How kernel parameters from different sources are combined

6.10 LPAR mode z/VM guest KVM guest

zipl allows for multiple sources of kernel parameters when preparing boot devices.

In command-line mode, you can use two possible sources of kernel parameters. The parameters are processed in the following order:
  1. Parameters in the kernel parameter file (specified with the -p or --parmfile option)
  2. Parameters that are specified on the command line (specified with the -P or --parameters option)
In configuration file mode, the possible sources of kernel parameters depend on where the configuration is specified, in a zipl configuration-file section or in a BLS snippet. The parameters are processed in the following order:
For a zipl configuration-file section
  1. Parameters in the kernel parameter file (specified with the parmfile= option)
  2. Parameters that are specified in the configuration section (specified with the parameters= option)
  3. Parameters that are specified on the command line (specified with the -P or --parameters option)
For a BLS snippet
  1. Parameters that are specified in the snippet (specified with the options option)
  2. Parameters that are specified on the command line (specified with the -P or --parameters option)

Parameters from different sources are concatenated and passed to the kernel in one string. At IPL time, the combined kernel parameter string is loaded to address 0x1000, unless an alternate address is provided.