How do I set cpp_flags for environment text files ?

[Michael Chaffin]

I am trying to understand a change to the u-boot, Makefile from last year, 10 Aug 2024 as commit 0x2956a84 ; The change commit messages says don't use CFLAGS for environment text files. I am unsure of how to properly set the Makefile variable 'cpp_flags' when compiling u-boot for the RaspberryPi5 ? Now when compiling for Pi5 I get the following error, 

   ENVP    include/generated/env.in
| cc1: warning: unknown register name: x18
| cc1: error: bad value ('armv8-a+crc') for '-march=' switch
| cc1: note: valid arguments to '-march=' switch are: nocona core2 nehalem corei7 westmere sandybridge corei7-avx ivybridge core-avx-i haswell core-avx2 broadwell skylake skylake-avx512 cannonlake icelake-client rocketlake icelake-server cascadelake tigerlake cooperlake sapphirerapids alderlake bonnell at
| make: *** [Makefile:1877: include/generated/env.in] Error 1
| WARNING: exit code 2 from a shell command.

Micheal S. Chaffin 
Principal Software Engineer
21 Software