The kernel plays an important role in managing USB device connections in Linux. Here's a simplified overview of the process:
1. Hardware Connection:
USB device (e.g., pen drive) connects to the USB port, triggering a hardware interrupt. The USB hardware interrupt service routine (ISR_USB) is executed, detecting and acknowledging the connection.
2. Driver Loading:
USB driver reads the device's firmware and loads the USB port driver into memory. Recognition of the USB device as storage triggers a software interrupt. ISR_USB_Storage is executed, loading the USB Storage Driver into memory.
3. File System Identification:
USB Storage Driver identifies the device as a SCSI file system, generating a software interrupt. SCSI ISR loads the SCSI driver into memory.
4. Core Driver and Block Driver Loading:
Software interrupt for the USB Core driver is generated. ISR_USB_Core loads the USB Core driver, registering a new interface for USB storage. The device is recognized as a Block storage device, leading to a software interrupt.
Block driver is loaded into memory, attaching the device to the system and listing it on the device table.
5. File System Mounting:
USB driver and Block driver collaborate to mount the file system on the device. The system names the device (e.g., sdb) and partitions (sdb1, sdb2, sdb3) based on block sizes.
This sequence ensures proper integration of USB devices into the Linux system, allowing users to access and utilize connected peripherals effectively.
