ofc you can switch to every 32bit distro you wish but I can tell you you just don't need to do that..
just don't waste your resources with 32bit stuff. ( I'm not saying stay with Frugalware )
I'm an coreboot noob and have no clue about it ( well I know how is working and is using kernel like Kconfig etc .. )
but this is all about it..
you are right one need an small patch to Makefile but this should go upstream ..
however this is easy to fix.. one have to quote $(AS) $(CC) for cross compiling.
here is what I did
( note I don't need to install any extra packages here )
cloned both repos
cd the_filo_folder and patched Makefile with this
export CC="gcc -m32" LD="ld -b elf32-i386" HOSTCC="gcc" AS="as --32"
chmod +x ./build.sh && ./build.sh ( followed Kconfig for the defconfigs .. just pressed enter to whatever )
wait stuff compiled :)
LC_ALL=C gcc -v
Reading specs from /usr/lib/gcc/x86_64-frugalware-linux/6.3.1/specs
crazy@zwerg:~/FILO/filo/build$ file filo filo.elf
filo: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, with debug_info, not stripped
filo.elf: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, stripped
crazy@zwerg:~/FILO/filo/build$ uname -a
Linux zwerg 4.11.4-fw1 #1 SMP PREEMPT Wed Jun 7 15:37:59 CEST 2017 x86_64 x86_64 x86_64 GNU/Linux
as you can see is really simple ...
I hope this help you a bit no matter what distro you want to use :)