linux usb mass storage device driver 이해하기

LINUX USB MASS STORAGE DEVICE DRIVER 이해하기 PC

If the library is built using the BUILD_TYPE=ISC parameter with make, it is distributed under the terms of the ISC License.

There are probably other limitations we don't even know about, due to the closed-source nature of this CFW.ĭual licensing is provided for this project depending on the way it is built:.

chdir(), rename(), dirreset() and utimes() aren't supported.

Only a single FAT volume from a single drive can be mounted.It also relies heavily on libnx features, which are not always compatible with sysmodule/MITM program contexts. It allocates a 8 MiB buffer per each UMS device, which is used for command and data transfers. This library is not suitable for custom sysmodules and/or service MITM projects.For the rest of the limitations, please take a look at the README from the lwext4 repository.This is because lwext4 uses an internal, stack-based registry of mount points and block devices, and increasing the limit can potentially exhaust the stack memory from the thread libusbhsfs runs under. Up to 8 EXT volumes can be mounted at the same time across all available UMS devices.This means that when a symbolic link in encountered, its hard link will be used instead.

LINUX USB MASS STORAGE DEVICE DRIVER 이해하기 PC

In cases where there has been heavy activity prior to the crash or power loss, it is recommended to plug the UMS device into a Windows PC and let it replay the journal properly before remounting with NTFS-3G, in order to prevent possible data loss and/or corruption.

Only partial journaling is supported, so unexpected crashes or power loss can leave the mounted NTFS volume in an inconsistent state.

Original limit was 10, but FatFs was slightly modified to allow for more volumes to be mounted simultaneously.

Up to 64 FAT volumes can be mounted at the same time across all available UMS devices.

Mutexes are used to avoid multiple SCSI operations from taking place at the same time on the same UMS device. This is an official limitation of the BOT protocol.

Only a single SCSI operation can be performed at any given time per UMS device, regardless of their number of logical units.

Increasing this limit isn't harmful, but makes the library take up additional heap memory.

Up to 32 different USB Mass Storage Class interfaces can be used at the same time.

Provides a way to safely unmount UMS devices at runtime.Painless listing of mounted partitions using a simple struct that provides the devoptab device name, as well as other interesting information (filesystem index, filesystem type, write protection, raw logical unit capacity, etc.).Provides an autoclear user event that is signaled each time a status change is detected by the background thread (new device mounted, device removed).fopen(), opendir(), etc.) on mounted filesystems from the available logical units. Uses devoptab virtual device interface to provide a way to use standard I/O calls from libc (e.g.Completely possible to add support for additional filesystems, as long as their libraries are ported over to Switch.GUID Partition Table (GPT) + protective MBR.Super Floppy Drive (SFD) (Volume Boot Record LBA 0).Background thread that takes care of starting all available logical units from each newly connected UMS device, as well as mounting the available filesystems from each one whenever possible.

Supports UMS devices with long logical block addresses (64-bit LBAs) and variable logical block sizes (512 - 4096 bytes).Bulk-Only Transport (BOT) driver written from scratch, which implements the most common SCSI Primary Command Set (SPC) commands as well as BOT class-specific requests.bInterfaceProtocol: 0x50 (Bulk-Only Transport Protocol).bInterfaceSubClass: 0x06 (SCSI Transparent Command Set SubClass).bInterfaceClass: 0x08 (USB Mass Storage Class).Supports USB Mass Storage (UMS) devices that implement at least one USB interface descriptor with the following properties:.USB Mass Storage Class Host + Filesystem Mounter static library for Nintendo Switch homebrew applications.

Linux usb mass storage device driver 이해하기