+.B ecam.addrs
+Physical addresses of PCIe ECAM mappings. Each mapping must contains first PCI
+bus number and physical address where mapping starts. And then it may contain
+the length of the mapping, the last PCI bus number and PCI domain number. When
+the last PCI bus number is not provided then it is calculated from the length
+of the mapping or it is assumed 0xff. When length of the mapping is provided
+then it is calculated from the last PCI bus number. And when PCI domain is not
+provided then 0x0 is assumed. All numbers must be supplied in hexadecimal form
+(leading prefix 0x is not required). Multiple mappings are separated by commas.
+Format: [domain:]start_bus[-end_bus]:start_addr[+length],...
+.TP
+.B ecam.acpimcfg
+Path to the ACPI MCFG table. Processed by the
+.BR glob (3)
+function, so it may contain wildcards (*).
+.TP
+.B ecam.efisystab
+Path to the EFI system table.
+.TP
+.B ecam.bsd
+When not set to 0 then use BSD kenv or sysctl to find ACPI MCFG table. Default
+value is 1 on BSD systems.
+.TP
+.B ecam.x86bios
+When not set to 0 then scan x86 BIOS memory for ACPI MCFG table. Default value
+is 1 on x86 systems.
+.TP