> I have seen ELF files which have this overlap and > where both segments are PT_LOAD. (I think in the cases > I've seen the contents in both segments agree rather than > being different data, but a loader is not going to be > expected to do a comparison of the file data.) Hmm ... OK. there are definitely things I haven't seen :-)
>> So for me just ignore NOLOAD section would do the trick. > > We already ignore all the ELF segments which are not > of type PT_LOAD: > http://git.qemu.org/?p=qemu.git;a=blob;f=include/hw/elf_ops.h;h=a172a6068a48e233dd802043b3304a9e0a5d3be6;hb=HEAD#l353 > > If you're hitting this error case then I think the > affected segments must both be of type PT_LOAD. > (If you're not sure you can post here the output > of running 'objdump -p' on the binary or otherwise > show us the program header.) Here is the objdump -p: hua@grass:~/git/usw $ arm-none-eabi-objdump -p output/qemu_arm_vexpress/qemu_arm _vexpress.elf output/qemu_arm_vexpress/qemu_arm_vexpress.elf: file format elf32-littlearm Program Header: 0x70000001 off 0x00076e6c vaddr 0x60076d8c paddr 0x60076d8c align 2**2 filesz 0x00000008 memsz 0x00000008 flags r-- LOAD off 0x000000e0 vaddr 0x60000000 paddr 0x60000000 align 2**5 filesz 0x0007773c memsz 0x00077c00 flags rwx LOAD off 0x00077820 vaddr 0x70000000 paddr 0x60077740 align 2**3 filesz 0x00000038 memsz 0x00000038 flags r-x LOAD off 0x00077858 vaddr 0x70080000 paddr 0x60077780 align 2**3 filesz 0x00000038 memsz 0x00000038 flags r-x LOAD off 0x00077890 vaddr 0x70090000 paddr 0x600777c0 align 2**3 filesz 0x00000038 memsz 0x00000038 flags r-x private flags = 5000200: [Version5 EABI] [soft-float ABI] hua@grass:~/git/usw $ nm output/^C hua@grass:~/git/usw $ arm-none-eabi-nm output/qemu_arm_vexpress/qemu_arm_vexpress.elf | sort | grep bss 60077738 B __bss_start 60077c00 B __bss_end hua@grass:~/git/usw $ configs/qemu_arm_vexpress.py run Note: you must have a locally modified qemu-system-arm to work with this build! Please contact Hua Yanghao for more details! echo "==> Ctrl-A X to exit"; export QEMU_AUDIO_DRV="none"; qemu-system-arm -M vexpress-a9 -m 512M -smp cpus=1 -nographic -kernel output/qemu_arm_vexpress/qemu_arm_vexpress.elf ==> Ctrl-A X to exit rom: requested regions overlap (rom phdr #2: output/qemu_arm_vexpress/qemu_arm_vexpress.elf. free=0x0000000060077c00, addr=0x0000000060077740) qemu-system-arm: rom check and register reset failed hua@grass:~/git/usw $ arm-none-eabi-nm output/qemu_arm_vexpress/qemu_arm_vexpress.elf | sort | grep 60077c00 60077c00 B __bss_end 60077c00 B _heap_low hua@grass:~/git/usw $ arm-none-eabi-nm output/qemu_arm_vexpress/qemu_arm_vexpress.elf | sort | grep 60077740 60077740 T _lmu0_load_start 60077740 T _lmu_load_start hua@grass:~/git/usw $ arm-none-eabi-nm output/qemu_arm_vexpress/qemu_arm_vexpress.elf | sort | grep lmu0 6006a458 t __lmu0_veneer 60077740 T _lmu0_load_start 60077778 T _lmu0_load_end 70000000 t lmu0 70000000 T _lmu0_start 70000038 T _lmu0_end hua@grass:~/git/usw $ > PS: you're consistently saying "section", but in the > ELF format "section" and "segment" are two different > things. QEMU doesn't actually look at the section table. > In an ELF file, sections are used by the linker, but a > program loader like QEMU (or the Linux kernel) > looks only at the segment table in the program header. Yes I am looking from the "section" perspective. As I intentionally want two sections to overlap (.bss and the lmu section starting from LMA _lmu0_load_start). I know loaders only care about segments. :-) BR, Yanghao
