On Mon, 16 Mar 2020 19:13:13 -0600
"Theo de Raadt" <dera...@openbsd.org> wrote:
> How are the bootblocks faring?
>
> And userland?
ofwboot with clang works for me.
I failed to make bsd.rd (in src/distrib/macppc/ramdisk) with clang,
but I don't remember exactly what I did, so I might have been making
it the wrong way. My build failed at
clang -static -L. -nopie -o instbin instbin.o dd.lo ...
/usr/bin/ld: dd.lo(.text+0x14): R_PPC_PLTREL24 reloc against local symbol
I was able to make bsd.rd with gcc.
"$CC -fno-pie -c something.c; objdump -dlr something.o" shows that
gcc -fno-pie uses R_PPC_REL24, but clang -fno-pie uses R_PPC_PLTREL24,
for calls to external functions. The symbols would be global until
crunchgen(8) hides them by marking them local. R_PPC_REL24 would
branch directly to a function, and R_PPC_PLTREL24 would go through
the PLT (for a function in a shared library). The compiler can't
know whether the function is in a shared lib; the linker must decide.
clang -fno-pie on amd64 uses R_X86_64_PLT32, so I guess that clang
-fno-pie on powerpc isn't wrong to use R_PPC_PLTREL24.
Passing -M to crunchgen(8), as we do on {longsoon,octeon,sgi}, might
work around the problem, but I haven't tried it, and I don't know
whether this is the only problem.
--George
