linux nvme command interface

I worked with NVME device recently. To challenge the firmware, NVME command has to be sent from host. I can choose to use LeCoy's software and hardware box to send command,, another way is to use a plain PC with linux installed.

The test framework is 3-layers architecture, the device driver (dnvme) at bottom,  dynamic link library in the middle to provides APIs, and test scripts (perl or python) on top. Here is available open source resources

NVMe Compliance Test
https://github.com/nvmecompliance/tnvme

Linux driver for NVMe Compliance Suite
https://github.com/nvmecompliance/dnvme

Linux NVME command interface
https://github.com/linux-nvme/nvme-cli

NVME windows command issuer
https://github.com/Miyavi-Chen/NVMe_CMD_issuer

memcpy for ARMv7

There is lot of ways to implement memcpy(), the most efficient way is of course the DMA, although it has overhead to setup the DMA descriptor. Armcc compiler just do it in a simple way

;r0 stores the destine and r1 stores the source


LDM r1!,{r3,r4,r12,lr} 
STM r0!,{r3,r4,r12,lr}

Each 2 machine cycle copies 16 bytes of data.  I ignored extra codes to handle non-16-bytes-aligned data.