Hi Jerome,
Le 6/10/20 à 10:10 AM, Jerome Forissier a écrit :
On 6/7/20 9:59 AM, Alexandre Ghiti wrote:
[...]
+config RELOCATABLE
+ bool
+ depends on MMU
+ help
+ This builds a kernel as a Position Independent Executable (PIE),
+ which retains all relocation metadata required to relocate the
+ kernel binary at runtime to a different virtual address than the
+ address it was linked at.
+ Since RISCV uses the RELA relocation format, this requires a
+ relocation pass at runtime even if the kernel is loaded at the
+ same address it was linked at.
Is this true? I thought that the GNU linker would write the "proper"
values by default, contrary to the LLVM linker (ld.lld) which would need
a special flag: --apply-dynamic-relocs (by default the relocated places
are set to zero). At least, it is my experience with Aarch64 on a
different project. So, sorry if I'm talking nonsense here -- I have not
looked at the details.
It seems that you're right, at least for aarch64 since they specifically
specify the --no-apply-dynamic-relocs option. I retried to boot without
relocating at runtime, and it fails on riscv. Can this be arch specific ?
Thanks,
Alex
