Specifications

Version 2.0
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Appendix A
UEFI Shell Consistent
Mapping Design
This appendix describes how device assignments are created.
A.1 Requirement:
1. The shell shall support consistent device assignments across (through)
reboots.
e.g. same concept as how you assign the letter D: to a partition under
DOS/Windows.
2. The shell commands shall support defining mappings.
For identical machines with the same hardware configurations the mapping
result should always be the same.
3. Not use the NV storage.
In the OS, it is easy to implement the consistent mapping, because it can
store the mapping info on the hard disk or other storage. The firmware has no
large storage to store all of this system info. To save space, it is strongly
desired that such mapping data does not use NV storage to maintain this data.
A.2 Design
A.2.1 What does consistent mapping mean?
If hardware configuration is not changed, the mappings should not change. EXAMPLE:
map –r, reboot, map -r will not change the mappings.
If two or more machines have the same hardware configurations, mapping result
should be the same.
A.2.2 Hardware configuration change:
Generally, buses, controllers, hubs or bridges changing mean hardware configuration
change.