From: Thomas Petazzoni Date: Sun, 28 Mar 2021 22:52:48 +0200 Subject: [Buildroot] [PATCH 1/1] linux: support uncompressed kernel In-Reply-To: <87zgyph67r.fsf@dell.be.48ers.dk> References: <20210324114522.285121-1-egorenar@linux.ibm.com> <87zgyph67r.fsf@dell.be.48ers.dk> Message-ID: <20210328225248.77bb3de4@windsurf.home> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On Fri, 26 Mar 2021 23:59:20 +0100 Peter Korsgaard wrote: > It looks like this is a s390-specific option: > > commit 89b5202e81df9f0f0f0a11cf8c78bc8bfdc52a21 > Author: Vasily Gorbik > Date: Wed Jun 13 00:00:25 2018 +0200 > > s390/decompressor: support uncompressed kernel > > > So it should depend on BR2_s390x. This is true... but in fact also applies to our other compression options. For example, if you enable BR2_LINUX_KERNEL_LZMA on arm64, it does nothing, because this is not supported on arm64. Or if you use BR2_LINUX_KERNEL_ZSTD, it will only work on mips and x86, none of the other CPU architectures support that. And of course, since this is changing from one version of the kernel to another, we can't really add such dependencies in Buildroot. I've done so for the uncompressed/s390 case because it felt a bit "special", but in the general case, it doesn't work :-/ The only way would be some kind of build-time verification that the option was really taken into account, to at least abort the build if the option doesn't do anything. Thomas -- Thomas Petazzoni, co-owner and CEO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com