cgpt: Add cgpt legacy parameter to set primary GPT signature to IGNOREME

Now that we have support for the IGNOREME signature in cgpt, we need a
way to set it on an existing disk. The easiest option is to shoehorn
this into the cgpt legacy command, because that's already made to modify
GPT header signatures (really, it would be nice to rename it to cgpt
signature or something, but let's not break existing uses for now).

TEST=unit tests

Change-Id: If2835fec28a9c39373abd050e2e057f73e5ec700
Signed-off-by: Julius Werner <>
Reviewed-by: Nam Nguyen <>
Commit-Queue: Philip Chen <>
Tested-by: Philip Chen <>
4 files changed