[PATCH 0/6] riscv: Relocatable NOMMU kernels

[Palmer Dabbelt]

On Sat, 26 Oct 2024 10:13:52 PDT (-0700), samuel.holland at sifive.com wrote:
> Currently, RISC-V NOMMU kernels are linked at CONFIG_PAGE_OFFSET, and
> since they are not relocatable, must be loaded at this address as well.
> CONFIG_PAGE_OFFSET is not a user-visible Kconfig option, so its value is
> not obvious, and users must patch the kernel source if they want to load
> it at a different address.
>
> Make NOMMU kernels more portable by making them relocatable by default.
> This allows a single kernel binary to work when loaded at any address.
>
>
> Samuel Holland (6):
>   riscv: Remove duplicate CONFIG_PAGE_OFFSET definition
>   riscv: Allow NOMMU kernels to access all of RAM
>   riscv: Support CONFIG_RELOCATABLE on NOMMU
>   asm-generic: Always define Elf_Rel and Elf_Rela
>   riscv: Support CONFIG_RELOCATABLE on riscv32
>   riscv: Remove CONFIG_PAGE_OFFSET
>
>  arch/riscv/Kconfig               | 10 +---
>  arch/riscv/Makefile              |  1 -
>  arch/riscv/include/asm/page.h    | 27 ++++-----
>  arch/riscv/include/asm/pgtable.h |  6 +-
>  arch/riscv/mm/init.c             | 97 ++++++++++++++++----------------
>  include/asm-generic/module.h     |  8 ---
>  6 files changed, 68 insertions(+), 81 deletions(-)

I'm getting some build failures

riscv64-unknown-linux-gnu-ld: arch/riscv/errata/sifive/errata.o: relocation R_RISCV_HI20 against `tlb_flush_all_threshold' can not be used when making a shared object; recompile with -fPIC
riscv64-unknown-linux-gnu-ld: arch/riscv/errata/thead/errata.o: relocation R_RISCV_HI20 against `riscv_cbom_block_size' can not be used when making a shared object; recompile with -fPIC