On Fri, Oct 27, 2017 at 5:27 PM, Russell King - ARM Linux <li...@armlinux.org.uk> wrote:
> > There's three things wrong, all of which I have patches to address: > > 1. The decompressor code reading the image data sometimes issues unaligned > reads. Some compilers get this wrong and cause an abort. Arnds patch > addresses this. > > 2. Additional sections can appear in the zImage binary which adds extra > bytes on the end of the image. Concatenating the zImage with the > extra bytes onto a DTB is the same thing as doing this: > > cat zImage extrabytes foo.dtb > image > > and the decompressor tolerates no additional bytes between the > _official_ end of the zImage and the DTB. I've added a patch which > detects this situation and fails the kernel build when it happens. > > 3. Ard's patch "efi/libstub: arm: omit sorting of the UEFI memory map" > gets rid of the additional sections that (a) change the alignment > of the compressed data, and (b) add additional unexpected bytes on > the end of zImage. It's possible that we still need yet another patch to address the gcc bug that Alex Graf found, i.e. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82445 Without the latest gcc, we might still get into a situation in which we get an unaligned strd when compiling for armv5te or armv6 with gcc-7.[012]. As someone mentioned in the bug report, that problem doesn't seem to happen with gcc-6 or -mtune=xscale, or with gcc-7 -march=armv7-a. Arnd
