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diff --git a/doc/README.nvme b/doc/README.nvme new file mode 100644 index 0000000..d2b917d --- /dev/null +++ b/doc/README.nvme @@ -0,0 +1,42 @@ +# +# Copyright (C) 2017 NXP Semiconductors +# Copyright (C) 2017 Bin Meng <bmeng.cn@gmail.com> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +What is NVMe +============ + +NVM Express (NVMe) is a register level interface that allows host software to +communicate with a non-volatile memory subsystem. This interface is optimized +for enterprise and client solid state drives, typically attached to the PCI +express interface. It is a scalable host controller interface designed to +address the needs of enterprise and client systems that utilize PCI express +based solid state drives (SSD). The interface provides optimized command +submission and completion paths. It includes support for parallel operation by +supporting up to 64K I/O queues with up to 64K commands per I/O queue. + +The device is comprised of some number of controllers, where each controller +is comprised of some number of namespaces, where each namespace is comprised +of some number of logical blocks. A namespace is a quantity of non-volatile +memory that is formatted into logical blocks. An NVMe namespace is equivalent +to a SCSI LUN. Each namespace is operated as an independent "device". + +How it works +------------ +There is an NVMe uclass driver (driver name "nvme"), an NVMe host controller +driver (driver name "nvme") and an NVMe namespace block driver (driver name +"nvme-blk"). The host controller driver is supposed to probe the hardware and +do necessary initialization to put the controller into a ready state at which +it is able to scan all available namespaces attached to it. Scanning namespace +is triggered by the NVMe uclass driver and the actual work is done in the NVMe +namespace block driver. + +Status +------ +It only support basic block read/write functions in the NVMe driver. + +Config options +-------------- +CONFIG_NVME Enable NVMe device support |