Hi, On 1/5/26 12:26 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. > > This series also marks my start into AI assisted programming as you can > see in the Co-Authored-By: Claude Sonnet 4.5 <[email protected]> > and 🤖 Generated with [Claude Code](https://claude.com/claude-code) > tags. Without it I wouldn't have started this series during my xmas > break, but with it it was actually quite fun to do; it felt like having > a programming team which I just had to delegate new tasks to while > having fun with my family myself ;)
Did you do size comparisons to determine how much this series affects binary size? I found that compressing every segment separately resulted in a smaller binary size even after addition of ELF parsing to PBL, but I used a purpose-built ELF loader unlike to what you did here. Cheers, Ahmad > > Co-Authored-By: Claude Sonnet 4.5 <[email protected]> > Signed-off-by: Sascha Hauer <[email protected]> > --- > Sascha Hauer (19): > elf: Use memcmp to make suitable for PBL > elf: build for PBL as well > elf: add dynamic relocation support > ARM: implement elf_apply_relocations() for ELF relocation support > riscv: implement elf_apply_relocations() for ELF relocation support > elf: implement elf_load_inplace() > elf: create elf_open_binary_into() > Makefile: add barebox.elf build target > PBL: allow to link ELF image into PBL > mmu: add MAP_CACHED_RO mapping type > mmu: introduce pbl_remap_range() > ARM: use relative jumps in exception table > ARM: exceptions: make in-binary exception table const > ARM: linker script: create separate PT_LOAD segments for text, rodata, > and data > ARM: link ELF image into PBL > ARM: PBL: setup MMU with proper permissions from ELF segments > riscv: link ELF image into PBL > riscv: linker script: create separate PT_LOAD segments for text, > rodata, and data > riscv: add ELF segment-based memory protection with MMU > > Makefile | 16 +- > arch/arm/Kconfig | 2 + > arch/arm/cpu/exceptions_32.S | 54 +++--- > arch/arm/cpu/interrupts_32.c | 41 +++- > arch/arm/cpu/mmu-common.c | 66 +------ > arch/arm/cpu/mmu-common.h | 3 +- > arch/arm/cpu/mmu_32.c | 19 +- > arch/arm/cpu/mmu_64.c | 10 +- > arch/arm/cpu/no-mmu.c | 11 +- > arch/arm/cpu/start.c | 4 - > arch/arm/cpu/uncompress.c | 46 ++++- > arch/arm/include/asm/barebox-arm.h | 4 +- > arch/arm/include/asm/barebox.lds.h | 14 +- > arch/arm/include/asm/elf.h | 11 ++ > arch/arm/include/asm/sections.h | 1 + > arch/arm/lib/pbl.lds.S | 8 +- > arch/arm/lib32/Makefile | 1 + > arch/arm/lib32/barebox.lds.S | 39 ++-- > arch/arm/lib32/elf_reloc.c | 105 ++++++++++ > arch/arm/lib64/Makefile | 1 + > arch/arm/lib64/barebox.lds.S | 31 ++- > arch/arm/lib64/elf_reloc.c | 105 ++++++++++ > arch/riscv/Kconfig | 18 ++ > arch/riscv/Kconfig.socs | 1 - > arch/riscv/boot/start.c | 4 - > arch/riscv/boot/uncompress.c | 41 +++- > arch/riscv/cpu/Makefile | 1 + > arch/riscv/cpu/mmu.c | 386 > +++++++++++++++++++++++++++++++++++++ > arch/riscv/cpu/mmu.h | 144 ++++++++++++++ > arch/riscv/include/asm/asm.h | 3 +- > arch/riscv/include/asm/mmu.h | 44 +++++ > arch/riscv/lib/Makefile | 1 + > arch/riscv/lib/barebox.lds.S | 38 ++-- > arch/riscv/lib/elf_reloc.c | 212 ++++++++++++++++++++ > common/Makefile | 2 +- > common/elf.c | 367 +++++++++++++++++++++++++++++++++-- > images/Makefile | 18 +- > images/piggy.S | 4 + > include/elf.h | 62 ++++++ > include/mmu.h | 12 +- > include/pbl/mmu.h | 29 +++ > lib/Makefile | 1 + > lib/elf_reloc.c | 15 ++ > pbl/Kconfig | 8 + > pbl/Makefile | 1 + > pbl/mmu.c | 111 +++++++++++ > scripts/prelink-riscv.inc | 9 +- > 47 files changed, 1922 insertions(+), 202 deletions(-) > --- > base-commit: e2d7e032281158b54541392b4d8108de204137a1 > 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 |
