[settings] Allow for multiple definitions of each predefined setting
Allow for multiple setting definitions with the same name but
different scopes and tags. For example, allow for a "filename"
setting with default scope and tag value 67 (for DHCPv4) and a
corresponding "filename" setting with IPv6 scope and tag value 59 (for
DHCPv6).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Explicitly separate the concept of a completed fetched setting
The fetch_setting() family of functions may currently modify the
definition of the specified setting (e.g. to add missing type
information). Clean up this interface by requiring callers to provide
an explicit buffer to contain the completed definition of the fetched
setting, if required.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Exploit the redefinition of iPXE error codes to include a "platform
error code" to allow for meaningful conversion of EFI_STATUS values to
iPXE errors and vice versa.
Signed-off-by: Michael Brown <mcb30@ipxe.org>