USB Gadget
Linux'u USB Cihazı Yap

Uygulama (configfs) → Gadget core → UDC driver (dwc2/dwc3/chipidea) → USB hardware → Host PC

# Mevcut UDC'leri listele
ls /sys/class/udc/
# fe800000.usb   (RPi Zero: dwc2)
# ci_hdrc.0      (i.MX6: ChipIdea)
# musb-hdrc.0.auto (BeagleBone: musb)

# UDC bilgisi
cat /sys/class/udc/fe800000.usb/state
# configured  (host bağlı ve gadget aktif)
# not attached (host bağlı değil)

# Test için sanal UDC yükle
sudo modprobe dummy_hcd
ls /sys/class/udc/

/sys/kernel/config/usb_gadget/
└── mygadget/              ← gadget ismi (serbest)
    ├── idVendor           ← USB vendor ID
    ├── idProduct          ← USB product ID
    ├── bcdDevice          ← cihaz versiyon numarası
    ├── bcdUSB             ← USB spec versiyon (0x0200 = USB 2.0)
    ├── strings/
    │   └── 0x409/         ← Dil kodu (0x409 = İngilizce)
    │       ├── manufacturer
    │       ├── product
    │       └── serialnumber
    ├── configs/
    │   └── c.1/           ← Konfigürasyon 1
    │       ├── MaxPower   ← mA cinsinden güç
    │       └── acm.0 → ../../functions/acm.usb0  ← symlink
    └── functions/
        └── acm.usb0/      ← Function instance

# libcomposite modülünü yükle
sudo modprobe libcomposite

# configfs bağlı değilse bağla
sudo mount -t configfs none /sys/kernel/config

# Gadget dizini oluştur
cd /sys/kernel/config/usb_gadget/
sudo mkdir mygadget
cd mygadget

# Cihaz kimlik bilgileri
sudo bash -c 'echo 0x1d6b > idVendor'   # Linux Foundation
sudo bash -c 'echo 0x0104 > idProduct'  # Multifunction Composite Gadget
sudo bash -c 'echo 0x0100 > bcdDevice'  # v1.0.0
sudo bash -c 'echo 0x0200 > bcdUSB'     # USB 2.0

# Dize tanımlayıcılar (İngilizce)
sudo mkdir strings/0x409
sudo bash -c 'echo "MyCompany"      > strings/0x409/manufacturer'
sudo bash -c 'echo "My USB Gadget"  > strings/0x409/product'
sudo bash -c 'echo "SERIAL001"      > strings/0x409/serialnumber'

# Konfigürasyon oluştur
sudo mkdir configs/c.1
sudo bash -c 'echo 250 > configs/c.1/MaxPower'  # 250 mA
sudo mkdir configs/c.1/strings/0x409
sudo bash -c 'echo "Config 1" > configs/c.1/strings/0x409/configuration'

# Function eklendikten sonra UDC'ye bağla (gadget etkinleşir)
UDC_NAME=$(ls /sys/class/udc | head -1)
sudo bash -c "echo $UDC_NAME > /sys/kernel/config/usb_gadget/mygadget/UDC"

# Gadget'ı devre dışı bırak (UDC'den ayır)
sudo bash -c 'echo "" > /sys/kernel/config/usb_gadget/mygadget/UDC'

# Gadget durumunu kontrol et
cat /sys/class/udc/fe800000.usb/state
# configured

# ACM modülünü yükle
sudo modprobe usb_f_acm

# Gadget temel yapısını oluştur (önceki bölümden)
cd /sys/kernel/config/usb_gadget/mygadget

# ACM function instance oluştur
sudo mkdir functions/acm.usb0

# Konfigürasyona bağla (symlink)
sudo ln -s functions/acm.usb0 configs/c.1/

# UDC'ye bağla
sudo bash -c "echo $(ls /sys/class/udc | head -1) > UDC"

# Host'ta /dev/ttyACM0 görünmeli
# Embedded Linux'ta /dev/ttyGS0 oluşur
ls /dev/ttyGS*
# /dev/ttyGS0

# Manuel getty başlatma
sudo getty -L ttyGS0 115200 vt100 &

# systemd ile kalıcı konsol
sudo systemctl enable serial-getty@ttyGS0.service
sudo systemctl start  serial-getty@ttyGS0.service

# Host bilgisayardan bağlanma (minicom)
minicom -D /dev/ttyACM0 -b 115200

# Host bilgisayardan bağlanma (screen)
screen /dev/ttyACM0 115200

# Host bilgisayardan bağlanma (picocom)
picocom -b 115200 /dev/ttyACM0

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>

int main(void)
{
    int fd = open("/dev/ttyGS0", O_RDWR | O_NOCTTY);
    if (fd < 0) { perror("open"); return 1; }

    struct termios tty;
    tcgetattr(fd, &tty);
    cfmakeraw(&tty);
    cfsetspeed(&tty, B115200);
    tcsetattr(fd, TCSANOW, &tty);

    const char *msg = "Hello from USB gadget!\r\n";
    write(fd, msg, strlen(msg));

    char buf[64];
    ssize_t n;
    while ((n = read(fd, buf, sizeof(buf))) > 0) {
        write(fd, buf, n);  /* Echo back */
    }

    close(fd);
    return 0;
}

# Gerekli modüller
sudo modprobe usb_f_ncm

# Gadget temel yapısını oluştur
cd /sys/kernel/config/usb_gadget/mygadget

# NCM function instance
sudo mkdir functions/ncm.usb0

# MAC adresleri (host ve device tarafı)
sudo bash -c 'echo "48:6f:73:74:50:43" > functions/ncm.usb0/host_addr'
sudo bash -c 'echo "42:61:64:55:53:42" > functions/ncm.usb0/dev_addr'

# Konfigürasyona bağla
sudo ln -s functions/ncm.usb0 configs/c.1/

# UDC'ye bağla
sudo bash -c "echo $(ls /sys/class/udc | head -1) > UDC"

# Ağ arayüzü görünmeli
ip link show usb0
# 3: usb0: <BROADCAST,MULTICAST,UP,LOWER_UP> ...

# Embedded Linux tarafında IP ata
sudo ip addr add 192.168.7.2/24 dev usb0
sudo ip link set usb0 up

# Host Linux tarafında (enp0s20f0u1 veya benzeri görünür)
sudo ip addr add 192.168.7.1/24 dev enp0s20f0u1
sudo ip link set enp0s20f0u1 up

# Host'tan embedded'e SSH
ssh root@192.168.7.2

# systemd-networkd ile otomatik IP (embedded taraf)
cat <<'EOF' | sudo tee /etc/systemd/network/usb0.network
[Match]
Name=usb0

[Network]
Address=192.168.7.2/24
EOF

sudo systemctl enable systemd-networkd
sudo systemctl start  systemd-networkd

# RNDIS modülü
sudo modprobe usb_f_rndis

# RNDIS function (ncm yerine)
sudo mkdir functions/rndis.usb0
sudo bash -c 'echo "48:6f:73:74:50:43" > functions/rndis.usb0/host_addr'
sudo bash -c 'echo "42:61:64:55:53:42" > functions/rndis.usb0/dev_addr'
sudo ln -s functions/rndis.usb0 configs/c.1/

# Modül yükle
sudo modprobe usb_f_mass_storage

# Backing dosyası oluştur (1 GB FAT32 imajı)
dd if=/dev/zero of=/storage.img bs=1M count=1024
mkfs.vfat /storage.img

# Mass storage function oluştur
cd /sys/kernel/config/usb_gadget/mygadget
sudo mkdir functions/mass_storage.usb0

# LUN (Logical Unit Number) yapılandır
# lun.0 otomatik oluşturulur
sudo bash -c 'echo /storage.img > functions/mass_storage.usb0/lun.0/file'
sudo bash -c 'echo 0 > functions/mass_storage.usb0/lun.0/ro'  # Yazılabilir
sudo bash -c 'echo 1 > functions/mass_storage.usb0/lun.0/removable'

# Konfigürasyona bağla
sudo ln -s functions/mass_storage.usb0 configs/c.1/

# UDC'ye bağla
sudo bash -c "echo $(ls /sys/class/udc | head -1) > UDC"

# Block device veya partition doğrudan kullan
sudo bash -c 'echo /dev/mmcblk0p1 > functions/mass_storage.usb0/lun.0/file'

# Sadece-okunur (ro=1: host değiştiremez)
sudo bash -c 'echo 1 > functions/mass_storage.usb0/lun.0/ro'

# CDROM modu (iso imajı için)
sudo bash -c 'echo 1 > functions/mass_storage.usb0/lun.0/cdrom'
sudo bash -c 'echo /firmware.iso > functions/mass_storage.usb0/lun.0/file'

# LUN sayısını artır
sudo bash -c 'echo 2 > functions/mass_storage.usb0/stall'

# İkinci LUN dizini oluştur ve yapılandır
sudo mkdir functions/mass_storage.usb0/lun.1
sudo bash -c 'echo /data.img > functions/mass_storage.usb0/lun.1/file'
sudo bash -c 'echo 0 > functions/mass_storage.usb0/lun.1/ro'

# Host iki ayrı USB disk görür:
# /dev/sdb  — lun.0 (storage.img)
# /dev/sdc  — lun.1 (data.img)

# Önce medyayı çıkar (host'u bilgilendir)
sudo bash -c 'echo 1 > functions/mass_storage.usb0/lun.0/forced_eject'

# Yeni dosya ata
sudo bash -c 'echo /new_storage.img > functions/mass_storage.usb0/lun.0/file'

# LUN özelliklerini görüntüle
ls /sys/kernel/config/usb_gadget/mygadget/functions/mass_storage.usb0/lun.0/
# cdrom  file  forced_eject  inquiry_string  nofua  removable  ro

# Modül yükle
sudo modprobe usb_f_hid

# HID function oluştur
cd /sys/kernel/config/usb_gadget/mygadget
sudo mkdir functions/hid.usb0

# Klavye için HID parametreleri
sudo bash -c 'echo 1 > functions/hid.usb0/protocol'   # 1=keyboard, 2=mouse
sudo bash -c 'echo 1 > functions/hid.usb0/subclass'   # 1=boot interface
sudo bash -c 'echo 8 > functions/hid.usb0/report_length' # 8 bayt rapor

# Klavye report descriptor (standart boot keyboard)
sudo bash -c 'echo -ne "\x05\x01\x09\x06\xa1\x01\x05\x07\x19\xe0\x29\xe7\x15\x00\x25\x01\x75\x01\x95\x08\x81\x02\x95\x01\x75\x08\x81\x03\x95\x05\x75\x01\x05\x08\x19\x01\x29\x05\x91\x02\x95\x01\x75\x03\x91\x03\x95\x06\x75\x08\x15\x00\x25\x65\x05\x07\x19\x00\x29\x65\x81\x00\xc0" > functions/hid.usb0/report_desc'

# Konfigürasyona bağla
sudo ln -s functions/hid.usb0 configs/c.1/
sudo bash -c "echo $(ls /sys/class/udc | head -1) > UDC"

# Host'ta /dev/hidg0 oluşur
ls /dev/hidg*

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>

/* HID klavye raporu: 8 bayt */
struct hid_keyboard_report {
    uint8_t modifier;   /* Ctrl/Shift/Alt/GUI bitleri */
    uint8_t reserved;
    uint8_t keycode[6]; /* Maksimum 6 eş zamanlı tuş */
};

/* USB HID tuş kodları (USB HID Usage Tables) */
#define KEY_A      0x04
#define KEY_RETURN 0x28
#define KEY_SPACE  0x2C
#define MOD_LSHIFT 0x02

static int hid_fd;

void send_key(uint8_t modifier, uint8_t keycode)
{
    struct hid_keyboard_report report = {0};
    report.modifier = modifier;
    report.keycode[0] = keycode;

    /* Tuşa bas */
    write(hid_fd, &report, sizeof(report));

    /* Tuşu bırak (tüm sıfır) */
    memset(&report, 0, sizeof(report));
    write(hid_fd, &report, sizeof(report));

    usleep(10000);  /* 10ms bekleme */
}

void type_string(const char *str)
{
    for (; *str; str++) {
        uint8_t mod = 0, key = 0;
        if (*str >= 'a' && *str <= 'z') {
            key = KEY_A + (*str - 'a');
        } else if (*str >= 'A' && *str <= 'Z') {
            key = KEY_A + (*str - 'A');
            mod = MOD_LSHIFT;
        } else if (*str == ' ') {
            key = KEY_SPACE;
        } else if (*str == '\n') {
            key = KEY_RETURN;
        }
        if (key) send_key(mod, key);
    }
}

int main(void)
{
    hid_fd = open("/dev/hidg0", O_RDWR | O_NONBLOCK);
    if (hid_fd < 0) { perror("open hidg0"); return 1; }

    type_string("Hello World\n");
    close(hid_fd);
    return 0;
}

# Fare için farklı HID parametreleri
sudo mkdir functions/hid.usb1
sudo bash -c 'echo 2 > functions/hid.usb1/protocol'   # mouse
sudo bash -c 'echo 1 > functions/hid.usb1/subclass'
sudo bash -c 'echo 4 > functions/hid.usb1/report_length' # 4 bayt fare raporu

/* Fare raporu: buttons | X_rel | Y_rel | wheel */
struct mouse_report {
    uint8_t buttons;  /* bit0=sol, bit1=sag, bit2=orta */
    int8_t  x;        /* Göreli X (-127..127) */
    int8_t  y;        /* Göreli Y (-127..127) */
    int8_t  wheel;
};

void move_mouse(int fd, int8_t dx, int8_t dy)
{
    struct mouse_report r = { .x = dx, .y = dy };
    write(fd, &r, sizeof(r));
}

void click_left(int fd)
{
    struct mouse_report r = { .buttons = 0x01 };
    write(fd, &r, sizeof(r));           /* Bas */
    r.buttons = 0;
    write(fd, &r, sizeof(r));           /* Bırak */
}

#!/bin/bash
# composite_gadget.sh — Tam composite gadget kurulum scripti

GADGET_DIR=/sys/kernel/config/usb_gadget
GADGET_NAME=composite

# Modülleri yükle
modprobe libcomposite
modprobe usb_f_acm
modprobe usb_f_ncm
modprobe usb_f_mass_storage

# configfs bağla
mount -t configfs none /sys/kernel/config 2>/dev/null || true

# Gadget oluştur
mkdir -p "$GADGET_DIR/$GADGET_NAME"
cd "$GADGET_DIR/$GADGET_NAME"

# USB cihaz kimliği
echo 0x1d6b > idVendor
echo 0x0104 > idProduct
echo 0x0200 > bcdUSB

# Dize tanımlayıcılar
mkdir -p strings/0x409
echo "EmbeddedDev"           > strings/0x409/manufacturer
echo "Composite USB Gadget"  > strings/0x409/product
echo "$(hostname)-usb"       > strings/0x409/serialnumber

# Konfigürasyon
mkdir -p configs/c.1/strings/0x409
echo "Composite Config"   > configs/c.1/strings/0x409/configuration
echo 500                  > configs/c.1/MaxPower

# Function 1: ACM (seri konsol)
mkdir -p functions/acm.usb0
ln -sf functions/acm.usb0 configs/c.1/

# Function 2: NCM (Ethernet)
mkdir -p functions/ncm.usb0
echo "48:6f:73:74:50:43"  > functions/ncm.usb0/host_addr
echo "42:61:64:55:53:42"  > functions/ncm.usb0/dev_addr
ln -sf functions/ncm.usb0 configs/c.1/

# Function 3: Mass Storage
mkdir -p functions/mass_storage.usb0
echo /storage.img          > functions/mass_storage.usb0/lun.0/file
echo 0                     > functions/mass_storage.usb0/lun.0/ro
ln -sf functions/mass_storage.usb0 configs/c.1/

# UDC'ye bağla (en son adım)
UDC=$(ls /sys/class/udc | head -1)
echo "$UDC" > UDC

echo "Composite gadget etkin: $UDC"
echo "  /dev/ttyGS0 — ACM seri konsol"
echo "  usb0        — NCM Ethernet"
echo "  /dev/sdb    — Mass Storage (host'ta)"

# İkinci konfigürasyon: yalnızca ACM (güç tasarruflu mod)
mkdir -p configs/c.2/strings/0x409
echo "Low Power Config" > configs/c.2/strings/0x409/configuration
echo 100               > configs/c.2/MaxPower

# Yalnızca ACM function ekle
ln -sf functions/acm.usb0 configs/c.2/

# Host iki seçenek görür; genellikle c.1 seçilir

#!/bin/bash
# teardown_gadget.sh

GADGET_DIR=/sys/kernel/config/usb_gadget/composite

# UDC'den ayır
echo "" > "$GADGET_DIR/UDC"

# Symlink'leri kaldır
rm -f "$GADGET_DIR"/configs/c.*/acm.usb0
rm -f "$GADGET_DIR"/configs/c.*/ncm.usb0
rm -f "$GADGET_DIR"/configs/c.*/mass_storage.usb0

# Dize dizinlerini kaldır
rmdir "$GADGET_DIR"/configs/c.*/strings/*
rmdir "$GADGET_DIR"/configs/c.*

# Function dizinlerini kaldır
rmdir "$GADGET_DIR"/functions/acm.usb0
rmdir "$GADGET_DIR"/functions/ncm.usb0
rmdir "$GADGET_DIR"/functions/mass_storage.usb0

# Gadget dize dizinleri ve gadget'ı kaldır
rmdir "$GADGET_DIR"/strings/*
rmdir "$GADGET_DIR"

echo "Gadget kaldırıldı"

# Modül yükle
sudo modprobe usb_f_fs

# FunctionFS function oluştur
cd /sys/kernel/config/usb_gadget/mygadget
sudo mkdir functions/ffs.usb0

# Konfigürasyona bağla
sudo ln -s functions/ffs.usb0 configs/c.1/

# FunctionFS bağla
sudo mkdir /dev/ffs-usb0
sudo mount -t functionfs usb0 /dev/ffs-usb0

# Kullanıcı programı /dev/ffs-usb0/ep0 yazarak başlar
# ep0: kontrol endpoint (descriptor'lar)
# ep1, ep2: bulk/interrupt endpoint'ler

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/usb/functionfs.h>

/* Descriptor: 2 bulk endpoint (IN + OUT) */
static const struct {
    struct usb_functionfs_descs_head_v2 header;
    __le32 fs_count;
    __le32 hs_count;
    struct { struct usb_interface_descriptor intf;
             struct usb_endpoint_descriptor_no_audio bulk_out;
             struct usb_endpoint_descriptor_no_audio bulk_in; } __attribute__((packed)) fs;
    struct { struct usb_interface_descriptor intf;
             struct usb_endpoint_descriptor_no_audio bulk_out;
             struct usb_endpoint_descriptor_no_audio bulk_in; } __attribute__((packed)) hs;
} __attribute__((packed)) descriptors = {
    .header = {
        .magic   = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
        .length  = cpu_to_le32(sizeof(descriptors)),
        .flags   = cpu_to_le32(FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC),
    },
    .fs_count = cpu_to_le32(3),
    .hs_count = cpu_to_le32(3),
    .fs = {
        .intf = {
            .bLength            = sizeof(descriptors.fs.intf),
            .bDescriptorType    = USB_DT_INTERFACE,
            .bNumEndpoints      = 2,
            .bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
        },
        .bulk_out = {
            .bLength          = USB_DT_ENDPOINT_SIZE,
            .bDescriptorType  = USB_DT_ENDPOINT,
            .bEndpointAddress = 1 | USB_DIR_OUT,
            .bmAttributes     = USB_ENDPOINT_XFER_BULK,
            .wMaxPacketSize   = cpu_to_le16(64),
        },
        .bulk_in = {
            .bLength          = USB_DT_ENDPOINT_SIZE,
            .bDescriptorType  = USB_DT_ENDPOINT,
            .bEndpointAddress = 2 | USB_DIR_IN,
            .bmAttributes     = USB_ENDPOINT_XFER_BULK,
            .wMaxPacketSize   = cpu_to_le16(64),
        },
    },
    /* hs aynı, wMaxPacketSize=512 */
};

int main(void)
{
    int ep0 = open("/dev/ffs-usb0/ep0", O_RDWR);
    /* Descriptor'ları yaz */
    write(ep0, &descriptors, sizeof(descriptors));
    /* String'leri yaz (boş) */
    static const struct usb_functionfs_strings_head strings = {
        .magic  = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
        .length = cpu_to_le32(sizeof(strings)),
        .str_count  = 0,
        .lang_count = 0,
    };
    write(ep0, &strings, sizeof(strings));

    /* UDC'ye bağla (main'den önce shell'de yapılmış olmalı) */

    int ep_out = open("/dev/ffs-usb0/ep1", O_RDONLY);
    int ep_in  = open("/dev/ffs-usb0/ep2", O_WRONLY);

    char buf[512];
    ssize_t n;
    while ((n = read(ep_out, buf, sizeof(buf))) > 0) {
        write(ep_in, buf, n);   /* Echo back */
    }
    return 0;
}

# /boot/config.txt dosyasına ekle
echo "dtoverlay=dwc2" | sudo tee -a /boot/config.txt

# /boot/cmdline.txt dosyasında rootwait'ten sonra ekle
# modules-load=dwc2,g_cdc
# Örnek: "console=serial0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait modules-load=dwc2,g_cdc"

# Tek function için g_serial (ACM) yeterli
echo "modules-load=dwc2,g_serial" | sudo tee -a /boot/cmdline.txt

# /usr/local/bin/usb-gadget-init.sh
cat <<'SCRIPT' | sudo tee /usr/local/bin/usb-gadget-init.sh
#!/bin/bash
set -e

modprobe libcomposite
mount -t configfs none /sys/kernel/config 2>/dev/null || true

GADGET=/sys/kernel/config/usb_gadget/pi_gadget
mkdir -p "$GADGET"
cd "$GADGET"

echo 0x1d6b > idVendor
echo 0x0104 > idProduct
echo 0x0200 > bcdUSB

mkdir -p strings/0x409
echo "Raspberry Pi Foundation" > strings/0x409/manufacturer
echo "Pi Zero USB Gadget"      > strings/0x409/product
echo "$(cat /proc/cpuinfo | grep Serial | cut -d' ' -f2)" > strings/0x409/serialnumber

mkdir -p configs/c.1/strings/0x409
echo "CDC Composite"  > configs/c.1/strings/0x409/configuration
echo 250              > configs/c.1/MaxPower

# ACM
mkdir -p functions/acm.usb0
ln -sf functions/acm.usb0 configs/c.1/

# NCM
mkdir -p functions/ncm.usb0
echo "48:6f:73:74:00:01" > functions/ncm.usb0/host_addr
echo "42:61:64:00:00:01" > functions/ncm.usb0/dev_addr
ln -sf functions/ncm.usb0 configs/c.1/

# UDC
UDC=$(ls /sys/class/udc | head -1)
echo "$UDC" > UDC
SCRIPT

sudo chmod +x /usr/local/bin/usb-gadget-init.sh

# systemd unit dosyası
cat <<'UNIT' | sudo tee /etc/systemd/system/usb-gadget.service
[Unit]
Description=USB Gadget Initialization
After=sysinit.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/local/bin/usb-gadget-init.sh

[Install]
WantedBy=multi-user.target
UNIT

sudo systemctl enable usb-gadget.service
sudo systemctl start  usb-gadget.service

# Host bilgisayarda: cihaz tanınıyor mu?
lsusb
# Bus 001 Device 003: ID 1d6b:0104 Linux Foundation Multifunction Composite Gadget

# Cihaz detayı
lsusb -v -d 1d6b:0104

# Embedded tarafta: kernel logları
dmesg | grep -i usb | tail -20
# [  5.123] dwc2 fe980000.usb: bound driver configfs-gadget
# [  5.456] dwc2 fe980000.usb: new device is full-speed

# UDC durumu
cat /sys/class/udc/fe800000.usb/state
# configured

# Gadget function'larını listele
ls /sys/kernel/config/usb_gadget/pi_gadget/functions/
# acm.usb0  ncm.usb0

# Host'ta ACM görünüyor mu?
ls /dev/ttyACM*
# /dev/ttyACM0

# dmesg host tarafında
dmesg | tail -10
# cdc_acm 1-1.3:1.0: ttyACM0: USB ACM device
# cdc_ncm 1-1.3:1.2 usb0: register 'cdc_ncm'

# USB trace (detaylı debug)
sudo modprobe usbmon
sudo tcpdump -i usbmon1 -w usb_capture.pcap

# BeagleBone Black: musb driver, OTG portu
ls /sys/class/udc/
# musb-hdrc.0.auto

# Debian tabanlı BBB'de g_multi modülü hali hazırda yüklü olabilir
lsmod | grep g_
# g_multi   komposit CDC gadget

# Manuel configfs yaklaşımı (g_multi yerine)
sudo modprobe musb_hdrc  # UDC driver
sudo modprobe libcomposite

# Gadget oluştur (önceki örneklerden aynı komutlar)
# UDC adı farklı:
echo "musb-hdrc.0.auto" > /sys/kernel/config/usb_gadget/mygadget/UDC