On 29 September 2017 at 21:26, Tom Rini <tr...@konsulko.com> wrote: > On Fri, Sep 29, 2017 at 02:06:21AM +0300, Riku Voipio wrote: > > [snip] >> On arm64, Kernel doesn't self-decompress. The bootloaders are stringly >> recommended to support decompressing kernel images. It's optional in >> grub, make sure your grub does. At least iPXE and u-boot don't support >> booting Image.gz on arm64, and should be fixed. > > Not strictly true. We do expect that if you're loading in a > compressed something that you uncompress it then boot it. I assume part > of the reason that Linux didn't go for self-decompression this time is > the "my goodness, it's tricky to get here's where we are, here's what > else is in the system, lets not stomp anything and get ourself to where > we need to be" is in fact tricky.
Thanks for the clarification. The kernel Documentation/arm64/booting.txt is vague in reasoning, but you are right it's tricky. Kernel developers assume the bootloader is better equipped to know where in memory to decompress than a early kernel decompress loop. > That said, patches to check for ${VALID_COMPRESSION_HEADER}, uncompress > a chunk, confirm valid Image header, and uncompress to where it needs to > reside would be welcome. While the unzip command hint is good, from cross-distro PoV I think this kind of transparent decompression is needed to make the syslinux bootmenu command "just work". Riku