tree 42225985b952f14faa1ba295ff31c7b7ed8050f2
parent 68a24c9ea5ce11c87fab22a3f4648c7d88c98fee
author Adriana Kobylak <anoo@us.ibm.com> 1701190310 -0600
committer Adriana Kobylak <anoo@us.ibm.com> 1701205656 -0600

vpnor: Look for files in rw directory first

IBM systems running PLDM create lid files for the host content instead
of PNOR partition files:
```
https://github.com/openbmc/pldm/blob/master/oem/ibm/configurations/fileTable.json
```

In order to continue to support mboxd (hiomapd), symlinks with the PNOR
partition file names are created to point to the lid files:
https://gerrit.openbmc.org/c/openbmc/openpower-pnor-code-mgmt/+/45249

Since these symlinks are created at runtime, they can only be created in
the read-write directory.
Update the mboxd (hiomapd) code to look at the rw directory first, since
in general the code searches in patch directories first to allow
overrides. Then if the partition files are not found default to the
read-only directory.

The symlinks are created prior to mboxd starting via a Before dependency
in the openpower service file:
```
https://github.com/openbmc/openpower-pnor-code-mgmt/blob/master/mmc/openpower-update-bios-attr-table.service#L6
```

Tested: Verified mboxd started successfully in a p10bmc and witherspoon
system.

Change-Id: I281cd41591ab55cd1b3de474ad25c5992ea2d498
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>