Modify the line 315 of rom_sbs.pl to access cpp.exe when not building for Unicode.
# component name "File Server Tests"
component base_f32test
source \sf\os\kernelhwsrv\kerneltest\f32test
binary \sf\os\kernelhwsrv\kerneltest\f32test\group all
exports \sf\os\kernelhwsrv\kerneltest\f32test\group
notes_source \component_defs\release.src
ipr T