Displaying current IPL parameters

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest KVM guest

To display the IPL parameters, use the lsreipl command with the -i option. Alternatively, a sysfs interface is available.

In sysfs, information about IPL parameters is available in subdirectories of /sys/firmware/ipl.

/sys/firmware/ipl/ipl_type

The /sys/firmware/ipl/ipl_type file contains the device type from which the kernel was booted. The following values are possible:

ccw: The IPL device is a CCW device, for example, a DASD, the z/VM® reader, or a virtio block device.
fcp: The IPL device is an FCP device.
nvme: The IPL device is an NVMe device.
unknown: The IPL device is not known.

Depending on the IPL type, there might be more files in /sys/firmware/ipl/.

Further attributes for IPL type ccw

For IPL from a CCW device, the following attributes are present:

device

Contains the bus ID of the CCW device that is used for IPL, for example:

# cat /sys/firmware/ipl/device
0.0.1234

loadparm

Contains up to 8 characters for the loadparm that is used for selecting from a zipl boot menu during IPL of a CCW device, for example:

# cat /sys/firmware/ipl/loadparm
1

parm

Contains additional kernel parameters that are specified with the PARM parameter when booting with the z/VM CP IPL command, for example:

# cat /sys/firmware/ipl/parm
novx

A leading equal sign (=) indicates that the existing kernel parameters used by the boot configuration were ignored and the kernel parameters of the parm attribute where the only kernel parameters used for booting Linux®.

Further attributes for IPL type fcp

For IPL from an FCP-attached SCSI device, the following attributes are present::

binary_parameter

Contains the information of the preceding files in binary format.

bootprog

Contains the boot program number. Used for selecting from a zipl boot menu during IPL of a SCSI disk device.

br_lba

Contains the logical block address of the boot record on the boot device (usually 0).

device

Contains the bus ID of the FCP device that is used for IPL, for example:

# cat /sys/firmware/ipl/device
0.0.50dc

has_secure

Indicates whether the host environment supports secure boot. If the value is 1, secure boot is supported and the secure-boot enabled format can be used.

lun

Contains the LUN used for IPL, for example:

# cat /sys/firmware/ipl/lun
0x5010000000000000

scp_data

Contains additional kernel parameters that are used when booting from a SCSI device. A leading equal sign (=) indicates that the existing kernel parameters used by the boot configuration were ignored and the kernel parameters of the scp_data attribute where the only kernel parameters used for booting Linux.

# cat /sys/firmware/ipl/scp_data
novx

secure

Read the sysfs attribute /sys/firmware/ipl/secure to check whether the Linux instance was IPLed with secure boot. Issue the following command:

# cat /sys/firmware/ipl/secure
1

If the value is 1, Linux was IPLed with secure boot.

wwpn

Contains the WWPN used for IPL, for example:

# cat /sys/firmware/ipl/wwpn
0x5005076300c20b8e

Further attributes for IPL type nvme

For IPL from an NVMe device, the following attributes are present:

binary_parameter

Contains the information of the other attributes a in binary format.

bootprog

Contains the boot program number that was used for selecting from a zipl boot menu during IPL of the NVMe device.

br_lba

Contains the logical block address of the boot record on the boot device (usually 0).

fid

PCIe function ID of the NVMe device.

has_secure

Indication of whether the host environment supports secure boot. If the value is 1, secure boot is supported and the secure-boot enabled format can be used.

loadparm

Contains up to 8 characters for the loadparm.

nsid

NVMe name space ID of the NVMe device. Name space IDs are assigned by NVMe disk controllers to divide a physical NVMe device into multiple logical devices.

scp_data

Contains any additional kernel parameters that were used when booting from the NVMe device, for example:

# cat /sys/firmware/ipl/scp_data
novx

A leading equal sign (=) indicates that the existing kernel parameters used by the boot configuration were ignored and the kernel parameters of the scp_data attribute where the only kernel parameters used for booting Linux.

secure

Indicates secure-boot mode. If the value is 1, the Linux instance was IPLed with secure boot.