Hello Sascha, On 1/14/26 1:14 PM, Sascha Hauer wrote: > Until now we linked the raw barebox proper binary into the PBL which > comes with a number of disadvantages. We rely on self-modifying code > to in barebox proper (relocate_to_current_adr()) and have no initialized > bss segment (setup_c()). Also we can only mark the .text and .rodata as > readonly during runtime of barebox proper. > > This series overcomes this by linking a ELF image into the PBL. This > image is properly layed out, linked and initialized in the PBL. With > this barebox proper has a proper C environment and text/rodata > protection from the start. > > As a bonus this series also adds initial MMU support for RISCV, also > based on loading the ELF image and configuring the MMU from the PBL. > > I lost track about the review feedback for v1, partly because I asked > Claude to integrate the review feedback for me, which it did, but not > completely. Nevertheless I think this series has enough changes for now > so that it deserves a second look. > > What I didn't care about yet is that we found out that neither ARM nor > RiscV use any absolute relocations, so we might be able to remove > support for them, make sure these are not emitted during compile time, > or properly test/fix them when we discover that they are indeed needed.
I am done with my review, so as far as I am concerned, this series can go in with the minor points mentioned addressed. Thanks, Ahmad > > Co-Authored-By: Claude Sonnet 4.5 <[email protected]> > Signed-off-by: Sascha Hauer <[email protected]> > --- > Changes in v4: > - remove --remove-section=.note.gnu.build-id, catched by > --remove-section=.note* > - actually use __image_* in remap_range_end_sans_image() > - drop pbl_remap_range in favor of remap_range() > - drop duplicate ELF entry point pr_debug() > - add static inline wrapper for pbl_mmu_setup_from_elf() > - reorder segments > - make dynamic section RO > - introduce elf_for_each_segment() > - Use lowest vaddr segment for base address > - Link to v3: > https://lore.barebox.org/[email protected] > > Changes in v3: > - integrate Ahmads feedback > - cleanup barebox proper entry > - add missing "ax" flag to ARM exception table, and let linker do the > fixup > - Link to v2: > https://lore.barebox.org/[email protected] > > Changes in v2: > - rebased on Ahmads patches and with it reused existing relocate_image() > - hopefully integrated all feedback for v1 > - Link to v1: > https://lore.barebox.org/[email protected] > > --- > Sascha Hauer (22): > Makefile.compiler: add objcopy-option > elf: only accept images matching the native ELF_CLASS > elf: build for PBL as well > elf: add elf segment iterator > elf: add dynamic relocation support > ARM: implement elf_apply_relocations() for ELF relocation support > riscv: define generic relocate_image > riscv: implement elf_apply_relocations() for ELF relocation support > elf: implement elf_load_inplace() > elf: create elf_open_binary_into() > Makefile: add vmbarebox build target > PBL: allow to link ELF image into PBL > mmu: add MAP_CACHED_RO mapping type > ARM: drop arm_fixup_vectors() > ARM: linker script: create separate PT_LOAD segments for text, rodata, > and data > ARM: link ELF image into PBL > ARM: cleanup barebox proper entry > ARM: PBL: setup MMU with proper permissions from ELF segments > riscv: linker script: create separate PT_LOAD segments for text, > rodata, and data > riscv: link ELF image into PBL > riscv: Allwinner D1: Drop M-Mode > riscv: add ELF segment-based memory protection with MMU > > Makefile | 14 +- > arch/arm/Kconfig | 1 + > arch/arm/cpu/exceptions_32.S | 54 +---- > arch/arm/cpu/interrupts_32.c | 5 +- > arch/arm/cpu/mmu-common.c | 31 ++- > arch/arm/cpu/mmu-common.h | 3 +- > arch/arm/cpu/mmu_32.c | 6 +- > arch/arm/cpu/mmu_64.c | 2 +- > arch/arm/cpu/no-mmu.c | 2 - > arch/arm/cpu/start.c | 22 +- > arch/arm/cpu/uncompress.c | 34 ++- > arch/arm/include/asm/barebox-arm.h | 4 - > arch/arm/include/asm/elf.h | 7 + > arch/arm/lib32/barebox.lds.S | 42 ++-- > arch/arm/lib32/reloc.c | 19 ++ > arch/arm/lib64/barebox.lds.S | 38 ++-- > arch/arm/lib64/reloc.c | 21 +- > arch/riscv/Kconfig | 18 ++ > arch/riscv/Kconfig.socs | 1 - > arch/riscv/boot/start.c | 19 +- > arch/riscv/boot/uncompress.c | 34 ++- > arch/riscv/cpu/Makefile | 1 + > arch/riscv/cpu/mmu.c | 354 +++++++++++++++++++++++++++++ > arch/riscv/cpu/mmu.h | 120 ++++++++++ > arch/riscv/include/asm/asm.h | 3 +- > arch/riscv/include/asm/mmu.h | 36 +++ > arch/riscv/lib/barebox.lds.S | 45 ++-- > arch/riscv/lib/reloc.c | 43 ++-- > common/Makefile | 2 +- > common/elf.c | 446 > +++++++++++++++++++++++++++++++++++-- > include/elf.h | 79 +++++++ > include/mmu.h | 3 +- > include/pbl/mmu.h | 38 ++++ > pbl/Kconfig | 9 + > pbl/Makefile | 1 + > pbl/mmu.c | 107 +++++++++ > scripts/Makefile.compiler | 5 + > 37 files changed, 1452 insertions(+), 217 deletions(-) > --- > base-commit: 2f99ee71fb44dc60b60d234fb38e0b3c6932f02b > change-id: 20251227-pbl-load-elf-cb4cb0ceb7d8 > > Best regards, -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
