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author | Tom Rini <trini@konsulko.com> | 2021-06-28 23:22:13 +0300 |
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committer | Tom Rini <trini@konsulko.com> | 2021-06-28 23:22:13 +0300 |
commit | 6d0453d88915feeece6e55748a2476d8509e5fad (patch) | |
tree | f4564a64f771cb071a74787f11471250fdbdf47b /doc/develop | |
parent | 67edf2553f15e5148efca213af3f41cef3410680 (diff) | |
parent | 3ef4572110a43acdd7d401b0cb184c6ebd6eaa17 (diff) | |
download | u-boot-6d0453d88915feeece6e55748a2476d8509e5fad.tar.xz |
Merge tag 'v2021.07-rc5' into next
Prepare v2021.07-rc5
# gpg: Signature made Mon 28 Jun 2021 03:39:36 PM EDT
# gpg: using RSA key 1A3C7F70E08FAB1707809BBF147C39FF9634B72C
# gpg: Good signature from "Thomas Rini <trini@konsulko.com>" [ultimate]
# Conflicts:
# configs/am64x_evm_r5_defconfig
Diffstat (limited to 'doc/develop')
-rw-r--r-- | doc/develop/driver-model/index.rst | 1 | ||||
-rw-r--r-- | doc/develop/driver-model/nvme.rst | 97 |
2 files changed, 98 insertions, 0 deletions
diff --git a/doc/develop/driver-model/index.rst b/doc/develop/driver-model/index.rst index 10a76256b0..7366ef818c 100644 --- a/doc/develop/driver-model/index.rst +++ b/doc/develop/driver-model/index.rst @@ -19,6 +19,7 @@ subsystems i2c-howto livetree migration + nvme of-plat pci-info pmic-framework diff --git a/doc/develop/driver-model/nvme.rst b/doc/develop/driver-model/nvme.rst new file mode 100644 index 0000000000..736c0a063d --- /dev/null +++ b/doc/develop/driver-model/nvme.rst @@ -0,0 +1,97 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (C) 2017 NXP Semiconductors +.. Copyright (C) 2017 Bin Meng <bmeng.cn@gmail.com> + +NVMe Support +============ + +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 +CONFIG_CMD_NVME Enable basic NVMe commands + +Usage in U-Boot +--------------- +To use an NVMe hard disk from U-Boot shell, a 'nvme scan' command needs to +be executed for all NVMe hard disks attached to the NVMe controller to be +identified. + +To list all of the NVMe hard disks, try: + +.. code-block:: none + + => nvme info + Device 0: Vendor: 0x8086 Rev: 8DV10131 Prod: CVFT535600LS400BGN + Type: Hard Disk + Capacity: 381554.0 MB = 372.6 GB (781422768 x 512) + +and print out detailed information for controller and namespaces via: + +.. code-block:: none + + => nvme detail + +Raw block read/write to can be done via the 'nvme read/write' commands: + +.. code-block:: none + + => nvme read a0000000 0 11000 + + => tftp 80000000 /tftpboot/kernel.itb + => nvme write 80000000 0 11000 + +Of course, file system command can be used on the NVMe hard disk as well: + +.. code-block:: none + + => fatls nvme 0:1 + 32376967 kernel.itb + 22929408 100m + + 2 file(s), 0 dir(s) + + => fatload nvme 0:1 a0000000 /kernel.itb + => bootm a0000000 + +Testing NVMe with QEMU x86 +-------------------------- +QEMU supports NVMe emulation and we can test NVMe driver with QEMU x86 running +U-Boot. Please see README.x86 for how to build u-boot.rom image for QEMU x86. + +Example command line to call QEMU x86 below with emulated NVMe device: + +.. code-block:: bash + + $ ./qemu-system-i386 -drive file=nvme.img,if=none,id=drv0 -device nvme,drive=drv0,serial=QEMUNVME0001 -bios u-boot.rom |