PCI driver

.idea/Linux.iml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module version="4">
+  <component name="FacetManager">
+    <facet type="Python" name="Python facet">
+      <configuration sdkName="Python 3.10 (Linux)" />
+    </facet>
+  </component>
+</module>

.idea/conventionalCommit.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="general">
+    <commitTypes>
+      <entry providerId="37415b03-9388-4c55-b949-8c4526f6934d" order="2" />
+      <entry providerId="e9ce9acf-f4a6-4b36-b43c-531169556c29" order="2" />
+      <entry providerId="e9d4e8de-79a0-48b8-b1ba-b4161e2572c0" order="1" />
+    </commitTypes>
+  </component>
+</project>

.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,16 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="Eslint" enabled="true" level="WARNING" enabled_by_default="true" />
+    <inspection_tool class="PyPackageRequirementsInspection" enabled="true" level="WARNING" enabled_by_default="true">
+      <option name="ignoredPackages">
+        <value>
+          <list size="1">
+            <item index="0" class="java.lang.String" itemvalue="psycopg2" />
+          </list>
+        </value>
+      </option>
+    </inspection_tool>
+    <inspection_tool class="TsLint" enabled="true" level="WARNING" enabled_by_default="true" />
+  </profile>
+</component>

counter_reader/counter_reader_bash.service

@@ -0,0 +1,31 @@
+[Unit]
+# A short human readable title of the unit
+Description=Counter reader in bash?
+# A list of units whose activations will wait until after this unit has completed.
+Before=
+# A list of units whose activations will occur before this unit starts.
+After=network.target
+# A list of units to activate when this one is activated, if any unit listed here fails this unit will deactivate.
+Requires=
+# A list of units to activate when this one is activated, if a unit listed here fails this unit will continue to run.
+Wants=
+
+[Service]
+# Configures the process start-up type for this service unit, one of:
+# simple - The process defined in ExecStart= will stay in the foreground while the unit is activated.
+# forking - The process defined in ExecStart= will fork a background process and exit right away.
+# oneshot - The process will exit right away, use with RemainAfterExit= to ensure the serice is marked as active.
+# Consult the documentantion for types (https://www.freedesktop.org/software/systemd/man/systemd.service.html#Type=) other options.
+Type=simple
+# Command with arguments to invoke when the unit is activated.
+ExecStart=
+# Command with arguments to invoke when the unit is deactivated.
+ExecStop=
+# Configures under what conditions the unit will be restarted.
+Restart=on-failure
+
+[Install]
+# A list of units who when activated will try and activate this unit
+WantedBy=multi-user.target
+# A list of units to enable or disable when this unit is enabled or disabled (e.g., with systemctl enable)
+Also=

pci/Makefile

@@ -0,0 +1,7 @@
+obj-m += ethernet.o
+# make -C $(nix-build -E '(import <nixpkgs> {}).linux.dev' --no-out-link)/lib/modules/*/build M=$(pwd)
+
+all:
+	make -C /nix/store/f0b11y3qv1y0l3yvwkl88m181fnbmn80-linux-5.15.92-dev/lib/modules/*/build M=/home/inex/dev/Linux/pci modules
+clean:
+	make -C /nix/store/f0b11y3qv1y0l3yvwkl88m181fnbmn80-linux-5.15.92-dev/lib/modules/*/build M=/home/inex/dev/Linux/pci clean

pci/ethernet.c

@@ -0,0 +1,164 @@
+// A symbol PCI driver that outputs the MAC address of the network card:
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Inex Code");
+MODULE_DESCRIPTION("A PCI driver");
+MODULE_VERSION("0.0.1");
+
+#define VENDOR_ID 0x10ec
+#define DEVICE_ID 0x8168
+
+#define DRIVER_NAME "network_card_pci_driver_mac"
+
+#define CTL_GET_MAC _IOR('mac', 1, char *)
+
+static struct pci_device_id network_card_pci_driver_mac_id_table[] = {
+        { PCI_DEVICE(VENDOR_ID, DEVICE_ID) },
+        { 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, network_card_pci_driver_mac_id_table);
+
+static int network_card_pci_driver_mac_probe(struct pci_dev *dev, const struct pci_device_id *id);
+static void network_card_pci_driver_mac_remove(struct pci_dev *dev);
+
+static struct pci_driver network_card_pci_driver_mac = {
+        .name = DRIVER_NAME,
+        .id_table = network_card_pci_driver_mac_id_table,
+        .probe = network_card_pci_driver_mac_probe,
+        .remove = network_card_pci_driver_mac_remove
+};
+
+static int network_card_open(struct inode *inode, struct file *file);
+static int network_card_release(struct inode *inode, struct file *file);
+static ssize_t network_card_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+
+static struct file_operations network_card_fops = {
+        .owner = THIS_MODULE,
+        .open = network_card_open,
+        .release = network_card_release,
+        .unlocked_ioctl = network_card_ioctl
+};
+
+static int Major;
+static struct class *network_card_class;
+
+unsigned char mac_addr[6];
+
+static atomic_t already_open = ATOMIC_INIT(0);
+
+static int __init network_card_pci_driver_mac_init(void) {
+    int register_result = pci_register_driver(&network_card_pci_driver_mac);
+    if (register_result < 0) {
+        printk(KERN_ERR
+        "pci_register_driver failed\n");
+        return register_result;
+    }
+
+    Major = register_chrdev(0, DRIVER_NAME, &network_card_fops);
+    if (Major < 0) {
+        printk(KERN_ERR
+        "register_chrdev failed\n");
+        return Major;
+    }
+
+    network_card_class = class_create(THIS_MODULE, DRIVER_NAME);
+    if (!network_card_class) {
+        printk(KERN_ERR
+        "class_create failed\n");
+        return -1;
+    }
+
+    device_create(network_card_class, NULL, MKDEV(Major, 0), NULL, DRIVER_NAME);
+
+    return 0;
+}
+
+static void __exit network_card_pci_driver_mac_exit(void) {
+    class_destroy(network_card_class);
+    unregister_chrdev(Major, DRIVER_NAME);
+    pci_unregister_driver(&network_card_pci_driver_mac);
+
+    printk(KERN_INFO
+    "Goodbye cruel world.\n");
+
+    return;
+}
+
+static int network_card_pci_driver_mac_probe(struct pci_dev *dev, const struct pci_device_id *id) {
+    u8 __iomem *mmio_base;
+
+    int bar = 2;
+
+    if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
+        mmio_base = pci_iomap(dev, bar, pci_resource_len(dev, bar));
+        if (!mmio_base) {
+            printk(KERN_ERR
+            "pci_iomap failed\n");
+            return -1;
+        }
+    } else {
+        printk(KERN_ERR
+        "Not a memory-mapped resource\n");
+        return -1;
+    }
+
+    int i;
+    for (i = 0; i < 6; i++) {
+        mac_addr[i] = ioread8(mmio_base + i);
+        printk(KERN_INFO
+        "MAC address byte %d: %02x\n", i, mmio_base[i]);
+    }
+
+    iounmap(mmio_base);
+
+    return 0;
+}
+
+static void network_card_pci_driver_mac_remove(struct pci_dev *dev) {
+    dev_t devno = MKDEV(Major, 0);
+    device_destroy(network_card_class, devno)
+}
+
+static int network_card_open(struct inode *inode, struct file *file) {
+    if (atomic_cmpxchg(&already_open, 0, 1)) {
+        printk(KERN_ERR
+        "already_open is true\n");
+        return -EBUSY;
+    }
+
+    try_module_get(THIS_MODULE);
+    return 0;
+}
+
+static int network_card_release(struct inode *inode, struct file *file) {
+    atomic_set(&already_open, 0);
+    module_put(THIS_MODULE);
+
+    return 0;
+}
+
+
+static ssize_t network_card_ioctl(struct file *file, unsigned int cmd, unsigned long arg) {
+    switch (cmd) {
+        case CTL_GET_MAC:
+            if (copy_to_user((unsigned long __user *) arg, mac_addr, 6) != 0) {
+                printk(KERN_ERR
+                "copy_to_user failed\n");
+                return -EFAULT;
+            }
+            break;
+        default:
+            printk(KERN_ERR
+            "unknown ioctl\n");
+            return -EINVAL;
+    }
+
+    return 0;
+}
+
+module_init(network_card_pci_driver_mac_init);
+module_exit(network_card_pci_driver_mac_exit);

pci/read.py

@@ -0,0 +1,16 @@
+import fcntl
+
+MAC_ADDRESS_SIZE = 6
+DEVICE_PATH = "/dev/network_card_pci_driver_mac"
+MY_IOCTL_GET_MAC_ADDRESS = 0xed696301
+
+if __name__ == "__main__":
+    device_file = open(DEVICE_PATH, "rb")
+
+    mac_address_buffer = bytearray(MAC_ADDRESS_SIZE)
+
+    fcntl.ioctl(device_file, MY_IOCTL_GET_MAC_ADDRESS, mac_address_buffer)
+
+    print(mac_address_buffer.hex())
+
+    device_file.close()

shell.nix

@@ -0,0 +1,21 @@
+with import <nixpkgs> {};
+stdenv.mkDerivation {
+  name = "env";
+  nativeBuildInputs = [ pkg-config ];
+  buildInputs = [
+    cryptsetup
+    dbus
+    systemd
+    libcap
+    libgcrypt
+    xz
+    zstd
+    lz4
+    libgpg-error
+    libnotify
+    gdk-pixbuf
+    glib
+    glibc
+
+  ];
+}