> -----Original Message----- > From: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel- > owner@xxxxxxxxxxxxxxx> On Behalf Of Palmer Dabbelt > Sent: Saturday, September 14, 2019 6:30 PM > To: mail@xxxxxxxxxxxx > Cc: Troy Benjegerdes <troy.benjegerdes@xxxxxxxxxx>; Paul Walmsley > <paul.walmsley@xxxxxxxxxx>; aou@xxxxxxxxxxxxxxxxx; linux- > riscv@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > kbuild@xxxxxxxxxxxxxxx > Subject: Re: [RFC] buildtar: add case for riscv architecture > > On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@xxxxxxxxxxxx wrote: > > > > > >> None of the available RiscV platforms that I’m aware of use compressed > images, unless there are some new bootloaders I haven’t seen yet. > >> > > > > I noticed that default build image is Image.gz, which is why I thought its a > good idea to copy it into the tarball. Does such a copy not make sense at this > point ? > > Image.gz can't be booted directly: it's just Image that's been compressed > with the standard gzip command. A bootloader would have to decompress > that image before loading it into memory, which requires extra bootloader > support. > Contrast that with the zImage style images (which are vmlinuz on x86), which > are self-extracting and therefor require no bootloader support. The > examples for u-boot all use the "booti" command, which expects > uncompressed images. > Poking around I couldn't figure out a way to have u-boot decompress the > images, but that applies to arm64 as well so I'm not sure if I'm missing > something. > > If I was doing this, I'd copy over arch/riscv/boot/Image and call it > "/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to > me because I'd expect vmlinuz to be a self-extracting compressed > executable and not a raw gzip file. On the contrary, it is indeed possible to boot Image.gz directly using U-Boot booti command so this patch would be useful. Atish had got it working on U-Boot but he has deferred booti Image.gz support due to few more dependent changes. May be he can share more info. Regards, Anup