs.cdev);
+    unregister_chrdev_region(devs.dev_t, instances);
+
+    int i;
+    for(i=0; i < instances; i++) {
+        kfree(devs.buffers[i]);
+    }
+    kfree(devs.buffers);
+
+    pr_info("----------------------\n");
+    pr_info("My module is unloaded\n");
+}
+
+module_init (skeleton_init);
+module_exit (skeleton_exit);
+
+MODULE_AUTHOR("Fastium <fastium.pro@proton.me>");
+MODULE_AUTHOR("Klagarge <remi@heredero.ch>");
+MODULE_DESCRIPTION ("Module pilot character oriented");
+MODULE_LICENSE ("GPL");

src/02-driver/exercice/ex1-memory-oriented.c

@@ -0,0 +1,56 @@
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/errno.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+int ex_memory_oriented(void) {
+
+    int fd = open("/dev/mem", O_RDWR);
+
+    if (fd < 0) {
+        printf("Failed to open /dev/mem: %s\n", strerror(errno));
+        return 1;
+    }
+
+    size_t page_size = getpagesize(); // return the number of byte in a page
+    off_t chip_id_addr = 0x01c14200; // physical address
+    off_t offset = chip_id_addr % page_size; // get the number of page until the chip is address
+    off_t start_page = chip_id_addr - offset; // align with pages
+
+    printf("page_size=0x%x offset=0x%x offset_page=0x%x\n", (unsigned int) page_size, (unsigned int) offset, (unsigned int) start_page);
+
+    // Get register virtual address from /dev/mem of the chip id
+    volatile uint32_t* regs = mmap(0, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, start_page);
+
+    if (regs == MAP_FAILED) {
+        printf("Failed to mmap: %s\n", strerror(errno));
+        return 1;
+    }
+
+
+
+    uint32_t chipid[4] = {[0] = 0,};
+
+    // Read values - Chip ID
+    chipid[0] = *(regs + (0x00 + offset) / sizeof(uint32_t));
+    chipid[1] = *(regs + (0x04 + offset) / sizeof(uint32_t));
+    chipid[2] = *(regs + (0x08 + offset) / sizeof(uint32_t));
+    chipid[3] = *(regs + (0x0c + offset) / sizeof(uint32_t));
+    printf(
+        "chipid=%08x'%08x'%08x'%08x\n",
+        chipid[0], chipid[1], chipid[2], chipid[3]
+    );
+
+    // Free space memory of the user¨
+    munmap((void*)regs, page_size);
+
+    // Close the file
+    close(fd);
+
+
+    return 0;
+}

src/02-driver/exercice/ex4-character-oriented.c

@@ -0,0 +1,49 @@
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/errno.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#define DATA_LENGTH 70
+
+static const char* data = "I've got chocolate stuck to the roof of my mouth, so I can't speak\0";
+
+static char data_read[DATA_LENGTH] = {};
+
+int ex_character_oriented(void) {
+    printf("Exercice 4 - character oriented\n");
+
+    int ret = 0;
+
+    const char* path = "/dev/toto0\0";
+
+    int fd = open(path, O_RDWR);
+
+    if (fd < 0) {
+        printf("Failed to open /dev/toto0: %s\n (maybe you need to create it)\n", strerror(errno));
+        return 1;
+    }
+
+    ret = write(fd, data, DATA_LENGTH);
+
+    fd = open(path, O_RDWR);
+
+    if(ret < 0) {
+        printf("Failed to write\n");
+        return 1;
+    }
+
+    ret = read(fd, data_read, DATA_LENGTH);
+
+    close(fd);
+
+    printf("Read from device: %s\n", path);
+    printf("Content: %s\n", data_read);
+
+
+    return 0;
+}

src/02-driver/main.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+#include "exercice/ex1-memory-oriented.c"
+// #define MEMORY_ORIENTED
+
+#include "exercice/ex4-character-oriented.c"
+#define CHARACTER_ORIENTED
+
+
+int main() {
+    int ret = 0;
+
+#ifdef MEMORY_ORIENTED
+    printf("--------------------------------------\n");
+    printf("Exercice 1: Memory oriented exercice\n");
+    ret = ex_memory_oriented();
+#endif
+
+#ifdef CHARACTER_ORIENTED
+    printf("--------------------------------------\n");
+    ret = ex_character_oriented();
+#endif
+
+    return ret;
+}

src/02-driver/sysfs/.clangd

@@ -0,0 +1,33 @@
+CompileFlags:
+    Add:
+        # Architecture and cross-compilation
+        - "--target=aarch64-linux-gnu"
+
+        # Exclude standard library
+        - "-nostdinc"
+
+        # Mandatory kernel definitions
+        - "-D__KERNEL__"
+        - "-DMODULE"
+        - "-DCONFIG_CC_HAS_K_CONSTRAINT=1"
+
+        # Force-included files
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/compiler-version.h"
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/kconfig.h"
+        - "-include"
+        - "/buildroot/output/build/linux-5.15.148/include/linux/compiler_types.h"
+
+        # Kernel include paths
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/generated"
+        - "-I/buildroot/output/build/linux-5.15.148/include"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/arch/arm64/include/generated/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/include/uapi"
+        - "-I/buildroot/output/build/linux-5.15.148/include/generated/uapi"
+
+        # GCC compiler system include path
+        - "-isystem"
+        - "/buildroot/output/host/lib/gcc/aarch64-buildroot-linux-gnu/11.3.0/include"

src/02-driver/sysfs/Makefile

@@ -0,0 +1,22 @@
+# Part executed when called from kernel build system:
+ifneq ($(KERNELRELEASE),)
+obj-m += mymodule.o		## name of the generated module
+
+mymodule-objs := skeleton.o	## list of objects needed for that module
+
+# Part executed when called from standard make in module source directory:
+else
+include ../../buildroot_path
+include ../../kernel_settings
+PWD := $(shell pwd)
+
+all:
+	$(MAKE) -C $(KDIR) M=$(PWD) ARCH=$(CPU) CROSS_COMPILE=$(TOOLS) modules
+
+clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+
+install:
+	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(MODPATH) modules_install
+
+endif

src/02-driver/sysfs/skeleton.c

@@ -0,0 +1,60 @@
+#include <linux/init.h>   /* needed for macros */
+#include <linux/kernel.h> /* needed for debugging */
+#include <linux/module.h> /* needed by all modules */
+
+#include <linux/cdev.h>    /* needed for char device driver */
+#include <linux/fs.h>      /* needed for device drivers */
+#include <linux/uaccess.h> /* needed to copy data to/from user */
+
+#include <linux/device.h> /* needed for sysfs handling */
+#include <linux/miscdevice.h>
+#include <linux/platform_device.h> /* needed for sysfs handling */
+
+static int val;
+
+ssize_t sysfs_show_val(struct device* dev, struct device_attribute* attr, char* buf) {
+    pr_info("sysfs_show_val: val=%d\n", val);
+    sprintf(buf, "%d\n", val);
+    return strlen(buf);
+}
+
+ssize_t sysfs_store_val(struct device* dev, struct device_attribute* attr, const char* buf, size_t count) {
+    pr_info("sysfs_store_val: buf=%s\n", buf);
+    val = simple_strtol(buf, 0, 10);
+    return count;
+}
+
+DEVICE_ATTR(val, 0664, sysfs_show_val, sysfs_store_val);
+
+static struct class* sysfs_class;
+static struct device* sysfs_device;
+
+static int __init skeleton_init(void) {
+
+    int status = 0;
+
+    sysfs_class = class_create(THIS_MODULE, "my_sysfs_class");
+    sysfs_device = device_create(sysfs_class, NULL, 0, NULL, "my_sysfs_device");
+    if (status == 0) status = device_create_file(sysfs_device, &dev_attr_val);
+
+    pr_info("Linux module skeleton loaded\n");
+    return 0;
+}
+
+
+static void __exit skeleton_exit(void) {
+
+    device_remove_file(sysfs_device, &dev_attr_val);
+    device_destroy(sysfs_class, 0);
+    class_destroy(sysfs_class);
+
+    pr_info("Linux module skeleton unloaded\n");
+}
+
+module_init (skeleton_init);
+module_exit (skeleton_exit);
+
+MODULE_AUTHOR("Fastium <fastium.pro@proton.me>");
+MODULE_AUTHOR("Klagarge <remi@heredero.ch>");
+MODULE_DESCRIPTION ("Module pilot charachter oriented");
+MODULE_LICENSE ("GPL");

src/03-led-controller/.clangd

@@ -0,0 +1,13 @@
+CompileFlags:
+    Add:
+        # Architecture and cross-compilation
+        - "--target=aarch64-linux-gnu"
+
+        # Setup sysroot for buildroot
+        - "--sysroot=/buildroot/output/host/aarch64-buildroot-linux-gnu/sysroot"
+
+        # Add specific header of linux from buildroot
+        - "-I/buildroot/output/build/linux-headers-5.15.148/include"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/arch/arm64/include"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/arch/arm64/include/generated"
+        - "-I/buildroot/output/build/linux-headers-5.15.148/**"

src/03-led-controller/Makefile

@@ -0,0 +1,5 @@
+EXE=led-controller
+SRCS=$(wildcard *.c)
+
+# Include the standard application Makefile for the CSEL1 labs
+include ../appl.mk

src/03-led-controller/justfile

@@ -0,0 +1,7 @@
+build:
+    make
+
+clean:
+    rm -rf build
+    rm -rf .obj
+    rm led-controller

src/03-led-controller/main.c

@@ -0,0 +1,162 @@
+/**
+ * Copyright 2018 University of Applied Sciences Western Switzerland / Fribourg
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Project: HEIA-FR / HES-SO MSE - MA-CSEL1 Laboratory
+ *
+ * Abstract: System programming -  file system
+ *
+ * Purpose: NanoPi silly status led control system
+ *
+ * Autĥor:  Daniel Gachet
+ * Date:    07.11.2018
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/timerfd.h>
+#include <sys/epoll.h>  
+
+#include "timer.h"
+
+/*
+ * status led - gpioa.10 --> gpio10
+ * power led  - gpiol.10 --> gpio362
+ */
+#define GPIO_EXPORT   "/sys/class/gpio/export"
+#define GPIO_UNEXPORT "/sys/class/gpio/unexport"
+#define GPIO_LED      "/sys/class/gpio/gpio10"
+#define LED           "10"
+#define DEFAULT_TIME_MS 1000
+#define DUTY_CYCLE_PERCENT 2
+
+typedef struct {
+    long flash_period_ms;
+    int timer_fd;
+    int epoll_fd;
+} ThreadData;
+
+static int open_led() {
+    // unexport pin out of sysfs (reinitialization)
+    int f = open(GPIO_UNEXPORT, O_WRONLY);
+    write(f, LED, strlen(LED));
+    close(f);
+
+    // export pin to sysfs
+    f = open(GPIO_EXPORT, O_WRONLY);
+    write(f, LED, strlen(LED));
+    close(f);
+
+    // config pin
+    f = open(GPIO_LED "/direction", O_WRONLY);
+    write(f, "out", 3);
+    close(f);
+
+    // open gpio value attribute
+    f = open(GPIO_LED "/value", O_RDWR);
+    return f;
+}
+
+void led_on(int led) {
+    pwrite(led, "1", sizeof("1"), 0);
+}
+
+void led_off(int led) {
+    pwrite(led, "0", sizeof("0"), 0);
+}
+
+static void* timer_thread(void* arg) {
+    ThreadData* data = (ThreadData*)arg;
+    
+    int led = open_led();
+    led_off(led);
+
+    
+    long time_on_ms = data->flash_period_ms / 100 * DUTY_CYCLE_PERCENT; // 2% duty
+    long time_off_ms = data->flash_period_ms - time_on_ms; // rest of the period
+
+    struct epoll_event ev;
+    
+    int isLedOn = 0;
+    int k = 0;
+    while(1) {
+
+        int n = epoll_wait(data->epoll_fd, &ev, 1, -1);
+        if (n == -1) {
+            perror("epoll_wait failed");
+            break;
+        }
+
+        uint64_t val;
+        if (read(data->timer_fd, &val, sizeof(val)) != sizeof(val)) {
+            perror("read timerfd failed");
+            break;
+        }
+
+
+        int delay = 0;
+        if (isLedOn == 0) {
+            delay = time_on_ms; // 2% duty
+            led_on(led);
+            printf("ping %d\n", k++);
+            isLedOn = 1;
+        } else {
+            delay = time_off_ms; // rest of the period
+            led_off(led);
+            isLedOn = 0;
+        }
+
+        timer_set_time(&data->timer_fd, delay);
+
+    }
+    return NULL;
+}
+
+
+
+int main(int argc, char* argv[]) {
+    ThreadData data;
+    pthread_t thread;
+
+    data.flash_period_ms = DEFAULT_TIME_MS;
+
+    // Create timerfd
+    data.timer_fd = timer_create_empty();
+    timer_set_time(&data.timer_fd, data.flash_period_ms);
+
+    // Create epoll instance
+    data.epoll_fd = epoll_create1(0);
+    if (data.epoll_fd == -1) {
+        perror("ERROR while create epoll");
+        exit(20);
+    }
+
+    timer_link_to_epoll(&data.timer_fd, &data.epoll_fd);
+
+
+    if (pthread_create(&thread, NULL, timer_thread, &data) != 0) {
+        perror("Failed to create timer thread");
+        exit(30);
+    }
+
+    pthread_join(thread, NULL);
+
+    return 0;
+}

src/03-led-controller/timer.c

@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/timerfd.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+
+
+int timer_create_empty() {
+
+    // Create timerfd
+    int timer_fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
+    if (timer_fd == -1) {
+        perror("timerfd_create failed");
+        exit(10);
+    }
+
+    return timer_fd;
+}
+
+
+void timer_set_time(int* timer_fd, long period_ms) {
+    // https://www.man7.org/linux/man-pages/man3/itimerspec.3type.html
+    struct itimerspec its;
+    
+    // Periodic interval
+    its.it_interval.tv_sec = 0;
+    its.it_interval.tv_nsec = 0;
+    
+    // Initial expiration
+    its.it_value.tv_sec = period_ms / 1000;
+    its.it_value.tv_nsec = (period_ms % 1000) * 1000000;
+
+    if (timerfd_settime(*timer_fd, 0, &its, NULL) == -1) {
+        perror("timerfd_settime failed");
+        exit(11);
+    }
+}
+
+void timer_link_to_epoll(int* timer_fd, int* epoll_fd) {
+    struct epoll_event ev;
+    ev.events = EPOLLIN;
+    ev.data.fd = *timer_fd;
+    if (epoll_ctl(*epoll_fd, EPOLL_CTL_ADD, *timer_fd, &ev) == -1) {
+        perror("ERROR while add timerfd to epoll");
+        exit(21);
+    }
+}

src/03-led-controller/timer.h

@@ -0,0 +1,4 @@
+
+int timer_create_empty();
+void timer_set_time(int* timer_fd, long period_ms);
+void timer_link_to_epoll(int* timer_fd, int* epoll_fd);

src/appl.mk

@@ -0,0 +1,45 @@
+CFLAGS=-Wall -Wextra -g -c -O0 -MD -std=gnu11
+CFLAGS+=$(EXTRA_CFLAGS)
+
+TOOLCHAIN_PATH=/buildroot/output/host/usr/bin/
+TOOLCHAIN=$(TOOLCHAIN_PATH)aarch64-linux-
+CFLAGS+=-mcpu=cortex-a53 -funwind-tables
+##CFLAGS+=-O2 -fno-omit-frame-pointer
+OBJDIR=.obj/nano
+EXEC=$(EXE)
+
+ifeq ($(target),host)
+EXEC=$(EXE)_h
+endif
+
+CC=$(TOOLCHAIN)gcc
+LD=$(TOOLCHAIN)gcc
+AR=$(TOOLCHAIN)ar
+STRIP=$(TOOLCHAIN)strip
+
+OBJDIR=.obj/$(target)
+OBJS= $(addprefix $(OBJDIR)/, $(SRCS:.c=.o))
+
+$(OBJDIR)/%o: %c
+	$(CC) $(CFLAGS) $< -o $@
+
+all: $(OBJDIR)/ $(EXEC)
+
+$(EXEC): $(OBJS) $(LINKER_SCRIPT)
+	$(LD) $(OBJS) $(LDFLAGS) -o $@
+
+$(OBJDIR)/:
+	mkdir -p $(OBJDIR)
+
+clean:
+	rm -Rf $(OBJDIR) $(EXEC) $(EXEC)_s *~
+
+clean_all: clean
+	rm -Rf .obj $(EXE) $(EXE)_s $(EXE)_a $(EXE)_a_s $(EXE)_h $(EXE)_h_s
+
+-include $(OBJS:.o=.d)
+
+.PHONY: all clean clean_all
+
+
+