nvme-id-ctrl − Send NVMe Identify Controller, return result and structure
nvme
id−ctrl <device> [−v |
−−vendor−specific] [−b |
−−raw−binary]
[−o <fmt> |
−−output−format=<fmt>]
For the NVMe device given, sends an identify controller command and provides the result and returned structure.
The <device> parameter is mandatory and may be either the NVMe character device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1).
On success, the structure may be returned in one of several ways depending on the option flags; the structure may be parsed by the program or the raw buffer may be printed to stdout.
−b, −−raw−binary
Print the raw buffer to stdout. Structure is not parsed by program. This overrides the vendor specific and human readable options.
−v, −−vendor−specific
In addition to parsing known fields, this option will dump the vendor specific region of the structure in hex with ascii interpretation.
−H, −−human−readable
This option will parse and format many of the bit fields into human−readable formats.
−o <format>, −−output−format=<format>
Set the reporting format to normal, json, or binary. Only one output format can be used at a time.
• Has the program interpret the returned buffer and display the known fields in a human readable format:
# nvme id−ctrl /dev/nvme0
• In addition to showing the known fields, has the program to display the vendor unique field:
# nvme
id−ctrl /dev/nvme0 −−vendor−specific
# nvme id−ctrl /dev/nvme0 −v
The above will dump the vs buffer in hex since it doesn’t know how to interpret it.
• Have the program return the raw structure in binary:
# nvme
id−ctrl /dev/nvme0 −−raw−binary >
id_ctrl.raw
# nvme id−ctrl /dev/nvme0 −b >
id_ctrl.raw
It is probably a bad idea to not redirect stdout when using this mode.
• Alternatively you may want to send the data to another program that can parse the raw buffer.
# nvme id−ctrl /dev/nvme0 −−raw−binary | nvme_parse_id_ctrl
The parse program in the above example can be a program that shows the structure in a way you like. The following program is such an example that will parse it and can accept the output through a pipe, '|', as shown in the above example, or you can 'cat' a saved output buffer to it.
/* File: nvme_parse_id_ctrl.c */
#include
<linux/nvme.h>
#include <stdio.h>
#include <unistd.h>
int main(int
argc, char **argv)
{
unsigned char buf[sizeof(struct nvme_id_ctrl)];
struct nvme_id_ctrl *ctrl = (struct nvme_id_ctrl *)buf;
if
(read(STDIN_FILENO, buf, sizeof(buf)))
return 1;
printf("vid
: %#x\n", ctrl−>vid);
printf("ssvid : %#x\n", ctrl−>ssvid);
return 0;
}
Part of the nvme−user suite