[ipxe-devel] how to provide a stable _build_id?

[Olaf Hering]

In the spirit of 335a7ddcd4e2d0faaee6d5b1edf0307dfba3d0e5 ("[build] Sort
objects in blib.a") to get reproducible binaries from the very same
source on different build hosts, the last missing piece to reach that
goal is this code in src/Makefile.housekeeping:

...
# Command to generate build ID.  Must be unique for each $(BIN)/%.tmp,
# even within the same build run.
#
BUILD_ID_CMD    := perl -e 'printf "0x%08x", int ( rand ( 0xffffffff ) );'
...
--defsym _build_id=`$(BUILD_ID_CMD)`
...

The comment makes it clear: appearently some code out there wants this ever
changing build_id. What code is it, what will break if _build_id gets a fixed
value, and what can be done to give each object an stable but unique id?

I think its up to me to figure out the last part.

Olaf